简栈文化

// 忽略了无关代码
protected Object doCreateBean(final String beanName, final RootBeanDefinition mbd, final @Nullable Object[] args)
      throws BeanCreationException {

   // Instantiate the bean.
   BeanWrapper instanceWrapper = null;
   if (instanceWrapper == null) {
       // 实例化阶段！
      instanceWrapper = createBeanInstance(beanName, mbd, args);
   }

   // Initialize the bean instance.
   Object exposedObject = bean;
   try {
       // 属性赋值阶段！
      populateBean(beanName, mbd, instanceWrapper);
       // 初始化阶段！
      exposedObject = initializeBean(beanName, exposedObject, mbd);
   }
}

@Override
protected Object createBean(String beanName, RootBeanDefinition mbd, @Nullable Object[] args)
        throws BeanCreationException {

    try {
        // Give BeanPostProcessors a chance to return a proxy instead of the target bean instance.
        // postProcessBeforeInstantiation方法调用点，这里就不跟进了，
        // 有兴趣的同学可以自己看下，就是for循环调用所有的InstantiationAwareBeanPostProcessor
        Object bean = resolveBeforeInstantiation(beanName, mbdToUse);
        if (bean != null) {
            return bean;
        }
    }
    
    try {   
        // 上文提到的doCreateBean方法，可以看到
        // postProcessBeforeInstantiation方法在创建Bean之前调用
        Object beanInstance = doCreateBean(beanName, mbdToUse, args);
        if (logger.isTraceEnabled()) {
            logger.trace("Finished creating instance of bean '" + beanName + "'");
        }
        return beanInstance;
    }  
}

protected void populateBean(String beanName, RootBeanDefinition mbd, @Nullable BeanWrapper bw) {

   // Give any InstantiationAwareBeanPostProcessors the opportunity to modify the
   // state of the bean before properties are set. This can be used, for example,
   // to support styles of field injection.
   boolean continueWithPropertyPopulation = true;
    // InstantiationAwareBeanPostProcessor#postProcessAfterInstantiation()
    // 方法作为属性赋值的前置检查条件，在属性赋值之前执行，能够影响是否进行属性赋值！
   if (!mbd.isSynthetic() && hasInstantiationAwareBeanPostProcessors()) {
      for (BeanPostProcessor bp : getBeanPostProcessors()) {
         if (bp instanceof InstantiationAwareBeanPostProcessor) {
            InstantiationAwareBeanPostProcessor ibp = (InstantiationAwareBeanPostProcessor) bp;
            if (!ibp.postProcessAfterInstantiation(bw.getWrappedInstance(), beanName)) {
               continueWithPropertyPopulation = false;
               break;
            }
         }
      }
   }
   // 忽略后续的属性赋值操作代码
}

public interface ApplicationContext extends EnvironmentCapable, ListableBeanFactory, HierarchicalBeanFactory,
        MessageSource, ApplicationEventPublisher, ResourcePatternResolver {
          
}

// 见名知意，初始化阶段调用的方法
protected Object initializeBean(final String beanName, final Object bean, @Nullable RootBeanDefinition mbd) {

    // 这里调用的是Group1中的三个Bean开头的Aware
    invokeAwareMethods(beanName, bean);

    Object wrappedBean = bean;
    
    // 这里调用的是Group2中的几个Aware，
    // 而实质上这里就是前面所说的BeanPostProcessor的调用点！
    // 也就是说与Group1中的Aware不同，这里是通过BeanPostProcessor（ApplicationContextAwareProcessor）实现的。
    wrappedBean = applyBeanPostProcessorsBeforeInitialization(wrappedBean, beanName);
    // 下文即将介绍的InitializingBean调用点
    invokeInitMethods(beanName, wrappedBean, mbd);
    // BeanPostProcessor的另一个调用点
    wrappedBean = applyBeanPostProcessorsAfterInitialization(wrappedBean, beanName);

    return wrappedBean;
}

@Override
public void refresh() throws BeansException, IllegalStateException {
    synchronized (this.startupShutdownMonitor) {

        try {
            // Allows post-processing of the bean factory in context subclasses.
            postProcessBeanFactory(beanFactory);

