diff --git a/ForDemo1.java b/ForDemo1.java
new file mode 100644
index 000000000..da881ebb3
--- /dev/null
+++ b/ForDemo1.java
@@ -0,0 +1,35 @@
+public class ForDemo1 {
+    public static void main(String[] args) {
+        System.out.println("----3次Hello World----");
+        for (int i = 0; i < 3; i++) {
+            if (i == 1) {
+                break; // 当i等于1时，跳出循环
+            }
+            System.out.println("Hello World");
+        }
+
+        System.out.println("----4次Hello MySQL----");
+        for (int i = 1; i < 5; i++) {
+            if (i == 3) {
+                continue; // 当i等于3时，跳过当前迭代
+            }
+            System.out.println("Hello MySQL");
+        }
+
+        System.out.println("----5次Hello Spring----");
+        for (int i = 1; i <= 5; i++) {
+            if (i == 3) {
+                continue; // 当i等于3时，跳过当前迭代
+            }
+            System.out.println("Hello Spring");
+        }
+
+        System.out.println("----3次Hello Redis----");
+        for (int i = 1; i <= 5; i += 2) {
+            if (i == 3) {
+                break; // 当i等于3时，跳出循环
+            }
+            System.out.println("Hello Redis");
+        }
+    }
+}
diff --git a/ForDemo2.java b/ForDemo2.java
new file mode 100644
index 000000000..254408732
--- /dev/null
+++ b/ForDemo2.java
@@ -0,0 +1,21 @@
+public class ForDemo2 {
+    public static void main(String[] args){
+        int [] numbers = {10, 20, 30, 40, 50};
+        for(int x : numbers ){
+            if (x == 30) {
+                break; // 当x等于30时，跳出循环
+            }
+            System.out.print( x );
+            System.out.print(",");
+        }
+        System.out.println();
+        String [] names ={"James", "Larry", "Tom", "Lacy"};
+        for( String name : names ) {
+            if (name.equals("Tom")) {
+                continue; // 当name等于"Tom"时，跳过当前循环，继续下一个循环
+            }
+            System.out.print( name );
+            System.out.print(",");
+        }
+    }
+}
diff --git a/ForDemo3.java b/ForDemo3.java
new file mode 100644
index 000000000..bf452b6aa
--- /dev/null
+++ b/ForDemo3.java
@@ -0,0 +1,21 @@
+public class ForDemo3 {
+    public static void main(String[] args) {
+        // 使用break
+        System.out.println("----使用break----");
+        for (int i = 1; i <= 5; i++) {
+            if (i == 3) {
+                break;
+            }
+            System.out.println("Hello Break");
+        }
+
+        // 使用continue
+        System.out.println("----使用continue----");
+        for (int i = 1; i <= 5; i++) {
+            if (i == 3) {
+                continue;
+            }
+            System.out.println("Hello Continue");
+        }
+    }
+}
diff --git a/IfDemo1.java b/IfDemo1.java
new file mode 100644
index 000000000..b9776de43
--- /dev/null
+++ b/IfDemo1.java
@@ -0,0 +1,18 @@
+public class IfDemo1 {
+    public static void main(String[] args) {
+        // 格式3： if(条件表达式){ 代码... } else if(条件表达式){ 代码... } ... else{ 代码... }
+        int score = 95;
+        // 绩效：0-60 C，60-80 B，80-90 A，90-100 A+
+        if (score >= 0 && score < 60) {
+            System.out.println("分数是：" + score + "，绩效是：C");
+        } else if (score >= 60 && score < 80) {
+            System.out.println("分数是：" + score + "，绩效是：B");
+        } else if (score >= 80 && score < 90) {
+            System.out.println("分数是：" + score + "，绩效是：A");
+        } else if (score >= 90 && score <= 100) {
+            System.out.println("分数是：" + score + "，绩效是：A+");
+        } else {
+            System.out.println("录入的分数有毛病！");
+        }
+    }
+}
\ No newline at end of file
diff --git a/IfDemo2.java b/IfDemo2.java
new file mode 100644
index 000000000..0080f8f70
--- /dev/null
+++ b/IfDemo2.java
@@ -0,0 +1,16 @@
+public class IfDemo2 {
+    public static void main(String[] args) {
+        // 嵌套的 if…else 语句
+        int x = 30;
+        int y = 10;
+        if (x == 30) {
+            if (y == 20) {
+                System.out.print("X = 30 and Y = 20");
+            } else {
+                System.out.println("X = 30 and Y != 20");
+            }
+        } else {
+            System.out.println("X != 30");
+        }
+    }
+}
diff --git a/Student.java b/Student.java
new file mode 100644
index 000000000..5c1a9fc18
--- /dev/null
+++ b/Student.java
@@ -0,0 +1,38 @@
+public class Student {
+    // 1.局部变量：在方法、构造函数或块内部声明的变量。
+    public void run() {
+        String weight = "100斤"; // 局部变量weight，必须有初始值。
+        // 因为实例变量age没赋值，所以默认是0
+        System.out.println(name + "现在" + age + "岁"); // 小明现在0岁
+        System.out.println(name + weight + "，跑得很快"); // 小明100斤，跑得很快
+    }
+
+    // 2.实例变量：在类中声明，但在方法、构造函数或块之外。
+    public String name = "小明"; // 公有实例变量name对子类可见
+    private int age; // 私有实例变量age，仅在该类可见，不赋值，默认是0
+
+    // main方法，程序入口
+    public static void main(String[] args) {
+        Student.onLineNumber++; // 22
+        System.out.println(onLineNumber);
+        Student student = new Student();
+        student.run();
+        student.eat("方便面");
+        student.study();
+    }
+
+    // 3.类变量：在类中用 static 关键字声明的变量，它们属于类而不是实例。
+    public static int onLineNumber = 21;
+    private String major = "计算机科学";
+
+    // 4.参数变量：是方法或构造函数声明中的变量
+    public void eat(String food) { // 参数变量food
+        System.out.println(name + "喜欢吃" + food); // 小明喜欢吃方便面
+    }
+
+    // 自定义方法
+    public void study() {
+        System.out.println(name + "正在学习" + major);
+    }
+}
+
diff --git a/da.java b/da.java
new file mode 100644
index 000000000..dec1539b3
--- /dev/null
+++ b/da.java
@@ -0,0 +1,12 @@
+public class da {
+    public static void main(String[] args) {
+        int n = 7;
+        if (n >= 0 && n < 10) {
+            for (int i = 0; i < n; i++) {
+                System.out.println("He" + n + n +"o" + " Wor" + n + "d");
+            }
+        } else {
+            System.out.println("n>10");
+        }
+    }
+}
diff --git a/das/.keep b/das/.keep
new file mode 100644
