Android中服务器端与客户端交互

一：服务器端建立

1：下载Tomcat 以及 struts（框架：为了解决文件上传更简洁），后面会提供两个资源的下载链接。然后解压下载好的Tomcat和struts

2：配置tomcat：打开Myeclipse,打开window->perferences查找tomcat，然后将地址映射到上面解压的Tomcat包。不知道是不是我的电脑配置出现问题，导致我在perferences中没有查找到tomcat属性。所以我在创建WEB project中发现了配置Tomcat路径的地方，可参考1-5图片，完成tomcat配置。创建的WEB工程如6图

3：引入strust包：

3.1：找到解压后的struts2-blank.war包，将这个包在进行解压，找到WEB-INF文件夹，将WEB-INF里lib包内的架包拷贝到工程对应lib目录下。

3.2：将WEB-INF\classes下的struts.xml拷贝到工程的src目录下，里面的代码参考7图

3.3：打开WEB-INF中webxml文件，将以下代码

<filter>

<filter-name>struts2</filter-name>

<filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>

</filter>

<filter-mapping>

<filter-name>struts2</filter-name>

<url-pattern>/*</url-pattern>

</filter-mapping> 拷贝到工程中web.xml文件

3.4：配置好之后，选择run as ，将之前配置的Tomcat作为service服务开启。

4：新建一个包：com.imook.action，然后新建一个类UserAction，然后服务器端所有的代码如下：

package com.imook.action;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.io.PrintWriter;import java.util.logging.Logger;import javax.servlet.ServletInputStream;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import mons.io.FileUtils;import org.apache.struts2.ServletActionContext;import com.opensymphony.xwork2.ActionSupport;public class UserAction extends ActionSupport{private String username;private String password;public File mPhoto;public String mPhotoFileName;//上传字符串到服务器public String postString() throws IOException{HttpServletRequest request = ServletActionContext.getRequest();ServletInputStream is = request.getInputStream();System.out.println("sessionId=" + request.getSession().getId());StringBuilder sb = new StringBuilder();int len = 0;byte[] buf = new byte[1024];while((len = is.read(buf)) != -1){sb.append(new String(buf,0,len));}System.out.println(sb.toString());return null;}//重命名图片以及username及passwordpublic String uploadInfo() throws IOException{System.out.println(username+" ," + password);if(mPhoto == null){System.out.println(mPhotoFileName+" is null .");}String dir = ServletActionContext.getServletContext().getRealPath("/files");File file = new File(dir,mPhotoFileName);FileUtils.copyFile(mPhoto, file);return null;}//上传图片文件public String postFile() throws IOException{HttpServletRequest request = ServletActionContext.getRequest();ServletInputStream is = request.getInputStream();System.out.println("sessionId=" + request.getSession().getId());String dir = ServletActionContext.getServletContext().getRealPath("files");File file = new File(dir,"wwx.jpg");FileOutputStream fos = new FileOutputStream(file);int len = 0;byte[] buf = new byte[1024];while((len = is.read(buf)) != -1){fos.write(buf, 0, len);}HttpServletResponse response = ServletActionContext.getResponse();PrintWriter writer = response.getWriter();writer.write(dir);writer.flush();System.out.println("dir:"+dir);fos.flush();fos.close();return null;}//登陆public String login() throws IOException{HttpServletRequest request = ServletActionContext.getRequest();//userService.login(username,password);System.out.println("sessionId=" + request.getSession().getId());System.out.println(username+" , "+password);HttpServletResponse response = ServletActionContext.getResponse();PrintWriter writer = response.getWriter();writer.write("Login success !");writer.flush();return null;}public String getUsername() {return username;}public void setUsername(String username) {this.username = username;}public String getPassword() {return password;}public void setPassword(String password) {this.password = password;}}

5：对应的struts代码：

<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE struts PUBLIC"-//Apache Software Foundation//DTD Struts Configuration 2.3//EN""/dtds/struts-2.3.dtd"><struts><constant name="struts.enable.DynamicMethodInvocation" value="true" /><constant name="struts.devMode" value="true" /><package name="default" namespace="/" extends="struts-default"><action name="login" class="com.imook.action.UserAction" method = "login"></action><action name="postString" class="com.imook.action.UserAction" method = "postString"></action><action name="postFile" class="com.imook.action.UserAction" method = "postFile"></action><action name="uploadInfo" class="com.imook.action.UserAction" method = "uploadInfo"></action></package><!-- Add packages here --></struts>

