JScrollPane滚动条自动滚至底部

在JScrollPane(JTextArea)的JTextArea中增加内容，为了达到如题之效果。

JTextArea ta = new JTextArea(10, 40);// 消息接收显示框
JScrollPane pane = new JScrollPane(ta);


	class ReadMsg extends Thread {
		public void run() {
			InputStream is = null;
			BufferedReader br = null;
			String msg = null;
			OutputStream os = null;
			PrintStream ps = null;

			// reader object from server
			try {
				is = client.getInputStream();
				br = new BufferedReader(new InputStreamReader(is, "utf-8"));

				// 客户端连接成功后,首先发送昵称过去
				os = client.getOutputStream();
				ps = new PrintStream(os);
				ps.println(nameInput.getText());
			} catch (Exception ex1) {
				// ex1.printStackTrace();
			}

			while (true) {
				try {
					while ((msg = br.readLine()) != null) {
						ta.append(msg + "\n");
                      //关键点：调用该方法，实现如题效果
                      ta.setSelectionStart(ta.getText().length());
					}
				} catch (Exception ex) {
					// ex.printStackTrace();
				}
			}
		}
	}