一、hibernate-validator 使用
1. maven 依赖
<dependencies>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-validator</artifactId>
<version>6.0.9.Final</version>
</dependency>
<dependency>
<groupId>org.glassfish</groupId>
<artifactId>jakarta.el</artifactId>
<version>3.0.3</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.22</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
</dependencies>2.示例
@AllArgsConstructor
public class Student {
@NotNull(message = "student id不能为空")
private Integer id;
@NotBlank(message = "student 姓名不能为空")
private String name;
@NotNull(message = "student 年龄不能为空")
@Min(value = 1, message = "student 年龄最小值不能小于1")
@Max(value = 200, message = "student 年龄最大值不能大于200")
private Integer age;
}
@AllArgsConstructor
public class School {
@NotNull(message = "school id不能为空")
private Integer id;
@NotBlank(message = "school 姓名不能为空")
private String name;
@Valid
@NotNull(message = "school student 不能为空")
private Student student;
public void setName(@NotBlank(message = "school 参数姓名不能为空") String name) {
this.name = name;
}
public void setStudent(@Valid Student student) {
this.student = student;
}
}测试类
@Test
public void testStudent() {
Student student = new Student(null, null, 800);
ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
Validator validator = factory.getValidator();
// 校验bean的所有约束
Set<ConstraintViolation<Student>> constraintViolation1 = validator.validate(student);
// 校验bean的单个字段
Set<ConstraintViolation<Student>> constraintViolation2 = validator.validateProperty(student, "name");
// 校验bean的单个字段
Set<ConstraintViolation<Student>> constraintViolation3
= validator.validateValue(Student.class, "age", 0);
System.out.println("- - -");
constraintViolation1.forEach(con -> System.out.println(con.getMessage()));
System.out.println("- - -");
constraintViolation2.forEach(con -> System.out.println(con.getMessage()));
System.out.println("- - -");
constraintViolation3.forEach(con -> System.out.println(con.getMessage()));
}
@Test
public void testSchool() throws NoSuchMethodException {
School school = new School(null, null, new Student(null, null, 800));
ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
Validator validator = factory.getValidator();
// 校验bean的所有约束
Set<ConstraintViolation<School>> constraintViolation1 = validator.validate(school);
// 校验方法参数
Set<ConstraintViolation<School>> constraintViolation2
= validator.forExecutables()
.validateParameters(school, School.class.getMethod("setName", String.class), new Object[]{null});
Set<ConstraintViolation<School>> constraintViolation3
= validator.forExecutables()
.validateParameters(school, School.class.getMethod("setStudent", Student.class),
new Object[]{new Student(null, null, 800)});
System.out.println("- - -");
constraintViolation1.forEach(con -> System.out.println(con.getMessage()));
System.out.println("- - -");
constraintViolation2.forEach(con -> System.out.println(con.getMessage()));
System.out.println("- - -");
constraintViolation3.forEach(con -> System.out.println(con.getMessage()));
}testStudent 结果:
- - -
student 姓名不能为空
student id不能为空
student 年龄最大值不能大于200
- - -
student 姓名不能为空
- - -
student 年龄最小值不能小于1testSchool 结果:
- - -
school 姓名不能为空
student 姓名不能为空
school id不能为空
student id不能为空
student 年龄最大值不能大于200
- - -
school 参数姓名不能为空
- - -
student 姓名不能为空
student id不能为空
student 年龄最大值不能大于200二、spring 使用 hibernate-validator
1. maven 依赖
<properties>
<spring.version>5.1.9.RELEASE</spring.version>
</properties>
<dependencies>
<!-- spring core -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-expression</artifactId>
<version>${spring.version}</version>
</dependency>
<!-- spring aop -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aspects</artifactId>
<version>${spring.version}</version>
</dependency>
<!-- validator -->
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-validator</artifactId>
<version>6.0.9.Final</version>
</dependency>
<dependency>
<groupId>org.glassfish</groupId>
<artifactId>jakarta.el</artifactId>
<version>3.0.3</version>
</dependency>
<!-- lombok -->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.22</version>
