node.js+android http请求响应

本文参照了 http://www.blogjava.net/jelver/articles/143082.html，http://www.blogjava.net/athrunwang/archive/2011/09/28/359680.html，《android SDK开发范例大全(第2版)》

上次做了一个demo，试验如何用node.js响应get post请求，http请求使用的浏览器。我现在正在学android，所以决定写一个两者结合的demo。node.js做服务端接收get post请求，android做客户端发送get post请求。

先上node.js的代码（保存为example6.js）：

var http = require('http');
var server = http.createServer();
var querystring = require('querystring');


var postResponse = function(req, res) {
	var info ='';
	req.addListener('data', function(chunk){
		info += chunk;
     })
	.addListener('end', function(){
		info = querystring.parse(info);
		res.setHeader('content-type','text/html; charset=UTF-8');//响应编码
		res.end('Hello World POST ' + info.name,'utf8');
	 })
}

var getResponse = function (req, res){
  res.writeHead(200, {'Content-Type': 'text/plain'});
  var name = require('url').parse(req.url,true).query.name
  res.end('Hello World GET ' + name,'utf8');
}

var requestFunction = function (req, res){
	req.setEncoding('utf8');//请求编码

	if (req.method == 'POST'){
		return postResponse(req, res);
	}

	return getResponse(req, res);
}

server.on('request',requestFunction);
server.listen(8080, "192.168.9.194");

console.log('Server running at http://192.168.9.194:8080/');

代码基本和上次一样，主要是绑定的地址和端口变了(这个很重要，后边再讲)

再上android源代码：

layout main,xml如下

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>
    
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content" >

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="java get" 
            android:onClick="javaGet"/>

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="java post" 
            android:onClick="javaPost"/>
    </LinearLayout> 
    
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content" >

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="apache get" 
            android:onClick="apacheGet"/>

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="apache post" 
            android:onClick="apachePost"/>
    </LinearLayout>
</LinearLayout>

AndroidManifest.xml需要添加如下内容：

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

java源代码如下：

package com.zhang.test08_01;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.io.Writer;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.ProtocolException;
import java.net.URL;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.ParseException;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HTTP;
import org.apache.http.util.EntityUtils;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;

public class Test08_01Activity extends Activity {
	
	private TextView textView1;
	
	// You can't use localhost; localhost is the (emulated) phone. You need 
	//to specify the IP address or DNS name of the actual web server. 
	private static final String TEST_URL = "http://192.168.9.194:8080/";
	
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        textView1 = (TextView)findViewById(R.id.textView1);
    }
    
    public void javaGet(View v) {
    	String str = "";
		try {
			str = URLEncoder.encode("抓哇", "UTF-8");
		} catch (UnsupportedEncodingException e) {
		}
    	URL url = null;
    	try {
			url = new URL(TEST_URL + "?name=javaGet"+str);
		} catch (MalformedURLException e) {
		}
		
		HttpURLConnection urlConnection = null;
    	try {
    		urlConnection = (HttpURLConnection) url.openConnection();
		} catch (IOException e) {
			textView1.setText(e.getMessage());
			return;
		}
		//method  The default value is "GET".
		
		getResponseJava(urlConnection);
    }

    public void javaPost(View v) {
    	URL url = null;
    	try {
			url = new URL(TEST_URL);
		} catch (MalformedURLException e) {
		}
		
		HttpURLConnection urlConnection = null;
    	try {
    		urlConnection = (HttpURLConnection) url.openConnection();
		} catch (IOException e) {
			textView1.setText(e.getMessage());
			return;
		}
		try {
			urlConnection.setRequestMethod("POST");
		} catch (ProtocolException e) {
		}
		urlConnection.setDoOutput(true);
		urlConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
		
		OutputStream out = null;
		try {
			out = new BufferedOutputStream(urlConnection.getOutputStream());//请求
		} catch (IOException e) {
			urlConnection.disconnect();
			textView1.setText(e.getMessage());
			return;
		}
		