index 000000000..0940aef0b
--- /dev/null
+++ b/das/.keep
@@ -0,0 +1,13 @@
+public class da {
+    public static void main(String[] args) {
+        int n = 7;
+        if (n >= 0 && n < 10) {
+            for (int i = 0; i < n; i++) {
+                System.out.println("He" + n + n +"o" + " Wor" + n + "d");
+            }
+        } else {
+            System.out.println("n>10");
+        }
+    }
+}
+
diff --git a/ruoyi-admin/src/main/resources/application-druid.yml b/ruoyi-admin/src/main/resources/application-druid.yml
index a69d8feb2..f116196a2 100644
--- a/ruoyi-admin/src/main/resources/application-druid.yml
+++ b/ruoyi-admin/src/main/resources/application-druid.yml
@@ -8,7 +8,7 @@ spring:
             master:
                 url: jdbc:mysql://localhost:3306/ry?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&useSSL=true&serverTimezone=GMT%2B8
                 username: root
-                password: password
+                password: root
             # 从库数据源
             slave:
                 # 从数据源开关/默认关闭
diff --git a/ruoyi-admin/src/main/resources/application.yml b/ruoyi-admin/src/main/resources/application.yml
index ffb65e8bd..eba813cf8 100644
--- a/ruoyi-admin/src/main/resources/application.yml
+++ b/ruoyi-admin/src/main/resources/application.yml
@@ -16,7 +16,7 @@ ruoyi:
 # 开发环境配置
 server:
   # 服务器的HTTP端口，默认为80
-  port: 80
+  port: 5555
   servlet:
     # 应用的访问路径
     context-path: /
diff --git a/ruoyi-system/src/main/ArrayToList.java b/ruoyi-system/src/main/ArrayToList.java
new file mode 100644
index 000000000..f831ffa3e
--- /dev/null
+++ b/ruoyi-system/src/main/ArrayToList.java
@@ -0,0 +1,10 @@
+import java.util.Arrays;
+import java.util.List;
+
+public class ArrayToList {
+    public static void main(String[] args) {
+        String[] array = {"A", "B", "C", "D"};
+        List<String> list = Arrays.asList(array);
+        System.out.println("列表内容： " + list);
+    }
+}
diff --git a/ruoyi-system/src/main/ForDemo1.java b/ruoyi-system/src/main/ForDemo1.java
new file mode 100644
index 000000000..bb45b0533
--- /dev/null
+++ b/ruoyi-system/src/main/ForDemo1.java
@@ -0,0 +1,35 @@
+public class ForDemo1 {
+    public static void main(String[] args) {
+        System.out.println("----3次Hello World----");
+        for (int i = 0; i < 3; i++) {
+            if (i == 1) {
+                break; // 当i等于1时，跳出循环
+            }
+            System.out.println("Hello World");
+        }
+
+        System.out.println("----4次Hello MySQL----");
+        for (int i = 1; i < 5; i++) {
+            if (i == 3) {
+                continue; // 当i等于3时，跳过当前迭代
+            }
+            System.out.println("Hello MySQL");
+        }
+
+        System.out.println("----5次Hello Spring----");
+        for (int i = 1; i <= 5; i++) {
+            if (i == 3) {
+                continue; // 当i等于3时，跳过当前迭代
+            }
+            System.out.println("Hello Spring");
+        }
+
+        System.out.println("----3次Hello Redis----");
+        for (int i = 1; i <= 5; i += 2) {
+            if (i == 3) {
+                break; // 当i等于3时，跳出循环
+            }
+            System.out.println("Hello Redis");
+        }
+    }
+}
\ No newline at end of file
diff --git a/ruoyi-system/src/main/ForDemo2.java b/ruoyi-system/src/main/ForDemo2.java
new file mode 100644
index 000000000..6753ab558
--- /dev/null
+++ b/ruoyi-system/src/main/ForDemo2.java
@@ -0,0 +1,21 @@
+public class ForDemo2 {
+    public static void main(String[] args){
+        int [] numbers = {10, 20, 30, 40, 50};
+        for(int x : numbers ){
+            if (x == 30) {
+                break; // 当x等于30时，跳出循环
+            }
+            System.out.print( x );
+            System.out.print(",");
+        }
+        System.out.println();
+        String [] names ={"James", "Larry", "Tom", "Lacy"};
+        for( String name : names ) {
+            if (name.equals("Tom")) {
+                continue; // 当name等于"Tom"时，跳过当前循环，继续下一个循环
+            }
+            System.out.print( name );
+            System.out.print(",");
+        }
+    }
+}
\ No newline at end of file
diff --git a/ruoyi-system/src/main/ListToArray.java b/ruoyi-system/src/main/ListToArray.java
new file mode 100644
index 000000000..f98b85dc6
--- /dev/null
+++ b/ruoyi-system/src/main/ListToArray.java
@@ -0,0 +1,13 @@
+import java.util.ArrayList;
+import java.util.List;
+public class ListToArray {
+    public static void main(String[] args) {
+        List<String> list = new ArrayList<>();
+        list.add("A");
+        list.add("B");
+        list.add("C");
+        // 列表转为数组
+        String[] array = list.toArray(new String[0]);
+        System.out.println("数组内容: " + list.toString());
+    }
+}
\ No newline at end of file
diff --git a/ruoyi-system/src/main/NewStuding.java b/ruoyi-system/src/main/NewStuding.java
new file mode 100644
index 000000000..31226450f
--- /dev/null
+++ b/ruoyi-system/src/main/NewStuding.java
@@ -0,0 +1,38 @@
+public class NewStudent {
+    /**
+     * 学生
+     */
+    private String name;
+    /**
+     * 名字
+     */
+    private String  age;//定义
+
+    /**
+     * 年龄
+     * @param inputName
+     * @param inputAge
+     */
+    public NewStudent(String inputName,String inputAge){
+        this.name = inputName;
+        this.age = inputAge;
+    }
+    public  void eat(){
+        System.out.println("吃饭");
+    }
+
+    /**
+     * 吃饭
+     * @param food
+     */
+
+    public void eat(String food){
+        System.out.println("学生吃的"+food);
+    }
+    public String eat(String food,String time){
+        System.out.println("学生在" + time + "吃的" + food);
+        return"吃饱了";//定义吃饭的方法
+    }
+}
+
+
diff --git a/ruoyi-system/src/main/Student.java b/ruoyi-system/src/main/Student.java
new file mode 100644
index 000000000..a0eb77e37
--- /dev/null
+++ b/ruoyi-system/src/main/Student.java
@@ -0,0 +1,37 @@
+public class Student {
+    // 1.局部变量：在方法、构造函数或块内部声明的变量。
+    public void run() {
