注释字段的读取值

Question

我有一个用 spring 编写的 restful 网络服务。 HTTP 请求被映射到一个 bean（我称之为请求对象）。我在 bean 的每个字段上都有自定义注释。我的要求是： 1. 获取所有带注释的字段并检查至少提供了一个值。我的问题是我不知道如何读取带注释字段的值。我写了下面的自定义注释

public class DocumentModifiedDateValidator implements ConstraintValidator<ValidDocumentModifiedDate, String> {

    private String[] validDocumentModifiedDateValues;

    public void initialize(ValidDocumentModifiedDate constraintAnnotation) {
        //this.validDocumentModifiedDateValues = constraintAnnotation.value();
    }

    public boolean isValid(String object, ConstraintValidatorContext constraintContext) {

    boolean canProceed = false;
    for(Field field  : DocumentSearchRequest_global.class.getDeclaredFields())
    {

        if (field.isAnnotationPresent(ValidDocumentModifiedDate.class))
            {
            String name = field.getName();
                System.out.println("1.name :   "+ name); //Iam able to get the name of the field
                System.out.println("2.            "+field.getType().getName());
                Class<?> targetType = field.getType();
                Object objectValue;
                try
                {
 //Idont know if i can use the below to read value of the field??? 
 //Please suggest a way so that 
  //so that i can read value of every element      
                    objectValue = targetType.newInstance();
                    Object value = field.get(new String());
                    System.out.println(value.toString());

                }
                catch (InstantiationException | IllegalAccessException e)
                {
                    // TODO Auto-generated catch block

                }





            }
    }
        }

Answer 1

根据 Spring Validation ，spring 允许您编写自定义验证器并使用注释来引用您的验证器。

注释字段的读取值

Reading Value of an annotated field

java

annotations

web-services

spring-mvc

java-8