使用Formatter格式化数据

使用Formatter处理日期

最新推荐文章于 2025-06-18 16:34:17 发布

原创最新推荐文章于 2025-06-18 16:34:17 发布 · 9.9k 阅读

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#格式化 #数据 #spring mvc #框架

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本文介绍了一个简单的示例，展示了如何在Java Web应用中利用Spring框架的Formatter接口来格式化和解析日期类型的输入。通过自定义DateFormatter类实现了Formatter接口，并在UserControl中处理了表单提交的数据。

代码：

registerForm.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!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>测试Formatter接口</title>
</head>
<body>
<h3>注册页面</h3>
<form action="register" method="post">
     <table>
         <tr>
         	<td><label>登录名: </label></td>
             <td><input type="text" id="loginname" name="loginname" ></td>
         </tr>
          <tr>
         	<td><label>生日: </label></td>
             <td><input type="text" id="birthday" name="birthday" ></td>
         </tr>
         <tr>
             <td><input id="submit" type="submit" value="登录"></td>
         </tr>
     </table>
</form>
</body>
</html>

success.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt"%>
<!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>测试Formatter</title>
</head>
<body>
登录名：${requestScope.user.loginname }<br>
生日：<fmt:formatDate value="${requestScope.user.birthday}" pattern="yyyy年MM月dd日"/><br>
</body>
</html>

User.java

package com.bean;

import java.io.Serializable;
import java.util.Date;

// 域对象，实现序列化接口
public class User implements Serializable{
	
	private String loginname;
	private Date birthday;

	public User() {
		super();
		// TODO Auto-generated constructor stub
	}

	public String getLoginname() {
		return loginname;
	}

	public void setLoginname(String loginname) {
		this.loginname = loginname;
	}

	public Date getBirthday() {
		return birthday;
	}

	public void setBirthday(Date birthday) {
		this.birthday = birthday;
	}

	@Override
	public String toString() {
		return "User [loginname=" + loginname + ", birthday=" + birthday + "]";
	}
}

DateFormatter.java

package com.formatter;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;

import org.springframework.format.Formatter;

public class DateFormatter implements Formatter<Date> {
	// 日期类型模板：如yyyy-MM-dd
	private String datePattern;
	// 日期格式化对象
	private SimpleDateFormat dateFormat;
	// 构造器，通过依赖注入的日期类型创建日期格式化对象
	public DateFormatter(String datePattern) {
		this.datePattern = datePattern;
		this.dateFormat = new SimpleDateFormat(datePattern);
	}

	// 显示Formatter<T>的T类型对象
	public String print(Date date,Locale locale){
		return dateFormat.format(date);
	}
	
	// 解析文本字符串返回一个Formatter<T>的T类型对象。
	public Date parse(String source, Locale locale) throws ParseException {
		try {
			return dateFormat.parse(source);
		} catch (Exception e) {
			throw new IllegalArgumentException();
		}
		
	}

}

UserController.java

package com.control;


import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

import com.bean.User;

@Controller
public class UserController{
	private static final Log logger = LogFactory.getLog(UserController.class);
	 
	@RequestMapping(value="/{formName}")
	 public String loginForm(@PathVariable String formName){
		// 动态跳转页面
		return formName;
	} 
	 @RequestMapping(value="/register",method=RequestMethod.POST)
	 public String register(@ModelAttribute User user, Model model) {
		 logger.info(user);
		 model.addAttribute("user", user);
	     return "success";
	 }
}

截图：