+        String weight = "100斤"; // 局部变量weight，必须有初始值。
+        // 因为实例变量age没赋值，所以默认是0
+        System.out.println(name + "现在" + age + "岁"); // 小明现在0岁
+        System.out.println(name + weight + "，跑得很快"); // 小明100斤，跑得很快
+    }
+
+    // 2.实例变量：在类中声明，但在方法、构造函数或块之外。
+    public String name = "小明"; // 公有实例变量name对子类可见
+    private int age; // 私有实例变量age，仅在该类可见，不赋值，默认是0
+
+    // main方法，程序入口
+    public static void main(String[] args) {
+        Student.onLineNumber++; // 22
+        System.out.println(onLineNumber);
+        Student student = new Student();
+        student.run();
+        student.eat("方便面");
+        student.study();
+    }
+
+    // 3.类变量：在类中用 static 关键字声明的变量，它们属于类而不是实例。
+    public static int onLineNumber = 21;
+    private String major = "计算机科学";
+
+    // 4.参数变量：是方法或构造函数声明中的变量
+    public void eat(String food) { // 参数变量food
+        System.out.println(name + "喜欢吃" + food); // 小明喜欢吃方便面
+    }
+
+    // 自定义方法
+    public void study() {
+        System.out.println(name + "正在学习" + major);
+    }
+}
diff --git a/ruoyi-system/src/main/Studing.java b/ruoyi-system/src/main/Studing.java
new file mode 100644
index 000000000..9ff152281
--- /dev/null
+++ b/ruoyi-system/src/main/Studing.java
@@ -0,0 +1,4 @@
+public class NewStudent {
+    private String name;
+    private int age;
+}
diff --git a/ruoyi-system/src/main/TestArray.java b/ruoyi-system/src/main/TestArray.java
new file mode 100644
index 000000000..3165e6e2f
--- /dev/null
+++ b/ruoyi-system/src/main/TestArray.java
@@ -0,0 +1,37 @@
+public class TestArray {
+    /**
+     *
+     * @param args
+     */
+    public static void main(String[] args) {
+        // double类型的数组
+        double[] scores = new double[]{99.5, 88.0, 75.5};
+        double[] scores1 = {99.5, 88.0, 75.5}; // 简化写法
+
+        // int类型的数组
+        int[] ages = new int[]{12, 24, 36};
+        int[] ages1 = {12, 24, 36}; // 简化写法
+
+        int size = 5; // 设置数组大小是10
+        String[] names = new String[size]; // 定义数组
+        names[0] = "孙悟空";
+        names[1] = "贝吉塔";
+        names[2] = "弗利萨";
+        names[3] = "沙鲁";
+        names[4] = "魔人布欧";
+        // 编译不报错，运行报错，因为数组大小是5，这是数组里第6个元素，数组越界ArrayIndexOutOfBoundsException
+        // names[5] = "布尔玛";
+        // 数组索引从 0 开始，所以索引值从 0 到 arrayRefVar.length-1
+        for (int i = 0; i < names.length; i++) {
+            System.out.print("索引：" + i + names[i] + " ");
+        }
+
+        System.out.println();
+
+        // 数组变量名存储的是数组在内存种的地址，数组是引用类型
+        // [ 指的是 数组
+        // D 指的是 数据类型double
+        // @ 指的是 在哪里
+        System.out.println(scores); // [D@776ec8df,指的是数组的十六进制地址
+    }
+}
diff --git a/ruoyi-system/src/main/TestStudent.java b/ruoyi-system/src/main/TestStudent.java
new file mode 100644
index 000000000..eb38f80a4
--- /dev/null
+++ b/ruoyi-system/src/main/TestStudent.java
@@ -0,0 +1,9 @@
+public class TestStudent {
+    public  static  void main(String[] args){
+        NewStudent student = new NewStudent("czh","19");
+        student.eat();
+        student.eat("sda");
+        student.eat("sda");
+        
+    }
+}
diff --git a/ruoyi-system/src/main/da.java b/ruoyi-system/src/main/da.java
new file mode 100644
index 000000000..80ae53852
--- /dev/null
+++ b/ruoyi-system/src/main/da.java
@@ -0,0 +1,12 @@
+public class da {
+    public static void main(String[] args) {
+        int n = 7;
+        if (n >= 0 && n < 10) {
+            for (int i = 0; i < n; i++) {
+                System.out.println("He" + n + n +"o" + " Wor" + n + "d");
+            }
+        } else {
+            System.out.println("n>10");
+        }
+    }
+}
\ No newline at end of file
diff --git a/ruoyi-system/src/main/dd.java b/ruoyi-system/src/main/dd.java
new file mode 100644
index 000000000..5ba87214f
--- /dev/null
+++ b/ruoyi-system/src/main/dd.java
@@ -0,0 +1,11 @@
+public class ss {
+    public static void main(String[] args) {
+        String studentId = "20233011082";
+        char lastDigit1 = studentId.charAt(studentId.length() - 2);
+        char lastDigit2 = studentId.charAt(studentId.length() - 1);
+        char[] lastTwoDigits = {lastDigit1, lastDigit2};
+        for (char c : lastTwoDigits) {
+            System.out.print(c + " ");
+        }
+    }
+}
diff --git a/ruoyi-system/src/main/java.java b/ruoyi-system/src/main/java.java
new file mode 100644
index 000000000..30d7f261c
--- /dev/null
+++ b/ruoyi-system/src/main/java.java
@@ -0,0 +1,39 @@
+
+
+/**
+ * 定义一个累
+ */
+public class Java {
+    /**
+     * 三个与类名相关的属性
+      */
+    private String name1;
+    private String name2;
+
+
+
+    /**
+     * @param name
+     * @param name2
+     */
+    public Java(String name, String name2) {
+        this.name1 = name1;
+        this.name2 = name2;
+
+    }
+
+
+
+    /**
+     * main函数创建对象并调用两个方法
+     */
+
+   public void java() {
+       System.out.println(name1 + "cc");
+   }
+    public void sha() {
+        System.out.println(name2 + "xx");
+    }
+}
+
+
diff --git a/ruoyi-system/src/main/java/ACoach.java b/ruoyi-system/src/main/java/ACoach.java
new file mode 100644
index 000000000..9749267f3
--- /dev/null
+++ b/ruoyi-system/src/main/java/ACoach.java
@@ -0,0 +1,9 @@
+/**
+ * A级教练实现
+ */
+public class ACoach implements Coach{
+    @Override
+    public void command(){
+        System.out.println("我是A级证书教练");
+    }
+}
diff --git a/ruoyi-system/src/main/java/ACoachFactory.java b/ruoyi-system/src/main/java/ACoachFactory.java
new file mode 100644
index 000000000..8d0e5dc62
--- /dev/null
+++ b/ruoyi-system/src/main/java/ACoachFactory.java
@@ -0,0 +1,9 @@
+/**
+ * A级教练工厂实现
+ */
+public class ACoachFactory implements CoachFactory {
+    @Override
+    public Coach createCoach() {
+        return new ACoach();
+    }
+}
\ No newline at end of file
diff --git a/ruoyi-system/src/main/java/ArrayToList.java b/ruoyi-system/src/main/java/ArrayToList.java
new file mode 100644
index 000000000..321ba902a
--- /dev/null
