final JTextArea text = new JTextArea();
		text.setBounds(10, 430, 600, 120);
		text.setCaretPosition(text.getText().length());
		text.setLineWrap(true);
		jF.add(text);
		
		
		OutputStream textAreaStream = new OutputStream() {
			public void write(int b) throws IOException {
				text.append(String.valueOf((char) b));
			}

			public void write(byte b[]) throws IOException {
				text.append(new String(b));
			}

			public void write(byte b[], int off, int len) throws IOException {
				text.append(new String(b, off, len));
			}
		};
		PrintStream myOut = new PrintStream(textAreaStream);
		System.setOut(myOut);
		System.setErr(myOut);

我是这么写的，将所有打印的信息放到JTextArea上，但是他不滚动，就显示框框大小的数据