Struts2+Android 使用struts2制作做webservice

sfshine

浏览: 122635 次

最近访客更多访客>>

枫下潇潇

sghdian

zhangly2011

追风浪子66

博主相关

博客

微博

相册

留言

关于我

文章分类

社区版块

存档分类

2012-11 ( 45)
2012-10 ( 34)
2012-09 ( 18)
更多存档...

昨天去青软那边,认识到自己的不足,只做Android是不行的.前几天公司也让做服务器.于是今天开始拿起javaEE 以后还是好好做JavaEE+Android吧

看了一下黎老师的WebService,还是很典型的应用(黎老师的课程确实很棒啊!受益一生),可惜的是他用的struts做的也是今天中午移植到struts2 也算是练手+重温了.

进正题>

做Struts2 首先是配置工程这个很烦人,和Android比差的很远.

首先是

web.xml没什么好说的其实就是配置struts2

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
	xmlns="http://java.sun.com/xml/ns/javaee" 
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
	http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
  <display-name></display-name>	
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
  
  <filter>
	<!-- 定义核心Filter的名称 -->
	<filter-name>struts2</filter-name>
	<!--定义核心Filter的实现类 -->
	<filter-class>
		org.apache.struts2.dispatcher.FilterDispatcher
	</filter-class>
</filter>

<filter-mapping>
	<!--核心Filter的名称 -->
	<filter-name>struts2</filter-name>
	<!--使用该核心Filter来接受所有的Web请求 -->
	<url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>

struts.xml相当于Android中的AndroidManifest.xm

l就一个action,返回两个结果,json和xml 貌似Android中现在很流行json的WebService

<?xml version="1.0" encoding="UTF-8" ?>

<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>
	<package name="struts2" extends="struts-default">
		<action name="List" class="com.su.action.VideoListAction">
			<result name="xml">/videos.jsp</result>
			<result name="json">/jsonvideos.jsp</result>
		</action>
	</package>
</struts>

然后就是结果返回页面,先看xml的:跳转到videos.jsp 注意这里有一个struts的迭代器可以把获取的videos处理后输出

<%@ page language="java" contentType="text/xml; charset=UTF-8" pageEncoding="UTF-8"%><%@taglib prefix="s" uri="/struts-tags"%><?xml version="1.0" encoding="UTF-8"?>
<videos> 
<s:iterator value="#request.videos" id="video">
	<video id="<s:property value="#video.id"/>">
	<title><s:property value="#video.title"/></title>
	<timelength><s:property value="#video.time"/></timelength>
	</video>
	</s:iterator>	
</videos>

如果返回的是json那么是jsonviedos.jsp

<%@ page language="java" contentType="text/plain; charset=UTF-8" pageEncoding="UTF-8"%>${videos}

需要注意!xml文件中

<%@ page language="java" contentType="text/xml; charset=UTF-8" pageEncoding="UTF-8"%><%@taglib prefix="s" uri="/struts-tags"%><?xml version="1.0" encoding="UTF-8"?>

这里尖括号直接不要有空格不然在chrome里不能识别为xml文件我想在解析的时候会报错(什么没有文件头什么的吧)

然后是java代码部分了

首先是VideoListAction.java也就是主action 相当于activity了

package com.su.action;

import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.List;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
import com.su.domain.Video;
import com.su.service.VideoService;
import com.su.service.impl.VideoServiceBean;

public class VideoListAction extends ActionSupport {
	private VideoService service = new VideoServiceBean();
	private String format;
	public String getFormat() {
		return format;
	}
	public void setFormat(String format) {
		this.format = format;
	}
	
	@Override
	public String execute() throws Exception {
		List<Video> videos = service.getLastVideos();
		if (format.equals("json")) {
			StringBuilder json = new StringBuilder();
			json.append('[');
			for(Video video : videos){ // {id:76,title:"xxxx",timelength:80}
				json.append('{');
				json.append("id:").append(video.getId()).append(',');
				json.append("title:\"").append(video.getTitle()).append("\",");
				json.append("timelength:").append(video.getTime());
				json.append('}').append(',');
			}
			json.deleteCharAt(json.length()-1);
			json.append(']');
			ServletActionContext.getRequest().setAttribute("videos", json);
			System.out.println("1111111111111111111111111111");
			return "json";
		}
		else {
	    ServletActionContext.getRequest().setAttribute("videos", videos);
		return "xml";
		}
		
	}
}

很简单json就是从videos里拼接把String放到servleactioncontext ; xml就更简单了,直接返回的list

这个是video的bean Video.java

package com.su.domain;

public class Video {
	private Integer id;
	private String title;
	private Integer time;
	
	public Video(){}
	
	public Video(Integer id, String title, Integer time) {
		this.id = id;
		this.title = title;
		this.time = time;
	}
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	public String getTitle() {
		return title;
	}
	public void setTitle(String title) {
		this.title = title;
	}
	public Integer getTime() {
		return time;
	}
	public void setTime(Integer time) {
		this.time = time;
	}
	
}

这个是VideoServicebean.java获取videos 这个在真实使用的时候数据是放在数据库的这个类就是来从数据库取出数据的,这里这是简单举例没有数据库

package com.su.service.impl;

import java.util.ArrayList;
import java.util.List;

import com.su.domain.Video;
import com.su.service.VideoService;


public class VideoServiceBean implements VideoService {

	public List<Video> getLastVideos() throws Exception{
		List<Video> videos = new ArrayList<Video>();
		videos.add(new Video(78, "视频1", 90));
		videos.add(new Video(78, "视频2", 20));
		videos.add(new Video(78, "视频3", 30));
		return videos;
	}
}