+++ b/ruoyi-system/src/main/java/ArrayToList.java
@@ -0,0 +1,22 @@
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * ArrayToList
+ */
+public class ArrayToList {
+    /**
+     * main方法
+     * @param args
+     */
+    public static void main(String[] args) {
+        String[] array = {"A", "B", "C", "D"};
+        /**
+         * 数组转为数列
+         */
+        List<String> list = Arrays.asList(array);
+        System.out.println("列表内容： " + list);
+    }
+}
+
+
diff --git a/ruoyi-system/src/main/java/Book.java b/ruoyi-system/src/main/java/Book.java
new file mode 100644
index 000000000..7977940f9
--- /dev/null
+++ b/ruoyi-system/src/main/java/Book.java
@@ -0,0 +1,6 @@
+/**
+ * 定义一个表示书本类型的接口
+ */
+public interface Book {
+    String name();
+}
diff --git a/ruoyi-system/src/main/java/BookInterface.java b/ruoyi-system/src/main/java/BookInterface.java
new file mode 100644
index 000000000..587901f88
--- /dev/null
+++ b/ruoyi-system/src/main/java/BookInterface.java
@@ -0,0 +1,9 @@
+/**
+ * 定义一个表示书本类型的接口
+ */
+public interface BookInterface {
+    String BookName();
+    String BookAuthor();
+    String BookISBN();
+    void setBookInfo(String name, String author, String isbn);
+}
\ No newline at end of file
diff --git a/ruoyi-system/src/main/java/Booking.java b/ruoyi-system/src/main/java/Booking.java
new file mode 100644
index 000000000..e30c2fc3e
--- /dev/null
+++ b/ruoyi-system/src/main/java/Booking.java
@@ -0,0 +1,25 @@
+public class Booking {
+    public static void main(String[] args) {
+        // 创建图书对象
+        Books books = new Books();
+
+        // 设置图书信息
+        books.setBookInfo("安德的游戏", "安德", "978-7-111-60453-3");
+
+        // 获取并打印图书名称
+        System.out.println("名称: " + books.BookName());
+
+        // 获取并打印图书作者
+        System.out.println("作者: " + books.BookAuthor());
+
+        // 获取并打印图书ISBN
+        System.out.println("ISBN: " + books.BookISBN());
+
+        // 使用多态形式调用图书信息类的方法
+        BookInterface bookInterface = new Books();
+        bookInterface.setBookInfo("中华上下五千年", "袁堂欣", "978-0-13-468599-1");
+        System.out.println("名称: " + bookInterface.BookName());
+        System.out.println("作者: " + bookInterface.BookAuthor());
+        System.out.println("ISBN: " + bookInterface.BookISBN());
+    }
+}
diff --git a/ruoyi-system/src/main/java/Books.java b/ruoyi-system/src/main/java/Books.java
new file mode 100644
index 000000000..b94ffcf0f
--- /dev/null
+++ b/ruoyi-system/src/main/java/Books.java
@@ -0,0 +1,27 @@
+public class Books implements BookInterface {
+    private String name;
+    private String author;
+    private String isbn;
+
+    @Override
+    public String BookName() {
+        return name;
+    }
+
+    @Override
+    public String BookAuthor() {
+        return author;
+    }
+
+    @Override
+    public String BookISBN() {
+        return isbn;
+    }
+
+    @Override
+    public void setBookInfo(String name, String author, String isbn) {
+        this.name = name;
+        this.author = author;
+        this.isbn = isbn;
+    }
+}
diff --git a/ruoyi-system/src/main/java/CCoach.java b/ruoyi-system/src/main/java/CCoach.java
new file mode 100644
index 000000000..0f2d83044
--- /dev/null
+++ b/ruoyi-system/src/main/java/CCoach.java
@@ -0,0 +1,9 @@
+/**
+ * C级教练实现
+ */
+public class CCoach implements Coach{
+    @Override
+    public void command() {
+        System.out.println("我是C级证书教练");
+    }
+}
diff --git a/ruoyi-system/src/main/java/CCoachFactory.java b/ruoyi-system/src/main/java/CCoachFactory.java
new file mode 100644
index 000000000..04a16a51e
--- /dev/null
+++ b/ruoyi-system/src/main/java/CCoachFactory.java
@@ -0,0 +1,9 @@
+/**
+ * C级教练工厂实现
+ */
+public class CCoachFactory implements CoachFactory{
+    @Override
+    public Coach createCoach() {
+        return new CCoach();
+    }
+}
diff --git a/ruoyi-system/src/main/java/Circle.java b/ruoyi-system/src/main/java/Circle.java
new file mode 100644
index 000000000..9cd73551b
--- /dev/null
+++ b/ruoyi-system/src/main/java/Circle.java
@@ -0,0 +1,9 @@
+/**
+ * 实现Shape接口的圆类
+ */
+public class Circle implements Shape {
+    @Override
+    public String name() {
+        return "圆";
+    }
+}
\ No newline at end of file
diff --git a/ruoyi-system/src/main/java/Coach.java b/ruoyi-system/src/main/java/Coach.java
new file mode 100644
index 000000000..c428222c7
--- /dev/null
+++ b/ruoyi-system/src/main/java/Coach.java
@@ -0,0 +1,6 @@
+/**
+ * 教练接口
+ */
+public interface Coach {
+    void command();
+}
diff --git a/ruoyi-system/src/main/java/CoachFactory.java b/ruoyi-system/src/main/java/CoachFactory.java
new file mode 100644
index 000000000..73aef82a1
--- /dev/null
+++ b/ruoyi-system/src/main/java/CoachFactory.java
@@ -0,0 +1,6 @@
+/**
+ * 教练工厂接口
+ */
+public interface CoachFactory {
+    Coach createCoach();
+}
diff --git a/ruoyi-system/src/main/java/Demo.java b/ruoyi-system/src/main/java/Demo.java
new file mode 100644
index 000000000..50cc603a7
--- /dev/null
+++ b/ruoyi-system/src/main/java/Demo.java
@@ -0,0 +1,12 @@
+/**
+ * 演示程序
+ */
+public class Demo {
+    public static void create(CoachFactory factory) {
+        factory.createCoach().command();
+    }
+    public static void main(String[] args) {
+        create(new ACoachFactory());
+        create(new CCoachFactory());
+    }
+}
diff --git a/ruoyi-system/src/main/java/ForDemo1.java b/ruoyi-system/src/main/java/ForDemo1.java
new file mode 100644
index 000000000..b2a6ee9a1
--- /dev/null
+++ b/ruoyi-system/src/main/java/ForDemo1.java
@@ -0,0 +1,55 @@
+public class ForDemo1 {
+    public static void main(String[] args) {
+        System.out.println("----3次Hello World----");
+        for (int i = 0; i < 3; i++) {
+            if (i == 1) {
+
+                /**
+                 *当1等于3时，跳出当前循环
+                 */
+
+                break; 
+                
+            }
+            System.out.println("Hello World");
+        }
+
+        System.out.println("----4次Hello MySQL----");
