用Android搭建客户端 手机和服务器交互开发实例

2011-03-28 17:24 Jclick JavaEye 我要评论(12) 字号：T | T





本文介绍了如何使用Android搭建客户端，实现手机和服务器的交互。让我们了解如何采用SSH框架，把服务器端的信息用JSON的形式发送到手机端。

AD：

笔者以前是学的Java EE，由于项目需要要开发Android，所以临时补了一个多星期，主要是手机端和服务器端交互，双向开发的。

首先在服务器端，我采用的是SSH框架，struts 2集合了JSON插件，服务器和客户端的信息交互采用的JSON来传输，由于在服务器端用了Struts 2，所以我就用装了一个JSON插件。这样，很轻易的就把服务器端的信息用JSON的形式发送到了手机端。以下是代码：

首先，在服务器端搭建好SSH框架，具体细节就不在陈述。struts.xml配置如下：

<packagename="login"extends="json-default">
<actionname="login"class="com.jclick.test.LoginAction"method="login">
<resulttype="json"><paramname="includeProperties">result</param></result>
</action>
</package>

<packagename="login"extends="json-default">
<actionname="login"class="com.jclick.test.LoginAction"method="login">
<resulttype="json"><paramname="includeProperties">result</param></result>
</action>
</package>

手机端的代码如下：

首先，手机端有一个缓存类，主要用于缓存一些手机端需要访问的数据，这样的好处是可以达达节省手机和服务器的交互，用单例实现的：

packagecom.jclick.cache;

importcom.jclick.bean.User;

publicclassCache{

privateUserUser;

privateCache(){

}
/**构造单例*/
privatestaticclassCacheHolder{
privatestaticfinalCacheINSTANCE=newCache();
}
publicCachegetInstance(){
returnCacheHolder.INSTANCE;
}
publicUsergetUser(){
returnUser;
}
publicvoidsetUser(UserUser){
this.User=User;
}

}

packagecom.jclick.cache;

importcom.jclick.bean.User;

publicclassCache{

privateUserUser;

privateCache(){

}
/**构造单例*/
privatestaticclassCacheHolder{
privatestaticfinalCacheINSTANCE=newCache();
}
publicCachegetInstance(){
returnCacheHolder.INSTANCE;
}
publicUsergetUser(){
returnUser;
}
publicvoidsetUser(UserUser){
this.User=User;
}

}

接着开始书写手机端的协议，用户向服务器发送请求，同时服务器反馈给手机端信息的：

packagecom.jclick.protocol;

importjava.io.BufferedReader;
importjava.io.InputStreamReader;
importjava.util.ArrayList;
importjava.util.List;

importorg.apache.http.HttpResponse;
importorg.apache.http.NameValuePair;
importorg.apache.http.client.HttpClient;
importorg.apache.http.client.entity.UrlEncodedFormEntity;
importorg.apache.http.client.methods.HttpPost;
importorg.apache.http.impl.client.DefaultHttpClient;
importorg.apache.http.message.BasicNameValuePair;
importorg.json.JSONException;
importorg.json.JSONObject;

publicclassBaseProtocol{
privateStringBuildersb=newStringBuilder();

privateHttpClienthttpClient;
privateHttpPosthttpRequest;
privateHttpResponseresponse;

privateList<NameValuePair>nameValuePair=newArrayList<NameValuePair>();

BaseProtocol(){
httpClient=newDefaultHttpClient();
}

/**
*向服务器端发送请求
*
*@paramurl
*@throwsException
*/
protectedvoidpack(Stringurl)throwsException{
httpClient=newDefaultHttpClient();
httpRequest=newHttpPost(url);

httpRequest.setEntity(newUrlEncodedFormEntity(nameValuePair));
response=httpClient.execute(httpRequest);
}

/**
*得到返回数据
*
*@paramurl
*@return
*@throwsException
*/
protectedvoidparse()throwsException{
//TODO状态处理500200
if(response.getStatusLine().getStatusCode()==200){

BufferedReaderbufferedReader2=newBufferedReader(
newInputStreamReader(response.getEntity().getContent()));
for(Strings=bufferedReader2.readLine();s!=null;s=bufferedReader2
.readLine()){
sb.append(s);
}
}
}

/**
*向服务器发送信息
*
*@paramkey
*@paramvalue
*/
publicvoidaddNameValuePair(Stringkey,Stringvalue){
nameValuePair.add(newBasicNameValuePair(key,value));
}

/**
*返回JSONObject对象数据模型
*
*@return
*@throwsJSONException
*/
publicJSONObjectgetJSON()throwsJSONException{
returnnewJSONObject(sb.toString());
}

}

packagecom.jclick.protocol;

importjava.io.BufferedReader;
importjava.io.InputStreamReader;
importjava.util.ArrayList;
importjava.util.List;

importorg.apache.http.HttpResponse;
importorg.apache.http.NameValuePair;
importorg.apache.http.client.HttpClient;
importorg.apache.http.client.entity.UrlEncodedFormEntity;
importorg.apache.http.client.methods.HttpPost;
importorg.apache.http.impl.client.DefaultHttpClient;
importorg.apache.http.message.BasicNameValuePair;
importorg.json.JSONException;
importorg.json.JSONObject;

publicclassBaseProtocol{
privateStringBuildersb=newStringBuilder();

privateHttpClienthttpClient;
privateHttpPosthttpRequest;
privateHttpResponseresponse;

privateList<NameValuePair>nameValuePair=newArrayList<NameValuePair>();

