spring boot 動態代理選擇

 1 public class DefaultAopProxyFactory implements AopProxyFactory, Serializable {
 2 
 3     @Override
 4     public AopProxy createAopProxy(AdvisedSupport config) throws AopConfigException {
 5         if (config.isOptimize() || config.isProxyTargetClass() || hasNoUserSuppliedProxyInterfaces(config)) {
 6             Class<?> targetClass = config.getTargetClass();
 7             if (targetClass == null) {
 8                 throw new AopConfigException("TargetSource cannot determine target class: " +
 9                         "Either an interface or a target is required for proxy creation.");
10             }
11             if (targetClass.isInterface() || Proxy.isProxyClass(targetClass)) {
12                 return new JdkDynamicAopProxy(config);
13             }
14             return new ObjenesisCglibAopProxy(config);
15         }
16         else {
17             return new JdkDynamicAopProxy(config);
18         }
19     }
20 
21     /**
22      * Determine whether the supplied {@link AdvisedSupport} has only the
23      * {@link org.springframework.aop.SpringProxy} interface specified
24      * (or no proxy interfaces specified at all).
25      */
26     private boolean hasNoUserSuppliedProxyInterfaces(AdvisedSupport config) {
27         Class<?>[] ifcs = config.getProxiedInterfaces();
28         return (ifcs.length == 0 || (ifcs.length == 1 && SpringProxy.class.isAssignableFrom(ifcs[0])));
29     }
30 
31 }

spring 動態代理有jdk和Cglib兩種方式，具體選擇是在DefaultAopProxyFactory這個類裏面進行選擇的。

若是AOP使用顯式優化，或者配置了目標類，或者只使用Spring支持的代理接口執行第一個分支，不然使用JDK動態代理。第一個分支若是代理類是接口或者能夠被JDK動態代理使用JDK動態代理，不然使用CGLIB。