Spring MVC中使用errors標簽
阿新 • • 發佈：2018-10-16
set etc obj www. req style prefix pat ava
先創建一個實體類，後續的驗證都基於這個實體類：
public class Goods { private String goodsName; private String city; private int amount; public String getGoodsName() { return goodsName; } public void setGoodsName(String goodsName) { this.goodsName = goodsName; }public String getCity() { return city; } public void setCity(String city) { this.city = city; } public int getAmount() { return amount; } public void setAmount(int amount) { this.amount = amount; } }
表單頁面的controller方法：
@RequestMapping("/test1")
表單jsp頁面
test1.jsp：
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%> <%@ taglib uri="http://java.sun.com/jsp/jstl/functions" prefix="fn"%> <%@ taglib prefix="form" uri="http://www.springframework.org/tags/form"%> <%@ taglib prefix="spring" uri="http://www.springframework.org/tags"%> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>test1</title> </head> <body> <form:form modelAttribute="goods" method="post" action="test2"> <form:input path="goodsName" /> <form:errors path="goodsName"></form:errors> <br /> <c:set var="citys" value="北京,上海,廣州" /> <c:set var="cityList" value="${fn:split(citys,‘,‘) }" /> <form:select path="city"> <form:option value="">請選擇</form:option> <form:options items="${cityList }" /> </form:select> <form:errors path="city"></form:errors> <br /> <form:button>提交</form:button> </form:form> </body> </html>
提交表單的controller：
@InitBinder public void initBinder(DataBinder binder) { binder.setValidator(new Validator() { @Override public void validate(Object target, Errors errors) { ValidationUtils.rejectIfEmpty(errors, "goodsName", null, "商品名稱不能為空"); ValidationUtils.rejectIfEmpty(errors, "city", null, "城市不能為空"); Goods goods = (Goods) target; if(goods.getGoodsName().length()<4) { errors.rejectValue("goodsName", null, "商品名稱不能少於4個字符"); } } @Override public boolean supports(Class<?> clazz) { return Goods.class.equals(clazz); } }); } @RequestMapping(value="/test2",method=RequestMethod.POST) public String test2(@Validated Goods goods,Errors errors,BindingResult result) { if(errors.hasErrors()) { return "/test1"; } else { return "/test2"; } }
通過@InitBinder註解的方法，會在test2方法前執行，如果檢查出了錯誤，會在test2方法裏通過errors.hasErrors()方法判斷
Spring MVC中使用errors標簽