+        for (int i = 1; i < 5; i++) {
+            if (i == 3) {
+
+                 /**
+                 *当1等于3时，跳出当前循环
+                 */
+
+                continue; 
+            }
+            System.out.println("Hello MySQL");
+        }
+
+        System.out.println("----5次Hello Spring----");
+        for (int i = 1; i <= 5; i++) {
+            if (i == 3) {
+
+                 /**
+                 *当i等于3时，跳过当前迭代
+                 */
+
+                continue;
+            }
+            System.out.println("Hello Spring");
+        }
+
+        System.out.println("----3次Hello Redis----");
+        for (int i = 1; i <= 5; i += 2) {
+            if (i == 3) {
+                 /**
+                 *当i等于3时，跳过当前迭代
+                 */
+
+                break; 
+            }
+            System.out.println("Hello Redis");
+        }
+    }
+}
\ No newline at end of file
diff --git a/ruoyi-system/src/main/java/ForDemo2.java b/ruoyi-system/src/main/java/ForDemo2.java
new file mode 100644
index 000000000..b7a67af99
--- /dev/null
+++ b/ruoyi-system/src/main/java/ForDemo2.java
@@ -0,0 +1,31 @@
+public class ForDemo2 {
+    public static void main(String[] args){
+        int [] numbers = {10, 20, 30, 40, 50};
+        for(int x : numbers ){
+            if (x == 30) { 
+
+                /**
+                 *当x等于30时，跳出循环
+                 */
+
+                break;
+            }
+            System.out.print( x );
+            System.out.print(",");
+        }
+        System.out.println();
+        String [] names ={"James", "Larry", "Tom", "Lacy"};
+        for( String name : names ) {
+            if (name.equals("Tom")) {
+
+                 /**
+                 *当name等于"Tom"时，跳过当前循环，继续下一个循环
+                 */
+
+                continue;
+            }
+            System.out.print( name );
+            System.out.print(",");
+        }
+    }
+}
\ No newline at end of file
diff --git a/ruoyi-system/src/main/java/ForDemo3.java b/ruoyi-system/src/main/java/ForDemo3.java
new file mode 100644
index 000000000..f2c648e49
--- /dev/null
+++ b/ruoyi-system/src/main/java/ForDemo3.java
@@ -0,0 +1,28 @@
+public class ForDemo3 {
+    public static void main(String[] args) {
+        
+        /**
+         * 使用break
+         */
+
+        System.out.println("----使用break----");
+        for (int i = 1; i <= 5; i++) {
+            if (i == 3) {
+                break;
+            }
+            System.out.println("Hello Break");
+        }
+
+        /**
+         * 使用continue
+         */
+         
+        System.out.println("----使用continue----");
+        for (int i = 1; i <= 5; i++) {
+            if (i == 3) {
+                continue;
+            }
+            System.out.println("Hello Continue");
+        }
+    }
+}
\ No newline at end of file
diff --git a/ruoyi-system/src/main/java/History.java b/ruoyi-system/src/main/java/History.java
new file mode 100644
index 000000000..8c7b2a6d9
--- /dev/null
+++ b/ruoyi-system/src/main/java/History.java
@@ -0,0 +1,10 @@
+/**
+ * 实现Book接口的历史类
+ */
+public class History implements Book {
+    @Override
+    public String name() {
+        return "历史";
+    }
+
+}
diff --git a/ruoyi-system/src/main/java/IfDemo1.java b/ruoyi-system/src/main/java/IfDemo1.java
new file mode 100644
index 000000000..a9b7d0fca
--- /dev/null
+++ b/ruoyi-system/src/main/java/IfDemo1.java
@@ -0,0 +1,18 @@
+public class IfDemo1 {
+    public static void main(String[] args) {
+        // 格式3： if(条件表达式){ 代码... } else if(条件表达式){ 代码... } ... else{ 代码... }
+        int score = 95;
+        // 绩效：0-60 C，60-80 B，80-90 A，90-100 A+
+        if (score >= 0 && score < 60) {
+            System.out.println("分数是：" + score + "，绩效是：C");
+        } else if (score >= 60 && score < 80) {
+            System.out.println("分数是：" + score + "，绩效是：B");
+        } else if (score >= 80 && score < 90) {
+            System.out.println("分数是：" + score + "，绩效是：A");
+        } else if (score >= 90 && score <= 100) {
+            System.out.println("分数是：" + score + "，绩效是：A+");
+        } else {
+            System.out.println("录入的分数有毛病！");
+        }
+    }
+}
\ No newline at end of file
diff --git a/ruoyi-system/src/main/java/IfDemo2.java b/ruoyi-system/src/main/java/IfDemo2.java
new file mode 100644
index 000000000..d03ca3a34
--- /dev/null
+++ b/ruoyi-system/src/main/java/IfDemo2.java
@@ -0,0 +1,16 @@
+public class IfDemo2 {
+    public static void main(String[] args) {
+        // 嵌套的 if…else 语句
+        int x = 30;
+        int y = 10;
+        if (x == 30) {
+            if (y == 20) {
+                System.out.print("X = 30 and Y = 20");
+            } else {
+                System.out.println("X = 30 and Y != 20");
+            }
+        } else {
+            System.out.println("X != 30");
+        }
+    }
+}
\ No newline at end of file
diff --git a/ruoyi-system/src/main/java/Java.java b/ruoyi-system/src/main/java/Java.java
new file mode 100644
index 000000000..fe931a4ed
--- /dev/null
+++ b/ruoyi-system/src/main/java/Java.java
@@ -0,0 +1,38 @@
+package test.java;
+
+/**
+ * 定义一个累
+ */
+
+public class Java {
+
+    /**
+     * 三个与类名相关的属性
+      */
+
+    private String name1;
+    private String name2;
+
+    /**
+     * @param name
+     * @param name2
+     */
+
+
+    public Java(String name, String name2) {
+        this.name1 = name1;
+        this.name2 = name2;
+
+    }
+
+    /**
+     * main函数创建对象并调用两个方法
+     */
+
+   public void java() {
+       System.out.println(name1 + "cc");
+   }
+    public void sha() {
+        System.out.println(name2 + "xx");
+    }
+}
diff --git a/ruoyi-system/src/main/java/ListToArray.java b/ruoyi-system/src/main/java/ListToArray.java
new file mode 100644
index 000000000..f613c1949
--- /dev/null
+++ b/ruoyi-system/src/main/java/ListToArray.java
@@ -0,0 +1,23 @@
+import java.util.ArrayList;
+import java.util.List;
+/**
+ * ListToArray
+ */
