Java通过反射获取Controller类、方法上注解和注解里的值

背景

在进行权限管理方面的开发过程中，尝试通过反射获取匹配的方法的注解，然后得到匹配路径进行鉴权。

反射获取类的注解@RequestMapping

//通过反射获取到类，填入类名
Class cl1 = Class.forName("");
//获取RequestMapping注解
RequestMapping anno = (RequestMapping) cl1.getAnnotation(RequestMapping.class);
//获取类注解的value值  
String[] value = anno.value();
//将字符串数组转成字符串
StringBuilder sb = new StringBuilder();
for (String ele : value) {
    sb.append(ele);
}
String classPath = sb.toString();

反射获取类注解 @GetMapping、@PutMapping、@PostMapping、@DeleteMapping

//获取类中所有的方法
Method[] methods = cl1.getDeclaredMethods();
for (Method method : methods) {
    GetMapping getRequestMothed = (GetMapping) method.getAnnotation(GetMapping.class);
    PutMapping putRequestMothed = (PutMapping) method.getAnnotation(PutMapping.class);
    PostMapping postRequestMothed = (PostMapping) method.getAnnotation(PostMapping.class);
    DeleteMapping deleteRequestMothed = (DeleteMapping)method.getAnnotation(DeleteMapping.class);
   //获取类注解的value值
   String[] value1 = getRequestMothed .value();
   String[] value2 = putRequestMothed .value();
   String[] value3 = postRequestMothed .value();
   String[] value4 = deleteRequestMothed.value();
} 

反射获取类注解 @ApiOperation

//获取类中所有的方法
Method[] methods = cl1.getDeclaredMethods();
for (Method method : methods) {
   ApiOperation apiOperation = method.getAnnotation(ApiOperation.class);
   //获取方法上@ApiOperation注解的value值
   apiOperationValue = apiOperation.value();
}

反射获取方法参数类表

//通过反射获取到类
String cl1 = Class.forName(string);
//获取类中所有的方法
Method[] methods = cl1.getDeclaredMethods();
for (Method method : methods) {
    //获取方法参数注解
    Annotation[][] parameterAnnotations = method.getParameterAnnotations();
    for (Annotation[] annotations : parameterAnnotations) {
        for (Annotation annotation : annotations) {
            //获取注解名
            String name = annotation.annotationType().getSimpleName();
        }
    }
}