Demo——使用Spring的Validator接口进行数据验证

package com.thomas.login.validator; import com.thomas.login.bean.Address; import com.thomas.login.bean.User; import org.springframework.validation.Errors; import org.springframework.validation.ValidationUtils; import org.springframework.validation.Validator; /** * Created by thomas on 16-1-9. */ public class UserValidator implements Validator { private static final Integer MIN_PASSWD_LEN = 6; private final Validator addressValidator; public UserValidator(Validator addressValidator) { if(null == addressValidator) throw new IllegalArgumentException("The address validator can't be null"); if(!addressValidator.supports(Address.class)) throw new IllegalArgumentException("The address validator must support Address Class"); this.addressValidator = addressValidator; } public boolean supports(Class<?> aClass) { return User.class.equals(aClass); } public void validate(Object o, Errors errors) { //名字、密码非空验证 ValidationUtils.rejectIfEmptyOrWhitespace(errors, "name", "name.empty"); ValidationUtils.rejectIfEmptyOrWhitespace(errors, "password", "password.empty"); User user = (User) o; //密码最短长度验证 if(!errors.hasFieldErrors("password")) { String password = user.getPassword(); if(password.length() < MIN_PASSWD_LEN) errors.rejectValue("password", "password.too.short", new Object[]{MIN_PASSWD_LEN}, null); } //地址验证 try{ errors.pushNestedPath("address"); ValidationUtils.invokeValidator(addressValidator, user.getAddress(), errors); }finally { errors.popNestedPath(); } } }