基于Spring的Validation校验

客官°小女子只卖身不卖艺 2022-10-01 02:52 195阅读 0赞

代码：

loginForm.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
    <%@taglib prefix= "form" uri= "http://www.springframework.org/tags/form" %>
    <!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Validator接口验证</title>
    </head>
    <body>
    <h3>登录页面</h3>
    
    <form:form modelAttribute="user" method="post" action="login" >
    	<table>
    		<tr>
    			<td>登录名:</td>
    			<td><form:input path="loginname"/></td>
    			
    			<td><form:errors path="loginname" cssStyle= "color:red"/></td>
    		</tr>
    		<tr>
    			<td>密码:</td>
    			<td><form:input path="password"/></td>
    			
    			<td><form:errors path="password" cssStyle= "color:red"/></td>
    		</tr>
    		<tr>
    			<td><input type="submit" value="提交"/></td>
    		</tr>
    	</table>
    </form: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ConversionService</title>
    </head>
    <body>
    登录名：${requestScope.user.loginname }<br>
    登录名：${requestScope.user.password }<br>
    </body>
    </html>

User.java

package com.bean;
    
    import java.io.Serializable;
    
    public class User implements Serializable {
    	private String loginname;
    	private String password;
    	public User() {
    		super();
    		// TODO Auto-generated constructor stub
    	}
    	public String getLoginname() {
    		return loginname;
    	}
    	public void setLoginname(String loginname) {
    		this.loginname = loginname;
    	}
    	public String getPassword() {
    		return password;
    	}
    	public void setPassword(String password) {
    		this.password = password;
    	}
    	@Override
    	public String toString() {
    		// TODO Auto-generated method stub
    		return "User [loginname=" + loginname + ", password=" + password + "]";
    	}
    	
    }

UserValidator.java

package com.validator;
    
    import com.bean.*;
    import org.springframework.stereotype.Repository;
    import org.springframework.validation.Errors;
    import org.springframework.validation.ValidationUtils;
    import org.springframework.validation.Validator;
    
    // 实现Spring的Validator接口
    @Repository("userValidator")
    public class UserValidator implements Validator {
    	@Override
    	public boolean supports(Class<?> clazz) {
    		// User指定的 Class 参数所表示的类或接口是否相同，或是否是其超类或超接口。
    		return User.class.isAssignableFrom(clazz);
    	}
    
    	// 对目标类target进行校验，并将校验错误记录在errors当中
    	@Override
    	public void validate(Object target, Errors errors) {
    		/*
    		使用ValidationUtils中的一个静态方法rejectIfEmpty()来对loginname属性进行校验，
    		假若'loginname'属性是 null 或者空字符串的话，就拒绝验证通过 。
    		*/
    		ValidationUtils.rejectIfEmpty(errors, "loginname", null, "登录名不能为空");  
    		ValidationUtils.rejectIfEmpty(errors, "password", null, "密码不能为空");  
    		User user = (User)target;
    		if(user.getLoginname().length() > 10){
    			errors.rejectValue("loginname", null, "用户名不能超过10个字符");
    		}
    		if(user.getPassword() != null && !user.getPassword().equals("") && user.getPassword().length() < 6){
    			errors.rejectValue("password", null, "密码不能小于6位");
    		}
    	}
    
    }

UserController.java

package com.control;
    
    
    import org.apache.commons.logging.Log;
    import org.apache.commons.logging.LogFactory;
    import com.bean.*;
    import com.validator.*;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.beans.factory.annotation.Qualifier;
    import org.springframework.stereotype.Controller;
    import org.springframework.ui.Model;
    import org.springframework.validation.Errors;
    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;
    
    @Controller
    public class UserController{
    	private static final Log logger = LogFactory.getLog(UserController.class);
    	 
    	// 注入UserValidator对象
    	@Autowired
    	@Qualifier("userValidator")
    	private UserValidator userValidator;
    	
    	@RequestMapping(value="/{formName}")
    	 public String loginForm(@PathVariable String formName,Model model){
    		User user = new User();
    		model.addAttribute("user",user);
    		// 动态跳转页面
    		return formName;
    	}
    	 
    	 @RequestMapping(value="/login",method=RequestMethod.POST)
    	 public String login(@ModelAttribute User user,Model model,Errors errors) {
    		 logger.info(user);
    		 model.addAttribute("user", user);
    		 // 调用userValidator的验证方法
    		 userValidator.validate(user, errors);
    		 // 如果验证不通过跳转到loginForm视图
    		 if(errors.hasErrors()){
    			 return "loginForm";
    		 }
    	     return "success";
    	 }
    }

截图：

![Center][]

![Center 1][]

[Center]: /images/20220705/09d33f3e3ff1408785a310c1cf8b5e25.png
[Center 1]: /images/20220705/84a411c14cdc42069af29e06a2518d6f.png