一天教你入门struts2

写在前面

• 自己也是一个java和java web的菜鸟。之前没有接触过java web方面的开发
• 想通过一个小项目，来熟悉struts2的开发流程
• 一个有趣的想法源于教研室项目上的一个功能实现–自己主动识别运营商，去做不同的处理。项目上採用的是IP地址库的方式，在本地做处理。这里为了简单就採用了淘宝提供的接口服务
• 已经将该项目作为开源项目放在：IP地址仓库 欢迎大家前来点赞

能够学到什么

• struts2的基本执行流程
• HttpClient和org.json库的使用
• 前端採用了bootstrap和ajax，做到了网页的自适应，后端返回json数据和前端交互

步入正题

• struts.xml文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
    "http://struts.apache.org/dtds/struts-2.3.dtd">

<struts>
<!-- 设置常量实现动态调用 -->  
   <constant name="struts.enable.DynamicMethodInvocation" value="true" /> 
   <!-- 名字必须唯一相应模块 -->  
   <package name="hello"  extends="json-default">     
          <default-action-ref name="index" />
          <action name="index" class="action.IPSearchAction" method="index">  
              <!--为了安全将其放在、WEB-INF/pages 不明确的也可放在webRoot  根文件夹下-->  
                <result name="success">/WEB-INF/pages/ip.jsp  </result>  
          </action>

          <action name="search" class="action.IPSearchAction" method="search">  
              <!--为了安全将其放在、WEB-INF/pages 不明确的也可放在webRoot  根文件夹下-->  
                <result name="success" type="json">
                    <param name="root">responseMap</param>
                </result>  
          </action>  
   </package>  

</struts>

• web.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0">
  <filter>
    <filter-name>struts2</filter-name>
    <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
  </filter>
  <filter-mapping>
    <filter-name>struts2</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>
  <welcome-file-list>
    <welcome-file>/WEB-INF/pages/ip.jsp</welcome-file>
  </welcome-file-list>
</web-app>

• action文件

package action;

import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.HashMap;
import java.util.Map;

import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.ParseException;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
import org.json.JSONObject;


public class IPSearchAction {

     String ip;          

     Map<String, Object> responseMap;   //查询的结果为json数据。struts2自己主动做序列化的工作

    public Map<String, Object> getResponseMap() {
        return responseMap;
    }

    public void setResponseMap(Map<String, Object> responseMap) {
        this.responseMap = responseMap;
    }   

    public String getIp() {
        return ip;
    }

    public void setIp(String ip) {
        System.out.println("input ip is: "+ip);
        this.ip = ip;
    }    

    public String search(){      
        setOutputValue();
        return "success";          
    }


   public String index(){
      return "success";
   }

   public void setOutputValue() {
       HttpClient httpclient = HttpClients.createDefault();
       System.out.println("the input ip is" + ip);
        URI uri = null;
        try {
            uri = new URIBuilder()
                .setScheme("http")
                .setHost("ip.taobao.com")
                .setPath("/service/getIpInfo.php")
                .setParameter("ip", ip)
                .build();
        } catch (URISyntaxException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        HttpGet httpget = new HttpGet(uri);

        HttpResponse response = null;
        try {
            response = httpclient.execute(httpget);
        } catch (ClientProtocolException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        int statusCode = response.getStatusLine().getStatusCode();
        if(statusCode == HttpStatus.SC_OK) { //状态==200，返回成功
            String result = null;
            try {
                result = EntityUtils.toString(response.getEntity());
            } catch (ParseException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            System.out.println(result);
            JSONObject resultJson  = new JSONObject(result);
            int code      = resultJson.getInt("code");
            String country = null;
            String region = null;
            String city = null;
            String county = null;
            String isp = null;
            if(code == 0) {
                country = resultJson.getJSONObject("data").getString("country");  
                region = resultJson.getJSONObject("data").getString("region"); 
                city = resultJson.getJSONObject("data").getString("city"); 
                county = resultJson.getJSONObject("data").getString("county"); 
                isp = resultJson.getJSONObject("data").getString("isp"); 
                System.out.println("code is: "+ code + "country is: " + country + "area is "+region+"county is "+county+
                        "isp is "+isp); 
            } 

            responseMap = new HashMap<String, Object>();
            responseMap.clear();
            responseMap.put("country", country);
            responseMap.put("region", region);
            responseMap.put("city", city);
            responseMap.put("county", county);
            responseMap.put("isp", isp);

        }
   }
}

• 依赖的库文件
  
  说明：
  
  • project依赖org.json库，採用的是：org.json ,下载的是源码，能够打包成json.jar，更方便的使用
  • project依赖httpclient，下载地址：httpclient ,使用能够查看它提供的手冊
  • project还依赖struts2提供的某些jar包，记得加入

终于效果

PS：

一些问题记录：

• struts2的静态资源的放置问题。參考：静态资源放置
• struts2更改项目名称，參考myeclipse更改项目名称 记得又一次部署tomcat和重新启动myeclipse

參考资源

• 淘宝地址库
• struts新手教程