用Android搭建客户端 手机和服务器交互开发实例

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。 

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