            // Invoke factory processors registered as beans in the context.
            invokeBeanFactoryPostProcessors(beanFactory);

            // Register bean processors that intercept bean creation.
            // 所有BeanPostProcesser初始化的调用点
            registerBeanPostProcessors(beanFactory);

            // Initialize message source for this context.
            initMessageSource();

            // Initialize event multicaster for this context.
            initApplicationEventMulticaster();

            // Initialize other special beans in specific context subclasses.
            onRefresh();

            // Check for listener beans and register them.
            registerListeners();

            // Instantiate all remaining (non-lazy-init) singletons.
            // 所有单例非懒加载Bean的调用点
            finishBeanFactoryInitialization(beanFactory);

            // Last step: publish corresponding event.
            finishRefresh();
        }

}

// First, invoke the BeanDefinitionRegistryPostProcessors that implement PriorityOrdered.
// 首先，加入实现了PriorityOrdered接口的BeanPostProcessors，顺便根据PriorityOrdered排了序
String[] postProcessorNames =
        beanFactory.getBeanNamesForType(BeanDefinitionRegistryPostProcessor.class, true, false);
for (String ppName : postProcessorNames) {
    if (beanFactory.isTypeMatch(ppName, PriorityOrdered.class)) {
        currentRegistryProcessors.add(beanFactory.getBean(ppName, BeanDefinitionRegistryPostProcessor.class));
        processedBeans.add(ppName);
    }
}
sortPostProcessors(currentRegistryProcessors, beanFactory);
registryProcessors.addAll(currentRegistryProcessors);
invokeBeanDefinitionRegistryPostProcessors(currentRegistryProcessors, registry);
currentRegistryProcessors.clear();

// Next, invoke the BeanDefinitionRegistryPostProcessors that implement Ordered.
// 然后，加入实现了Ordered接口的BeanPostProcessors，顺便根据Ordered排了序
postProcessorNames = beanFactory.getBeanNamesForType(BeanDefinitionRegistryPostProcessor.class, true, false);
for (String ppName : postProcessorNames) {
    if (!processedBeans.contains(ppName) && beanFactory.isTypeMatch(ppName, Ordered.class)) {
        currentRegistryProcessors.add(beanFactory.getBean(ppName, BeanDefinitionRegistryPostProcessor.class));
        processedBeans.add(ppName);
    }
}
sortPostProcessors(currentRegistryProcessors, beanFactory);
registryProcessors.addAll(currentRegistryProcessors);
invokeBeanDefinitionRegistryPostProcessors(currentRegistryProcessors, registry);
currentRegistryProcessors.clear();

// Finally, invoke all other BeanDefinitionRegistryPostProcessors until no further ones appear.
// 最后加入其他常规的BeanPostProcessors
boolean reiterate = true;
while (reiterate) {
    reiterate = false;
    postProcessorNames = beanFactory.getBeanNamesForType(BeanDefinitionRegistryPostProcessor.class, true, false);
    for (String ppName : postProcessorNames) {
        if (!processedBeans.contains(ppName)) {
            currentRegistryProcessors.add(beanFactory.getBean(ppName, BeanDefinitionRegistryPostProcessor.class));
            processedBeans.add(ppName);
            reiterate = true;
        }
    }
    sortPostProcessors(currentRegistryProcessors, beanFactory);
    registryProcessors.addAll(currentRegistryProcessors);
    invokeBeanDefinitionRegistryPostProcessors(currentRegistryProcessors, registry);
    currentRegistryProcessors.clear();
}

/**
 * Useful constant for the highest precedence value.
 * @see java.lang.Integer#MIN_VALUE
 */
int HIGHEST_PRECEDENCE = Integer.MIN_VALUE;

/**
 * Useful constant for the lowest precedence value.
 * @see java.lang.Integer#MAX_VALUE
 */
int LOWEST_PRECEDENCE = Integer.MAX_VALUE;

