详解如何在Spring Boot项目使用参数校验

<dependency>
  <groupId>org.hibernate</groupId>
  <artifactId>hibernate-validator</artifactId>
  <version>5.3.1.Final</version>
</dependency>

@Configuration
@EnableAutoConfiguration
public class FactoryConfig {
  
  final static Logger logger= LoggerFactory.getLogger(FactoryConfig.class);
 
  @Bean
  public MethodValidationPostProcessor methodValidationPostProcessor(){
   return new MethodValidationPostProcessor();
  }
  
  }

@AssertFalse 校验false
@AssertTrue 校验true
@DecimalMax(value=,inclusive=) 小于等于value，
inclusive=true,是小于等于
@DecimalMin(value=,inclusive=) 与上类似
@Max(value=) 小于等于value
@Min(value=) 大于等于value
@NotNull 检查Null
@Past 检查日期
@Pattern(regex=,flag=) 正则
@Size(min=, max=) 字符串，集合，map限制大小
@Valid 对po实体类进行校验

package hello;

import javax.validation.constraints.Min;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;

public class PersonForm {

  //名字不能为空，而且长度必须在2和30之间
  @NotNull(message = "名称不能为空")
  @Size(min=2, max=30, message = "名字长度必须在2和30之间")
  private String name;
  
  //年龄不能为空，而且必须大于等于18岁
  @NotNull
  @Min(18)
  private Integer age;

  public String getName() {
    return this.name;
  }

  public void setName(String name) {
    this.name = name;
  }

  public Integer getAge() {
    return age;
  }

  public void setAge(Integer age) {
    this.age = age;
  }

  public String toString() {
    return "Person(Name: " + this.name + ", Age: " + this.age + ")";
  }
}

//非实体类参数可以直接使用注解
 @GetMapping("/check")
@ResponseBody
public String check(@Min(0,message = "kpId必须大于等于0") @RequestParam int kpId,@RequestParam int level) {
    return "ok";
}
  //实体类注解校验使用@Valid
  @PostMapping("/")
  public String checkPersonInfo(@Valid PersonForm personForm, BindingResult bindingResult) {
    if (bindingResult.hasErrors()) {
      return "form";
    }
    return "redirect:/results";
  }

<td th:if="${#fields.hasErrors('age')}" th:errors="*{age}">Age Error</td>