数据存储之五网络数据交互

昨天我们只对Android接收网络数据进行了简单介绍，今天我们完成了Android数据存储网络部分的所有内容。在此我将对这非常重要的内容进行总结。



       本篇日志是对Android与WEB应用服务之间进行数据交互的总结，下篇日志是一个经典而又让人十分好奇的Android多线程断点下载应用的总结。下面我们开始Android与网络数据的交互。



一、创建WEB应用服务

       使用eclipse3.5创建一个动态WEB应用，使用Struts1处理用户请求。我们此应用添加一个DispatchAction，并为它添加四个方法创建用于处理Android以各种方式提交的请求。



       1.创建动态WEB工程

       Project name:AndroidWebServer

       Target runtime:Apache Tomcat v6.0

       Dynamic web module version:2.5

       Configuration:Default Configuration for Apache Tomcat v6.0



       2.添加DispatchAction

package com.changcheng.web.struts.actions;



import java.io.File;

import java.io.FileOutputStream;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import org.apache.struts.action.ActionForm;

import org.apache.struts.action.ActionForward;

import org.apache.struts.action.ActionMapping;

import org.apache.struts.actions.DispatchAction;

import com.changcheng.web.struts.forms.DataForm;



public class AndroidWebServer extends DispatchAction {



         // Andoird以Get方式发送的请求

         public ActionForward sendDataByGet(ActionMapping mapping, ActionForm form,

                            HttpServletRequest request, HttpServletResponse response)

                            throws Exception {

                   String name = request.getParameter("name");

                   request.setAttribute("message", "Hello " + name);

                   return mapping.findForward("success");

         }



         // Andoird以Post方式发送的请求

         public ActionForward sendDataByPost(ActionMapping mapping, ActionForm form,

                            HttpServletRequest request, HttpServletResponse response)

                            throws Exception {

                   String name = request.getParameter("name");

                   request.setAttribute("message", "Hello " + name);

                   return mapping.findForward("success");

         }

                 

         // Andoird以表单方式发送的请求

         public ActionForward sendDataByForm(ActionMapping mapping, ActionForm form,

                            HttpServletRequest request, HttpServletResponse response)

                            throws Exception {

                   DataForm formbean = (DataForm) form;

                   System.out.println("StrData:" + formbean.getStrData());

                   // 获取上传的文件

                   if (formbean.getFileData() != null

                                     && formbean.getFileData().getFileSize() > 0) {

                            // 设置保存目录

                            File dir = new File(request.getSession().getServletContext()

                                               .getRealPath("/images"));

                            if (!dir.exists())

                                     dir.mkdirs();

                            // 保存文件

                            FileOutputStream outStream = new FileOutputStream(new File(dir,

                                               formbean.getFileData().getFileName()));

                            outStream.write(formbean.getFileData().getFileData());// 保存文件

                            outStream.close();

                   }

                   return null;

         }

}



       3.向web.xml添加Struts1的ActionServlet

<servlet>

         <servlet-name>struts</servlet-name>

         <servlet-class>org.apache.struts.action.ActionServlet</servlet-class>

         <init-param>

                   <param-name>config</param-name>

                   <param-value>/WEB-INF/struts-config.xml</param-value>

         </init-param>

</servlet>

<servlet-mapping>

         <servlet-name>struts</servlet-name>

         <url-pattern>*.do</url-pattern>

</servlet-mapping>



       4.struts-config.xml

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE struts-config PUBLIC

          "-//Apache Software Foundation//DTD Struts Configuration 1.3//EN"

          "http://struts.apache.org/dtds/struts-config_1_3.dtd">



<struts-config>

         <form-beans>

                   <form-bean name="dataForm" type="com.changcheng.web.struts.forms.DataForm" />

         </form-beans>

         <action-mappings>

                   <action path="/server"

                            type="com.changcheng.web.struts.actions.AndroidWebServer" name="dataForm"