二：客户端

客户端就是创建一个Android 工程，具体的请参考代码：

1：MainActivity代码：

package nuro.nuro.okhttp;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.os.Bundle;import android.os.Environment;import android.support.v7.app.AppCompatActivity;import android.util.Log;import android.view.View;import android.widget.ImageView;import android.widget.TextView;import com.squareup.okhttp.Call;import com.squareup.okhttp.Callback;import com.squareup.okhttp.FormEncodingBuilder;import com.squareup.okhttp.MediaType;import com.squareup.okhttp.MultipartBuilder;import com.squareup.okhttp.OkHttpClient;import com.squareup.okhttp.Request;import com.squareup.okhttp.RequestBody;import com.squareup.okhttp.Response;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import .CookieManager;import .CookiePolicy;public class MainActivity extends AppCompatActivity {private TextView tv_result;private ImageView iv_result;OkHttpClient okHttpClient = new OkHttpClient();private String mBaseUrl="http://192.168.1.113:8080/imook_okHttp/";private String TAG = "MainActivity";@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.content_main);okHttpClient.setCookieHandler(new CookieManager(null, CookiePolicy.ACCEPT_ALL));//保证服务器端的sessionId保证一致，保证用户登录一致tv_result = (TextView) findViewById(R.id.tv_result);iv_result = (ImageView)findViewById(R.id.iv_result);}/*封装代码步骤* 1：拿到okHttpClient对象* 2：构造Request2.1构造requestBody2.2包装requestBody3.call -> execute* */public void doPost(View view){//1：拿到okHttpClient对象FormEncodingBuilder requestBodyBuilder = new FormEncodingBuilder();//2：构造Request//2.1构造requestBodyRequestBody requestBody = requestBodyBuilder.add("username","wwx").add("password","930820").build();Request.Builder builder = new Request.Builder();Request request = builder.url(mBaseUrl + "login").post(requestBody).build();executeRequest(request);}public void doPostString(View view){//1：拿到okHttpClient对//2：构造Request//2.1构造requestBodyRequestBody requestBody = RequestBody.create(MediaType.parse("text/plain:charset=utf-8"), "{username:wwx,password:930820,sex:man,age:25}");Request.Builder builder = new Request.Builder();Request request = builder.url(mBaseUrl + "postString").post(requestBody).build();executeRequest(request);}public void doPostFile(View view){File file = new File(Environment.getExternalStorageDirectory(),"wwx.jpg");Log.i(TAG,Environment.getExternalStorageState());if (!file.exists()){L.e(file.getAbsolutePath()+" not exist!");return;}//mime type查看各个文件的MediaTypeRequestBody requestBody = RequestBody.create(MediaType.parse("application/octet-stream"),file);Request.Builder builder = new Request.Builder();Request request = builder.url(mBaseUrl + "postFile").post(requestBody).build();executeRequest(request);}public void doUpload(View view){File file = new File(Environment.getExternalStorageDirectory(),"ziji.png");Log.i(TAG,Environment.getExternalStorageState());if (!file.exists()){L.e(file.getAbsolutePath()+" not exist!");return;}MultipartBuilder multipartBuilder = new MultipartBuilder();RequestBody requestBody = multipartBuilder.type(MultipartBuilder.FORM)//.addFormDataPart("username", "wwx")//.addFormDataPart("password", "930820")//.addFormDataPart("mPhoto", "jizi.png", RequestBody.create(MediaType.parse("application/octet-stream"), file)).build();CountingRequestbody countingRequestbody = new CountingRequestbody(requestBody, new CountingRequestbody.Listner() {@Overridepublic void onRequestProgress(long bytesWrited, long contentLength) {L.e(bytesWrited + "/" + contentLength);}});//mime type查看各个文件的MediaTypeRequest.Builder builder = new Request.Builder();Request request = builder.url(mBaseUrl + "uploadInfo").post(countingRequestbody).build();executeRequest(request);}public void doDownload(View view){Request.Builder builder = new Request.Builder();Request request = builder.get().url(mBaseUrl+"files/wwx.jpg").build();Call call = okHttpClient.newCall(request);call.enqueue(new Callback() {//异步执行@Overridepublic void onFailure(Request request, IOException e) {L.e("onFailure :" + e.getMessage());e.printStackTrace();}@Overridepublic void onResponse(Response response) throws IOException {L.e("onResponse :");final long total = response.body().contentLength();//文件总长度long sum = 0L;InputStream is = response.body().byteStream();int len = 0;File file = new File(Environment.getExternalStorageDirectory(), "wwx12306.jpg");byte[] buf = new byte[128];FileOutputStream fos = new FileOutputStream(file);while ((len = is.read(buf)) != -1) {fos.write(buf, 0, len);sum += len;//进度比例L.e(sum + "/" + total);final long finalsum = sum;runOnUiThread(new Runnable() {@Overridepublic void run() {tv_result.setText(finalsum+"/"+total);}});}fos.flush();fos.close();is.close();L.e("download success!");}});}public void doDownloadImg(View view){Request.Builder builder = new Request.Builder();Request request = builder.get().url(mBaseUrl+"files/jizi.png").build();Call call = okHttpClient.newCall(request);call.enqueue(new Callback() {//异步执行@Overridepublic void onFailure(Request request, IOException e) {L.e("onFailure :" + e.getMessage());e.printStackTrace();}@Overridepublic void onResponse(Response response) throws IOException {L.e("onResponse :");InputStream is = response.body().byteStream();final Bitmap bitmap = BitmapFactory.decodeStream(is);runOnUiThread(new Runnable() {@Overridepublic void run() {iv_result.setImageBitmap(bitmap);}});}});}public void doGet(View view) throws IOException {//1：拿到okHttpClient对象//2：构造RequestRequest.Builder builder = new Request.Builder();Request request = builder.get().url(mBaseUrl+"login?username=wwx&password=654321").build();executeRequest(request);}private void executeRequest(Request request) {//3：将request封装成callCall call = okHttpClient.newCall(request);//4:执行//call.execute();//立即执行call.enqueue(new Callback() {//异步执行@Overridepublic void onFailure(Request request, IOException e) {L.e("onFailure :" + e.getMessage());e.printStackTrace();}@Overridepublic void onResponse(Response response) throws IOException {L.e("onResponse :");final String res = response.body().string();L.e(res);//此时是子线程,不能直接设置UI控件更新的原因可能是为了支持大文件的下载runOnUiThread(new Runnable() {@Overridepublic void run() {tv_result.setText(res);}});}});}}

