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Androidannotation使用之@Rest与服务器交互的JSON数据转换(二)

开篇

之前的一篇博客:Androidannotation使用之@Rest获取资源及用户登录验证(一):http://blog.csdn.net/nupt123456789/article/details/24384713 主要写了Rest在用户登录的时候,需要JSESSION字段的问题。本博客主要写JSON格式的转换。

@Rest的参考文档:

https://github.com/excilys/androidannotations/wiki/Rest-API#rest

简介:

从上一篇博客中,我们可以看出,我们直接再浏览器中请求http://192.168.0.101:8080/cbvr/getUserInfoList.action 的时候,返回的字符串其实是JSON格式。我们上一篇博客,就是把它直接当String进行处理了,没有出现什么问题。当然,我们接下来,可以使用GSON对String进行解析,这没有什么问题。然而,我们通常想,我们换一个转换器不就行了吗?代码如下:

/*
 * $filename: UserService.java,v $
 * $Date: 2014-4-20  $
 * Copyright (C) ZhengHaibo, Inc. All rights reserved.
 * This software is Made by Zhenghaibo.
 */
package com.example.testaa;

import org.androidannotations.annotations.rest.Accept;
import org.androidannotations.annotations.rest.Post;
import org.androidannotations.annotations.rest.Rest;
import org.androidannotations.api.rest.MediaType;
import org.androidannotations.api.rest.RestClientErrorHandling;
import org.springframework.http.ResponseEntity;
import org.springframework.http.converter.json.GsonHttpMessageConverter;

/*
 *@author: ZhengHaibo  
 *web:     http://blog.csdn.net/nuptboyzhb
 *mail:    zhb931706659@126.com
 *2014-4-20  Nanjing,njupt,China
 */
@Rest(rootUrl = "http://192.168.0.101:8080/cbvr", converters = {GsonHttpMessageConverter.class})
public interface UserService extends RestClientErrorHandling{
	@Post("/getUserInfoList.action")
	@Accept(MediaType.APPLICATION_JSON)
	ResponseEntity<DataGrid> getUserInfoList();
}

这样,我们就使用了Gson的消息转换器,当然,需要导入GSON相关的包。但是运行程序的时候,发现报错如下:

05-02 16:58:32.644: W/System.err(7454): org.springframework.web.client.RestClientException: Could not extract response: no suitable HttpMessageConverter found for response type [com.example.testaa.DataGrid] and content type [text/html;charset=UTF-8]

说什么没有合适的HttpMessageConverter,我以为是android端的问题,就换了好几个转换器,结果依然报错。然后,才发现,原来不是android端的问题,是服务端。服务端每次输出json字符串时,都设置了如下属性:

response.setContentType("text/html;charset=UTF-8");

原来是这个原因,于是,将服务端的修改为如下:

response.setContentType("application/json;charset=utf-8");

然后,再次运行,OK了,大功告成!这样,我们就可以直接获得到转换为JSON格式之后的对象了。为了增加程序的健壮性,为其添加了ErrorHandler处理。余下代码如下:

package com.example.testaa;


/*
 *@author: ZhengHaibo  
 *web:     http://blog.csdn.net/nuptboyzhb
 *GitHub   https://github.com/nuptboyzhb
 *mail:    zhb931706659@126.com
 *2014-1-12  Nanjing,njupt,China
 */
public class Userinfo {
	/**
	 * {field : ‘yhm‘,title : ‘用户名‘,width : 150}, 
			{field : ‘pwd‘,title : ‘密码‘,width : 150},
			{field : ‘yhqx‘,title : ‘用户权限‘,width : 150}, 
			{field : ‘zcsj‘,title : ‘注册时间‘,width : 150},
			{field : ‘bz‘,title : ‘备注‘,width : 180}] ];
	 */
	private String id;
	private String yhm;
	private String pwd;
	private String yhqx;
	private String zcsj;
	private String bz;
	public String getId() {
		return id;
	}
	public void setId(String id) {
		this.id = id;
	}
	public String getYhm() {
		return yhm;
	}
	public void setYhm(String yhm) {
		this.yhm = yhm;
	}
	public String getPwd() {
		return pwd;
	}
	public void setPwd(String pwd) {
		this.pwd = pwd;
	}
	public String getYhqx() {
		return yhqx;
	}
	public void setYhqx(String yhqx) {
		this.yhqx = yhqx;
	}
	public String getZcsj() {
		return zcsj;
	}
	public void setZcsj(String zcsj) {
		this.zcsj = zcsj;
	}
	public String getBz() {
		return bz;
	}
	public void setBz(String bz) {
		this.bz = bz;
	}
}

