add ability to append to files

classpath/java-io.cpp

@@ -593,11 +593,11 @@ Java_java_io_FileInputStream_close(JNIEnv* e, jclass, jint fd)
 }
 
 extern "C" JNIEXPORT jint JNICALL
-Java_java_io_FileOutputStream_open(JNIEnv* e, jclass, jstring path)
+Java_java_io_FileOutputStream_open(JNIEnv* e, jclass, jstring path, jboolean append)
 {
   string_t chars = getChars(e, path);
   if (chars) {
-    int fd = doOpen(e, chars, O_WRONLY | O_CREAT | O_TRUNC);
+    int fd = doOpen(e, chars, append ? (O_WRONLY | O_APPEND) : (O_WRONLY | O_CREAT | O_TRUNC));
     releaseChars(e, path, chars);
     return fd;
   } else {

classpath/java/io/FileOutputStream.java

@@ -22,14 +22,19 @@ public class FileOutputStream extends OutputStream {
   }
 
   public FileOutputStream(String path) throws IOException {
-    fd = open(path);
+    this(path, false);
   }
 
+  public FileOutputStream(String path, boolean append) throws IOException {
+    fd = open(path, append);
+  }
+  
+
   public FileOutputStream(File file) throws IOException {
     this(file.getPath());
   }
 
-  private static native int open(String path) throws IOException;
+  private static native int open(String path, boolean append) throws IOException;
 
   private static native void write(int fd, int c) throws IOException;
 

test/FileOutput.java

@@ -0,0 +1,23 @@
+import java.io.FileOutputStream;
+import java.io.IOException;
+
+
+public class FileOutput {
+
+  /**
+   * @param args
+   * @throws IOException 
+   */
+  public static void main(String[] args) throws IOException {
+      FileOutputStream f = new FileOutputStream("test.txt");
+      f.write("Hello world!\n".getBytes());
+      f.close();
+      
+      FileOutputStream f2 = new FileOutputStream("test.txt", true);
+      f2.write("Hello world again!".getBytes());
+      f2.close();
+      
+
+  }
+
+}