Spring AOP創(chuàng)建代理對(duì)象源碼解析
1 工程簡(jiǎn)介
1.1 pom
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
<spring.version>5.2.8.RELEASE</spring.version>
</properties>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.13</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.16.20</version>
</dependency>
<!-- 日志相關(guān)依賴 -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.10</version>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>1.1.2</version>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-core</artifactId>
<version>1.1.2</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aspects</artifactId>
<version>${spring.version}</version>
</dependency>
</dependencies>1.2 AOP配置文件
@Configuration
@EnableAspectJAutoProxy
@Import({ServiceAopConfig.class, DaoAopConfig.class})
public class AopConfig {
}
@Configuration
@Aspect
public class DaoAopConfig {
/**
* 聲明切點(diǎn)
*/
@Pointcut("execution(* com.rosh.dao.*.*(..))")
public void pointCut() {
}
@Around("pointCut()")
public Object around(ProceedingJoinPoint proceedingJoinPoint) throws Throwable {
System.out.println("DaoAopConfig invoke around start");
Object proceed = proceedingJoinPoint.proceed();
System.out.println("DaoAopConfig invoke around end");
return proceed;
}
}
@Configuration
@Aspect
public class ServiceAopConfig {
/**
* 聲明切點(diǎn)
*/
@Pointcut("execution(* com.rosh.service.*.*(..))")
public void pointCut() {
}
@Around("pointCut()")
public Object around(ProceedingJoinPoint proceedingJoinPoint) throws Throwable {
System.out.println("ServiceAopConfig invoke around start");
Object proceed = proceedingJoinPoint.proceed();
System.out.println("ServiceAopConfig invoke around end");
return proceed;
}
@Before("pointCut()")
public void before(){
System.out.println("ServiceAopConfig invoke before");
}
@After("pointCut()")
public void after() {
System.out.println("ServiceAopConfig invoke after");
}
}1.3 StudentDao
@Repository
public class StudentDao {
public void addStudent() {
System.out.println("StudentDao invoke addStudent");
}
}1.4 Service
public interface StudentService {
void addStudent();
}
@Service
public class StudentServiceImpl implements StudentService {
@Override
public void addStudent() {
System.out.println("StudentServiceImpl invoke addStudent()");
}
}1.5 RoshTest
public class RoshTest {
@Test
public void mainTest(){
AnnotationConfigApplicationContext applicationContext=new AnnotationConfigApplicationContext("com.rosh");
StudentService studentService = (StudentService) applicationContext.getBean("studentServiceImpl");
studentService.addStudent();
System.out.println("===============分割線================");
StudentDao studentDao=(StudentDao) applicationContext.getBean("studentDao");
studentDao.addStudent();
}
}
2 AbstractAutoProxyCreator概述
描述：該類作用在，Spring Aop初始化源碼分析中具體分析過，核心作用是，在bean初始化時(shí)，后置加強(qiáng)。
protected Object wrapIfNecessary(Object bean, String beanName, Object cacheKey) {
if (StringUtils.hasLength(beanName) && this.targetSourcedBeans.contains(beanName)) {
return bean;
}
if (Boolean.FALSE.equals(this.advisedBeans.get(cacheKey))) {
return bean;
}
if (isInfrastructureClass(bean.getClass()) || shouldSkip(bean.getClass(), beanName)) {
this.advisedBeans.put(cacheKey, Boolean.FALSE);
return bean;
}
// Create proxy if we have advice.