<scope>provided</scope>
</dependency>
<!-- junit -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
</dependencies>2.示例
bean 类
import lombok.AllArgsConstructor;
import javax.validation.constraints.Max;
import javax.validation.constraints.Min;
import javax.validation.constraints.NotBlank;
import javax.validation.constraints.NotNull;
@AllArgsConstructor
public class Person {
@NotNull(message = "id不能为空")
private Integer id;
@NotBlank(message = "姓名不能为空")
private String name;
@NotNull(message = "年龄不能为空")
@Min(value = 1, message = "年龄最小值不能小于1")
@Max(value = 200, message = "年龄最大值不能大于200")
private Integer age;
public void setName(@NotBlank(message = "参数姓名不能为空") String name) {
this.name = name;
}
}service 层
import org.springframework.validation.annotation.Validated;
import javax.validation.Valid;
@Validated
public interface PersonService {
Boolean create(@Valid Person person);
}import org.springframework.stereotype.Service;
@Service
public class PersonServiceImpl implements PersonService {
@Override
public Boolean create(Person person) {
return true;
}
}配置类
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.validation.beanvalidation.MethodValidationPostProcessor;
import javax.validation.Validation;
import javax.validation.Validator;
import javax.validation.ValidatorFactory;
@Configuration
public class BeanConfig {
@Bean
public PersonService personService() {
return new PersonServiceImpl();
}
@Bean
public static MethodValidationPostProcessor methodValidationPostProcessor() {
ValidatorFactory validatorFactory = Validation.buildDefaultValidatorFactory();
Validator validator = validatorFactory.getValidator();
MethodValidationPostProcessor processor = new MethodValidationPostProcessor();
// 相当于 <aop:config proxy-target-class="false">
processor.setProxyTargetClass(false);
processor.setValidator(validator);
return processor;
}
}测试类
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
public class ValidatorTest {
@Test
public void test() {
ApplicationContext context = new AnnotationConfigApplicationContext(BeanConfig.class);
PersonService personService = context.getBean(PersonService.class);
Person p = new Person(null, null, 800);
Boolean flag = personService.create(p);
System.out.println(flag);
}
}3.原理
3.1 创建代理对象
MethodValidationPostProcessor 继承 AbstractAdvisingBeanPostProcessor，在 spring 在实例化每个 bean的同时，执行 AbstractAdvisingBeanPostProcessor 的 postProcessAfterInitialization 方法
@Validated标注的类，形成切点
Advisor advisor 值为 DefaultPointcutAdvisor
// MethodValidationPostProcessor.java
private Class<? extends Annotation> validatedAnnotationType = Validated.class;
@Nullable
private Validator validator;
@Override
public void afterPropertiesSet() {
Pointcut pointcut = new AnnotationMatchingPointcut(this.validatedAnnotationType, true);
this.advisor = new DefaultPointcutAdvisor(pointcut, createMethodValidationAdvice(this.validator));
}
protected Advice createMethodValidationAdvice(@Nullable Validator validator) {
return (validator != null ? new MethodValidationInterceptor(validator) : new MethodValidationInterceptor());
}// AbstractAdvisingBeanPostProcessor.java
@Override
public Object postProcessAfterInitialization(Object bean, String beanName) {
if (this.advisor == null || bean instanceof AopInfrastructureBean) {
// Ignore AOP infrastructure such as scoped proxies.
return bean;
}
if (bean instanceof Advised) {
Advised advised = (Advised) bean;
if (!advised.isFrozen() && isEligible(AopUtils.getTargetClass(bean))) {
// Add our local Advisor to the existing proxy's Advisor chain...
if (this.beforeExistingAdvisors) {
advised.addAdvisor(0, this.advisor);
}
else {
advised.addAdvisor(this.advisor);
}
return bean;
}
}
if (isEligible(bean, beanName)) {
ProxyFactory proxyFactory = prepareProxyFactory(bean, beanName);
if (!proxyFactory.isProxyTargetClass()) {
evaluateProxyInterfaces(bean.getClass(), proxyFactory);
}
proxyFactory.addAdvisor(this.advisor);
customizeProxyFactory(proxyFactory);
return proxyFactory.getProxy(getProxyClassLoader());
}
// No proxy needed.
