用HTTP操作和文件操作把网页下载到sd卡

这里先把代码贴到这里做一个存档，写到SD卡的是一个txt文件，改成HTML格式之后会出现百度主页，但是中文是乱码，这一点先暂时不去研究了。

代码：

package com.larry.gotcha;

import java.io.BufferedReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import android.app.Activity;
import android.os.Bundle;
import android.os.Environment;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

import..

public class MainActivity extends Activity {

private Button requestButton = null ;
private HttpResponse httpResponse = null ;
private HttpEntity httpEntity = null ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
requestButton =(Button)findViewById(R.id.requestButton);
requestButton.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v) {
//生成一个请求对象
HttpGet httpGet = new HttpGet("http://www.baidu.com/");
//生成客户端对象
HttpClient httpClient = new DefaultHttpClient();
//使用客户端发送请求对象
InputStream inputStream = null ;

try {
//execute返回一个HttpResponse类型的参数，代表服务器返回的响应
httpResponse = httpClient.execute(httpGet);
//HttpResponse代表返回的响应，那么HttpEntity就代表响应的内容Obtains the message entity of this response, if any.
httpEntity = httpResponse.getEntity();
inputStream = httpEntity.getContent();//注意getContent()方法很常用
BufferedReader br = new BufferedReader(new InputStreamReader(inputStream));

String sd = Environment.getExternalStorageDirectory().getPath();
@SuppressWarnings("resource")
FileWriter fw = new FileWriter( sd + "/gotcha.txt");

String line = "" ;
String result = "" ;
while((line = br.readLine()) != null)
{
result = line + result ;
}
System.out.println(result);
fw.write(result , 0 , result.length());

}
catch (ClientProtocolException e)
{
e.printStackTrace();
}
catch (IOException e)
{
e.printStackTrace();
}
finally
{
try
{
inputStream.close();
}
catch(Exception e)
{
e.printStackTrace();
}
}
}
});
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}

}

HTTP操作顺序是：HttpGet--HttpClient--HttpResponse--HttpEntity。

这里I/O流里用的是InputStream、BufferedReader和FileWriter。

注意要在Mainifest里添加两个权限（这次忘了添加写入SD卡的权限，下午在英语课上想到了。。）

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