Struts2 restful配置及使用

1.Struts2 restful配置及使用

前面介绍使用Maven构建Struts2时提到下载Struts2的GA完整版，解压后在apps目录里有struts2-rest-showcase.war这个示例，这里就以这个示例为例讲解一下
Struts restful的用法。所有的内容在官方文档(http://struts.apache.org/development/2.x/docs/convention-plugin.html，
http://struts.apache.org/development/2.x/docs/rest-plugin.html)有详细讲解，我这里只是粗略过一下。

1.1在pom.xml添加rest依赖，如下所示：

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.carson.demo</groupId>
  <artifactId>struts2</artifactId>
  <packaging>war</packaging>
  <version>0.0.1-SNAPSHOT</version>
  <name>struts2 Maven Webapp</name>
  <url>http://maven.apache.org</url>
  
  <!-- 属性配置 -->  
  <properties>  
      <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>  
  </properties>
  
  <dependencies>
  <!-- junit -->
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.9</version>
      <scope>test</scope>
    </dependency>
    
    <!-- struts2依赖包 -->
    <dependency>
    	<groupId>org.apache.struts</groupId>
    	<artifactId>struts2-core</artifactId>
    	<version>2.3.14</version>
    </dependency>
	
    <!-- struts restful 依赖包 -->
    <dependency>
    <groupId>org.apache.struts</groupId>
    <artifactId>struts2-convention-plugin</artifactId>
    <version>2.3.14</version>
    </dependency>                                                                                                                                        
    <dependency>
    <groupId>org.apache.struts</groupId>
    <artifactId>struts2-rest-plugin</artifactId>
    <version>2.3.14</version>
    </dependency>
    
    <!-- log4j依赖包-->
    <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>1.2.14</version>
        <scope>runtime</scope>
    </dependency> 

  </dependencies>
  <build>
    <finalName>struts2</finalName>
  </build>
</project>

1.2在struts.xml添加rest plugin的配置，代码如下：

<constant name="struts.convention.action.suffix" value="Controller"/>
<constant name="struts.convention.action.mapAllMatches" value="true"/>
<constant name="struts.convention.default.parent.package" value="rest-default"/>

<?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>

    <constant name="struts.i18n.reload" value="false" />
    <constant name="struts.devMode" value="false" />
    <!-- struts2 restful -->
    <constant name="struts.convention.action.suffix" value="Controller"/>
    <constant name="struts.convention.action.mapAllMatches" value="true"/>
    <constant name="struts.convention.default.parent.package" value="rest-default"/>
   
    <include file="struts-default.xml" />

</struts>

1.3 restful命名

rest返回结果的页面默认在WEB-INF/content目录下，它的风格是jsp页面的命名与控制层Action的命名一致，如Action为OrdersController，则jsp页面以orders-打头。这里强调下，整个Action的命名中除去Controller以外，只有首字母大写其他全部小写，否则会报错。

OrdersController.java

package com.carson.demo.action;

import java.util.Collection;


import org.apache.struts2.rest.DefaultHttpHeaders;
import org.apache.struts2.rest.HttpHeaders;
import org.apache.struts2.convention.annotation.Results;
import org.apache.struts2.convention.annotation.Result;
import com.carson.demo.model.Order;
import com.carson.demo.service.OrdersService;
import com.opensymphony.xwork2.ModelDriven;
import com.opensymphony.xwork2.Validateable;
import com.opensymphony.xwork2.ValidationAwareSupport;

@Results({
    @Result(name="success", type="redirectAction", params = {"actionName" , "orders"})
})
public class OrdersController extends ValidationAwareSupport implements ModelDriven<Object>, Validateable{
    
    private Order model = new Order();
    private String id;
    private Collection<Order> list;
    private OrdersService ordersService = new OrdersService();

    // GET /orders/1
    public HttpHeaders show() {
        return new DefaultHttpHeaders("show");
    }

    // GET /orders
    public HttpHeaders index() {
        list = ordersService.getAll();
        return new DefaultHttpHeaders("index")
            .disableCaching();
    }
    
    // GET /orders/1/edit
    public String edit() {
        return "edit";
    }

    // GET /orders/new
    public String editNew() {
        model = new Order();
        return "editNew";
    }

    // GET /orders/1/deleteConfirm
    public String deleteConfirm() {
        return "deleteConfirm";
    }

