httpgetexample.java

《精通JAVA手机游戏与应用程序设计》随书光盘

/*
 * 使用Get方式访问Servlet
 */

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import javax.microedition.io.*;
import java.io.*;

public class HttpGetExample extends MIDlet implements CommandListener {
	private Display display;

	private Form mainForm;

	private Command exitCommand;

	String account = "newuser";

	String password = "123456";

	public HttpGetExample() {
		display = Display.getDisplay(this);

		exitCommand = new Command("Exit", Command.EXIT, 1);

		mainForm = new Form("Data from servlet");
		mainForm.addCommand(exitCommand);
		mainForm.setCommandListener(this);

	}
	
	public void startApp() {
		display.setCurrent(mainForm);
		//访问服务器servlet
		try {
			callServlet();
		} catch (Exception e) {
			System.out.println(e.toString());
		}
	}

	public void pauseApp() {
	}

	public void destroyApp(boolean unconditional) {
	}

	private void callServlet() throws IOException {
		HttpConnection http = null;
		InputStream iStrm = null;

		// Data is passed at the end of url for GET
		String url = "http://127.0.0.1:8080/TEst/hello" + "?" + "account="
				+ account + "&" + "password=" + password;

		try {
			http = (HttpConnection) Connector.open(url);
			//使用HttpConnection.GET方式
			// 发送Get请求
			http.setRequestMethod(HttpConnection.GET);

			// 服务器响应
			if (http.getResponseCode() == HttpConnection.HTTP_OK) {
				iStrm = http.openInputStream();
				// 获得头信息，没有返回

				//获得数据信息
				int length = (int) http.getLength();
				if (length > 0) {
					byte servletData[] = new byte[length];
					iStrm.read(servletData);

					//显示返回信息
					mainForm.append("验证通过: \n"
							+ new String(servletData));
				} else
					mainForm.append("不能访问数据！");
			}
		} catch (Exception e) {
			mainForm.append("网络出错");
			System.out.println(e.toString());
		} finally {
			//关闭连接对象
			if (iStrm != null)
				iStrm.close();
			if (http != null)
				http.close();
		}
	}

	public void commandAction(Command c, Displayable s) {
		if (c == exitCommand) {
			destroyApp(false);
			notifyDestroyed();
		}
	}
}