2：xml文件：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="/apk/res/android"xmlns:app="/apk/res-auto"xmlns:tools="/tools"android:layout_width="match_parent"android:layout_height="match_parent"android:paddingBottom="@dimen/activity_vertical_margin"android:paddingLeft="@dimen/activity_horizontal_margin"android:paddingRight="@dimen/activity_horizontal_margin"android:paddingTop="@dimen/activity_vertical_margin"android:orientation="vertical"app:layout_behavior="@string/appbar_scrolling_view_behavior"tools:context="nuro.nuro.okhttp.MainActivity"tools:showIn="@layout/activity_main"><Buttonandroid:layout_width="wrap_content"android:layout_height="wrap_content"android:text="Get"android:onClick="doGet"/><Buttonandroid:layout_width="wrap_content"android:layout_height="wrap_content"android:text="post"android:onClick="doPost"/><Buttonandroid:layout_width="wrap_content"android:layout_height="wrap_content"android:text="post String"android:onClick="doPostString"/><Buttonandroid:layout_width="wrap_content"android:layout_height="wrap_content"android:text="post File"android:onClick="doPostFile"/><Buttonandroid:layout_width="wrap_content"android:layout_height="wrap_content"android:text="Upload"android:onClick="doUpload"/><Buttonandroid:layout_width="wrap_content"android:layout_height="wrap_content"android:text="Download"android:onClick="doDownload"/><Buttonandroid:layout_width="wrap_content"android:layout_height="wrap_content"android:text="DownloadImage"android:onClick="doDownloadImg"/><TextViewandroid:id="@+id/tv_result"android:layout_width="match_parent"android:layout_height="wrap_content"android:text="Hello World!" /><ImageViewandroid:id="@+id/iv_result"android:layout_width="match_parent"android:layout_height="wrap_content"android:scaleType="centerCrop"/></LinearLayout>

3：封装的一个打印信息L代码：

package nuro.nuro.okhttp;/*** Created by Administrator on /8/1.*/public class L{private static boolean debug = true;private static String TAG = "imook_okhttp";public static void e(String msg){if (debug){android.util.Log.e(TAG,msg);}}}

4：在MainFest中记得添加相应的权限：

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

三：总结：

这个例子介绍了服务器的简单搭建，做到了Android客户端上传string（也可以是json格式），图片、文件到服务器的指定目录下，然后提供了从服务器上下载图片文件的方法。

其中在：

1：客户端上传图片到服务器中，因为映射到服务器的地址不对，导致客户端上传的图片，服务器一直没有接收到。产生这个的原因是：没有将Tomcat映射的路径配置正确。正确的方式是要在新建web工程后配置Tomcat的路径。

2：另外一个是比较大的图片不能显示，原因：代码里没有增加压缩图片的步骤，部分图片过大显示不出来。

3：上传以及下载的进度可以在进行完善，使用进度条来显示。

各位：有不明白的或者有错误的地方，大家请指教。QQ：1143403680