    // DELETE /orders/1
    public String destroy() {
        ordersService.remove(id);
        addActionMessage("Order removed successfully");
        return "success";
    }

    // POST /orders
    public HttpHeaders create() {
        ordersService.save(model);
        addActionMessage("New order created successfully");
        return new DefaultHttpHeaders("success")
            .setLocationId(model.getId());
    }

    // PUT /orders/1
    public String update() {
        ordersService.save(model);
        addActionMessage("Order updated successfully");
        return "success";
    }

    public void validate() {
        if (model.getClientName() == null || model.getClientName().length() ==0) {
            addFieldError("clientName", "The client name is empty");
        }
    }

    public void setId(String id) {
        if (id != null) {
            this.model = ordersService.get(id);
        }
        this.id = id;
    }
    
    public Object getModel() {
        return (list != null ? list : model);
    }

}

Orders.java

package com.carson.demo.model;

public class Order {
    String id;
    String clientName;
    int amount;
    
    public Order() {}
    
    public Order(String id, String clientName, int amount) {
        super();
        this.id = id;
        this.clientName = clientName;
        this.amount = amount;
    }
    public int getAmount() {
        return amount;
    }
    public void setAmount(int amount) {
        this.amount = amount;
    }
    public String getClientName() {
        return clientName;
    }
    public void setClientName(String clientName) {
        this.clientName = clientName;
    }
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + amount;
        result = prime * result
                + ((clientName == null) ? 0 : clientName.hashCode());
        result = prime * result + ((id == null) ? 0 : id.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        final Order other = (Order) obj;
        if (amount != other.amount)
            return false;
        if (clientName == null) {
            if (other.clientName != null)
                return false;
        } else if (!clientName.equals(other.clientName))
            return false;
        if (id == null) {
            if (other.id != null)
                return false;
        } else if (!id.equals(other.id))
            return false;
        return true;
    }
    
    
    
    
}

OrdersService.java

package com.carson.demo.service;

import java.util.*;

import com.carson.demo.model.Order;

public class OrdersService {

    private static Map<String,Order> orders = new HashMap<String,Order>();
    private static int nextId = 6;
    static {
        orders.put("3", new Order("3", "Bob", 33));
        orders.put("4", new Order("4", "Sarah", 44));
        orders.put("5", new Order("5", "Jim", 66));
    }

    public Order get(String id) {
        return orders.get(id);
    }

    public List<Order> getAll() {
        return new ArrayList<Order>(orders.values());
    }

    public void save(Order order) {
        if (order.getId() == null) {
            order.setId(String.valueOf(nextId++));
        }

        orders.put(order.getId(), order);
    }

    public void remove(String id) {
        orders.remove(id);
    }

}

order-index.jsp

<!DOCTYPE html PUBLIC 
	"-//W3C//DTD XHTML 1.1 Transitional//EN"
	"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<%@taglib prefix="s" uri="/struts-tags" %>

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
	<title>Orders</title>
</head>
<body>
    <s:actionmessage />
    <table>
        <tr>
            <th>ID</th>
            <th>Client</th>
            <th>Amount</th>
            <th>Actions</th>
        </tr>
        <s:iterator value="model">
        <tr>
            <td>${id}</td>
            <td><s:property value="clientName"/></td>
            <td><s:property value="amount"/></td>
            <td><a href="orders/${id}">View</a> |
                <a href="orders/${id}/edit">Edit</a> |
                <a href="orders/${id}/deleteConfirm">Delete</a></td>
        </tr>
        </s:iterator>
    </table>    	
    <a href="orders/new">Create a new order</a>
</body>
</html>
	

web.xml

<!DOCTYPE web-app PUBLIC
 "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
 "http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app>
  <display-name>Archetype Created Web Application</display-name>
	<init-param>
		<param-name>config</param-name>
		<!-- <param-value>../../resources/struts.xml</param-value> -->
		<param-value>classpath:struts.xml</param-value>
	</init-param>
	
	<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>

    <!-- log4j -->
    <context-param> 
        <param-name>log4jConfigLocation</param-name> 
        <param-value>WEB-INF/log4j.properties</param-value> 
    </context-param> 
	<welcome-file-list>
		<welcome-file>login.jsp</welcome-file>
	</welcome-file-list>
</web-app>

先介绍这么多，后续有时间继续补充。