@Test
public void testSearchAgg() throws Exception {
    String mappath = "esmapper/LoanApply.xml";
    //创建加载配置文件的客户端工具，用来检索文档，单实例多线程安全
    ClientInterface clientInterface = bbossESStarter.getConfigRestClient(mappath);
    Map<String, Object> params = new HashMap<String, Object>();
    params.put("from", "2017-01-14 12:14:09");
    params.put("to", "2018-05-14 12:14:09");
    String path = index + "/" + type + "/_search";
    ESAggDatas<LongAggHit> response = clientInterface.searchAgg(path,
            "pieLoanSuccessAndGroupByProduct",
            params,
            LongAggHit.class,
            "list");
    log.info("response={}", JSONUtils.toFormatJsonString(response));
}

/**
 * Created with vernon-test
 * Description:
 * User: chenyuan
 * Date: 16/4/25
 * Time: 上午9:25
 */
public class Target {
    public String execute() {
        String message = "----------test()----------";
        System.out.println(message);
        return message;
    }
}

/**
 * Created with vernon-test
 * Description:
 * User: chenyuan
 * Date: 16/4/25
 * Time: 上午9:25
 */
public class MyMethodInterceptor  implements MethodInterceptor {

    @Override
    public Object intercept(Object obj, Method method, Object[] args, MethodProxy proxy) throws Throwable {
        System.out.println(">>>MethodInterceptor start...");
        Object result = proxy.invokeSuper(obj, args);
        System.out.println(">>>MethodInterceptor ending...");
        return "haha";
    }
}

/**
 * Created with vernon-test
 * Description:
 * User: chenyuan
 * Date: 16/4/25
 * Time: 上午9:28
 */
public class CglibProxyTest {

    public Object createProxy(Class targetClass) {
       // 第一步
       Enhancer enhancer = new Enhancer();
       // 第二步
       enhancer.setSuperclass(targetClass);
       // 第三步
       enhancer.setCallback(new MyMethodInterceptor());
       // 第四步
       return enhancer.create();
    }

    public static void main(String rags[]) {
        CglibProxyTest cglibProxyTest = new CglibProxyTest();
        Target proxyTarget = (Target) cglibProxyTest.createProxy(Target.class);
        String res = proxyTarget.execute();
        System.out.println(res);
    }

}

//以下代码省略部分内容
public Object invoke(MethodInvocation invocation) throws Throwable {
//获取事务调用的目标方法
Class<?> targetClass = (invocation.getThis() != null ? AopUtils.getTargetClass(invocation.getThis()) : null);
//执行带事务调用
return invokeWithinTransaction(invocation.getMethod(), targetClass, invocation::proceed);
}

public Object getProxy(@Nullable ClassLoader classLoader) {
		if (logger.isTraceEnabled()) {
			logger.trace("Creating CGLIB proxy: " + this.advised.getTargetSource());
		}

		try {
			Class<?> rootClass = this.advised.getTargetClass();
			Assert.state(rootClass != null, "Target class must be available for creating a CGLIB proxy");

			Class<?> proxySuperClass = rootClass;
			if (ClassUtils.isCglibProxyClass(rootClass)) {
				proxySuperClass = rootClass.getSuperclass();
				Class<?>[] additionalInterfaces = rootClass.getInterfaces();
				for (Class<?> additionalInterface : additionalInterfaces) {
					this.advised.addInterface(additionalInterface);
				}
			}

			// Validate the class, writing log messages as necessary.
			validateClassIfNecessary(proxySuperClass, classLoader);

			// 第一点：Configure CGLIB Enhancer...
			Enhancer enhancer = createEnhancer();
			if (classLoader != null) {
				enhancer.setClassLoader(classLoader);
				if (classLoader instanceof SmartClassLoader &&
						((SmartClassLoader) classLoader).isClassReloadable(proxySuperClass)) {
					enhancer.setUseCache(false);
				}
			}
      // 第二点：setSuperclass
			enhancer.setSuperclass(proxySuperClass);
			enhancer.setInterfaces(AopProxyUtils.completeProxiedInterfaces(this.advised));
			enhancer.setNamingPolicy(SpringNamingPolicy.INSTANCE);
			enhancer.setStrategy(new ClassLoaderAwareUndeclaredThrowableStrategy(classLoader));
			// 第三点：获取Callback
			Callback[] callbacks = getCallbacks(rootClass);
			Class<?>[] types = new Class<?>[callbacks.length];
			for (int x = 0; x < types.length; x++) {
				types[x] = callbacks[x].getClass();
			}
			// fixedInterceptorMap only populated at this point, after getCallbacks call above
			enhancer.setCallbackFilter(new ProxyCallbackFilter(
					this.advised.getConfigurationOnlyCopy(), this.fixedInterceptorMap, this.fixedInterceptorOffset));
			enhancer.setCallbackTypes(types);

