SpringMVC之数据校验总结版

验证请求参数和处理校验结果

1.注解@Valid

①  @Valid注解验证请求参数的合法性

import org.hiberate.validator.constraints.NotBlank;
public class User {
    private String username;

    @NotBlank
    private String password;

    /** getter/setter **/
}

这方法的参数中添加@Valid注解才会使上面实体类的注解生效。

@PostMapping(value = "/user")
public User create(@Valid @RequestBody User user){
    System.out.println(user.getUsername());
    System.out.println(user.getPassword());
    return user;
}

2.注解@BindingResult处理校验结果

@PostMapping(value = "/user")
public User create(@Valid @RequestBody User user, BindingResult errors){
    if(errors.hasErrors()){
        errors.getAllErrors().stream().forEach(error -> System.out.println(error.getDefaultMessage()) );
    }
    System.out.println(user.getUsername());
    System.out.println(user.getPassword());
    return user;
}

@PutMapping("/user/{id}")
public User update(@Valid @RequestBody User user, BindingResult errors){
    if(errors.hasErrors()){
        errors.getAllErrors().stream().forEach(error -> {
            FieldError fieldError = (FieldError)error;
            String message = fieldError.getField() + " " + error.getDefaultMessage();
            System.out.println(message);
        });
    }
    System.out.println(user.getUsername());
    System.out.println(user.getPassword());
    user.setId("1");
    return user;
}

3.注解中有message属性，可以在实体类中指定message，如下：

@Past(message = "生日不能是未来的")
private Date birthday;

if(errors.hasErrors()){
    errors.getAllErrors().stream().forEach(error -> {
        System.out.println(error.getDefaultMessage());
    });
}

4.自定义注解进行校验。

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})
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = MyConstraintValidator.class)
public @interface MyConstraint {
    //以下三个是必须要有的
    String message() default "{org.hibernate.validator.constraints.NotBlank.message}";
    Class<?>[] groups() default {};
    Class<? extends Payload>[] payload() default {};
}

import com.learn.service.HelloService;
import org.springframework.beans.factory.annotation.Autowired;

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;

public class MyConstraintValidator implements ConstraintValidator<MyConstraint,Object> {

    @Autowired
    private HelloService helloService;

    @Override
    public void initialize(MyConstraint myConstraint) {
        System.out.println("my validator init");
    }

    /**
     * 校验逻辑
     *  这里为了方便测试，返回设为false，这样就能把message打印出来
     *  @MyConstraint(message = "测试自定义注解")
     */
    @Override
    public boolean isValid(Object value, ConstraintValidatorContext context) {
        helloService.greeting("tom");
        System.out.println(value);
        return false;
    }
}

使用：

@MyConstraint(message = "测试自定义注解")
private String username;

附录：

1.注解说明：