在上一篇文https://juejin.im/post/5a5e1159518825732b19d8ce，通過AOP對@RequestBody註解進行的引數進行校驗 那麼對於 @PathVariable和@RequestParam 卻沒有對應的spring mvc 預設自帶的校驗機制 @Valid + BindingResult。那麼此時該校驗的話，只能程式碼上逐一進行校驗。
先說明一下@PathVariable和@RequestParam；兩個註解的用法。
1.原版本講解
1.1 @PathVariable
1.1.1 RESTful風格
格式：path/1/catalpaFlat eg:
@GetMapping("path/{isInt}/{isString}")
public ResponseVO pathGet(@PathVariable Integer isInt,
@PathVariable String isString) {
log.info("int:" + isInt);
log.info("String:" + isString);
JSONObject resultJson = new JSONObject();
resultJson.put("isInt", isInt);
resultJson.put("isString", isString);
return new ResponseVO(HttpStatus.OK.value(), "pathGet", resultJson);
}
複製程式碼request： http://localhost:8888/path/3/dadas
1.1.2 校驗
程式碼式校驗
if(isInt < 2){
return new ResponseVO(HttpStatus.BAD_REQUEST.value(), "pathGet", "isInt must be more than 2");
}
複製程式碼程式碼式校驗的話，個人覺得就有點兒不必要，除非是一些特殊需求
1.2 @RequestParam
1.2.1 表單提交（query）
格式：query?isInt=2&isString=catalpaFlat
@GetMapping("query?")
public ResponseVO queryGet(@RequestParam Integer isInt,
@RequestParam String isString) {
log.info("int:" + isInt);
log.info("String:" + isString);
JSONObject resultJson = new JSONObject();
resultJson.put("isInt", isInt);
resultJson.put("isString", isString);
return new ResponseVO(HttpStatus.OK.value(), "queryGet", resultJson);
}
複製程式碼1.2.2 校驗
同樣也需要程式碼式校驗
if(isInt < 2){
return new ResponseVO(HttpStatus.BAD_REQUEST.value(), "queryGet", "isInt must be more than 2");
}
複製程式碼因為@Valid + BindingResult只能用於@ResponseBody這種型別註解。
2. AOP改良版
可以感受到原版本都得在程式碼中進行校驗，只要使用到@PathVariable和@RequestParam的都得進行一波引數校驗，因此就想能不能像@Valid一樣，為其新增註解式校驗，這樣程式碼量就減少並讓程式碼優雅了很多。
2.1 介面層（IDAL）
以下程式碼再則是改良之後的程式碼：
- @ParameterValid 相當於@Valid，並且在其屬性中進行配置引數校驗規則
- @PathAndQueryParamValid 相當於AOP的切入點
@PathAndQueryParamValid
@GetMapping("path/{isInt}/{isString}")
public ResponseVO pathGet(@PathVariable @ParameterValid(type = Integer.class, msg = "isInt must be more than 2", isMin = true, min = 2) Integer isInt,
@PathVariable @ParameterValid(type = String.class, msg = "isString is empty") String isString) {
log.info("int:" + isInt);
log.info("String:" + isString);
JSONObject resultJson = new JSONObject();
resultJson.put("isInt", isInt);
resultJson.put("isString", isString);
return new ResponseVO(HttpStatus.OK.value(), "pathGet", resultJson);
}
@GetMapping("query")
@PathAndQueryParamValid
public ResponseVO queryGet(@RequestParam @ParameterValid(type = Integer.class, msg = "isInt must be more than 2 ", isMin = true, min = 2) Integer isInt,
@RequestParam @ParameterValid(type = String.class, msg = "isString is empty") String isString) {
log.info("int:" + isInt);
log.info("String:" + isString);
JSONObject resultJson = new JSONObject();
resultJson.put("isInt", isInt);
resultJson.put("isString", isString);
return new ResponseVO(HttpStatus.OK.value(), "queryGet", resultJson);
}
複製程式碼2.2 自定義註解（annotation）
2.2.1 @PathAndQueryParamValid
只是簡單的用於方法型別註解：
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface PathAndQueryParamValid {
}
複製程式碼2.2.1 @ParameterValid
@ParameterValid 可以根據實際業務需求新增屬於你的校驗規則:
@Documented
@Target(ElementType.PARAMETER)
@Retention(RetentionPolicy.RUNTIME)
public @interface ParameterValid {
Class<?> type();
String msg();
boolean request() default true;
boolean isEmpty() default true;
boolean isBlank() default true;
boolean isNull() default false;
int min() default 0;
int max() default 0;
int[] section() default {0,0};
boolean isMin() default false;
boolean isMax() default false;
boolean isSection() default false;
}
複製程式碼2.3 AOP切面（重點-1）
- 通過joinPoint獲取切點方法名以及類名，後續（重點）有大用
- 通過JoinPoint獲取方法的引數
- 呼叫（重點2）ParamValidSupport
- AdvanceResponseSupport和上一篇文章內容一樣，其實就是響應而已。
@Aspect
@Component
public class PathAndQueryParamValidAspect {
private static final Logger log = LoggerFactory.getLogger(PathAndQueryParamValidAspect.class);
@Before("@annotation(paramValid)")
public void paramValid(JoinPoint joinPoint, PathAndQueryParamValid paramValid) {
String className = joinPoint.getTarget().getClass().getName();
String methodName = joinPoint.getSignature().getName();
Object[] param = joinPoint.getArgs();
try {
List<String> errorLists = ParamValidSupport.get().validate(className, methodName,
