Struts2内建类型转换器数据器使用简介

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struts2 内建了类型转换器，可以方便的将我们在页面上输入的字符串数据转换成JavaBean中的Boolean,Float,Integer,Double,Long等数据类型，在无法转换成功时，还可以给出错误提示，非常方便

首先简历JavaBean:

 

package  HelloWorld;

public   class  User  ... {
    private String username;
      private Integer password;

      private String[] books;
      public String[] getBooks() ...{
            return books;
        }
        public void setBooks(String[] books) ...{
            this.books = books;
        }
        public String getUsername() ...{
            return username;
        }
        public void setUsername(String username) ...{
            this.username = username;
        }
        public Integer getPassword() ...{
            return password;
        }
        public void setPassword(Integer password) ...{
            this.password = password;
        }

    
}

 

编写Action,需要继承ActionSupport,在action中有两个变量，一个是User类，一个是birth属性

我们定义birth属性和user类中的password属性都必须是Integer类型

 

package  HelloWorld;

import  com.opensymphony.xwork2.ActionSupport;

public   class  LoginAction  extends  ActionSupport ... {
 

private String tip;
private User user;
private Integer birth;


public Integer getBirth() ...{
    return birth;
}

public void setBirth(Integer birth) ...{
    this.birth = birth;
}

public String execute() throws Exception...{
    System.out.println(this.getUser().getUsername());
    System.out.println(this.getUser().getPassword());
          return SUCCESS;
    
  }

public User getUser() ...{
    return user;
}

public void setUser(User user) ...{
    this.user = user;
}

public String getTip() ...{
    return tip;
}
public void setTip(String tip) ...{
    this.tip = tip;
}


  
}

 

web.xml

 

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" >
     < filter >
       < filter-name > struts2 filter-name >
       < filter-class > org.apache.struts2.dispatcher.FilterDispatcher filter-class >
     filter >
     < filter-mapping >
       < filter-name > struts2 filter-name >
       < url-pattern > /* url-pattern >
     filter-mapping >


web-app >

 

struts.xml (WEB-INF/classes下)

 

xml version="1.0" encoding="GBK"  ?>
DOCTYPE struts PUBLIC
        "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
        "http://struts.apache.org/dtds/struts-2.0.dtd" >

< struts >
     < package  name ="struts"  extends ="struts-default" >
        < action  name ="Login"  class ="HelloWorld.LoginAction" >
          < result  name ="input" > /helloworld/index.jsp result >
          < result  name ="success" > /helloworld/welcome.jsp result >
         
          < result  name ="error" > /helloworld/error.jsp result >
        action >
     package >
struts >

 

struts.properties(WEB-INF/classes下)

struts.custom.i18n.resources=messageResource

 

信息录入页面：

<%@ page language="java" contentType="text/html; charset=gb2312"
    pageEncoding="gb2312"%>
<%@ taglib prefix="s" uri="/struts-tags" %>

 
   
 
       
  

   

    
      

      
 
      
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
 

信息展示页面：

<%@ page language="java" contentType="text/html; charset=gb2312"
    pageEncoding="gb2312"%>
<%@ page isELIgnored="false" %>
   
<%@ taglib prefix="s" uri="/struts-tags" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>

 
   
 
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
  
        转换成功!

  用户1的用户名为：

  用户1的密码为：

  
   

 

 

我们在资源文件中加入：

xwork.default.invalid.fieldvalue={0}类型转换错误，运行index.jsp.,在三个输入框中都输入admin,则会出现以下提示：

user.password字段类型转换失败
birth字段类型转换失败

 

在资源文件中定义的是全局转换错误提示的内容，如果想对具体Action中的字段进行提示，则编写ActionName.properties,本文中对应的就是LoginAction.properties,放在和Action同一个目录下，内容格式如下：invalid.fieldvalue.birth （其中birth为action中属性名）

本文LoginAction.properties内容为：invalid.fieldvalue.birth=生日必须为数字

再次运行index.jsp.结果如下：

user.password字段类型转换失败
生日必须位数字