Add a convenience method to write CSR to an OutputStream

acme4j-utils/src/main/java/org/shredzone/acme4j/util/CSRBuilder.java

@@ -14,6 +14,8 @@
 package org.shredzone.acme4j.util;
 
 import java.io.IOException;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
 import java.io.Writer;
 import java.security.KeyPair;
 import java.security.PrivateKey;
@@ -189,7 +191,7 @@ public class CSRBuilder {
     }
 
     /**
-     * Writes the signed certificate request to a file.
+     * Writes the signed certificate request to a {@link Writer}.
      *
      * @param w
      *            {@link Writer} to write the PEM file to
@@ -204,6 +206,16 @@ public class CSRBuilder {
         }
     }
 
+    /**
+     * Writes the signed certificate request to an {@link OutputStream}.
+     *
+     * @param out
+     *            {@link OutputStream} to write the PEM file to
+     */
+    public void write(OutputStream out) throws IOException {
+        write(new OutputStreamWriter(out, "utf-8"));
+    }
+
     @Override
     public String toString() {
         StringBuilder sb = new StringBuilder();

acme4j-utils/src/test/java/org/shredzone/acme4j/util/CSRBuilderTest.java

@@ -16,6 +16,7 @@ package org.shredzone.acme4j.util;
 import static org.hamcrest.Matchers.*;
 import static org.junit.Assert.*;
 
+import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.StringReader;
 import java.io.StringWriter;
@@ -180,6 +181,14 @@ public class CSRBuilderTest {
         // Verify that both keypairs are the same
         assertThat(builder.getCSR(), not(sameInstance(readCsr)));
         assertThat(builder.getEncoded(), is(equalTo(readCsr.getEncoded())));
+
+        // OutputStream is identical?
+        byte[] pemBytes;
+        try (ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
+            builder.write(baos);
+            pemBytes = baos.toByteArray();
+        }
+        assertThat(new String(pemBytes, "utf-8"), is(equalTo(pem)));
     }
 
     /**