                            scope="request" parameter="method">

                            <forward name="success" path="/WEB-INF/pages/success.jsp"/>

                   </action>

         </action-mappings>

</struts-config>





二、创建Android应用

       1.创建Android工程

       Project name:AndroidWebClient

       BuildTarget:Android2.1

       Application name:AndroidWEB应用客户端

       Package name:com.changcheng.web.client

       Create Activity:AndroidWebClient

       Min SDK Version:7



       2.AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>

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

       package="com.changcheng.web.client" android:versionCode="1"

       android:versionName="1.0">

       <application android:icon="@drawable/icon" android:label="@string/app_name">

              <!-- 单元测试 -->

              <uses-library android:name="android.test.runner" />

              <activity android:name=".AndroidWebClient" android:label="@string/app_name">

                     <intent-filter>

                            <action android:name="android.intent.action.MAIN" />

                            <category android:name="android.intent.category.LAUNCHER" />

                     </intent-filter>

              </activity>



       </application>

       <uses-sdk android:minSdkVersion="7" />

       <!-- 访问internet权限 -->

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

       <!-- 在SDCard中创建与删除文件权限 -->

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

       <!-- 往SDCard写入数据权限 -->

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

       <!-- 单元测试 -->

       <instrumentation android:name="android.test.InstrumentationTestRunner"

              android:targetPackage="com.changcheng.web.client" android:label="Tests for My App" />

</manifest>

       Android应用要访问Internet需要添加权限。



       3.ClientService类

package com.changcheng.web.client.service;



import java.io.ByteArrayOutputStream;

import java.io.DataOutputStream;

import java.io.File;

import java.io.FileInputStream;

import java.io.InputStream;

import java.net.HttpURLConnection;

import java.net.URL;

import java.util.HashMap;

import java.util.Map;

import android.os.Environment;

import android.util.Log;



public class ClientService {



         private static final String TAG = "ClientService";



         // 以get方式发送请求

         public static void sendDataToServerByGet() throws Exception {

                   // 主机地址不可以设置为localhost或127.0.0.1，必须是本机或其他机器所在Internet网或局域网地址。

                   String path = "http://192.168.0.2:8080/AndroidWebServer/server.do?"

                                     + "method=sendDataByGet&name=changcheng";

                   URL url = new URL(path);

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

                   conn.setConnectTimeout(6 * 1000);

                   // 请求成功

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

                            // 获取服务器返回的数据

                            byte[] data = readStream(conn.getInputStream());

                            Log.i(TAG, new String(data, "UTF-8"));

                   }

         }



         // 以Post方式发送请求，面向HTTP协议编程

         public static void sendDataTOserverByPost() throws Exception {

                   String path = "http://192.168.0.2:8080/AndroidWebServer/server.do";

                   String params = "method=sendDataByPost&name=tingting";// 请求参数

                   byte[] data = params.getBytes();

                   URL url = new URL(path);

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

                   conn.setConnectTimeout(6 * 1000);

                   conn.setDoOutput(true);// 发送POST请求必须设置允许输出

                   conn.setUseCaches(false);// 不使用Cache

                   conn.setRequestMethod("POST");

                   conn.setRequestProperty("Connection", "Keep-Alive");// 维持长连接

                   conn.setRequestProperty("Charset", "UTF-8");

                   conn.setRequestProperty("Content-Length", String.valueOf(data.length));

                   conn.setRequestProperty("Content-Type",

                                     "application/x-www-form-urlencoded");

                   DataOutputStream outStream = new DataOutputStream(conn

                                     .getOutputStream());

                   outStream.write(data);// 以内容实体方式发送请求参数

                   outStream.flush();

                   outStream.close();

                   // 请求成功

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

                            // 获取服务器返回的数据

                            byte[] html = readStream(conn.getInputStream());

                            Log.i(TAG, new String(html, "UTF-8"));

                   }

         }



         // 以表单方式发送请求

         public static void sendDataToServerByForm() throws Exception {

                   Map<String, String> params = new HashMap<String, String>();

                   params.put("method", "sendDataByForm");

                   params.put("strData", "字符串数据");

                   // 获取SDCard中的good.jpg

                   File file = new File(Environment.getExternalStorageDirectory(),

                                     "app_Goog_Android_w.png");

                   FormFile fileData = new FormFile("app_Goog_Android_w.png", new FileInputStream(file),

                                     "fileData", "application/octet-stream");

                   HttpRequester.post(

                                     "http://192.168.0.2:8080/AndroidWebServer/server.do", params,

                                     fileData);

         }



         // 获取输入流数据

         private static byte[] readStream(InputStream inStream) throws Exception {

                   byte[] buffer = new byte[1024];

                   int len = -1;

                   ByteArrayOutputStream outStream = new ByteArrayOutputStream();

                   while ((len = inStream.read(buffer)) != -1) {

                            outStream.write(buffer, 0, len);