+public class ListToArray {
+    /**
+     *
+     * @param args
+     */
+    public static void main(String[] args) {
+
+        List<String> list = new ArrayList<>();
+        list.add("A");
+        list.add("B");
+        list.add("C");
+        /**
+         * 数组转为数列
+         */
+        String[] array = list.toArray(new String[0]);
+        System.out.println("数组内容: " + list.toString());
+    }
+}
\ No newline at end of file
diff --git a/ruoyi-system/src/main/java/Literature.java b/ruoyi-system/src/main/java/Literature.java
new file mode 100644
index 000000000..5880a670d
--- /dev/null
+++ b/ruoyi-system/src/main/java/Literature.java
@@ -0,0 +1,10 @@
+/**
+ * 实现Book接口的文学类
+ */
+public class Literature implements Book {
+    @Override
+    public String name() {
+        return "文学";
+    }
+
+}
diff --git a/ruoyi-system/src/main/java/New.java b/ruoyi-system/src/main/java/New.java
new file mode 100644
index 000000000..0a9ffdc30
--- /dev/null
+++ b/ruoyi-system/src/main/java/New.java
@@ -0,0 +1,30 @@
+//字符与字符串查找
+public class New{
+    public static void main(String args[]){
+        String str = "How qi bocome handsome like qi ge"; //定义一个长字符串
+        System.out.println("该字符串为："+str);
+        /***1、indexOf()方法查找字符首个出现位置格式1,2***/
+        int index1 = str.indexOf(" ");  //找到第一个空格所在的索引
+        int index2 = str.indexOf(" ",4); //找到索引4以后的第一个空格所在索引
+        System.out.println("第一个空格所在索引为："+index1);
+        System.out.println("索引4以后的第一个空格所在索引为："+index2);
+        System.out.println("*****************");
+        /***2、lastIndexOf()方法查找字符最后出现位置格式1,2***/
+        int index3 = str.lastIndexOf(" ");  //找到最后一个空格所在的索引
+        int index4 = str.lastIndexOf(" ",10);//找到索引10以后的第一个空格所在索引
+        System.out.println("最后一个空格所在索引为："+index3);
+        System.out.println("索引10以前最后一个空格所在索引为："+index4);
+        System.out.println("*****************");
+        /***3、indexOf()方法查找子字符串第一次出现位置格式1,2***/
+        int index5 = str.indexOf("qi"); //找到"qi"子字符串第一次出现位置的索引
+        int index6 = str.indexOf("qi",5);//找到索引5以后子字符串"qi"第一个出现位置所在索引
+        System.out.println("子字符串qi第一次出现位置的索引号为："+index5);
+        System.out.println("索引5以后子字符串qi第一次出现位置的索引号为："+index6);
+        System.out.println("*****************");
+        /***4、lastIndexOf()方法查找子字符串最后一次出现位置格式1,2***/
+        int index7 = str.lastIndexOf("qi");
+        int index8 = str.lastIndexOf("qi",5);
+        System.out.println("子字符串qi最后一次出现位置的索引号为："+index7);
+        System.out.println("索引号5以后子字符串qi最后一次出现位置的索引号为："+index8);
+    }
+}
\ No newline at end of file
diff --git a/ruoyi-system/src/main/java/NewStudent.java b/ruoyi-system/src/main/java/NewStudent.java
new file mode 100644
index 000000000..afcd30b1d
--- /dev/null
+++ b/ruoyi-system/src/main/java/NewStudent.java
@@ -0,0 +1,36 @@
+public class NewStudent {
+    /**
+     * 学生
+     */
+    private String name;
+    /**
+     * 名字
+     */
+    private String  age;//定义
+
+    /**
+     * 年龄
+     * @param inputName
+     * @param inputAge
+     */
+    public NewStudent(String inputName,String inputAge){
+        this.name = inputName;
+        this.age = inputAge;
+    }
+    public  void eat(){
+        System.out.println("吃饭");
+    }
+
+    /**
+     * 吃饭
+     * @param food
+     */
+
+    public void eat(String food){
+        System.out.println("学生吃的"+food);
+    }
+    public String eat(String food,String time){
+        System.out.println("学生在" + time + "吃的" + food);
+        return"吃饱了";//定义吃饭的方法
+    }
+}
diff --git a/ruoyi-system/src/main/java/Shape.java b/ruoyi-system/src/main/java/Shape.java
new file mode 100644
index 000000000..e8f03ca49
--- /dev/null
+++ b/ruoyi-system/src/main/java/Shape.java
@@ -0,0 +1,6 @@
+/**
+ * 定义一个表示形状的接口
+ */
+public interface Shape {
+    String name();
+}
diff --git a/ruoyi-system/src/main/java/Square.java b/ruoyi-system/src/main/java/Square.java
new file mode 100644
index 000000000..185d3c14f
--- /dev/null
+++ b/ruoyi-system/src/main/java/Square.java
@@ -0,0 +1,9 @@
+/**
+ * 实现Shape接口的正方形类
+  */
+public class Square implements Shape {
+    @Override
+    public String name() {
+        return "正方形";
+    }
+}
\ No newline at end of file
diff --git a/ruoyi-system/src/main/java/StringBufferDemo1.java b/ruoyi-system/src/main/java/StringBufferDemo1.java
new file mode 100644
index 000000000..9f75a2764
--- /dev/null
+++ b/ruoyi-system/src/main/java/StringBufferDemo1.java
@@ -0,0 +1,107 @@
+/**
+ * @ClassName: StringBufferDemo1
+ * @Description: StringBuffer 拼接字符串
+ * 多线程操作大量数据，用StringBuffer。
+ * StringBuffer 对方法加了synchronized（同步锁）或者对调用的方法加了同步锁，所以是线程安全的。
+ * StringBuffer和StringBuilder这两个可变类的原理和操作基本相同。
+ * @author: Zh
+ * @date: 2024/4/8 16:56
+ */
+public class StringBufferDemo1 {
+    public static void main(String[] args) {
+
+        /**
+         * 创建StringBuffer对象
+         */
+
+        StringBuffer sb = new StringBuffer("孙悟空");
+
+        /**
+         * 在字符串后面追加新的字符串
+         */
+
+        sb.append("会龟派气功");
+
+        /**
+         * StringBuffer对象：孙悟空会龟派气功
+         */
+
+        System.out.println("StringBuffer对象：" + sb);
+
+        /**
+         * 删除指定位置上的字符串，从指定的下标开始和结束，下标从0开始
+         */
+
+        /**
+         * 0 孙 1悟 2空 3会 4龟 5派 6气 7功
+         */
+
+        /**
+         * 2空 3会
+         */
+
+        sb.delete(2, 4);
+
+        /**
+         * delete删除：孙悟龟派气功
+         */
+
+        System.out.println("delete删除：" + sb);
+
+        /**
+         * 在指定下标位置上添加指定的字符串
+         */
+
+        sb.insert(2, "123");
+        System.out.println("insert新增：" + sb); // insert新增：孙悟123龟派气功
+
+        /**
+         * 将字符串翻转
+         */
+
+        sb.reverse();
+
+        /**
+         * reverse反转：功气派龟321悟孙
+         */
+
+        System.out.println("reverse反转：" + sb);
+
+
+        /**
+         * 将StringBuffer转换成String类型
+         */
+
+
+        String s = sb.toString();
+
+        /**
+         * String类型：功气派龟321悟孙
+         */
+
+        check(s); //
+
+    }
+
+
+
