android和javaEE更完美的通信-传递对象_app传到java后台的文件用什么对象接受-优快云博客

继续完善上一篇中的那个代码片，《android和javaEE通信的代码片》中只是简单的向服务器发送请求，没有获取服务器返回数据的操作。
继续看着新浪SDK中的代码，它是通过json来实现的，其实说json，不过是一种数据格式，就算是服务器端传送过来一样要本地解析成数组（新浪是这么做的），代码实现思路到不复杂，只要把json字符串放到json类中（这个类是json提供的），可直接转换对象，或者数组。
不过考虑到新浪是由android和php服务器端进行通信的，json必然是一个简单的方法。但是对于android和javaEE服务器端通信，用json的话还是需要一些操作来处理的，不如直接在网络中传递java对象来的方便（当然，仅仅是一个小实验，两者的安全性如何还不知晓）。
于是写下这些代码，供以后参考：
需要提示的一点：在网络上传递的类，在两端一定要属于相同的包，最起码所属的的包名应该一样。
HttpClient.java:

import java.io.OutputStream ;
import java.net.HttpURLConnection ;
import java.net.URL ;
import java.net.URLEncoder ;

public class HttpClient {
   public static Response httpRequest ( String url, PostParameter [ ] postParams,
String httpMethod ) {
   int responseCode = - 1 ;
Response res = null ;

   try {
   HttpURLConnection con = null ;
   OutputStream osw = null ;
   try {
con = ( HttpURLConnection ) new URL (url ). openConnection ( ) ;

con. setDoInput ( true ) ;
   if ( null != postParams || "POST". equals (httpMethod ) ) {
con. setRequestMethod ( "POST" ) ;
con. setRequestProperty ( "Content-Type",
"application/x-www-form-urlencoded" ) ;
con. setDoOutput ( true ) ;
String postParam = "" ;
if (postParams != null ) {
postParam = encodeParameters (postParams ) ;
}
byte [ ] bytes = postParam. getBytes ( "UTF-8" ) ;

con. setRequestProperty ( "Content-Length",
Integer. toString (bytes. length ) ) ;
osw = con. getOutputStream ( ) ;
osw. write (bytes ) ;
osw. flush ( ) ;
osw. close ( ) ;
   }
responseCode = con. getResponseCode ( ) ;

res = new Response (con ) ;

   } finally {

   }
   } catch ( Exception e ) {
e. printStackTrace ( ) ;
   }
   return res ;
   }

   private static String encodeParameters (PostParameter [ ] postParams ) {
   StringBuffer buf = new StringBuffer ( ) ;
   for ( int j = 0 ; j < postParams. length ; j ++ ) {
   if (j != 0 ) {
buf. append ( "&" ) ;
   }
   try {
buf. append ( URLEncoder. encode (postParams [j ]. getName ( ), "UTF-8" ) )
. append ( "=" ). append ( URLEncoder. encode (postParams [j ]. getValue ( ), "UTF-8" ) ) ;
   } catch (java. io. UnsupportedEncodingException neverHappen ) {
   }
   }
   return buf. toString ( ) ;
   }

   public static void main ( String [ ] args ) {
PostParameter [ ] postParameters = new PostParameter [ 1 ] ;
postParameters [ 0 ] = new PostParameter ( "loginName", "demo" ) ;
Response res = httpRequest ( "http://localhost:8090/mlabs/user/checkLoginName.action", postParameters,
"POST" ) ;
   System. out. println ( "获得服务器端返回对象：" + res. getObjectList ( ) ) ;
   }
}

PostParamenter.java

public class PostParameter implements java. io. Serializable, Comparable {

   /**
*
*/
   private static final long serialVersionUID = 1L ;

@Override
   public int compareTo ( Object o ) {
   // TODO Auto-generated method stub
   return 0 ;
   }

   public PostParameter ( String name, String value ) {
   super ( ) ;
   this. name = name ;
   this. value = value ;
   }
public PostParameter ( ) {

}
   private String name ;
   private String value ;

   public String getName ( ) {
   return name ;
   }
   public void setName ( String name ) {
   this. name = name ;
   }
   public String getValue ( ) {
   return value ;
   }
   public void setValue ( String value ) {
   this. value = value ;
   }
}

Response.java

public class Response {
   private HttpURLConnection con = null ;

   public Response ( ) {   }

   public Response ( HttpURLConnection con ) {
   this. con = con ;
   }

   /**
* 获取数据
*/
   public List <Student > getObjectList ( ) {
   InputStream is ;
List <Student > stus = null ;
   try {
is = con. getInputStream ( ) ;
   ObjectInputStream ois = new ObjectInputStream (is ) ;
stus = (List <Student > )ois. readObject ( ) ;
   } catch ( IOException e ) {
e. printStackTrace ( ) ;
   } catch ( ClassNotFoundException e ) {
e. printStackTrace ( ) ;
   }
   return stus ;
   }
}

Student.java

public class Student implements java. io. Serializable, Comparable {
   private static final long serialVersionUID = 1L ;

public int compareTo ( Object o ) {
// TODO Auto-generated method stub
return 0 ;
}

   private String name ;
   private int age ;

   public String getName ( ) {
   return name ;
   }

   public void setName ( String name ) {
   this. name = name ;
   }

   public int getAge ( ) {
   return age ;
   }

   public void setAge ( int age ) {
   this. age = age ;
   }

@Override
   public String toString ( ) {
   return "Student [name=" + name + ", age=" + age + "]" ;
   }
}

另外在服务器端返回数据的代码片段，我是写在一个Action中的：

System. out. println ( "loginName:" +loginName ) ;
HttpServletRequest request = ServletActionContext. getRequest ( ) ;
HttpServletResponse response = ServletActionContext. getResponse ( ) ;
response. setCharacterEncoding ( "UTF-8" ) ;
response. setContentType ( "text/plain" ) ;
Student student = new Student ( ) ;
student. setName ( "huyang" ) ;
student. setAge ( 24 ) ;
Student student1 = new Student ( ) ;
student1. setName ( "the5fire" ) ;
student1. setAge ( 21 ) ;
List <Student > list = new ArrayList <Student > ( 2 ) ;
list. add (student ) ;

list. add (student1 ) ;
System. out. println (list ) ;
//TODO 仅仅为了测试
   OutputStream outs = response. getOutputStream ( ) ;
   ObjectOutputStream oos = new ObjectOutputStream (outs ) ;
oos. writeObject (list ) ;
   return null ;

最终结果展示：