return bean;
}创建代理
// ProxyFactory
public Object getProxy(@Nullable ClassLoader classLoader) {
return createAopProxy().getProxy(classLoader);
}config 是 ProxyFactory
// DefaultAopProxyFactory.java
@Override
public AopProxy createAopProxy(AdvisedSupport config) throws AopConfigException {
if (config.isOptimize() || config.isProxyTargetClass() || hasNoUserSuppliedProxyInterfaces(config)) {
Class<?> targetClass = config.getTargetClass();
if (targetClass == null) {
throw new AopConfigException("TargetSource cannot determine target class: " +
"Either an interface or a target is required for proxy creation.");
}
if (targetClass.isInterface() || Proxy.isProxyClass(targetClass)) {
return new JdkDynamicAopProxy(config);
}
return new ObjenesisCglibAopProxy(config);
}
else {
return new JdkDynamicAopProxy(config);
}
}3.2 代理拦截
从 spring 拿到 bean，调用 bean 方法时候，会调用 JdkDynamicAopProxy 的 invoke 方法
// JdkDynamicAopProxy.java
@Override
@Nullable
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
Object oldProxy = null;
boolean setProxyContext = false;
TargetSource targetSource = this.advised.targetSource;
Object target = null;
try {
if (!this.equalsDefined && AopUtils.isEqualsMethod(method)) {
// The target does not implement the equals(Object) method itself.
return equals(args[0]);
}
else if (!this.hashCodeDefined && AopUtils.isHashCodeMethod(method)) {
// The target does not implement the hashCode() method itself.
return hashCode();
}
else if (method.getDeclaringClass() == DecoratingProxy.class) {
// There is only getDecoratedClass() declared -> dispatch to proxy config.
return AopProxyUtils.ultimateTargetClass(this.advised);
}
else if (!this.advised.opaque && method.getDeclaringClass().isInterface() &&
method.getDeclaringClass().isAssignableFrom(Advised.class)) {
// Service invocations on ProxyConfig with the proxy config...
return AopUtils.invokeJoinpointUsingReflection(this.advised, method, args);
}
Object retVal;
if (this.advised.exposeProxy) {
// Make invocation available if necessary.
oldProxy = AopContext.setCurrentProxy(proxy);
setProxyContext = true;
}
// Get as late as possible to minimize the time we "own" the target,
// in case it comes from a pool.
target = targetSource.getTarget();
Class<?> targetClass = (target != null ? target.getClass() : null);
// Get the interception chain for this method.
List<Object> chain = this.advised.getInterceptorsAndDynamicInterceptionAdvice(method, targetClass);
// Check whether we have any advice. If we don't, we can fallback on direct
// reflective invocation of the target, and avoid creating a MethodInvocation.
if (chain.isEmpty()) {
// We can skip creating a MethodInvocation: just invoke the target directly
// Note that the final invoker must be an InvokerInterceptor so we know it does
// nothing but a reflective operation on the target, and no hot swapping or fancy proxying.
Object[] argsToUse = AopProxyUtils.adaptArgumentsIfNecessary(method, args);
retVal = AopUtils.invokeJoinpointUsingReflection(target, method, argsToUse);
}
else {
// We need to create a method invocation...
MethodInvocation invocation =
new ReflectiveMethodInvocation(proxy, target, method, args, targetClass, chain);
// Proceed to the joinpoint through the interceptor chain.
retVal = invocation.proceed();
}
// Massage return value if necessary.