    	String str = "";
		try {
			str = URLEncoder.encode("抓哇", "UTF-8");
		} catch (UnsupportedEncodingException e) {
		}
		Writer writer = null;
		try {
			writer = new OutputStreamWriter(out,"UTF-8");
		} catch (UnsupportedEncodingException e1) {
		}
		try {
			writer.write("name=javaPost"+str);
		} catch (IOException e) {
			urlConnection.disconnect();
			textView1.setText(e.getMessage());
			return;
		} finally{
			try {
				writer.flush();
				writer.close();
			} catch (IOException e) {
			}
		}
		
		getResponseJava(urlConnection);
    }
    
    
    public void apacheGet(View v) {
    	HttpGet request = new HttpGet(TEST_URL + "?name=apacheGet阿帕奇");
    	getResponseApache(request);
    }
    
    public void apachePost(View v) {
    	HttpPost request = new HttpPost(TEST_URL);
    	
    	List<NameValuePair> params = new ArrayList<NameValuePair>(1);
    	params.add(new BasicNameValuePair("name", "apachePost阿帕奇"));
    	HttpEntity formEntity = null;
		try {
			formEntity = new UrlEncodedFormEntity(params,HTTP.UTF_8);
		} catch (UnsupportedEncodingException e) {
		}
    	request.setEntity(formEntity);
    	
    	getResponseApache(request);
    }
    
    
	private void getResponseJava(HttpURLConnection urlConnection) {
		InputStream in = null;
		try {
			in = new BufferedInputStream(urlConnection.getInputStream());//响应
		} catch (IOException e) {
			urlConnection.disconnect();			
			textView1.setText(e.getMessage());
			return;
		}
		
		BufferedReader reader = null;
		try {
			reader = new BufferedReader(new InputStreamReader(in,"UTF-8"));
		} catch (UnsupportedEncodingException e1) {
		}
		StringBuilder result = new StringBuilder();
		String tmp = null;
		try {
			while((tmp = reader.readLine()) != null){
				result.append(tmp);
			}
		} catch (IOException e) {
			textView1.setText(e.getMessage());
			return;
		} finally {
			try {
				reader.close();
				urlConnection.disconnect();
			} catch (IOException e) {
			}
		}
		textView1.setText(result);
	}
    
	private void getResponseApache(HttpUriRequest request) {
		HttpClient client = new DefaultHttpClient();
    	HttpResponse response = null;
    	try {
			response = client.execute(request);
		} catch (ClientProtocolException e) {
			textView1.setText(e.getMessage());
		} catch (IOException e) {
			textView1.setText(e.getMessage());
		}
		
		if (response == null) {
			return;
		}
		
		String result = null;
		if (response.getStatusLine().getStatusCode() == 200) {
			try {
				result = EntityUtils.toString(response.getEntity(),"UTF-8");
			} catch (ParseException e) {
				result = e.getMessage();
			} catch (IOException e) {
				result = e.getMessage();
			}
		} else {
			result = "error response" + response.getStatusLine().toString();
		}
		textView1.setText(result);
	}
}

运行起来，看看结果。

先启动node.js服务，在命令行中键入 node example6.js

启动成功

再启动android模拟器

分别点击四个按钮，效果如下：

整个过程最让我晕倒的是，我开始绑定和访问的地址是localhost:8080，可以一直无法访问，后来上网找了以下，发现自己太SB了

http://groups.google.com/group/android-developers/browse_thread/thread/801645febf0523ea

关键这句话：You can't use localhost; localhost is the (emulated) phone. You need   
to specify the IP address or DNS name of the actual web server. 

我忘了一件很重要的事，我的代码运行时启动的java虚拟机是在android模拟器上，localhost是模拟器啊。。。

以后要注意啊，android写的代码访问的本地文件系统或者网络环境等都是在模拟器上。