事務簡單介紹
- 本文原始碼基於spring-framework-5.3.10。
- 事務是基於AOP的機制進行實現的!
Spring事務基本執行原理
- 一個Bean在執行Bean的建立生命週期時,會經過InfrastructureAdvisorAutoProxyCreator的初始化後的方法,會判斷當前當前Bean物件是否和BeanFactoryTransactionAttributeSourceAdvisor匹配,匹配邏輯為判斷該Bean的類上是否存在@Transactional註解,或者類中的某個方法上是否存在@Transactional註解,如果存在則表示該Bean需要進行動態代理產生一個代理物件作為Bean物件。
Spring事務基本執行流程
- 利用所配置的PlatformTransactionManager事務管理器新建一個資料庫連線。
- 修改資料庫連線的autocommit為false。
- 執行MethodInvocation.proceed()方法,簡單理解就是執行業務方法,其中就會執行sql。
- 如果沒有拋異常,則提交。
- 如果拋了異常,則回滾。
原始碼執行流程
- 加了@Transactional註解的類,或者類中擁有@Transactional註解的方法,都會生成代理物件作為bean。
- 代理物件執行方法時。
- 獲取當前正在執行的方法上的@Transactional註解的資訊TransactionAttribute。
- 檢視@Transactional註解上是否指定了TransactionManager,如果沒有指定,則預設獲取TransactionManager型別的bean作為TransactionManager。
- 對於TransactionManager有一個限制,必須是PlatformTransactionManager。
- 生成一個joinpointIdentification,作為事務的名字。
- 開始建立事務。
- 建立事務成功後執行業務方法。
- 如果執行業務方法出現異常,則會進行回滾,然後執行完finally中的方法後再將異常丟擲。
- 如果執行業務方法沒有出現異常,那麼則會執行完finally中的方法後再進行提交。
建立事務原始碼流程
- 得到一個TransactionStatus物件、
- 將PlatformTransactionManager、TransactionAttribute、TransactionStatus構造成為一個TransactionInfo物件,並返回TransactionInfo物件。
回滾事務原始碼流程
- 判斷當前異常是否需要回滾。不需要回滾直接走提價的流程。
- 觸發同步器的beforeCompletion()。
- 呼叫資料庫連線物件的rollback()。
- 觸發同步器的afterCompletion()。
- 判斷是否有事務掛起。
- 如果有則把掛起的事務重新設定到TransactionSynchronizationManager中去,並執行同步器的resume()方法。
提交事務原始碼流程
- 觸發同步器的beforeCommit。
- 觸發同步器的beforeCompletion()。
- 呼叫資料庫連線物件的commit()。
- 觸發同步器的afterCommit。
- 觸發同步器的afterCompletion()。
- 判斷是否有事務掛起。
- 如果有則把掛起的事務重新設定到TransactionSynchronizationManager中去,並執行同步器的resume()方法。
建立TransactionStatus的原始碼流程
- 呼叫AbstractPlatformTransactionManager類中的getTransaction(txAttr)方法,實際上這個方法就是真正去開啟事務的方法。
- 呼叫DataSourceTransactionManager中的doGetTransaction()得到一個事務物件,得到的事務物件中可能持有也可能沒有持有資料庫連線物件。不同船舶機制下,是否持有事務,邏輯不同!
