![spring mvc controller中的参数验证机制(二) spring mvc controller中的参数验证机制(二)](https://image.shishitao.com:8440/aHR0cHM6Ly9ia3FzaW1nLmlrYWZhbi5jb20vdXBsb2FkL2NoYXRncHQtcy5wbmc%2FIQ%3D%3D.png?!?w=700&webp=1)
这里我们介绍以下自定义的校验器的简单的使用示例
一、包结构和主要文件
二、代码
1.自定义注解文件MyConstraint
package com.knyel.validator; import javax.validation.Constraint;
import javax.validation.Payload;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target; @Target({ElementType.METHOD,ElementType.FIELD})//注解可以标注在什么元素上
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = MyConstraintValidator.class)
public @interface MyConstraint {
String message(); Class<?>[] groups() default {}; Class<? extends Payload>[] payload() default {};
}
2.自定义校验逻辑文件MyConstraintValidator
package com.knyel.validator; import com.knyel.service.HelloKnyel;
import org.springframework.beans.factory.annotation.Autowired; import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext; //ConstraintValidator<A,T>
//A参数:表示要验证的注解
//T参数:表示要验证的东西是什么类型
public class MyConstraintValidator implements ConstraintValidator<MyConstraint,Object> { @Autowired
HelloKnyel helloKnyel; @Override
public void initialize (MyConstraint myConstraint){
//校验器初始化的时候做的一些工作
System.out.println("myvalidator init");
} /*
真正的校验逻辑
Object o :传进来的校验的值
ConstraintValidatorContext constraintValidatorContext :校验的上下文
*/
@Override
public boolean isValid (Object value, ConstraintValidatorContext constraintValidatorContext){
//处理校验逻辑
helloKnyel.welcome("knyel");
System.out.println(value);
//true代表校验成功,false代表校验失败
return false;
}
}
3.在2中isValid方法中调用的校验逻辑业务HelloKnyelImpl及接口
package com.knyel.service; public interface HelloKnyel {
String welcome(String name);
}
package com.knyel.service.impl; import com.knyel.service.HelloKnyel;
import org.springframework.stereotype.Service; @Service
public class HelloKnyelImpl implements HelloKnyel { @Override
public String welcome (String name){
System.out.println("welcome");
return "hello knyel";
}
}
4.待校验的实体
package com.knyel.dto; import com.fasterxml.jackson.annotation.JsonView;
import com.knyel.validator.MyConstraint;
import org.hibernate.validator.constraints.NotBlank; import javax.validation.constraints.Past;
import java.util.Date; public class User { public interface UserSimpleView {};
public interface UserDetailView extends UserSimpleView {}; private String id;
@MyConstraint(message = "测试校验器")
private String username;
@NotBlank(message="密码不能为空")
private String password;
@Past(message = "生日必须是过去的时间")
private Date birthday; @JsonView(UserSimpleView.class)
public String getUsername (){
return username;
} public void setUsername (String username){
this.username = username;
}
@JsonView(UserDetailView.class)
public String getPassword (){
return password;
} public void setPassword (String password){
this.password = password;
} @JsonView(UserSimpleView.class)
public String getId (){
return id;
}
@JsonView(UserSimpleView.class)
public void setId (String id){
this.id = id;
} public Date getBirthday (){
return birthday;
} public void setBirthday (Date birthday){
this.birthday = birthday;
} @Override
public String toString (){
return "User{" + "id='" + id + '\'' + ", username='" + username + '\'' + ", password='" + password + '\'' + ", birthday=" + birthday + '}';
}
}
5.controller
@PutMapping("/{id:\\d+}")
public User update (@Valid @RequestBody User user, BindingResult errors){
if (errors.hasErrors()) {
errors.getAllErrors().stream().forEach((ObjectError error) ->{
// FieldError fieldError=(FieldError) error;
// String message=fieldError.getField()+":"+fieldError.getDefaultMessage();
System.out.println(error.getDefaultMessage());
});
}
System.out.println(user.getId());
System.out.println(user.getUsername());
System.out.println(user.getPassword());
System.out.println(user.getBirthday());
user.setId("1");
return user;
}
执行测试用例后
myvalidator init
welcome
knyel
测试校验器
1