note-44 HttpURLConnection and HttpClient

from:

http://blog.csdn.net/ainibaifenbai/article/details/6711564

HttpURLConnection和HttpClient联网

2011-08-23 13:59 830人阅读 评论(0) 收藏 举报

  Android中提供的HttpURLConnection和HttpClient接口可以用来开发HTTP程序。以下是本人在学习中的总结与归纳。
1. HttpURLConnection接口
    首先需要明确的是,Http通信中的POST和GET请求方式的不同。GET可以获得静态页面,也可以把参数放在URL字符串后面,传递给服务器。而POST方法的参数是放在Http请求中。因此,在编程之前,应当首先明确使用的请求方法,然后再根据所使用的方式选择相应的编程方式。
    HttpURLConnection是继承于URLConnection类,二者都是抽象类。其对象主要通过URL的openConnection方法获得。创建方法如下代码所示:

 
 

  1. URL url = new URL("http://www.51cto.com/index.jsp?par=123456");  
  2. HttpURLConnection urlConn=(HttpURLConnection)url.openConnection(); 
   

    通过以下方法可以对请求的属性进行一些设置,如下所示:

 
 

  1. //设置输入和输出流  
  2. urlConn.setDoOutput(true);  
  3. urlConn.setDoInput(true);  
  4. //设置请求方式为POST  
  5. urlConn.setRequestMethod("POST");  
  6. //POST请求不能使用缓存  
  7. urlConn.setUseCaches(false);  
  8. //关闭连接  
  9. urlConn.disConnection();  
  10.  


HttpURLConnection默认使用GET方式,例如下面代码所示:

 
 

  1. //使用HttpURLConnection打开连接  
  2.                 HttpURLConnection urlConn = (HttpURLConnection) url.openConnection();  
  3.                 //得到读取的内容(流)  
  4.                 InputStreamReader in = new InputStreamReader(urlConn.getInputStream());  
  5.                 // 为输出创建BufferedReader  
  6.                 BufferedReader buffer = new BufferedReader(in);  
  7.                 String inputLine = null;  
  8.                 //使用循环来读取获得的数据  
  9.                 while (((inputLine = buffer.readLine()) != null))  
  10.                 {  
  11.                     //我们在每一行后面加上一个"\n"来换行  
  12.                     resultData += inputLine + "\n";  
  13.                 }           
  14.                 //关闭InputStreamReader  
  15.                 in.close();  
  16.                 //关闭http连接  
  17.                 urlConn.disconnect(); 


    如果需要使用POST方式,则需要setRequestMethod设置。代码如下:

 
 

  1. String httpUrl = "http://192.168.1.110:8080/httpget.jsp";  
  2.         //获得的数据  
  3.         String resultData = "";  
  4.         URL url = null;  
  5.         try 
  6.         {  
  7.             //构造一个URL对象  
  8.             url = new URL(httpUrl);   
  9.         }  
  10.         catch (MalformedURLException e)  
  11.         {  
  12.             Log.e(DEBUG_TAG, "MalformedURLException");  
  13.         }  
  14.         if (url != null)  
  15.         {  
  16.             try 
  17.             {  
  18.                 // 使用HttpURLConnection打开连接  
  19.                 HttpURLConnection urlConn = (HttpURLConnection) url.openConnection();  
  20.                 //因为这个是post请求,设立需要设置为true  
  21.                 urlConn.setDoOutput(true);  
  22.                 urlConn.setDoInput(true);  
  23.                 // 设置以POST方式  
  24.                 urlConn.setRequestMethod("POST");  
  25.                 // Post 请求不能使用缓存  
  26.                 urlConn.setUseCaches(false);  
  27.                 urlConn.setInstanceFollowRedirects(true);  
  28.                 // 配置本次连接的Content-type,配置为application/x-www-form-urlencoded的  
  29.                 urlConn.setRequestProperty("Content-Type","application/x-www-form-urlencoded");  
  30.                 // 连接,从postUrl.openConnection()至此的配置必须要在connect之前完成,  
  31.                 // 要注意的是connection.getOutputStream会隐含的进行connect。  
  32.                 urlConn.connect();  
  33.                 //DataOutputStream流  
  34.                 DataOutputStream out = new DataOutputStream(urlConn.getOutputStream());  
  35.                 //要上传的参数  
  36.                 String content = "par=" + URLEncoder.encode("ABCDEFG", "gb2312");  
  37.                 //将要上传的内容写入流中  
  38.                 out.writeBytes(content);   
  39.                 //刷新、关闭  
  40.                 out.flush();  
  41.                 out.close();  