			// Generate the proxy class and create a proxy instance.
			return createProxyClassAndInstance(enhancer, callbacks);
		}
		catch (CodeGenerationException | IllegalArgumentException ex) {
			throw new AopConfigException("Could not generate CGLIB subclass of " + this.advised.getTargetClass() +
					": Common causes of this problem include using a final class or a non-visible class",
					ex);
		}
		catch (Throwable ex) {
			// TargetSource.getTarget() failed
			throw new AopConfigException("Unexpected AOP exception", ex);
		}
	}

private Callback[] getCallbacks(Class<?> rootClass) throws Exception {
		// Parameters used for optimization choices...
		boolean exposeProxy = this.advised.isExposeProxy();
		boolean isFrozen = this.advised.isFrozen();
		boolean isStatic = this.advised.getTargetSource().isStatic();

		// Choose an "aop" interceptor (used for AOP calls).
		Callback aopInterceptor = new DynamicAdvisedInterceptor(this.advised);

		// Choose a "straight to target" interceptor. (used for calls that are
		// unadvised but can return this). May be required to expose the proxy.
		Callback targetInterceptor;
		if (exposeProxy) {
			targetInterceptor = (isStatic ?
					new StaticUnadvisedExposedInterceptor(this.advised.getTargetSource().getTarget()) :
					new DynamicUnadvisedExposedInterceptor(this.advised.getTargetSource()));
		}
		else {
			targetInterceptor = (isStatic ?
					new StaticUnadvisedInterceptor(this.advised.getTargetSource().getTarget()) :
					new DynamicUnadvisedInterceptor(this.advised.getTargetSource()));
		}

		// Choose a "direct to target" dispatcher (used for
		// unadvised calls to static targets that cannot return this).
		Callback targetDispatcher = (isStatic ?
				new StaticDispatcher(this.advised.getTargetSource().getTarget()) : new SerializableNoOp());

		Callback[] mainCallbacks = new Callback[] {
				aopInterceptor,  // for normal advice
				targetInterceptor,  // invoke target without considering advice, if optimized
				new SerializableNoOp(),  // no override for methods mapped to this
				targetDispatcher, this.advisedDispatcher,
				new EqualsInterceptor(this.advised),
				new HashCodeInterceptor(this.advised)
		};

		Callback[] callbacks;

		// If the target is a static one and the advice chain is frozen,
		// then we can make some optimizations by sending the AOP calls
		// direct to the target using the fixed chain for that method.
		if (isStatic && isFrozen) {
			Method[] methods = rootClass.getMethods();
			Callback[] fixedCallbacks = new Callback[methods.length];
			this.fixedInterceptorMap = new HashMap<>(methods.length);

			// TODO: small memory optimization here (can skip creation for methods with no advice)
			for (int x = 0; x < methods.length; x++) {
				List<Object> chain = this.advised.getInterceptorsAndDynamicInterceptionAdvice(methods[x], rootClass);
				fixedCallbacks[x] = new FixedChainStaticTargetInterceptor(
						chain, this.advised.getTargetSource().getTarget(), this.advised.getTargetClass());
				this.fixedInterceptorMap.put(methods[x].toString(), x);
			}

			// Now copy both the callbacks from mainCallbacks
			// and fixedCallbacks into the callbacks array.
			callbacks = new Callback[mainCallbacks.length + fixedCallbacks.length];
			System.arraycopy(mainCallbacks, 0, callbacks, 0, mainCallbacks.length);
			System.arraycopy(fixedCallbacks, 0, callbacks, mainCallbacks.length, fixedCallbacks.length);
			this.fixedInterceptorOffset = mainCallbacks.length;
		}
		else {
			callbacks = mainCallbacks;
		}
		return callbacks;
	}

protected Object createProxyClassAndInstance(Enhancer enhancer, Callback[] callbacks) {
		enhancer.setInterceptDuringConstruction(false);
		enhancer.setCallbacks(callbacks);
		return (this.constructorArgs != null && this.constructorArgTypes != null ?
				enhancer.create(this.constructorArgTypes, this.constructorArgs) :
				enhancer.create());
	}