                   }

                   byte[] data = outStream.toByteArray();

                   outStream.close();

                   inStream.close();

                   return data;

         }

}

       其中使用到的FormFile类：

package com.changcheng.web.client.service;



import java.io.InputStream;



/**

* 上传文件

*/

public class FormFile {

         /* 上传文件的数据 */

         private byte[] data;

         private InputStream inStream;

         /* 文件名称 */

         private String filname;

         /* 表单字段名称*/

         private String formname;

         /* 内容类型 */

         private String contentType = "application/octet-stream";

       

         public FormFile(String filname, byte[] data, String formname, String contentType) {

                   this.data = data;

                   this.filname = filname;

                   this.formname = formname;

                   if(contentType!=null) this.contentType = contentType;

         }

       

         public FormFile(String filname, InputStream inStream, String formname, String contentType) {

                   this.filname = filname;

                   this.formname = formname;

                   this.inStream = inStream;

                   if(contentType!=null) this.contentType = contentType;

         }

       

         public InputStream getInStream() {

                   return inStream;

         }



         public void setInStream(InputStream inStream) {

                   this.inStream = inStream;

         }



         public byte[] getData() {

                   return data;

         }



         public void setData(byte[] data) {

                   this.data = data;

         }



         public String getFilname() {

                   return filname;

         }



         public void setFilname(String filname) {

                   this.filname = filname;

         }



         public String getFormname() {

                   return formname;

         }



         public void setFormname(String formname) {

                   this.formname = formname;

         }



         public String getContentType() {

                   return contentType;

         }



         public void setContentType(String contentType) {

                   this.contentType = contentType;

         }

       

}



       其中使用到的HttpRequester类：

package com.changcheng.web.client.service;



import java.io.DataOutputStream;

import java.io.InputStream;

import java.net.HttpURLConnection;

import java.net.URL;

import java.util.ArrayList;

import java.util.List;

import java.util.Map;

import org.apache.http.HttpResponse;

import org.apache.http.NameValuePair;

import org.apache.http.client.entity.UrlEncodedFormEntity;

import org.apache.http.client.methods.HttpPost;

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.util.Log;



/**

* http请求发送器

*/

public class HttpRequester {

         /**

          * 直接通过HTTP协议提交数据到服务器,实现如下面表单提交功能:

          *   <FORM METHOD=POST ACTION="http://192.168.0.200:8080/ssi/fileload/test.do" enctype="multipart/form-data">

                            <INPUT TYPE="text" NAME="name">

                            <INPUT TYPE="text" NAME="id">

                            <input type="file" name="imagefile"/>

                       <input type="file" name="zip"/>

                    </FORM>

          * @param actionUrl 上传路径(注：避免使用localhost或127.0.0.1这样的路径测试，因为它会指向手机模拟器，你可以使用http://www.itcast.cn或http://192.168.1.10:8080这样的路径测试)

          * @param params 请求参数 key为参数名,value为参数值

          * @param file 上传文件

          */

         public static String post(String actionUrl, Map<String, String> params, FormFile[] files) {

             try {           

                 String BOUNDARY = "---------7d 4a6d158c9"; //数据分隔线

                 String MULTIPART_FORM_DATA = "multipart/form-data";

               

                 URL url = new URL(actionUrl);

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

                 conn.setConnectTimeout(6* 1000);

                 conn.setDoInput(true);//允许输入

                 conn.setDoOutput(true);//允许输出

                 conn.setUseCaches(false);//不使用Cache

                 conn.setRequestMethod("POST");              

                 conn.setRequestProperty("Connection", "Keep-Alive");

                 conn.setRequestProperty("Charset", "UTF-8");

                 conn.setRequestProperty("Content-Type", MULTIPART_FORM_DATA + "; boundary=" + BOUNDARY);



                 StringBuilder sb = new StringBuilder();

                 for (Map.Entry<String, String> entry : params.entrySet()) {//构建表单字段内容

                     sb.append("--");

                     sb.append(BOUNDARY);

                     sb.append("\r\n");

                     sb.append("Content-Disposition: form-data; name=\""+ entry.getKey() + "\"\r\n\r\n");

                     sb.append(entry.getValue());

                     sb.append("\r\n");

