<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    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=".MainActivity"

    android:orientation="vertical"

    >

    <Button

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="查看源文件"

        android:onClick="click"

        />

    <ScrollView

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        >

    <TextView

        android:id="@+id/tv"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        />

</ScrollView>

</LinearLayout>

package com.itheima.htmlviewer;

import java.io.InputStream;

import java.net.HttpURLConnection;

import java.net.MalformedURLException;

import java.net.URL;

import com.itheima.htmlviewer.utils.Utils;

import android.os.Bundle;

import android.os.Handler;

import android.os.Message;

import android.app.Activity;

import android.view.Menu;

import android.view.View;

import android.widget.TextView;

//请求网上的文本（网页）

public class MainActivity extends Activity {

    Handler handler = new Handler(){

        public void handleMessage(android.os.Message msg) {

            TextView tv = (TextView) findViewById(R.id.tv);

            tv.setText((String)msg.obj);

        }

    };

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

    }

    public void click(View v){

        Thread t = new Thread(){

            @Override

            public void run() {

                String path = "http://192.168.13.13:8080/baidu.html";

                try {

                    URL url = new URL(path);

                    //获取连接对象，此时还未建立连接

                    HttpURLConnection conn = (HttpURLConnection) url.openConnection();

                    conn.setRequestMethod("GET");

                    conn.setConnectTimeout(5000);

                    conn.setReadTimeout(5000);

                    //先建立连接，然后获取响应码

                    if(conn.getResponseCode() == 200){

                        //拿到服务器返回的输入流，流里的数据就是html的源文件

                        InputStream is = conn.getInputStream();

                        //从流里把文本数据取出来

                        String text = Utils.getTextFromStream(is);

                        //发送消息，让主线程刷新ui，显示源文件

                        Message msg = handler.obtainMessage();

                        msg.obj = text;

                        handler.sendMessage(msg);

                    }

                } catch (Exception e) {

                    // TODO Auto-generated catch block

                    e.printStackTrace();

                }

            }

        };

        t.start();

    }

}

package com.itheima.htmlviewer.utils;

import java.io.ByteArrayOutputStream;

import java.io.IOException;

import java.io.InputStream;

public class Utils {

    public static String getTextFromStream(InputStream is){

        //乱码是因为服务器和客户端码表不一致

        byte[] b = new byte[1024];

        int len = 0;

        //创建字节数组输出流，读取输入流的文本数据时，同步把数据写入数组输出流

        ByteArrayOutputStream bos = new ByteArrayOutputStream();

        try {

            while((len = is.read(b)) != -1){

                bos.write(b, 0, len);//写入到数组输出流

            }

            //把字节数组输出流里的数据转换成字节数组

            String text = new String(bos.toByteArray(),"utf-8");//安卓默认是utf-8

            return text;

        } catch (IOException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

        return null;

    }

}