HttpURLConnection读取网页文件

一.关键代码

public class MainActivity extends Activity {

    TextView content;
    private static final  int SHOWRESPONSE = ;

    Handler handler = new Handler(){
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what){
                case SHOWRESPONSE:
                    String response = (String)msg.obj;
                    content.setText(response);
                    break;
            }
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        content = (TextView)findViewById(R.id.context);
    }

    protected void myClick(View v){
        if( v.getId() == R.id.btn ){
            sendRequest();
        }
    }

    private void sendRequest(){

        new Thread(new Runnable() {
            @Override
            public void run() {
                HttpURLConnection connection = null;
                try {
                    URL url = new URL("https://www.baidu.com");
                    connection = (HttpURLConnection)url.openConnection();
                    connection.setRequestMethod("GET");
                    connection.setConnectTimeout();
                    connection.setReadTimeout();
                    InputStream in = connection.getInputStream();
                    BufferedReader reader = new BufferedReader(new InputStreamReader(in));
                    StringBuilder response = new StringBuilder();
                    String line;
                    while( (line = reader.readLine()) != null ){
                        response.append(line);
                    }
                    Message msg = handler.obtainMessage();
                    msg.what = SHOWRESPONSE;
                    msg.obj = response.toString();
                    handler.sendMessage(msg);

                }catch (Exception e){
                    e.printStackTrace();
                }finally {
                    if(connection != null){
                        connection.disconnect();
                    }
                }
            }
        }).start();
    }
}

二.布局文件:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.aotian.guo.httpurlconnectiondemo.MainActivity">

    <Button
        android:text="Button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:id="@+id/btn"
        android:onClick="myClick"/>

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_below="@+id/btn"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true">

        <TextView
            android:text="TextView"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:id="@+id/context"/>
    </ScrollView>
</RelativeLayout>

三.所需权限

<uses-permission android:name="android.permission.INTERNET" />