+    /**
+
+     * 检查传入的参数是否是String类型
+
+     *
+
+     * @param abc
+
+     */
+
+    public static void check(String abc) {
+
+        System.out.println("String类型：" + abc);
+
+    }
+
+
+
+}
+
diff --git a/ruoyi-system/src/main/java/StringBuilderDemo1.java b/ruoyi-system/src/main/java/StringBuilderDemo1.java
new file mode 100644
index 000000000..02792b3ed
--- /dev/null
+++ b/ruoyi-system/src/main/java/StringBuilderDemo1.java
@@ -0,0 +1,123 @@
+/**
+ * @ClassName: StringBuilderDemo1
+ * @Description: StringBuilder 拼接字符串
+ * 单线程操作大量数据，用StringBuilder。
+ * StringBuilder 并没有对方法进行加synchronized（同步锁），所以是非线程安全的。
+ * StringBuffer和StringBuilder这两个可变类的原理和操作基本相同。
+ * @author: Zh
+ * @date: 2024/4/8 16:41
+ */
+
+public class StringBuilderDemo1 {
+
+    public static void main(String[] args) {
+        // StringBuilder的字符串拼接.append
+        StringBuilder sb = new StringBuilder();
+
+        /**
+         * 字符
+         */
+
+        sb.append("a");
+
+        /**
+         * 整数
+         */
+
+        sb.append(1);
+
+        /**
+         * 布尔类型
+         */
+
+        sb.append(false);
+
+        /**
+         * 小数
+         */
+
+        sb.append(3.3);
+
+        /**
+         * 字符串
+         */
+
+        sb.append("abc");
+
+        /**
+         * append的应用：a1false3.3abc
+         */
+
+        System.out.println("append的应用：" + sb);
+
+        StringBuilder sb1 = new StringBuilder();
+
+        /**
+         * 支持链式编程
+         */
+
+        sb1.append("a").append("b").append("c").append("我爱你中国");
+
+        /**
+         * append支持链式编程：abc我爱你中国
+         */
+
+        System.out.println("append支持链式编程：" + sb1);
+
+        /**
+         * reverse反转
+         */
+
+        sb1.reverse();
+
+        /**
+         * reverse反转：国中你爱我cba
+         */
+
+        System.out.println("reverse反转：" + sb1);
+
+        /**
+         * 字符串长度length
+         * 字符串长度length：8
+         */
+
+        System.out.println("字符串长度length：" + sb1.length());
+
+        /**
+         * 注意：StringBuilder只是拼接字符串的手段：效率好。
+         * 最终的目的还是要恢复成String类型。
+         */
+
+        StringBuilder sb2 = new StringBuilder();
+        sb2.append("123").append("阿拉伯数字");
+
+        /**
+         * check(sb2); // 报错，因为sb2不是String类型
+         * 拼接字符串：123阿拉伯数字
+         */
+
+        System.out.println("拼接字符串：" + sb2);
+
+        /**
+         * 恢复成String类型
+         */
+
+        String rs = sb2.toString();
+
+        /**
+         * String类型：123阿拉伯数字
+         */
+
+        check(rs);
+    }
+
+    /**
+     * 检查传入的参数是否是String类型
+     *
+     * @param abc
+     */
+
+    public static void check(String abc) {
+        System.out.println("String类型：" + abc);
+    }
+}
diff --git a/ruoyi-system/src/main/java/Student.java b/ruoyi-system/src/main/java/Student.java
new file mode 100644
index 000000000..727b636ef
--- /dev/null
+++ b/ruoyi-system/src/main/java/Student.java
@@ -0,0 +1,37 @@
+public class Student {
+    // 1.局部变量：在方法、构造函数或块内部声明的变量。
+    public void run() {
+        String weight = "100斤"; // 局部变量weight，必须有初始值。
+        // 因为实例变量age没赋值，所以默认是0
+        System.out.println(name + "现在" + age + "岁"); // 小明现在0岁
+        System.out.println(name + weight + "，跑得很快"); // 小明100斤，跑得很快
+    }
+
+    // 2.实例变量：在类中声明，但在方法、构造函数或块之外。
+    public String name = "小明"; // 公有实例变量name对子类可见
+    private int age; // 私有实例变量age，仅在该类可见，不赋值，默认是0
+
+    // main方法，程序入口
+    public static void main(String[] args) {
+        Student.onLineNumber++; // 22
+        System.out.println(onLineNumber);
+        Student student = new Student();
+        student.run();
+        student.eat("方便面");
+        student.study();
+    }
+
+    // 3.类变量：在类中用 static 关键字声明的变量，它们属于类而不是实例。
+    public static int onLineNumber = 21;
+    private String major = "计算机科学";
+
+    // 4.参数变量：是方法或构造函数声明中的变量
+    public void eat(String food) { // 参数变量food
+        System.out.println(name + "喜欢吃" + food); // 小明喜欢吃方便面
+    }
+
+    // 自定义方法
+    public void study() {
+        System.out.println(name + "正在学习" + major);
+    }
+}
\ No newline at end of file
diff --git a/ruoyi-system/src/main/java/Test.java b/ruoyi-system/src/main/java/Test.java
new file mode 100644
index 000000000..e69de29bb
diff --git a/ruoyi-system/src/main/java/TestArray.java b/ruoyi-system/src/main/java/TestArray.java
new file mode 100644
index 000000000..7669f3419
--- /dev/null
+++ b/ruoyi-system/src/main/java/TestArray.java
@@ -0,0 +1,37 @@
+public class TestArray {
+    /**
+     *
+     * @param args
+     */
+    public static void main(String[] args) {
+        // double类型的数组
+        double[] scores = new double[]{99.5, 88.0, 75.5};
+        double[] scores1 = {99.5, 88.0, 75.5}; // 简化写法
+
+        // int类型的数组
+        int[] ages = new int[]{12, 24, 36};
+        int[] ages1 = {12, 24, 36}; // 简化写法
+
+        int size = 5; // 设置数组大小是10
+        String[] names = new String[size]; // 定义数组
+        names[0] = "孙悟空";
+        names[1] = "贝吉塔";
+        names[2] = "弗利萨";
+        names[3] = "沙鲁";
+        names[4] = "魔人布欧";
+        // 编译不报错，运行报错，因为数组大小是5，这是数组里第6个元素，数组越界ArrayIndexOutOfBoundsException
+        // names[5] = "布尔玛";
+        // 数组索引从 0 开始，所以索引值从 0 到 arrayRefVar.length-1
+        for (int i = 0; i < names.length; i++) {
+            System.out.print("索引：" + i + names[i] + " ");
+        }
+
+        System.out.println();
+
+        // 数组变量名存储的是数组在内存种的地址，数组是引用类型
+        // [ 指的是 数组
+        // D 指的是 数据类型double
+        // @ 指的是 在哪里
+        System.out.println(scores); // [D@776ec8df,指的是数组的十六进制地址
+    }
+}
diff --git a/ruoyi-system/src/main/java/TestBook.java b/ruoyi-system/src/main/java/TestBook.java
new file mode 100644
index 000000000..008b5b4b8
--- /dev/null
+++ b/ruoyi-system/src/main/java/TestBook.java
@@ -0,0 +1,22 @@
+/**
+ * 测试多态性的类
+ */
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * 测试类 演示多样性
+ */
+public class TestBook {
+    public static void main (String[] args) {
+        List<Book> books = new ArrayList<>();