2. HttpClient接口
    使用Apache提供的HttpClient接口同样可以进行HTTP操作。
    对于GET和POST请求方法的操作有所不同。GET方法的操作代码示例如下:

 
 

  1. // http地址  
  2.         String httpUrl = "http://192.168.1.110:8080/httpget.jsp?par=HttpClient_android_Get";  
  3.         //HttpGet连接对象  
  4.         HttpGet httpRequest = new HttpGet(httpUrl);  
  5.          //取得HttpClient对象  
  6.             HttpClient httpclient = new DefaultHttpClient();  
  7.             //请求HttpClient,取得HttpResponse  
  8.             HttpResponse httpResponse = httpclient.execute(httpRequest);  
  9.             //请求成功  
  10.             if (httpResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK)  
  11.             {  
  12.                 //取得返回的字符串  
  13.                 String strResult = EntityUtils.toString(httpResponse.getEntity());  
  14.                 mTextView.setText(strResult);  
  15.             }  
  16.             else 
  17.             {  
  18.                 mTextView.setText("请求错误!");  
  19.             }  
  20.         } 


    使用POST方法进行参数传递时,需要使用NameValuePair来保存要传递的参数。,另外,还需要设置所使用的字符集。代码如下所示:

 
 

  1. // http地址  
  2.         String httpUrl = "http://192.168.1.110:8080/httpget.jsp";  
  3.         //HttpPost连接对象  
  4.         HttpPost httpRequest = new HttpPost(httpUrl);  
  5.         //使用NameValuePair来保存要传递的Post参数  
  6.         List<NameValuePair> params = new ArrayList<NameValuePair>();  
  7.         //添加要传递的参数  
  8.         params.add(new BasicNameValuePair("par", "HttpClient_android_Post"));  
  9.         //设置字符集  
  10.             HttpEntity httpentity = new UrlEncodedFormEntity(params, "gb2312");  
  11.             //请求httpRequest  
  12.             httpRequest.setEntity(httpentity);  
  13.             //取得默认的HttpClient  
  14.             HttpClient httpclient = new DefaultHttpClient();  
  15.             //取得HttpResponse  
  16.             HttpResponse httpResponse = httpclient.execute(httpRequest);  
  17.             //HttpStatus.SC_OK表示连接成功  
  18.             if (httpResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK)  
  19.             {  
  20.                 //取得返回的字符串  
  21.                 String strResult = EntityUtils.toString(httpResponse.getEntity());  
  22.                 mTextView.setText(strResult);  
  23.             }  
  24.             else 
  25.             {  
  26.                 mTextView.setText("请求错误!");  
  27.             }  
  28.         } 

    HttpClient实际上是对Java提供方法的一些封装,在HttpURLConnection中的输入输出流操作,在这个接口中被统一封装成了HttpPost(HttpGet)和HttpResponse,这样,就减少了操作的繁琐性。

    另外,在使用POST方式进行传输时,需要进行字符编码。

上一个例子,用两种方法连接HttpServer:

//HttpClient
//				HttpClient client=new DefaultHttpClient();
//				HttpGet get=new HttpGet(arg0[0]);
//				HttpResponse response=client.execute(get);
//				HttpEntity entity=response.getEntity();
//				
//				long length=entity.getContentLength();
//				InputStream is=entity.getContent();
				