/**
* 【1】獲取當(dāng)前bean有效的Advisor，Advisor = advice + pointCut
*/
Object[] specificInterceptors = getAdvicesAndAdvisorsForBean(bean.getClass(), beanName, null);
if (specificInterceptors != DO_NOT_PROXY) {
this.advisedBeans.put(cacheKey, Boolean.TRUE);
/**
* 【2】創(chuàng)建代理對(duì)象
*/
Object proxy = createProxy(
bean.getClass(), beanName, specificInterceptors, new SingletonTargetSource(bean));
this.proxyTypes.put(cacheKey, proxy.getClass());
return proxy;
}
this.advisedBeans.put(cacheKey, Boolean.FALSE);
return bean;
}3 創(chuàng)建代理對(duì)象源碼解析
3.1 createProxy
描述：主流程調(diào)用方法AbstractAutoProxyCreator類createProxy 方法。
protected Object createProxy(Class<?> beanClass, @Nullable String beanName,
@Nullable Object[] specificInterceptors, TargetSource targetSource) {
if (this.beanFactory instanceof ConfigurableListableBeanFactory) {
AutoProxyUtils.exposeTargetClass((ConfigurableListableBeanFactory) this.beanFactory, beanName, beanClass);
}
/**
* 【1】創(chuàng)建代理工廠，賦值。
*/
ProxyFactory proxyFactory = new ProxyFactory();
proxyFactory.copyFrom(this);
/**
* 【2】 proxyTargetClass為true時(shí)代表使用cglib，為false使用jdk，默認(rèn)值是false。
* 判斷當(dāng)前被代理對(duì)象是使用jdk增強(qiáng)還是使用cglib增強(qiáng)
*
*/
if (!proxyFactory.isProxyTargetClass()) {
//根據(jù)最開始@EnableAspectJAutoProxy注解中的proxyTargetClass參數(shù)判斷是否應(yīng)該使用cglib代理
if (shouldProxyTargetClass(beanClass, beanName)) {
proxyFactory.setProxyTargetClass(true);
}
else {
//如果是接口增強(qiáng)那么使用jdk，否則使用cglib
evaluateProxyInterfaces(beanClass, proxyFactory);
}
}
//構(gòu)建advisor
Advisor[] advisors = buildAdvisors(beanName, specificInterceptors);
//把a(bǔ)dvisor加入到代理工廠中
proxyFactory.addAdvisors(advisors);
//把targetSource對(duì)象加入代理工廠(實(shí)際對(duì)象、被代理對(duì)象)
proxyFactory.setTargetSource(targetSource);
customizeProxyFactory(proxyFactory);
proxyFactory.setFrozen(this.freezeProxy);
if (advisorsPreFiltered()) {
proxyFactory.setPreFiltered(true);
}
/**
* 【3】 獲取代理對(duì)象
*/
return proxyFactory.getProxy(getProxyClassLoader());
}3.2 ProxyFactory 獲取代理對(duì)象
描述：先獲取AOP代理
public Object getProxy(@Nullable ClassLoader classLoader) {
/**
* 創(chuàng)建AOP代理（JDK、CGLIB）并且獲得代理對(duì)象
*/
return createAopProxy().getProxy(classLoader);
}protected final synchronized AopProxy createAopProxy() {
if (!this.active) {
activate();
}
return getAopProxyFactory().createAopProxy(this);
}@Override
public AopProxy createAopProxy(AdvisedSupport config) throws AopConfigException {
if (config.isOptimize() || config.isProxyTargetClass() || hasNoUserSuppliedProxyInterfaces(config)) {
// 如果targetClass是接口類，使用JDK來生成Proxy
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);
}
// 如果不是接口類，使用CGLIB生成Proxy
return new ObjenesisCglibAopProxy(config);
}
else {
return new JdkDynamicAopProxy(config);
}
}3.3 根據(jù)AOP不同的代理獲取代理對(duì)象
4 StudentDao 代理Debug
描述：每個(gè)代理對(duì)象都對(duì)應(yīng)一個(gè)代理工廠，工廠是new 創(chuàng)建的。
描述：選擇cglib、jdk代理生成代理對(duì)象。
描述：創(chuàng)建AOP代理。
描述：CglibAopProxy獲取代理對(duì)象。
描述：獲取到cglib增強(qiáng)代理對(duì)象。
5 StudentServiceImpl 代理Debug
描述：StudentServiceImpl 實(shí)現(xiàn)StudentService接口使用jdk代理。
描述：AOP獲取JDK代理。
描述：獲取代理對(duì)象。
出處：https://blog.csdn.net/qq_34125999/article/details/115107521
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