Springboot源码 TargetSource解析

 public class SingletonTargetSource implements TargetSource, Serializable {  /** Target cached and invoked using reflection. */ private final Object target; //省略无关代码...... @Override public Object getTarget() {  return this.target; } //省略无关代码...... }

 public class PrototypeTargetSource extends AbstractPrototypeBasedTargetSource {  /** * Obtain a new prototype instance for every call. * @see #newPrototypeInstance() */ @Override public Object getTarget() throws BeansException {  return newPrototypeInstance(); }  /** * Destroy the given independent instance. * @see #destroyPrototypeInstance */ @Override public void releaseTarget(Object target) {  destroyPrototypeInstance(target); } //省略无关代码...... }

 public abstract class AbstractPrototypeBasedTargetSource extends AbstractBeanFactoryBasedTargetSource {  //省略无关代码...... /** * Subclasses should call this method to create a new prototype instance. * @throws BeansException if bean creation failed */ protected Object newPrototypeInstance() throws BeansException {  if (logger.isDebugEnabled()) {  logger.debug("Creating new instance of bean '" + getTargetBeanName() + "'");  }  return getBeanFactory().getBean(getTargetBeanName()); }  /** * Subclasses should call this method to destroy an obsolete prototype instance. * @param target the bean instance to destroy */ protected void destroyPrototypeInstance(Object target) {  if (logger.isDebugEnabled()) {  logger.debug("Destroying instance of bean '" + getTargetBeanName() + "'");  }  if (getBeanFactory() instanceof ConfigurableBeanFactory) {  ((ConfigurableBeanFactory) getBeanFactory()).destroyBean(getTargetBeanName(), target);  }  else if (target instanceof DisposableBean) {  try {  ((DisposableBean) target).destroy();  }  catch (Throwable ex) {  logger.warn("Destroy method on bean with name '" + getTargetBeanName() + "' threw an exception", ex);  }  } }  //省略无关代码......  }

 public class ThreadLocalTargetSource extends AbstractPrototypeBasedTargetSource  implements ThreadLocalTargetSourceStats, DisposableBean {  /** * ThreadLocal holding the target associated with the current * thread. Unlike most ThreadLocals, which are static, this variable * is meant to be per thread per instance of the ThreadLocalTargetSource class. */ private final ThreadLocal<Object> targetInThread =  new NamedThreadLocal<>("Thread-local instance of bean '" + getTargetBeanName() + "'");  /** * Set of managed targets, enabling us to keep track of the targets we've created. */ private final Set<Object> targetSet = new HashSet<>();  //省略无关代码...... /** * Implementation of abstract getTarget() method. * We look for a target held in a ThreadLocal. If we don't find one, * we create one and bind it to the thread. No synchronization is required. */ @Override public Object getTarget() throws BeansException {  ++this.invocationCount;  Object target = this.targetInThread.get();  if (target == null) {  if (logger.isDebugEnabled()) {  logger.debug("No target for prototype '" + getTargetBeanName() + "' bound to thread: " +   "creating one and binding it to thread '" + Thread.currentThread().getName() + "'");  }  // Associate target with ThreadLocal.  target = newPrototypeInstance();  this.targetInThread.set(target);  synchronized (this.targetSet) {  this.targetSet.add(target);  }  }  else {  ++this.hitCount;  }  return target; }  /** * Dispose of targets if necessary; clear ThreadLocal. * @see #destroyPrototypeInstance */ @Override public void destroy() {  logger.debug("Destroying ThreadLocalTargetSource bindings");  synchronized (this.targetSet) {  for (Object target : this.targetSet) {  destroyPrototypeInstance(target);  }  this.targetSet.clear();  }  // Clear ThreadLocal, just in case.  this.targetInThread.remove(); } //省略无关代码...... }

 package com.github.dqqzj.springboot.target;  import org.springframework.aop.TargetSource; import org.springframework.util.Assert;  import java.lang.reflect.Array; import java.util.concurrent.ThreadLocalRandom; import java.util.concurrent.atomic.AtomicInteger;  /** * @author qinzhongjian * @date created in 2019-08-25 12:43 * @description: TODO * @since JDK 1.8.0_212-b10z */ public class DqqzjTargetSource implements TargetSource { private final AtomicInteger idx = new AtomicInteger(); private final Object[] target;; public DqqzjTargetSource(Object[] target) {  Assert.notNull(target, "Target object must not be null");  this.target = target; } @Override public Class<?> getTargetClass() {  return target.getClass(); }  @Override public boolean isStatic() {  return false; }  @Override public Object getTarget() throws Exception {  return this.target[this.idx.getAndIncrement() & this.target.length - 1]; }  @Override public void releaseTarget(Object target) throws Exception {  } }