MethodA{
	MethodB；
	MethodC;
}
MethodB{

}
MethodC{

}

//以下代码省略部分内容
public Object invoke(MethodInvocation invocation) throws Throwable {
//获取事务调用的目标方法
Class<?> targetClass = (invocation.getThis() != null ? AopUtils.getTargetClass(invocation.getThis()) : null);
//执行带事务调用
return invokeWithinTransaction(invocation.getMethod(), targetClass, invocation::proceed);
}

//TransactionAspectSupport.class
//省略了部分代码
protected Object invokeWithinTransaction(Method method, @Nullable Class<?> targetClass,
                                         final InvocationCallback invocation) throws Throwable {
    Object retVal;
    try {
        //调用真正的方法体
        retVal = invocation.proceedWithInvocation();
    }
    catch (Throwable ex) {
        // 如果出现异常，执行事务异常处理
        completeTransactionAfterThrowing(txInfo, ex);
        throw ex;
    }
    finally {
        //最后做一下清理工作，主要是缓存和状态等
        cleanupTransactionInfo(txInfo);
    }
    //如果没有异常，直接提交事务。
    commitTransactionAfterReturning(txInfo);
    return retVal;

}

//省略部分代码
protected void completeTransactionAfterThrowing(@Nullable TransactionInfo txInfo, Throwable ex) {
				//判断是否需要回滚，判断的逻辑就是看有没有声明事务属性，同时判断是不是在目前的这个异常中执行回滚。
			if (txInfo.transactionAttribute != null && txInfo.transactionAttribute.rollbackOn(ex)) {
				//执行回滚
					txInfo.getTransactionManager().rollback(txInfo.getTransactionStatus());
			} 
			else {
						//否则不需要回滚，直接提交即可。
					txInfo.getTransactionManager().commit(txInfo.getTransactionStatus());
			
			}
		}
	}

@Override
	protected void doRollback(DefaultTransactionStatus status) {
		DataSourceTransactionObject txObject = (DataSourceTransactionObject) status.getTransaction();
		Connection con = txObject.getConnectionHolder().getConnection();
		if (status.isDebug()) {
			logger.debug("Rolling back JDBC transaction on Connection [" + con + "]");
		}
		try {
		//调用jdbc的 rollback进行回滚事务。
			con.rollback();
		}
		catch (SQLException ex) {
			throw new TransactionSystemException("Could not roll back JDBC transaction", ex);
		}
	}

/**
 * @description:
 * @author: luozhou 
 * @create: 2020-03-29 17:05
 **/
@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Inherited
@Documented
public @interface MyTransaction {
    //指定异常回滚
    Class<? extends Throwable>[] rollbackFor() default {};
}

/**
 * @description:
 * @author: luozhou 
 * @create: 2020-03-29 21:14
 **/
@Component
public class DataSourceConnectHolder {
    @Autowired
    DataSource dataSource;
    /**
     * 线程绑定对象
     */
    ThreadLocal<Connection> resources = new NamedThreadLocal<>("Transactional resources");

    public Connection getConnection() {
        Connection con = resources.get();
        if (con != null) {
            return con;
        }
        try {
            con = dataSource.getConnection();
            //为了体现事务，全部设置为手动提交事务
            con.setAutoCommit(false);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        resources.set(con);
        return con;
    }

    public void cleanHolder() {
        Connection con = resources.get();
        if (con != null) {
            try {
                con.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        resources.remove();
    }
}

/**
 * @description:
 * @author: luozhou 
 * @create: 2020-03-29 17:08
 **/
@Aspect
@Component
public class MyTransactionAopHandler {
    @Autowired
    DataSourceConnectHolder connectHolder;
    Class<? extends Throwable>[] es;