VideoService.java定义的获取videos的接口

package com.su.service;

import java.util.List;

import com.su.domain.Video;

public interface VideoService {

	public List<Video> getLastVideos() throws Exception;

}

然后是Android端了这里就不详细介绍了,挺简单的解析json和xml这是黎老师的代码

主activity

package cn.itcast.videoclient;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import cn.itcast.domain.Video;
import cn.itcast.service.VideoService;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Toast;

public class MainActivity extends Activity {
    private ListView listView;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        listView = (ListView)this.findViewById(R.id.listView);
        try {
			List<Video> videos = VideoService.getJSONLastVideos();
			List<HashMap<String, Object>> data = new ArrayList<HashMap<String,Object>>();
			for(Video video : videos){
				HashMap<String, Object> item = new HashMap<String, Object>();
				item.put("id", video.getId());
				item.put("title", video.getTitle());
				item.put("timelength", "时长:"+ video.getTime());
				data.add(item);
			}
			SimpleAdapter adapter = new SimpleAdapter(this, data, R.layout.item, //放入了Adapter中
					new String[]{"title", "timelength"}, new int[]{R.id.title, R.id.timelength});
			listView.setAdapter(adapter);
		} catch (Exception e) {
			Toast.makeText(MainActivity.this, "获取最新视频资讯失败", 1).show();
			Log.e("MainActivity", e.toString());
		} 
    }
}

VideoService.java从服务器获取数据

package cn.itcast.service;

import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

import org.json.JSONArray;
import org.json.JSONObject;
import org.xmlpull.v1.XmlPullParser;

import android.util.Xml;

import cn.itcast.domain.Video;
import cn.itcast.utils.StreamTool;

public class VideoService {
	/**
	 * 获取最新的视频资讯
	 * @return
	 * @throws Exception
	 */
	public static List<Video> getLastVideos() throws Exception{
		String path = "http://10.1.27.35:8080/VideoWeb2/List.action";
		URL url = new URL(path);
		HttpURLConnection conn = (HttpURLConnection)url.openConnection();
		conn.setReadTimeout(5*1000);
		conn.setRequestMethod("GET");
		InputStream inStream = conn.getInputStream();
		return parseXML(inStream);
	}
	
	public static List<Video> getJSONLastVideos() throws Exception{
		List<Video> videos = new ArrayList<Video>();
		String path = "http://10.1.27.35:8080/VideoWeb2/List.action?format=json";
		URL url = new URL(path);
		HttpURLConnection conn = (HttpURLConnection)url.openConnection();
		conn.setReadTimeout(5*1000);
		conn.setRequestMethod("GET");
		InputStream inStream = conn.getInputStream();
		byte[] data = StreamTool.readInputStream(inStream);
		String json = new String(data);
		JSONArray array = new JSONArray(json);
		for(int i=0 ; i < array.length() ; i++){
			JSONObject item = array.getJSONObject(i);
			int id = item.getInt("id");
			String title = item.getString("title");
			int timelength = item.getInt("timelength");
			videos.add(new Video(id, title, timelength));
		}
		return videos;
	}
	/**
	 * 解析服务器返回的协议，得到视频资讯
	 * @param inStream
	 * @return
	 * @throws Exception
	 */
	private static List<Video> parseXML(InputStream inStream) throws Exception{
		List<Video> videos = null;
		Video video = null;
		XmlPullParser parser = Xml.newPullParser();
		parser.setInput(inStream, "UTF-8");
		int eventType = parser.getEventType();//产生第一个事件
		while(eventType!=XmlPullParser.END_DOCUMENT){//只要不是文档结束事件
			switch (eventType) {
			case XmlPullParser.START_DOCUMENT:
				videos = new ArrayList<Video>();
				break;
	
			case XmlPullParser.START_TAG:
				String name = parser.getName();//获取解析器当前指向的元素的名称
				if("video".equals(name)){
					video = new Video();
					video.setId(new Integer(parser.getAttributeValue(0)));
				}
				if(video!=null){
					if("title".equals(name)){
						video.setTitle(parser.nextText());//获取解析器当前指向元素的下一个文本节点的值
					}
					if("timelength".equals(name)){
						video.setTime(new Integer(parser.nextText()));
					}
				}
				break;
				
			case XmlPullParser.END_TAG:
				if("video".equals(parser.getName())){
					videos.add(video);
					video = null;
				}
				break;
			}
			eventType = parser.next();
		}
		return videos;
	}
}

StreamTool.java 这个类是处理instream的

package cn.itcast.utils;

import java.io.ByteArrayOutputStream;
import java.io.InputStream;

public class StreamTool {

	/**
	 * 从输入流中获取数据输入一个input 输出一个byte[],获取的数据就可以通过new String(data)转换为String
	 * @param inStream 输入流
	 * @return
	 * @throws Exception
	 */
	public static byte[] readInputStream(InputStream inStream) throws Exception{
		ByteArrayOutputStream outStream = new ByteArrayOutputStream();
		byte[] buffer = new byte[1024];
		int len = 0;
		while( (len=inStream.read(buffer)) != -1 ){
			outStream.write(buffer, 0, len);
		}
		inStream.close();
		return outStream.toByteArray();
	}
}

也有一个video.java

package cn.itcast.domain;

public class Video {//video的bean
	private Integer id;
	private String title;
	private Integer time;
	
	public Video(){}
	
	public Video(Integer id, String title, Integer time) {
		this.id = id;
		this.title = title;
		this.time = time;
	}
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	public String getTitle() {
		return title;
	}
	public void setTitle(String title) {
		this.title = title;
	}
	public Integer getTime() {
		return time;
	}
	public void setTime(Integer time) {
		this.time = time;
	}
	
}