more classpath progress

classpath/java/io/StringWriter.java

@@ -0,0 +1,17 @@
+package java.io;
+
+public class StringWriter extends Writer {
+  private final StringBuilder out = new StringBuilder();
+  
+  public void write(char[] b, int offset, int length) throws IOException {
+    out.append(new String(b, offset, length));
+  }
+
+  public String toString() {
+    return out.toString();
+  }
+
+  public void flush() throws IOException { }
+
+  public void close() throws IOException { }
+}