    //拦截所有MyTransaction注解的方法
    @org.aspectj.lang.annotation.Pointcut("@annotation(luozhou.top.annotion.MyTransaction)")
    public void Transaction() {

    }

    @Around("Transaction()")
    public Object TransactionProceed(ProceedingJoinPoint proceed) throws Throwable {
        Object result = null;
        Signature signature = proceed.getSignature();
        MethodSignature methodSignature = (MethodSignature) signature;
        Method method = methodSignature.getMethod();
        if (method == null) {
            return result;
        }
        MyTransaction transaction = method.getAnnotation(MyTransaction.class);
        if (transaction != null) {
            es = transaction.rollbackFor();
        }
        try {
            result = proceed.proceed();
        } catch (Throwable throwable) {
            //异常处理
            completeTransactionAfterThrowing(throwable);
            throw throwable;
        }
        //直接提交
        doCommit();
        return result;
    }
		/**
		* 执行回滚，最后关闭连接和清理线程绑定
		*/
    private void doRollBack() {
        try {
            connectHolder.getConnection().rollback();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            connectHolder.cleanHolder();
        }

    }
		/**
		*执行提交，最后关闭连接和清理线程绑定
		*/
    private void doCommit() {
        try {
            connectHolder.getConnection().commit();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            connectHolder.cleanHolder();
        }
    }
		/**
		*异常处理，捕获的异常是目标异常或者其子类，就进行回滚，否则就提交事务。
		*/
    private void completeTransactionAfterThrowing(Throwable throwable) {
        if (es != null && es.length > 0) {
            for (Class<? extends Throwable> e : es) {
                if (e.isAssignableFrom(throwable.getClass())) {
                    doRollBack();
                }
            }
        }
        doCommit();
    }
}

/**
 * @description:
 * @author: luozhou kinglaw1204@gmail.com
 * @create: 2020-03-29 22:05
 **/
@Service
public class MyTransactionTest implements TestService {
    @Autowired
    DataSourceConnectHolder holder;
		//一个事务中执行两个sql插入
   @MyTransaction(rollbackFor = NullPointerException.class)
    @Override
    public void saveTest(int id) {
        saveWitharamters(id, "luozhou@gmail.com");
        saveWitharamters(id + 10, "luozhou@gmail.com");
        int aa = id / 0;
    }
		//执行sql
   private void saveWitharamters(int id, String email) {
        String sql = "insert into tb_test values(?,?)";
        Connection connection = holder.getConnection();
        PreparedStatement stmt = null;
        try {
            stmt = connection.prepareStatement(sql);
            stmt.setInt(1, id);
            stmt.setString(2, email);
            stmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    
}

@SpringBootTest
@RunWith(SpringRunner.class)
class SpringTransactionApplicationTests {
    @Autowired
    private TestService service;

    @Test
    void contextLoads() throws SQLException {
        service.saveTest(1);
    }

}

public static void main(String[] args) {
    val sets = new HashSet<String>();
    val lists = new ArrayList<String>();
    val maps = new HashMap<String, String>();
    //=>相当于如下
    final Set<String> sets2 = new HashSet<>();
    final List<String> lists2 = new ArrayList<>();
    final Map<String, String> maps2 = new HashMap<>();
}

public void notNullExample(@NonNull String string) {
    string.length();
}
//=>相当于
public void notNullExample(String string) {
    if (string != null) {
        string.length();
    } else {
        throw new NullPointerException("null");
    }
}

public static void main(String[] args) {
    try {
        @Cleanup InputStream inputStream = new FileInputStream(args[0]);
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    }
    //=>相当于
    InputStream inputStream = null;
    try {
        inputStream = new FileInputStream(args[0]);
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } finally {
        if (inputStream != null) {
            try {
                inputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

@Setter(AccessLevel.PUBLIC)
@Getter(AccessLevel.PROTECTED)
private int id;
private String shap;

@ToString(exclude = "id", callSuper = true, includeFieldNames = true)
public class LombokDemo {
    private int id;
    private String name;
    private int age;
    public static void main(String[] args) {
        //输出LombokDemo(super=LombokDemo@48524010, name=null, age=0)
        System.out.println(new LombokDemo());
    }
}