傳播機制 |
含義 |
之前方法持有事務的邏輯 |
之前方法未持有事務的邏輯 |
REQUIRED(TransactionDefinition.PROPAGATION_REQUIRED) |
支援當前事務,如果沒有事務會建立一個新的事務 |
在當前事務執行 |
建立一個新的事務 |
SUPPORTS(TransactionDefinition.PROPAGATION_SUPPORTS) |
支援當前事務,如果沒有事務的話以非事務方式執行 |
在當前事務執行 |
使用非事務的方式執行 |
MANDATORY(TransactionDefinition.PROPAGATION_MANDATORY) |
支援當前事務,如果沒有事務丟擲異常 |
在當前事務執行 |
拋異常 |
REQUIRES_NEW(TransactionDefinition.PROPAGATION_REQUIRES_NEW) |
建立一個新的事務並掛起當前事務 |
建立一個新的事務並掛起當前事務 |
建立一個新的事務 |
NOT_SUPPORTED(TransactionDefinition.PROPAGATION_NOT_SUPPORTED) |
以非事務方式執行,如果當前存在事務則將當前事務掛起 |
掛起當前事務 |
使用非事務的方式執行 |
NEVER(TransactionDefinition.PROPAGATION_NEVER) |
以非事務方式進行,如果存在事務則丟擲異常 |
拋異常 |
使用非事務的方式執行 |
NESTED(TransactionDefinition.PROPAGATION_NESTED) |
如果當前存在事務,則在巢狀事務內執行。如果當前沒有事務,則建立一個新事務 |
利用資料庫連線物件,設定一個savepoint,比如mysql就支援,在一個事務中,可以在某個位置設定一個savepoint,後續可以只回滾到某個savepoint |
建立一個新的事務 |
doBegin原始碼流程
- 如果事務物件中沒有持有資料庫連線物件,那麼則呼叫DataSource獲取一個資料庫連線物件,並設定到事務物件中去
- 設定當前資料庫連線的隔離級別。
- 設定資料庫連線的autoCommit為false。
- 設定資料庫連線的timeout。
- 把獲得的資料庫連線物件通過TransactionSynchronizationManager設定到當前執行緒的ThreadLocal中。
同步器使用方式
TransactionSynchronizationManager.registerSynchronization(new TransactionSynchronizationAdapter() {
@Override
public void afterCommit() {
System.out.println("after commit...");
}
}
開啟事務的註解@EnableTransactionManagement原始碼分析
/**
* 這個註解匯入了TransactionManagementConfigurationSelector類
*/
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Import(TransactionManagementConfigurationSelector.class)
public @interface EnableTransactionManagement {
boolean proxyTargetClass() default false;
AdviceMode mode() default AdviceMode.PROXY;
int order() default Ordered.LOWEST_PRECEDENCE;
}
匯入的TransactionManagementConfigurationSelector原始碼分析
/**
* 在呼叫process方法的時候會呼叫到這裡
*/
protected String[] selectImports(AdviceMode adviceMode) {
switch (adviceMode) {
case PROXY:
// 預設是PROXY。往Spring容器中新增了兩個Bean:AutoProxyRegistrar、ProxyTransactionManagementConfiguration
return new String[] {AutoProxyRegistrar.class.getName(),
ProxyTransactionManagementConfiguration.class.getName()};
case ASPECTJ:
// 表示不用動態代理技術,用ASPECTJ技術,比較麻煩了
return new String[] {determineTransactionAspectClass()};
default:
return null;
}
}
AutoProxyRegistrar的Bean原始碼分析
/**
* 這個類實現了ImportBeanDefinitionRegistrar,他在啟動的時候會呼叫registerBeanDefinitions方法。
* 最核心的邏輯是往Spring容器中註冊了一個InfrastructureAdvisorAutoProxyCreator的Bean。
* InfrastructureAdvisorAutoProxyCreator繼承了AbstractAdvisorAutoProxyCreator,所以這個類的主要作用就是開啟自動代理的作用,也就是一個BeanPostProcessor,會在初始化後步驟中去尋找Advisor型別的Bean,並判斷當前某個Bean是否有匹配的Advisor,是否需要利用動態代理產生一個代理物件。
*/
public class AutoProxyRegistrar implements ImportBeanDefinitionRegistrar {
public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
boolean candidateFound = false;
Set<String> annTypes = importingClassMetadata.getAnnotationTypes();
for (String annType : annTypes) {
AnnotationAttributes candidate = AnnotationConfigUtils.attributesFor(importingClassMetadata, annType);
if (candidate == null) {
continue;
}
Object mode = candidate.get("mode");
Object proxyTargetClass = candidate.get("proxyTargetClass");
if (mode != null && proxyTargetClass != null && AdviceMode.class == mode.getClass() &&
Boolean.class == proxyTargetClass.getClass()) {
candidateFound = true;
if (mode == AdviceMode.PROXY) {
// 註冊InfrastructureAdvisorAutoProxyCreator,才可以Bean進行AOP
AopConfigUtils.registerAutoProxyCreatorIfNecessary(registry);
if ((Boolean) proxyTargetClass) {
// 設定InfrastructureAdvisorAutoProxyCreator的proxyTargetClass為true
AopConfigUtils.forceAutoProxyCreatorToUseClassProxying(registry);
return;
}
}
}
}
if (!candidateFound && logger.isInfoEnabled()) {
String name = getClass().getSimpleName();
logger.info(String.format("%s was imported but no annotations were found " +
"having both 'mode' and 'proxyTargetClass' attributes of type " +
"AdviceMode and boolean respectively. This means that auto proxy " +
"creator registration and configuration may not have occurred as " +
"intended, and components may not be proxied as expected. Check to " +
"ensure that %s has been @Import'ed on the same class where these " +
"annotations are declared; otherwise remove the import of %s " +
"altogether.", name, name, name));
}
}
}
匯入的ProxyTransactionManagementConfiguration原始碼分析
/**
* ProxyTransactionManagementConfiguration是一個配置類,它又定義了另外三個bean:
* BeanFactoryTransactionAttributeSourceAdvisor:一個Advisor
* AnnotationTransactionAttributeSource:相當於BeanFactoryTransactionAttributeSourceAdvisor中的Pointcut