+        Book literatureBook = new Literature();
+        Book historyBook = new History();
+        books.add(literatureBook);
+        books.add(historyBook);
+        for (Book book : books){
+            System.out.println(book.name());
+        }
+    }
+}
diff --git a/ruoyi-system/src/main/java/TestShape.java b/ruoyi-system/src/main/java/TestShape.java
new file mode 100644
index 000000000..9ad97874c
--- /dev/null
+++ b/ruoyi-system/src/main/java/TestShape.java
@@ -0,0 +1,22 @@
+/**
+ * 测试多态性的类
+ */
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * 测试类 演示多样性
+ */
+public class TestShape {
+    public static void main(String[] args) {
+        List<Shape> shapes = new ArrayList<>();
+        Shape circleShape = new Circle(); // 创建Circle
+        Shape squareShape = new Square(); // 创建Square
+        shapes.add(circleShape); // 将Circle添加到列表中
+        shapes.add(squareShape); // 将Square添加到列表中
+        for (Shape shape : shapes) { // 遍历列表中的每个Shape对象
+            System.out.println(shape.name()); // 打印
+        }
+    }
+}
\ No newline at end of file
diff --git a/ruoyi-system/src/main/java/TestTop.java b/ruoyi-system/src/main/java/TestTop.java
new file mode 100644
index 000000000..7ce7487ad
--- /dev/null
+++ b/ruoyi-system/src/main/java/TestTop.java
@@ -0,0 +1,13 @@
+public class TestTop {
+    public static void main(String[] args){
+        Top topPerson = new Top("xx","20","2");//创建top对象
+        topPerson.name();
+        topPerson.age();
+        topPerson.ranking();//输出
+
+        Top topPer = new Top("cc","21","1");//创建top对象
+        topPer.name();
+        topPer.age();
+        topPer.ranking();//输出
+    }
+}
diff --git a/ruoyi-system/src/main/java/Top.java b/ruoyi-system/src/main/java/Top.java
new file mode 100644
index 000000000..d1603c70e
--- /dev/null
+++ b/ruoyi-system/src/main/java/Top.java
@@ -0,0 +1,75 @@
+/**
+ * 表示排名的类
+ */
+public class Top {
+
+    /**
+     * 名字
+     */
+    private String name;
+
+    /**
+     *年龄
+     */
+    private String age;
+
+    /**
+     * 名次
+     */
+    private String ranking;
+
+    /**
+     * 构造法
+     * @param name
+     * @param age
+     * @param ranking
+     */
+    public Top(String name,String age,String ranking){
+        this.name=name;
+        this.age=age;
+        this.ranking=ranking;
+    }
+
+    /**
+     * 获取名字
+     */
+    public void name() {
+        System.out.println("名字: " + name);
+    }
+
+    /**
+     * 获取年龄
+     */
+    public void age() {
+        System.out.println("年龄: " + age);
+    }
+
+    /**
+     * 获取名次
+     */
+    public void ranking() {
+        System.out.println("名次: " + ranking);
+    }
+
+    /**
+     * 获取名字
+     */
+    public void name1() {
+        System.out.println("名字: " + name);
+    }
+
+    /**
+     * 获取年龄
+     */
+    public void age1() {
+        System.out.println("年龄: " + age);
+    }
+
+    /**
+     * 获取名次
+     */
+    public void ranking1() {
+        System.out.println("名次: " + ranking);
+    }
+
+}
diff --git a/ruoyi-system/src/main/java/Word.java b/ruoyi-system/src/main/java/Word.java
new file mode 100644
index 000000000..bd9798655
--- /dev/null
+++ b/ruoyi-system/src/main/java/Word.java
@@ -0,0 +1,12 @@
+public class Word {
+    public static void main(String[] args) {
+        int n = 7;
+        if (n >= 0 && n < 10) {
+            for (int i = 0; i < n; i++) {
+                System.out.println("He" + n + n +"o" + " Wor" + n + "d");
+            }
+        } else {
+            System.out.println("n>10");
+        }
+    }
+}
\ No newline at end of file
diff --git a/ruoyi-system/src/main/java/Wount.java b/ruoyi-system/src/main/java/Wount.java
new file mode 100644
index 000000000..135c18f38
--- /dev/null
+++ b/ruoyi-system/src/main/java/Wount.java
@@ -0,0 +1,11 @@
+public class Wount {
+    public static void main(String[] args) {
+        String studentId = "20233011082";
+        char lastDigit1 = studentId.charAt(studentId.length() - 2);
+        char lastDigit2 = studentId.charAt(studentId.length() - 1);
+        char[] lastTwoDigits = {lastDigit1, lastDigit2};
+        for (char c : lastTwoDigits) {
+            System.out.print(c + " ");
+        }
+    }
+}
\ No newline at end of file
diff --git a/ruoyi-system/src/main/ss.java b/ruoyi-system/src/main/ss.java
new file mode 100644
index 000000000..cb6ca8ffe
--- /dev/null
+++ b/ruoyi-system/src/main/ss.java
@@ -0,0 +1,30 @@
+//字符与字符串查找
+public class da{
+    public static void main(String args[]){
+        String str = "How qi bocome handsome like qi ge"; //定义一个长字符串
+        System.out.println("该字符串为："+str);
+        /***1、indexOf()方法查找字符首个出现位置格式1,2***/
+        int index1 = str.indexOf(" ");  //找到第一个空格所在的索引
+        int index2 = str.indexOf(" ",4); //找到索引4以后的第一个空格所在索引
+        System.out.println("第一个空格所在索引为："+index1);
+        System.out.println("索引4以后的第一个空格所在索引为："+index2);
+        System.out.println("*****************");
+        /***2、lastIndexOf()方法查找字符最后出现位置格式1,2***/
+        int index3 = str.lastIndexOf(" ");  //找到最后一个空格所在的索引
+        int index4 = str.lastIndexOf(" ",10);//找到索引10以后的第一个空格所在索引
+        System.out.println("最后一个空格所在索引为："+index3);
+        System.out.println("索引10以前最后一个空格所在索引为："+index4);
+        System.out.println("*****************");
+        /***3、indexOf()方法查找子字符串第一次出现位置格式1,2***/
+        int index5 = str.indexOf("qi"); //找到"qi"子字符串第一次出现位置的索引
+        int index6 = str.indexOf("qi",5);//找到索引5以后子字符串"qi"第一个出现位置所在索引
+        System.out.println("子字符串qi第一次出现位置的索引号为："+index5);
+        System.out.println("索引5以后子字符串qi第一次出现位置的索引号为："+index6);
+        System.out.println("*****************");
+        /***4、lastIndexOf()方法查找子字符串最后一次出现位置格式1,2***/
+        int index7 = str.lastIndexOf("qi");
+        int index8 = str.lastIndexOf("qi",5);
+        System.out.println("子字符串qi最后一次出现位置的索引号为："+index7);
+        System.out.println("索引号5以后子字符串qi最后一次出现位置的索引号为："+index8);
+    }
+}
\ No newline at end of file