				
				//HttpUrlConnection
				URL url=new URL(arg0[0]);
				HttpURLConnection httpURLConnection=(HttpURLConnection)url.openConnection();
				InputStream is=httpURLConnection.getInputStream();
				long length=httpURLConnection.getContentLength();
package com.example.asynctasktest;

import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.telephony.TelephonyManager;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends Activity {
	
	private TextView message;
	private Button open;
	private EditText url;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		
		
		message=(TextView)this.findViewById(R.id.message);
		url=(EditText)this.findViewById(R.id.url);
		open=(Button)this.findViewById(R.id.open);
		
		open.setOnClickListener(new View.OnClickListener(){

			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				connect();
			}
			
		});
		
		getTelephonyMethod();
	}
	
	private void getTelephonyMethod(){
		TelephonyManager tm=(TelephonyManager)this.getSystemService(Context.TELEPHONY_SERVICE);
		
		String tel=tm.getLine1Number();
		String imei=tm.getDeviceId();
		String imsi=tm.getSubscriberId();
		
		
		Log.d("l","line1 number:"+tel);
		Log.d("l","imei:"+imei); //device id;
		Log.d("l","imsi:"+imsi); //sim card id;
		
		
	}
	
	private void connect(){
		PageTask task=new PageTask(this);
		task.execute(url.getText().toString());		
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		getMenuInflater().inflate(R.menu.activity_main, menu);
		return true;
	}
	
	
	
	/**
	 * internal class
	 * params: <input class type, the percentage of running, return class type>
	 */
	class PageTask extends AsyncTask<String,Integer,String>{
		
		ProgressDialog pdialog;
		
		public PageTask(Context context){
			pdialog=new ProgressDialog(context,0);
			pdialog.setButton("cancel", new DialogInterface.OnClickListener() {
				
				@Override
				public void onClick(DialogInterface dialog, int which) {
					// TODO Auto-generated method stub
					dialog.cancel();
				}
			});
			
			pdialog.setOnCancelListener(new DialogInterface.OnCancelListener() {
				
				@Override
				public void onCancel(DialogInterface dialog) {
					// TODO Auto-generated method stub
					finish();
				}
			});
			
			pdialog.setCancelable(true);
			pdialog.setMax(100);
			pdialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
			pdialog.show();
		}

		@Override
		protected String doInBackground(String... arg0) {
			// TODO Auto-generated method stub
			
			try{
				Log.d("l","url address input:"+arg0[0]);
				
				//HttpClient
//				HttpClient client=new DefaultHttpClient();
//				HttpGet get=new HttpGet(arg0[0]);
//				HttpResponse response=client.execute(get);
//				HttpEntity entity=response.getEntity();
//				
//				long length=entity.getContentLength();
//				InputStream is=entity.getContent();
				
				
				//HttpUrlConnection
				URL url=new URL(arg0[0]);
				HttpURLConnection httpURLConnection=(HttpURLConnection)url.openConnection();
				InputStream is=httpURLConnection.getInputStream();
				long length=httpURLConnection.getContentLength();
				
				
				String s=null;
				
				if(is!=null){
					ByteArrayOutputStream baos=new ByteArrayOutputStream();
					byte[] buf=new byte[1024];
					int ch=-1;
					int count=0;
					
					while((ch=is.read(buf))!=-1){
						baos.write(buf,0,ch);
						count+=ch;
						
						if(length>0){
							//this data will show back on the onProgressUpdate Fn;
							publishProgress((int)(  (count/(float)length)*100)  );
						}
						
						Thread.sleep(100);
					}
					s=new String(baos.toByteArray());
					
				}
				return s;
								
			}
			catch(Exception e){
				e.printStackTrace();
				Log.e("l","inputStream error:"+e.getMessage());
			}
			
			return null;
		}

		@Override
		protected void onPostExecute(String result) {
			// TODO Auto-generated method stub
//			super.onPostExecute(result);
			Log.i("l","string content:"+result);
			message.setText(result);
			pdialog.dismiss();
		}

		@Override
		protected void onPreExecute() {
			// TODO Auto-generated method stub
//			super.onPreExecute();
			message.setText("onPreExcute");
		}

		@Override
		protected void onProgressUpdate(Integer... values) {
			// TODO Auto-generated method stub
//			super.onProgressUpdate(values);
			
			System.out.println();
			message.setText(""+values[0]);
			pdialog.setProgress(values[0]);
		}

		@Override
		protected void onCancelled() {
			// TODO Auto-generated method stub
			super.onCancelled();
		}
		
		
		
		
		
		
	}
}

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