Android 制作一个网页源代码浏览器（HttpURLConnection）

package com.wuyou.htmlcodeviewer;



import android.os.Bundle;

import android.os.Handler;

import android.os.Message;

import android.support.v7.app.ActionBarActivity;

import android.text.TextUtils;

import android.view.View;

import android.widget.EditText;

import android.widget.TextView;

import android.widget.Toast;



import java.io.BufferedReader;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.net.HttpURLConnection;

import java.net.URL;



public class MainActivity extends ActionBarActivity {

    private static final int ERROR = 0;

    private static final int CHANGE_TEXT = 1;



    private EditText editText;

    private TextView textView;



    private Handler handler = new Handler() {

        @Override

        public void handleMessage(Message msg) {

            if (msg.what == CHANGE_TEXT) {

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

            } else if (msg.what == ERROR) {

                Toast.makeText(MainActivity.this, (String) msg.obj, Toast.LENGTH_LONG).show();

            }

        }

    };



    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);



        editText = (EditText) findViewById(R.id.et);

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

    }



    public void click(View view) {

        new Thread(new Runnable() {

            @Override

            public void run() {

                try {

                    String path = editText.getText().toString().trim();

                    if (TextUtils.isEmpty(path)) {

                        Message message = new Message();

                        message.what = ERROR;

                        message.obj = "地址不能为空！";

                        handler.sendMessage(message);

                    } else {

                        URL url = new URL(path);

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

                        httpURLConnection.setRequestMethod("GET");

                        httpURLConnection.setRequestProperty("User-Agent", "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:22.0) Gecko/20100101 Firefox/22.0");

                        httpURLConnection.setConnectTimeout(5000);//设置连接服务器如果没有在5秒钟运行则抛出错误

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

                            InputStream is = httpURLConnection.getInputStream();

                            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(is, "UTF-8"));

                            String line = null;

                            StringBuilder sb = new StringBuilder();

                            while ((line = bufferedReader.readLine()) != null) {

                                sb.append(line);

                            }

                            Message message = new Message();

                            message.what = CHANGE_TEXT;

                            message.obj = sb.toString();

                            handler.sendMessage(message);

                        }

                    }



                } catch (Exception e) {

                    e.printStackTrace();

                    Message message = new Message();

                    message.what = ERROR;

                    message.obj = "出错了！";

                    handler.sendMessage(message);

                }

            }

        }).start();

    }



}

 

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

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

    android:id="@+id/container"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="vertical"

    tools:context=".MainActivity"

    tools:ignore="MergeRootFrame">



    <EditText

        android:id="@+id/et"

        android:text="http://www.baidu.com/"

        android:layout_height="wrap_content"

        android:layout_width="fill_parent" />



    <Button

        android:text="查看源代码"

        android:onClick="click"

        android:layout_height="wrap_content"

        android:layout_width="wrap_content" />





    <ScrollView

        android:id="@+id/scroll"

        android:layout_height="fill_parent"

        android:layout_width="fill_parent">



        <TextView

            android:id="@+id/tv"

            android:layout_height="fill_parent"

            android:layout_width="fill_parent" />

    </ScrollView>





</LinearLayout>

 

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