使用HTTP协议访问网路

使用HTTP协议访问网路

一、使用HttpURLConnection

//new一个URL对象
URL url = new URL("http://www.qq.com");//千万不要用www.baidu.com，坑爹东西
//调用openConnection()方法,得到HttpURLConnection对象
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
//对HttpURLConnection对象设置模式，GET 表示希望从服务器那里获取数据，而 POST 则表示希望提交数据给服务器。
connection.setRequestMethod("GET");
//设置连接超时、读取超时的毫秒数
connection.setConnectTimeout(8000);
connection.setReadTimeout(8000);
//调用 getInputStream()方法获取到服务器返回的输入流
InputStream in = connection.getInputStream();
//对输入流进行读取操作
BufferedReader reader = new BufferedReader(new InputStreamReader(in));
StringBuilder response = new StringBuilder();
String line;
//当该行不为空，返回一行
while ((line = reader.readLine()) != null) {
    Log.d(TAG, "line != null" + line);
    response.append(line);
}
//通过handler把message发送出去
Message message = new Message();
message.what = SHOW_RESPONSE;
if (response.toString() == null) {
    message.obj = response.toString() + "啥也没有";
} else {
    message.obj = response.toString();
}
mHandler.sendMessage(message);

主线程中创建handler，并重写handlerMessage()方法，等待来自sendMessage的信息

private Handler mHandler = new Handler() {
    @Override
    public void handleMessage(Message msg) {
        switch (msg.what) {
            case SHOW_RESPONSE:
            //判断信息并更新UI操作
                String response = (String) msg.obj;
                NetworkTextView.setText(response);
                break;
        }
    }
};

向服务器推送数据

connection.setRequestMethod("POST");
DataOutputStream out = new DataOutputStream(connection.getOutputStream());
out.writeBytes("username=admin&password=123456");//数据与数据之间用"&"隔开