Class<?> returnType = method.getReturnType();
if (retVal != null && retVal == target &&
returnType != Object.class && returnType.isInstance(proxy) &&
!RawTargetAccess.class.isAssignableFrom(method.getDeclaringClass())) {
// Special case: it returned "this" and the return type of the method
// is type-compatible. Note that we can't help if the target sets
// a reference to itself in another returned object.
retVal = proxy;
}
else if (retVal == null && returnType != Void.TYPE && returnType.isPrimitive()) {
throw new AopInvocationException(
"Null return value from advice does not match primitive return type for: " + method);
}
return retVal;
}
finally {
if (target != null && !targetSource.isStatic()) {
// Must have come from TargetSource.
targetSource.releaseTarget(target);
}
if (setProxyContext) {
// Restore old proxy.
AopContext.setCurrentProxy(oldProxy);
}
}
}// AdvisedSupport.java
public List<Object> getInterceptorsAndDynamicInterceptionAdvice(Method method, @Nullable Class<?> targetClass) {
MethodCacheKey cacheKey = new MethodCacheKey(method);
List<Object> cached = this.methodCache.get(cacheKey);
if (cached == null) {
cached = this.advisorChainFactory.getInterceptorsAndDynamicInterceptionAdvice(
this, method, targetClass);
this.methodCache.put(cacheKey, cached);
}
return cached;
}advisors 有：DefaultPointcutAdvisor
取出 advisor 的 advice ；如果 advice 继承 MethodInterceptor，则放到 interceptors 中；继续看 advice 是否继承 MethodBeforeAdvice、AfterReturningAdvice、ThrowsAdvice，如果符合，包装成 MethodBeforeAdviceInterceptor(advice)、AfterReturningAdviceInterceptor(advice)、ThrowsAdviceInterceptor(advice)
- DefaultPointcutAdvisor 的 MethodValidationInterceptor
// DefaultAdvisorChainFactory.java
@Override
public List<Object> getInterceptorsAndDynamicInterceptionAdvice(
Advised config, Method method, @Nullable Class<?> targetClass) {
// This is somewhat tricky... We have to process introductions first,
// but we need to preserve order in the ultimate list.
AdvisorAdapterRegistry registry = GlobalAdvisorAdapterRegistry.getInstance();
Advisor[] advisors = config.getAdvisors();
List<Object> interceptorList = new ArrayList<>(advisors.length);
Class<?> actualClass = (targetClass != null ? targetClass : method.getDeclaringClass());
Boolean hasIntroductions = null;
for (Advisor advisor : advisors) {
if (advisor instanceof PointcutAdvisor) {
// Add it conditionally.
PointcutAdvisor pointcutAdvisor = (PointcutAdvisor) advisor;
if (config.isPreFiltered() || pointcutAdvisor.getPointcut().getClassFilter().matches(actualClass)) {
MethodMatcher mm = pointcutAdvisor.getPointcut().getMethodMatcher();
boolean match;
if (mm instanceof IntroductionAwareMethodMatcher) {
if (hasIntroductions == null) {
hasIntroductions = hasMatchingIntroductions(advisors, actualClass);
}
match = ((IntroductionAwareMethodMatcher) mm).matches(method, actualClass, hasIntroductions);
}
else {
match = mm.matches(method, actualClass);
}
if (match) {
MethodInterceptor[] interceptors = registry.getInterceptors(advisor);
if (mm.isRuntime()) {
// Creating a new object instance in the getInterceptors() method
// isn't a problem as we normally cache created chains.
