Struts2之ModelDriven和Preparable拦截器

首先struts.xml文件配置如下 默认拦截器设置为paramsPrepareParamsStack

<package name="default" namespace="/" extends="struts-default">

        <!-- 配置使用 paramsPrepareParamsStack 作为默认的拦截器栈 -->
        <!-- 修改 PrepareInterceptor 拦截器的 alwaysInvokePrepare 属性值为 false -->
        <interceptors>
            <interceptor-stack name="teststack">
                <interceptor-ref name="paramsPrepareParamsStack">
                    <param name="prepare.alwaysInvokePrepare">false</param>
                </interceptor-ref>
            </interceptor-stack>
        </interceptors>
 
        <default-interceptor-ref name="teststack"/>

        <action name="emp-*" 
            class="com.app.EmployeeAction"
            method="{1}">
            <result name="{1}">/emp-{1}.jsp</result>
            <result name="success" type="redirectAction">emp-list</result>    
        </action>
          <action name="emp-edit"  <!--这段代码按理上面的应该可以用但是如果不加页面跳转错误 不清除是字打错了还是怎么了-->
            class="com.app.EmployeeAction"
            method="edit">
            <result name="edit">/emp-edit.jsp</result>
        </action>
        
        
        
        
    </package>

拦截顺序

 <interceptor-stack name="paramsPrepareParamsStack">
                <interceptor-ref name="exception"/>
                <interceptor-ref name="alias"/>
                <interceptor-ref name="i18n"/>
                <interceptor-ref name="checkbox"/>
                <interceptor-ref name="datetime"/>
                <interceptor-ref name="multiselect"/>
                <interceptor-ref name="params"/>      //1.栈顶对象为当前Action将参数赋值给Action类中对应属性
                <interceptor-ref name="servletConfig"/>
                <interceptor-ref name="prepare"/>      //2.调用prepareXxx方法为ModelDriven准备model
                <interceptor-ref name="chain"/>
                <interceptor-ref name="modelDriven"/>   //3.将model中的参数置于栈顶
                <interceptor-ref name="fileUpload"/>
                <interceptor-ref name="staticParams"/>
                <interceptor-ref name="actionMappingParams"/>
                <interceptor-ref name="params"/>       //4.输入参数赋值给栈顶元素
                <interceptor-ref name="conversionError"/>
                <interceptor-ref name="validation">
                    <param name="excludeMethods">input,back,cancel,browse</param>
                </interceptor-ref>
                <interceptor-ref name="workflow">
                    <param name="excludeMethods">input,back,cancel,browse</param>
                </interceptor-ref>
            </interceptor-stack>

Java代码 实现ModelDriven, Preparable接口

package com.app;

import java.util.Map;

import org.apache.struts2.interceptor.RequestAware;

import com.opensymphony.xwork2.ModelDriven;
import com.opensymphony.xwork2.Preparable;

public class EmployeeAction implements RequestAware, ModelDriven<Employee>, Preparable{
    
    private Dao dao = new Dao();
    
    private Employee employee;
    
    public String update(){
        dao.update(employee);
        return "success";
    }
    
    public void prepareUpdate(){
        employee = new Employee();
    }

    public String edit(){    
       // System.out.println(222222);
        return "edit";
    }
    
    public void prepareEdit(){
        //System.out.println(1111111);
        employee = dao.get(employeeId);
    }
    
    public String save(){
        dao.save(employee);
        return "success";
    }
    
    public void prepareSave(){
        employee = new Employee();
    }
    
    public String delete(){
        dao.delete(employeeId);
        return "success";
    }
    
    public String list(){
        request.put("emps", dao.getEmployees());
        return "list";
    }
    
    private Map<String, Object> request;

    @Override
    public void setRequest(Map<String, Object> arg0) {
        this.request = arg0;
    }
    
    private Integer employeeId;
    
    public void setEmployeeId(Integer employeeId) {
        this.employeeId = employeeId;
    }
    
    @Override
    public Employee getModel() {
        return employee; //将employee置于栈顶
    }

    @Override
    public void prepare() throws Exception {
        System.out.println("prepare...");
    }
    
}

list.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags" %>    
    
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>

    <s:form action="emp-save">
        
        <s:textfield name="name" label="Name"></s:textfield>
        <s:textfield name="email" label="Email"></s:textfield>
        
        <s:submit></s:submit>        
    </s:form>

    <br>
    <hr>
    <br>
    
    <table cellpadding="10" cellspacing="0" border="1">
        <thead>
            <tr>
                <td>ID</td>
                <td>Name</td>
                <td>Email</td>
                <td>Edit</td>
                <td>Delete</td>
            </tr>
        </thead>
        
        <tbody>
            <s:iterator value="#request.emps">
                <tr>
                    <td>${employeeId }</td>
                    <td>${name }</td>
                    <td>${email }</td>
                    <td><a href="emp-edit?employeeId=${employeeId }">Edit</a></td>
                    <td><a href="emp-delete?employeeId=${employeeId }">Delete</a></td>
                </tr>
            </s:iterator>
        </tbody>
        
    </table>

</body>
</html>

edit.jsp

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

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
    
    <s:debug></s:debug>
    
    <br>
    <br>
    
    <s:form action="emp-update">
        
        <s:hidden name="employeeId"></s:hidden>
        
        <s:textfield name="name" label="Name"></s:textfield>
        <s:textfield name="email" label="Email"></s:textfield>
        
        <s:submit></s:submit>        
    </s:form>
    
</body>
</html>