DataGrid类

/*
 * $filename: DataGrid.java,v $
 * $Date: 2013-10-11  $
 * Copyright (C) ZhengHaibo, Inc. All rights reserved.
 * This software is Made by Zhenghaibo.
 */
package com.example.testaa;


/*
 *@author: ZhengHaibo  
 *web:     http://blog.csdn.net/nuptboyzhb
 *mail:    zhb931706659@126.com
 *2013-10-11  Nanjing,njupt,China
 */
public class DataGrid{
    private int total;
    private Userinfo[] rows;
	public Userinfo[] getRows() {
		return rows;
	}
	public void setRows(Userinfo[] rows) {
		this.rows = rows;
	}
	public int getTotal() {
		return total;
	}
	public DataGrid(int total, Userinfo[] rows) {
		this.total = total;
		this.rows = rows;
	}
	public DataGrid( ) {
	}
	public void setTotal(int total) {
		this.total = total;
	}
}

ErrorHandler

/*
 * $filename: ErrorHandlerForUserService.java,v $
 * $Date: 2014-4-29  $
 * Copyright (C) ZhengHaibo, Inc. All rights reserved.
 * This software is Made by Zhenghaibo.
 */
package com.example.testaa;

import org.androidannotations.annotations.EBean;
import org.androidannotations.annotations.RootContext;
import org.androidannotations.annotations.UiThread;
import org.androidannotations.api.rest.RestErrorHandler;
import org.springframework.web.client.RestClientException;

import android.content.Context;
import android.util.Log;
import android.widget.Toast;

/*
 *@author: ZhengHaibo  
 *web:     http://blog.csdn.net/nuptboyzhb
 *mail:    zhb931706659@126.com
 *2014-4-29  Nanjing,njupt,China
 */
@EBean
public class MyErrorHandler implements RestErrorHandler {

	@RootContext
	Context context;
	
	@Override
	public void onRestClientExceptionThrown(RestClientException e) {
		// TODO Auto-generated method stub
		e.printStackTrace();
		Log.d("REST", e.toString());
		showError();
	}
	
	@UiThread
	void showError(){
		Toast.makeText(context, "Rest Error...", Toast.LENGTH_SHORT).show();
	}

}

剩下的就是MainActivity

package com.example.testaa;

import org.androidannotations.annotations.AfterViews;
import org.androidannotations.annotations.Background;
import org.androidannotations.annotations.Bean;
import org.androidannotations.annotations.Click;
import org.androidannotations.annotations.EActivity;
import org.androidannotations.annotations.UiThread;
import org.androidannotations.annotations.ViewById;
import org.androidannotations.annotations.rest.RestService;
import org.springframework.http.ResponseEntity;

import android.app.Activity;
import android.util.Log;
import android.widget.Button;
import android.widget.TextView;
/*
 *@author: ZhengHaibo  
 *web:     http://blog.csdn.net/nuptboyzhb
 *mail:    zhb931706659@126.com
 *2014-4-15  Nanjing,njupt,China
 */
@EActivity(R.layout.activity_main)
public class MainActivity extends Activity {
	
	private static final String TAG="AAREST";
	@ViewById
	Button getUser;

	@ViewById
	TextView myTextView;

	@RestService
	UserService userService;
	
	@Bean
	MyErrorHandler  errorHandlerForUserService;
	
	@AfterViews
	void afterView(){
		//设置ErrorHandler
		userService.setRestErrorHandler(errorHandlerForUserService);
	}
	/**
	 * 获取用户列表
	 */
	@Click
	void getUser() {
		getUserInBackground();
	}
	/**
	 * 获取用户列表
	 * 无需登录
	 */
	@Background
	void getUserInBackground(){
		//String result = userService.getUserInfoList();
		//Gson gson = new Gson();
		//DataGrid  dataGrid = gson.fromJson(result, DataGrid.class);
		ResponseEntity<DataGrid> responseEntiy = userService.getUserInfoList();
		if(null == responseEntiy){
			return;
		}
		DataGrid  dataGrid = responseEntiy.getBody();
		Userinfo[] userinfos= dataGrid.getRows();
		String string = "";
		for(Userinfo userinfo:userinfos){
			string = string + "user:"+ userinfo.getYhm();
			Log.d(TAG, userinfo.getYhm());
		}
		Log.d(TAG, string);
		displayTextView(string);
	}
	
	@UiThread
	void displayTextView(String string){
		myTextView.setText(string);
	}
}


总结:

整个项目使用AndroidAnnotation框架。本次博客主要解决服务端和android进行json交互的情况。

缺点:Response的setContentType设置修改后,可能影响原网站对浏览器的支持,因此,需要根据不同场景进行选择。

整个项目下载地址:http://download.csdn.net/detail/nuptboyzhb/7283863

未经允许,不得用于商业目的