Add PageJacksonSerializer for unifying page response

src/main/java/cc/ryanc/halo/web/support/PageJacksonSerializer.java

@@ -0,0 +1,32 @@
+package cc.ryanc.halo.web.support;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.JsonSerializer;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import org.springframework.boot.jackson.JsonComponent;
+import org.springframework.data.domain.Page;
+
+import java.io.IOException;
+
+/**
+ * Custom serializer for Page object.
+ *
+ * @author johnniang
+ * @date 3/19/19
+ */
+@JsonComponent
+public class PageJacksonSerializer extends JsonSerializer<Page> {
+
+    @Override
+    public void serialize(Page page, JsonGenerator generator, SerializerProvider serializers) throws IOException {
+        generator.writeStartObject();
+
+        generator.writeObjectField("content", page.getContent());
+        generator.writeNumberField("pages", page.getTotalPages());
+        generator.writeNumberField("total", page.getTotalElements());
+        generator.writeNumberField("page", page.getNumber());
+        generator.writeNumberField("rpp", page.getSize());
+
+        generator.writeEndObject();
+    }
+}