【实战】android网页源代码查看器

点击查看源代码，可以查看该网页的源代码

一、文件结构

MainActivity.java:

package com.example.viewpagesource;


import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;


import com.example.viewpagesource.utils.StreamTool;


import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.app.Activity;
import android.text.TextUtils;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;


public class MainActivity extends Activity implements View.OnClickListener {


	protected static final int SUCCESS = 0;
	protected static final int ERROR = 1;
	protected static final int NETWORK_ERROR = 2;
	private Button btn;
	private EditText ed_path;
	private TextView tv;
	
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        btn=(Button) findViewById(R.id.btn);
        btn.setOnClickListener(this);
        ed_path=(EditText) findViewById(R.id.ed_path);
        tv=(TextView) findViewById(R.id.tv);
    }


    //定义一个秘书
    Handler handler=new Handler(){
    	public void handleMessage(android.os.Message msg) {
    		switch (msg.what) {
			case SUCCESS:
				String value=(String) msg.obj;
				tv.setText(value);
				break;
			case ERROR:
				System.out.println("ERROR");
				Toast.makeText(MainActivity.this, "错误发生了", 0).show();
				break;
			case NETWORK_ERROR:
				System.out.println("NETWORK_ERROR");
				Toast.makeText(MainActivity.this, "错误发生了", 0).show();
				break;
			default:
				break;
			}
    	};
    };
  




    String path;
	@Override
	public void onClick(View v) {
		// TODO Auto-generated method stub
		path = ed_path.getText().toString().trim();
		if(TextUtils.isEmpty(path)){
			Toast.makeText(this, "路径有错误", 0).show();
			return;
		}
		
		//连接网络,要启动一个新的线程去，干耗时的事情
		new Thread(){
			public void run() {
				try {
					URL url=new URL(path);
					HttpURLConnection conn = (HttpURLConnection) url.openConnection();
					//设置连接超时为5秒钟
					conn.setConnectTimeout(5000);
					conn.setRequestMethod("GET");
					String contentType = conn.getContentType();
					
					
					int code = conn.getResponseCode();
					if(code==200){
						InputStream in = conn.getInputStream();
						
						//这里的data是从服务器返回的
						String data=StreamTool.decodeStream(in);
						
						//展示在屏幕上
						Message msg=Message.obtain();
						msg.what=SUCCESS;
						msg.obj=data;
						
						handler.sendMessage(msg);
					}else{
						Message msg=Message.obtain();
						msg.what=ERROR;
						
						
						handler.sendMessage(msg);
					}
				} catch (Exception e) {
					// TODO Auto-generated catch block
					Message msg=Message.obtain();
					msg.what=NETWORK_ERROR;
					
					
					handler.sendMessage(msg);
					
					e.printStackTrace();
				}
			};
		}.start();
	}
    
}

StreamTool.java

package com.example.viewpagesource.utils;


import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;


public class StreamTool {


	public static String decodeStream(InputStream in) throws IOException {
		// TODO Auto-generated method stub
		//底层流
		
		ByteArrayOutputStream baos=new ByteArrayOutputStream();
			
			int len=0;
			byte[] buf=new byte[1024];
			while((len=in.read(buf))>0){
				baos.write(buf,0,len);
			}
			
			String data = baos.toString();
			return data;
		
	}


}

activity_main.xml:

AndroidMainfest.xml