                 }

                 DataOutputStream outStream = new DataOutputStream(conn.getOutputStream());

                 outStream.write(sb.toString().getBytes());//发送表单字段数据

                 for(FormFile file : files){//发送文件数据

                      StringBuilder split = new StringBuilder();

                          split.append("--");

                          split.append(BOUNDARY);

                          split.append("\r\n");

                          split.append("Content-Disposition: form-data;name=\""+ file.getFormname()+"\";filename=\""+ file.getFilname() + "\"\r\n");

                          split.append("Content-Type: "+ file.getContentType()+"\r\n\r\n");

                          outStream.write(split.toString().getBytes());

                          if(file.getInStream()!=null){

                               byte[] buffer = new byte[1024];

                               int len = 0;

                               while((len = file.getInStream().read(buffer))!=-1){

                                         outStream.write(buffer, 0, len);

                               }

                               file.getInStream().close();

                          }else{

                               outStream.write(file.getData(), 0, file.getData().length);

                          }

                          outStream.write("\r\n".getBytes());

                 }

                 byte[] end_data = ("--" + BOUNDARY + "--\r\n").getBytes();//数据结束标志      

                 outStream.write(end_data);

                 outStream.flush();

                 int cah = conn.getResponseCode();

                 if (cah != 200) throw new RuntimeException("请求url失败");

                 InputStream is = conn.getInputStream();

                 int ch;

                 StringBuilder b = new StringBuilder();

                 while( (ch = is.read()) != -1 ){

                      b.append((char)ch);

                 }

                 Log.i("ItcastHttpPost", b.toString());            

                 outStream.close();

                 conn.disconnect();

                 return b.toString();

             } catch (Exception e) {

                throw new RuntimeException(e);

             }

         }

       

         /**

          * 提交数据到服务器

          * @param actionUrl 上传路径(注：避免使用localhost或127.0.0.1这样的路径测试，因为它会指向手机模拟器，你可以使用http://www.itcast.cn或http://192.168.1.10:8080这样的路径测试)

          * @param params 请求参数 key为参数名,value为参数值

          * @param file 上传文件

          */

         public static String post(String actionUrl, Map<String, String> params, FormFile file) {

            return post(actionUrl, params, new FormFile[]{file});

         }

       

         /**

          * 提交数据到服务器

          * @param actionUrl 上传路径(注：避免使用localhost或127.0.0.1这样的路径测试，因为它会指向手机模拟器，你可以使用http://www.itcast.cn或http://192.168.1.10:8080这样的路径测试)

          * @param params 请求参数 key为参数名,value为参数值

          */

         public static String post(String actionUrl, Map<String, String> params) {

                      HttpPost httpPost = new HttpPost(actionUrl);

                      List<NameValuePair> list = new ArrayList<NameValuePair>();

                      for (Map.Entry<String, String> entry : params.entrySet()) {//构建表单字段内容

                               list.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));

                      }

                      try {

                            httpPost.setEntity(new UrlEncodedFormEntity(list, HTTP.UTF_8));

                            HttpResponse httpResponse = new DefaultHttpClient().execute(httpPost);

                            if(httpResponse.getStatusLine().getStatusCode() == 200){

                                     return EntityUtils.toString(httpResponse.getEntity());

                       }

                   } catch (Exception e) {

                            throw new RuntimeException(e);

                   }

                   return null;

    }

}

       我们最好对HTTP协议有深入的了解，这样在编写简单数据交互应用时直接面向HTTP协议编程可以提高运行速度并减少资源的占用。

       我们在最后一个方法中使用到的HttpPost类，是Apache开源组织提供的httpcomponents-client-4.0.1包。httpcomponents-client-4.0.1可以实现浏览器的大部分功能，但如果我们能不使用它就尽量不使用它，因为这会造成对手机硬件资源的占用，从而减慢应用程序的运行速度。



       4.测试类

package com.changcheng.web.client.test;



import com.changcheng.web.client.service.ClientService;

import android.test.AndroidTestCase;



public class TestAndroidClientService extends AndroidTestCase {



         public void testSendDataToServerByGet() throws Throwable {

                   ClientService.sendDataToServerByGet();

         }



         public void testSendDataToServerByPost() throws Throwable {

                   ClientService.sendDataTOserverByPost();

         }



         public void testSendDataToServerByForm() throws Throwable {

                   ClientService.sendDataToServerByForm();

         }

}





       5.运行

       首先启动AndroidWebService应用程序，然后运行测试方法，查看运行结果。