* TransactionInterceptor:相當於BeanFactoryTransactionAttributeSourceAdvisor中的Advice
*/
@Configuration(proxyBeanMethods = false)
@Role(BeanDefinition.ROLE_INFRASTRUCTURE)
public class ProxyTransactionManagementConfiguration extends AbstractTransactionManagementConfiguration {
// 定義一個Advisor的Bean
@Bean(name = TransactionManagementConfigUtils.TRANSACTION_ADVISOR_BEAN_NAME)
@Role(BeanDefinition.ROLE_INFRASTRUCTURE)
public BeanFactoryTransactionAttributeSourceAdvisor transactionAdvisor(
TransactionAttributeSource transactionAttributeSource, TransactionInterceptor transactionInterceptor) {
BeanFactoryTransactionAttributeSourceAdvisor advisor = new BeanFactoryTransactionAttributeSourceAdvisor();
advisor.setTransactionAttributeSource(transactionAttributeSource);
advisor.setAdvice(transactionInterceptor);
if (this.enableTx != null) {
advisor.setOrder(this.enableTx.<Integer>getNumber("order"));
}
return advisor;
}
// 定義Advisor的Pointcut
@Bean
@Role(BeanDefinition.ROLE_INFRASTRUCTURE)
public TransactionAttributeSource transactionAttributeSource() {
// AnnotationTransactionAttributeSource中定義了一個Pointcut
// 並且AnnotationTransactionAttributeSource可以用來解析@Transactional註解,並得到一個RuleBasedTransactionAttribute物件
return new AnnotationTransactionAttributeSource();
}
// 定義Advisor的Advice
// 開啟事務、回滾、提交都在這個TransactionInterceptor中
@Bean
@Role(BeanDefinition.ROLE_INFRASTRUCTURE)
public TransactionInterceptor transactionInterceptor(TransactionAttributeSource transactionAttributeSource) {
TransactionInterceptor interceptor = new TransactionInterceptor();
interceptor.setTransactionAttributeSource(transactionAttributeSource);
if (this.txManager != null) {
interceptor.setTransactionManager(this.txManager);
}
return interceptor;
}
}
使用用到的Pointcut原始碼分析
public class BeanFactoryTransactionAttributeSourceAdvisor extends AbstractBeanFactoryPointcutAdvisor {
/**
* pointcut就是一個new TransactionAttributeSourcePointcut物件
*/
private final TransactionAttributeSourcePointcut pointcut = new TransactionAttributeSourcePointcut() {
@Override
@Nullable
protected TransactionAttributeSource getTransactionAttributeSource() {
return transactionAttributeSource;
}
};
/**
* 獲取pointcut採用的是內部類的方式構建
*/
@Override
public Pointcut getPointcut() {
return this.pointcut;
}
}
/**
* 構建Pointcut用到的類
*/
abstract class TransactionAttributeSourcePointcut extends StaticMethodMatcherPointcut implements Serializable {
// 外部構造方法呼叫到這裡,其實就是設定new TransactionAttributeSourceClassFilter()
// 這裡面主要進行類的判斷
protected TransactionAttributeSourcePointcut() {
setClassFilter(new TransactionAttributeSourceClassFilter());
}
// 判斷方法是否匹配
@Override
public boolean matches(Method method, Class<?> targetClass) {
// 呼叫外部重寫的方法
TransactionAttributeSource tas = getTransactionAttributeSource();
return (tas == null || tas.getTransactionAttribute(method, targetClass) != null);
}
// 具體的匹配邏輯
private class TransactionAttributeSourceClassFilter implements ClassFilter {
@Override
public boolean matches(Class<?> clazz) {
// 事務內部的一些類,直接返回false
if (TransactionalProxy.class.isAssignableFrom(clazz) ||
TransactionManager.class.isAssignableFrom(clazz) ||
PersistenceExceptionTranslator.class.isAssignableFrom(clazz)) {
return false;
}
// 呼叫外部重寫的方法
TransactionAttributeSource tas = getTransactionAttributeSource();
// 判斷有沒有@Transaction註解
return (tas == null || tas.isCandidateClass(clazz));
}
}
}
/**
* 原始碼位置:org.springframework.transaction.annotation.AnnotationTransactionAttributeSource.isCandidateClass(Class<?>)
* 判斷是否能成為候選者
*/
public boolean isCandidateClass(Class<?> targetClass) {
for (TransactionAnnotationParser parser : this.annotationParsers) {
if (parser.isCandidateClass(targetClass)) {
return true;
}
}
return false;
}
/**
* 原始碼位置:org.springframework.transaction.interceptor.AbstractFallbackTransactionAttributeSource.getTransactionAttribute(Method, Class<?>)
* 判斷當前類上面是否有@Transactional註解
*/
public boolean isCandidateClass(Class<?> targetClass) {
return AnnotationUtils.isCandidateClass(targetClass, Transactional.class);
}
/**
* 原始碼位置:org.springframework.transaction.annotation.SpringTransactionAnnotationParser.isCandidateClass(Class<?>)
* 獲取方法上或者類上是否有@Transaction註解
*/
public TransactionAttribute getTransactionAttribute(Method method, @Nullable Class<?> targetClass) {
// Object類直接返回null
if (method.getDeclaringClass() == Object.class) {
return null;
}
// First, see if we have a cached value.
