Controller参数校验

1.拦截Controller抛出的异常

@ControllerAdvice
public class ControllerValidationHandler {
    @ExceptionHandler(MethodArgumentNotValidException.class)   //拦截@valid没有通过的异常
    @ResponseBody
    public String processValidationError(MethodArgumentNotValidException ex) {
        BindingResult result = ex.getBindingResult();
        FieldError error = result.getFieldError();
        if (error != null) {
            return result.getObjectName() + ":" + error.getDefaultMessage();
        }
        return null;
    }

    @ExceptionHandler(HttpMessageNotReadableException.class)   //拦截json转换不成功的异常
    @ResponseBody
    public String processValidationError2(HttpMessageNotReadableException ex) {

       return ex.getMessage();
    }
}

2.Controller层代码

@Controller
@RequestMapping("/user")
public class UserController {

    @Autowired
    IUserService userService;

    @RequestMapping(value = "/test", method = RequestMethod.POST)
    @ResponseBody
    public String test(HttpServletRequest request, @Valid @RequestBody TestVO restVO) {
      return restVO.toString();
    }

}

3.TestVO实体类

public class TestVO {
    private Integer price;
    @Length(min = 3, max = 10,message = "内容应该在3-10字符之间")
    private String content;
    public Integer getPrice() {
        return price;
    }
    public void setPrice(Integer price) {
        this.price = price;
    }
    public String getContent() {
        return content;
    }
    public void setContent(String content) {
        this.content = content;
    }
    @Override
    public String toString() {
        return "TestVO{" +
                "price=" + price +
                ", content='" + content + '\'' +
                '}';
    }
}

4.pom配置

<dependency>
      <groupId>javax.validation</groupId>
      <artifactId>validation-api</artifactId>
　　<version>2.0.0.Final</version>
</dependency>
<dependency>
    <groupId>org.apache.bval</groupId>
    <artifactId>bval-jsr</artifactId>
    <version>1.1.2</version>
</dependency>

5.注解类

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.FIELD)
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = LengthValidator.class)
public @interface Length {
int min() default 0;
int max() default 2147483647;
String message() default "length is wrong";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}

 

 

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

public class LengthValidator implements ConstraintValidator<Length, CharSequence> {
private int min;
private int max;

public LengthValidator() {
}

public void initialize(Length parameters) {
this.min = parameters.min();
this.max = parameters.max();
}

public boolean isValid(CharSequence value, ConstraintValidatorContext constraintValidatorContext) {
if(value == null) {
return true;
} else {
int length = value.length();
return length >= this.min && length <= this.max;
}
}
}

6、总结
这里使用的是自己实现的@length注解，实际使用中可以使用hibernate-validation这个包的实现