ParameterValid.class, param);
if (errorLists != null) {
AdvanceResponseSupport.advanceResponse(
new ResponseVO(HttpStatus.BAD_REQUEST.value(), "parameter empty", errorLists));
}
} catch (NotFoundException | NoSuchMethodException | ClassNotFoundException e) {
log.error("e-name：" + e.getClass().getName() + "： message：" + e.getMessage());
}
}
}
複製程式碼2.4 校驗（重點-2）
- 通過方法名和類名，根據ClassPool獲取CtClass和CtMethod
- 從而獲取引數註解，解析引數註解規則進行校驗引數
（這裡還可以重構的，只是對int和string兩種型別進行校驗，還可以新增其他需求。把主要內容先呈現出來）
public class ParamValidSupport {
private static final Logger logger = LoggerFactory.getLogger(ParamValidSupport.class);
private static final String PARAM_TYPE_ERROR = "param type error";
private static final String INT_PARAM_ERROR = "Invalid interva";
private static final int INT_PARAM_TYPE_MAX_SIZE = 2;
private static final int INT_PARAM_SIZE_SUBSCRIPT_MIN = 0;
private static final int INT_PARAM_SIZE_SUBSCRIPT_MAX = 0;
private static final int STRING_SIZE = 2;
private static final char STRING_TYPE_END = '}';
private static final char STRING_TYPE_BEGIN = '{';
private static final char STRING_EMPTY_DOUBLE_CHARACTER = '"';
private static final char STRING_EMPTY_SINGLE_CHARACTER = '\'';
private static ParamValidSupport mInstance;
private ParamValidSupport() {
}
public static ParamValidSupport get() {
if (mInstance == null) {
synchronized (ParamValidSupport.class) {
if (mInstance == null) {
mInstance = new ParamValidSupport();
}
}
}
return mInstance;
}
/**
* 校驗
*/
public List<String> validate(String className, String methodName,
Class<?> annotationClass, Object[] args)
throws NotFoundException, NoSuchMethodException, ClassNotFoundException {
if (StringUtils.isBlank(className)) {
return null;
}
if (StringUtils.isBlank(methodName)) {
return null;
}
if (annotationClass == null) {
return null;
}
ClassPool pool = ClassPool.getDefault();
CtClass ct = pool.get(className);
CtMethod ctMethod = ct.getDeclaredMethod(methodName);
Object[][] parameterAnnotations = ctMethod.getParameterAnnotations();
List<String> errorLists = new ArrayList<>();
for (int i = 0; i < parameterAnnotations.length; i++) {
Object[] parameterAnnotation = parameterAnnotations[i];
Object param = args[i];
for (Object object : parameterAnnotation) {
Annotation annotation = (Annotation) object;
Class<? extends Annotation> aClass = annotation.annotationType();
if (aClass.equals(annotationClass)) {
boolean isEmpty = ((ParameterValid) object).isEmpty();
if (isEmpty) {
ParameterValid parameterValid = (ParameterValid) object;
String errorMsg = parameterValid.msg();
if (Integer.class.isAssignableFrom(param.getClass())){
int paramInt = (int) param;
if (parameterValid.isMin() && paramInt < parameterValid.min()) {
errorLists.add(errorMsg);
}
if (parameterValid.isMax() && paramInt < parameterValid.max()) {
errorLists.add(errorMsg);
}
if (parameterValid.isSection()) {
int[] section = parameterValid.section();
if (section.length != INT_PARAM_TYPE_MAX_SIZE) {
logger.error(INT_PARAM_ERROR);
throw new ParameterValidException(INT_PARAM_ERROR);
}
if (!(paramInt > section[INT_PARAM_SIZE_SUBSCRIPT_MIN] && paramInt < section[INT_PARAM_SIZE_SUBSCRIPT_MAX])) {
errorLists.add(errorMsg);
} else if (!(paramInt > section[INT_PARAM_SIZE_SUBSCRIPT_MAX] && paramInt < section[INT_PARAM_SIZE_SUBSCRIPT_MIN])) {
errorLists.add(errorMsg);
}
}
}
if (String.class.isAssignableFrom(param.getClass())){
String paramStr = (String) param;
if (parameterValid.isNull()) {
if (StringUtils.isEmpty(paramStr)) {
errorLists.add(errorMsg);
}
} else {
if (parameterValid.isBlank()) {
if (StringUtils.isBlank(paramStr)) {
errorLists.add(errorMsg);
} else {
int length = paramStr.length();
char begin = paramStr.charAt(0);
char end = paramStr.charAt(length - 1);
if (STRING_TYPE_BEGIN == begin &&
STRING_TYPE_END == end) {
errorLists.add(errorMsg);
}
if (length == STRING_SIZE && STRING_EMPTY_DOUBLE_CHARACTER == begin
&& STRING_EMPTY_DOUBLE_CHARACTER == end) {
errorLists.add(errorMsg);
}
if (length == STRING_SIZE && STRING_EMPTY_SINGLE_CHARACTER == begin
&& STRING_EMPTY_SINGLE_CHARACTER == end) {
errorLists.add(errorMsg);
}
}
}
}
}
}
}
}
}
if (errorLists.size() != 0) {
return errorLists;
}
return null;
}
}
複製程式碼2.4 測試結果