// 檢查快取裡的結果,快取裡存了當前類和方法是否存在Transactional註解
Object cacheKey = getCacheKey(method, targetClass);
TransactionAttribute cached = this.attributeCache.get(cacheKey);
if (cached != null) {
// Value will either be canonical value indicating there is no transaction attribute,
// or an actual transaction attribute.
// 快取中沒有,直接返回null
if (cached == NULL_TRANSACTION_ATTRIBUTE) {
return null;
}
else {
return cached;
}
}
else {
// We need to work it out.
// 解析。實際物件為RuleBasedTransactionAttribute
TransactionAttribute txAttr = computeTransactionAttribute(method, targetClass);
// Put it in the cache.
// 為空,快取一個空的
if (txAttr == null) {
this.attributeCache.put(cacheKey, NULL_TRANSACTION_ATTRIBUTE);
}
else {
String methodIdentification = ClassUtils.getQualifiedMethodName(method, targetClass);
if (txAttr instanceof DefaultTransactionAttribute) {
DefaultTransactionAttribute dta = (DefaultTransactionAttribute) txAttr;
dta.setDescriptor(methodIdentification);
dta.resolveAttributeStrings(this.embeddedValueResolver);
}
if (logger.isTraceEnabled()) {
logger.trace("Adding transactional method '" + methodIdentification + "' with attribute: " + txAttr);
}
// 不為空,快取結果
this.attributeCache.put(cacheKey, txAttr);
}
return txAttr;
}
}
最終執行的Advisor:TransactionInterceptor原始碼分析
/**
* 原始碼位置:org.springframework.transaction.interceptor.TransactionInterceptor.invoke(MethodInvocation)
*/
public Object invoke(MethodInvocation invocation) throws Throwable {
// Work out the target class: may be {@code null}.
// The TransactionAttributeSource should be passed the target class
// as well as the method, which may be from an interface.
// 獲取代理類
Class<?> targetClass = (invocation.getThis() != null ? AopUtils.getTargetClass(invocation.getThis()) : null);
// Adapt to TransactionAspectSupport's invokeWithinTransaction...
return invokeWithinTransaction(invocation.getMethod(), targetClass, new CoroutinesInvocationCallback() {
@Override
@Nullable
public Object proceedWithInvocation() throws Throwable {
// 執行後續的Interceptor,以及被代理的方法
return invocation.proceed(); // test() sql
}
@Override
public Object getTarget() {
return invocation.getThis();
}
@Override
public Object[] getArguments() {
return invocation.getArguments();
}
});
}
/**
* 具體的執行程式碼
*/
protected Object invokeWithinTransaction(Method method, @Nullable Class<?> targetClass,
final InvocationCallback invocation) throws Throwable {
// If the transaction attribute is null, the method is non-transactional.
