struts2--（局部）自定义类型转换

超、凢脫俗 2024-02-18 00:38 9阅读 0赞

（局部）类型转换的基本流程：

提交表单

struts.xml查找action

Action类根据表单中的name属性调用set方法将值赋给对应的属性，调用每个属性之前，检查又没有定义这个类型的自定义类型转换

如果没有，则根据默认的规则转换；如果有，则检查在同一目录下，有木有资源文件存在

到自定义转换类中，检查转换的方向，返回对象

到Action中，将返回的对象，set到对应属性中

执行execute()方法

根据struts.xml文件中，result的值找到要转到的页面

页面中有,再到Action类中，寻找get方法，直接把值放到输出框中

当找到自定义类型时，又会寻找自定义类型转换类，检查转换方向，返回对象

显示到页面

做类型转化时，需要注意：

\*-conversion.properties需要和Action放到一个包下，\*代表Action的类名

其内容为：要转换的对象=自定义转换类具体地址

案例：

登录index.jsp页面：

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
    <%@ taglib prefix = "s" uri = "/struts-tags"%>
    <%
    String path = request.getContextPath();
    String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
    %>
    
    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
    <html>
      <head>
        <base href="<%=basePath%>">
        
        <title>My JSP 'index.jsp' starting page</title>
    	<meta http-equiv="pragma" content="no-cache">
    	<meta http-equiv="cache-control" content="no-cache">
    	<meta http-equiv="expires" content="0">    
    	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    	<meta http-equiv="description" content="This is my page">
    	
      </head>
      
      <body>
        <s:form action = "login" method = "post">
          <s:textfield name = "user" label = "用户名及密码"></s:textfield>
          <s:submit value = "提交"></s:submit>
        </s:form>
      </body>
    </html>

Action:

package com.action;
    
    import com.bean.User;
    import com.opensymphony.xwork2.ActionSupport;
    
    public class LoginAction extends ActionSupport{
      private User user;
      private String massage ;
      
      public String execute() {
    	  this.setMassage("用户名："+user.getUsername()+" 密码："+user.getPassword());
    	return SUCCESS;
    }
      
    public User getUser() {
    	return user;
    }
    public void setUser(User user) {
    	this.user = user;
    }
    public String getMassage() {
    	return massage;
    }
    public void setMassage(String massage) {
    	this.massage = massage;
    }
    
    }

javabean:

package com.bean;
    
    public class User {
      private String username ;
      private String password ;
    public String getUsername() {
    	return username;
    }
    public void setUsername(String username) {
    	this.username = username;
    }
    public String getPassword() {
    	return password;
    }
    public void setPassword(String password) {
    	this.password = password;
    }
      
    }

结果界面ok.jsp：

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
    <%@ taglib prefix = "s" uri = "/struts-tags" %>
    <%
    String path = request.getContextPath();
    String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
    %>
    
    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
    <html>
      <head>
        <base href="<%=basePath%>">
        
        <title>My JSP 'ok.jsp' starting page</title>
        
    	<meta http-equiv="pragma" content="no-cache">
    	<meta http-equiv="cache-control" content="no-cache">
    	<meta http-equiv="expires" content="0">    
    	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    	<meta http-equiv="description" content="This is my page">
    	
    
      </head>
      
      <body>
        <s:property value = "user"/>
      </body>
    </html>

类型转换器UserConverter.java：

package com.converter;
    
    import java.util.Map;
    
    import com.bean.User;
    import com.opensymphony.xwork2.conversion.impl.DefaultTypeConverter;
    
    public class UserConverter extends DefaultTypeConverter{
    	  public Object convertValue(Map<String, Object> context, Object value, Class toType)
    	  {
    		  System.out.println("yes");
    		  if(toType == User.class){
    			  String[] user = (String[])value;
    			  String[] user0 = user[0].split(",");
    			  User u = new User();
    			  u.setUsername(user0[0]);
    			  u.setPassword(user0[1]);
    			  return u;
    		  }
    		  else if(toType == String.class){
    			  User user = (User)value;
    			  return "用户名："+user.getUsername()+" 密码："+user.getPassword()+"!";
    		  }
    	    return null;
    	  }
    }

struts.xml配置：

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE struts PUBLIC
        "-//Apache Software Foundation//DTD Struts Configuration 2.1.7//EN"
        "http://struts.apache.org/dtds/struts-2.1.7.dtd">
    <struts>
      <package name="defalut" namespace = "/" extends = "struts-default">
        <action name="login" class = "com.action.LoginAction">
          <result>/ok.jsp</result>
        </action>
      </package>
    </struts>

自定义类型转换属性配置文件LoginAction-conversion.properties：

user=com.converter.UserConverter  
  
  
当然全局配置就很简单了。配置了全局的类型转换之后，就会对该javabean的所有实例起作用，配置如下xwork-conversion.properties：

com.bean.User=com.converter.UserConverter