for (MethodInterceptor interceptor : interceptors) {
interceptorList.add(new InterceptorAndDynamicMethodMatcher(interceptor, mm));
}
}
else {
interceptorList.addAll(Arrays.asList(interceptors));
}
}
}
}
else if (advisor instanceof IntroductionAdvisor) {
IntroductionAdvisor ia = (IntroductionAdvisor) advisor;
if (config.isPreFiltered() || ia.getClassFilter().matches(actualClass)) {
Interceptor[] interceptors = registry.getInterceptors(advisor);
interceptorList.addAll(Arrays.asList(interceptors));
}
}
else {
Interceptor[] interceptors = registry.getInterceptors(advisor);
interceptorList.addAll(Arrays.asList(interceptors));
}
}
return interceptorList;
}// DefaultAdvisorAdapterRegistry.java
public DefaultAdvisorAdapterRegistry() {
registerAdvisorAdapter(new MethodBeforeAdviceAdapter());
registerAdvisorAdapter(new AfterReturningAdviceAdapter());
registerAdvisorAdapter(new ThrowsAdviceAdapter());
}
@Override
public MethodInterceptor[] getInterceptors(Advisor advisor) throws UnknownAdviceTypeException {
List<MethodInterceptor> interceptors = new ArrayList<>(3);
Advice advice = advisor.getAdvice();
if (advice instanceof MethodInterceptor) {
interceptors.add((MethodInterceptor) advice);
}
for (AdvisorAdapter adapter : this.adapters) {
if (adapter.supportsAdvice(advice)) {
interceptors.add(adapter.getInterceptor(advisor));
}
}
if (interceptors.isEmpty()) {
throw new UnknownAdviceTypeException(advisor.getAdvice());
}
return interceptors.toArray(new MethodInterceptor[0]);
}ReflectiveMethodInvocation 执行拦截器链
// ReflectiveMethodInvocation.java
@Override
@Nullable
public Object proceed() throws Throwable {
// We start with an index of -1 and increment early.
if (this.currentInterceptorIndex == this.interceptorsAndDynamicMethodMatchers.size() - 1) {
return invokeJoinpoint();
}
Object interceptorOrInterceptionAdvice =
this.interceptorsAndDynamicMethodMatchers.get(++this.currentInterceptorIndex);
if (interceptorOrInterceptionAdvice instanceof InterceptorAndDynamicMethodMatcher) {
// Evaluate dynamic method matcher here: static part will already have
// been evaluated and found to match.
InterceptorAndDynamicMethodMatcher dm =
(InterceptorAndDynamicMethodMatcher) interceptorOrInterceptionAdvice;
Class<?> targetClass = (this.targetClass != null ? this.targetClass : this.method.getDeclaringClass());
if (dm.methodMatcher.matches(this.method, targetClass, this.arguments)) {
return dm.interceptor.invoke(this);
}
else {
// Dynamic matching failed.
// Skip this interceptor and invoke the next in the chain.
return proceed();
}
}
else {
// It's an interceptor, so we just invoke it: The pointcut will have
// been evaluated statically before this object was constructed.
return ((MethodInterceptor) interceptorOrInterceptionAdvice).invoke(this);
}
}通过每个拦截器，链式调用
使用 ExecutableValidator 的 validateParameters 方法 校验参数
// MethodValidationInterceptor.java
@Override
@SuppressWarnings("unchecked")
public Object invoke(MethodInvocation invocation) throws Throwable {
// Avoid Validator invocation on FactoryBean.getObjectType/isSingleton
if (isFactoryBeanMetadataMethod(invocation.getMethod())) {
return invocation.proceed();
}
Class<?>[] groups = determineValidationGroups(invocation);
// Standard Bean Validation 1.1 API
ExecutableValidator execVal = this.validator.forExecutables();
Method methodToValidate = invocation.getMethod();
Set<ConstraintViolation<Object>> result;
try {
result = execVal.validateParameters(
invocation.getThis(), methodToValidate, invocation.getArguments(), groups);
}
catch (IllegalArgumentException ex) {
// Probably a generic type mismatch between interface and impl as reported in SPR-12237 / HV-1011
// Let's try to find the bridged method on the implementation class...
methodToValidate = BridgeMethodResolver.findBridgedMethod(
ClassUtils.getMostSpecificMethod(invocation.getMethod(), invocation.getThis().getClass()));
result = execVal.validateParameters(
invocation.getThis(), methodToValidate, invocation.getArguments(), groups);
}
if (!result.isEmpty()) {
throw new ConstraintViolationException(result);
}
Object returnValue = invocation.proceed();
result = execVal.validateReturnValue(invocation.getThis(), methodToValidate, returnValue, groups);
if (!result.isEmpty()) {
throw new ConstraintViolationException(result);
}
return returnValue;
}