BaseProtocol(){
httpClient=newDefaultHttpClient();
}

/**
*向服务器端发送请求
*
*@paramurl
*@throwsException
*/
protectedvoidpack(Stringurl)throwsException{
httpClient=newDefaultHttpClient();
httpRequest=newHttpPost(url);

httpRequest.setEntity(newUrlEncodedFormEntity(nameValuePair));
response=httpClient.execute(httpRequest);
}

/**
*得到返回数据
*
*@paramurl
*@return
*@throwsException
*/
protectedvoidparse()throwsException{
//TODO状态处理500200
if(response.getStatusLine().getStatusCode()==200){

BufferedReaderbufferedReader2=newBufferedReader(
newInputStreamReader(response.getEntity().getContent()));
for(Strings=bufferedReader2.readLine();s!=null;s=bufferedReader2
.readLine()){
sb.append(s);
}
}
}

/**
*向服务器发送信息
*
*@paramkey
*@paramvalue
*/
publicvoidaddNameValuePair(Stringkey,Stringvalue){
nameValuePair.add(newBasicNameValuePair(key,value));
}

/**
*返回JSONObject对象数据模型
*
*@return
*@throwsJSONException
*/
publicJSONObjectgetJSON()throwsJSONException{
returnnewJSONObject(sb.toString());
}

}

接着是登陆协议，在这里我只是模拟登陆使用的一个类，仅供大家参考：

packagecom.jclick.protocol;

importorg.json.JSONObject;

importcom.jclick.bean.User;

publicclassLoginProtocolextendsBaseProtocol{

privatefinalstaticStringURL="http://localhost:8080/test/login";

publicbooleancheckLogin(Userusr){
try{
pack(URL);
parse();
JSONObjectobj=this.getJSON();
if(obj.getString("result").equals("failed")){
returnfalse;
}else{
returntrue;
}
}catch(Exceptione){
e.printStackTrace();
returnfalse;
}
}

}

packagecom.jclick.protocol;

importorg.json.JSONObject;

importcom.jclick.bean.User;

publicclassLoginProtocolextendsBaseProtocol{

privatefinalstaticStringURL="http://localhost:8080/test/login";

publicbooleancheckLogin(Userusr){
try{
pack(URL);
parse();
JSONObjectobj=this.getJSON();
if(obj.getString("result").equals("failed")){
returnfalse;
}else{
returntrue;
}
}catch(Exceptione){
e.printStackTrace();
returnfalse;
}
}

}

然后是User实体类，主要用于保存用户信息：

packagecom.jclick.bean;

publicclassUser{
privateStringusername;
privateStringpassword;
publicStringgetUsername(){
returnusername;
}
publicvoidsetUsername(Stringusername){
this.username=username;
}
publicStringgetPassword(){
returnpassword;
}
publicvoidsetPassword(Stringpassword){
this.password=password;
}

}

packagecom.jclick.bean;

publicclassUser{
privateStringusername;
privateStringpassword;
publicStringgetUsername(){
returnusername;
}
publicvoidsetUsername(Stringusername){
this.username=username;
}
publicStringgetPassword(){
returnpassword;
}
publicvoidsetPassword(Stringpassword){
this.password=password;
}

}

最后就是LoginActivity里边判断登陆的代码了，详细代码不再贴出来了，仅贴一个判断登陆的代码：

privatevoidcheckedData(){
username=((EditText)findViewById(R.id.username)).getText().toString();
password=((EditText)findViewById(R.id.password)).getText().toString();

Useruser=newUser();
user.setUsername(username);
user.setPassword(password);
LoginProtocollogin=newLoginProtocol();
booleanresult=login.checkLogin(user);

if(result){SpiderCache.getInstance().setUserSession(user);
Toast.makeText(getApplicationContext(),"登录成功",1000).show();
Intentintent=newIntent();
intent.setClass(LoginActivity.this,WelcomeActivity.class);
startActivity(intent);
}else{Toast.makeText(LoginActivity.this,"密码或用户名不匹配，请重新输入！",1000).show();
}
}

privatevoidcheckedData(){
username=((EditText)findViewById(R.id.username)).getText().toString();
password=((EditText)findViewById(R.id.password)).getText().toString();

Useruser=newUser();
user.setUsername(username);
user.setPassword(password);
LoginProtocollogin=newLoginProtocol();
booleanresult=login.checkLogin(user);

if(result){             SpiderCache.getInstance().setUserSession(user);
Toast.makeText(getApplicationContext(),"登录成功",1000).show();
Intentintent=newIntent();
intent.setClass(LoginActivity.this,WelcomeActivity.class);
startActivity(intent);
}else{              Toast.makeText(LoginActivity.this,"密码或用户名不匹配，请重新输入！",1000).show();
}
}

以上代码为了跟大家分享一下，感觉手机端和服务器双向开发非常过瘾。同时对Android的兴趣大大提升，它也没有我们想象中的那么难。