// TransactionAttribute就是@Transactional中的配置
TransactionAttributeSource tas = getTransactionAttributeSource();
// 獲取@Transactional註解中的屬性值
final TransactionAttribute txAttr = (tas != null ? tas.getTransactionAttribute(method, targetClass) : null);
// 返回Spring容器中型別為TransactionManager的Bean物件。事務的開啟,提交,回滾都會用到TransactionManager物件。
final TransactionManager tm = determineTransactionManager(txAttr);
// ReactiveTransactionManager用得少,並且它只是執行方式是響應式的,原理流程和普通的是一樣的
if (this.reactiveAdapterRegistry != null && tm instanceof ReactiveTransactionManager) {
boolean isSuspendingFunction = KotlinDetector.isSuspendingFunction(method);
boolean hasSuspendingFlowReturnType = isSuspendingFunction &&
COROUTINES_FLOW_CLASS_NAME.equals(new MethodParameter(method, -1).getParameterType().getName());
if (isSuspendingFunction && !(invocation instanceof CoroutinesInvocationCallback)) {
throw new IllegalStateException("Coroutines invocation not supported: " + method);
}
CoroutinesInvocationCallback corInv = (isSuspendingFunction ? (CoroutinesInvocationCallback) invocation : null);
ReactiveTransactionSupport txSupport = this.transactionSupportCache.computeIfAbsent(method, key -> {
Class<?> reactiveType =
(isSuspendingFunction ? (hasSuspendingFlowReturnType ? Flux.class : Mono.class) : method.getReturnType());
ReactiveAdapter adapter = this.reactiveAdapterRegistry.getAdapter(reactiveType);
if (adapter == null) {
throw new IllegalStateException("Cannot apply reactive transaction to non-reactive return type: " +
method.getReturnType());
}
return new ReactiveTransactionSupport(adapter);
});
InvocationCallback callback = invocation;
if (corInv != null) {
callback = () -> CoroutinesUtils.invokeSuspendingFunction(method, corInv.getTarget(), corInv.getArguments());
}
Object result = txSupport.invokeWithinTransaction(method, targetClass, callback, txAttr, (ReactiveTransactionManager) tm);
if (corInv != null) {
Publisher<?> pr = (Publisher<?>) result;
return (hasSuspendingFlowReturnType ? KotlinDelegate.asFlow(pr) :
KotlinDelegate.awaitSingleOrNull(pr, corInv.getContinuation()));
}
return result;
}
// 把tm強制轉換為PlatformTransactionManager,所以我們在定義時得定義PlatformTransactionManager型別
PlatformTransactionManager ptm = asPlatformTransactionManager(tm);
// joinpoint的唯一標識,就是當前在執行的方法名字
final String joinpointIdentification = methodIdentification(method, targetClass, txAttr);
// CallbackPreferringPlatformTransactionManager表示擁有回撥功能的PlatformTransactionManager,也不常用
if (txAttr == null || !(ptm instanceof CallbackPreferringPlatformTransactionManager)) {
// Standard transaction demarcation with getTransaction and commit/rollback calls.
// 如果有必要就建立事務,這裡就涉及到事務傳播機制的實現了
// TransactionInfo表示一個邏輯事務,比如兩個邏輯事務屬於同一個物理事務
TransactionInfo txInfo = createTransactionIfNecessary(ptm, txAttr, joinpointIdentification);
Object retVal;
try {
// This is an around advice: Invoke the next interceptor in the chain.
// This will normally result in a target object being invoked.
// 執行下一個Interceptor或被代理物件中的方法
retVal = invocation.proceedWithInvocation(); //test
}
catch (Throwable ex) {
// target invocation exception
// 拋異常了,則回滾事務
completeTransactionAfterThrowing(txInfo, ex);
throw ex;
}
finally {
cleanupTransactionInfo(txInfo);
}
if (retVal != null && vavrPresent && VavrDelegate.isVavrTry(retVal)) {
// Set rollback-only in case of Vavr failure matching our rollback rules...
TransactionStatus status = txInfo.getTransactionStatus();
if (status != null && txAttr != null) {
retVal = VavrDelegate.evaluateTryFailure(retVal, txAttr, status);
}
}
// 提交事務
commitTransactionAfterReturning(txInfo);
return retVal;
}
else {
Object result;
final ThrowableHolder throwableHolder = new ThrowableHolder();
// It's a CallbackPreferringPlatformTransactionManager: pass a TransactionCallback in.
try {
result = ((CallbackPreferringPlatformTransactionManager) ptm).execute(txAttr, status -> {
TransactionInfo txInfo = prepareTransactionInfo(ptm, txAttr, joinpointIdentification, status);
try {
Object retVal = invocation.proceedWithInvocation();
if (retVal != null && vavrPresent && VavrDelegate.isVavrTry(retVal)) {
// Set rollback-only in case of Vavr failure matching our rollback rules...
retVal = VavrDelegate.evaluateTryFailure(retVal, txAttr, status);
}
return retVal;
}
catch (Throwable ex) {
if (txAttr.rollbackOn(ex)) {
// A RuntimeException: will lead to a rollback.
if (ex instanceof RuntimeException) {
throw (RuntimeException) ex;
}
else {
throw new ThrowableHolderException(ex);
}
}
else {
// A normal return value: will lead to a commit.
throwableHolder.throwable = ex;
return null;
}
}
finally {
cleanupTransactionInfo(txInfo);
}
});
}
catch (ThrowableHolderException ex) {
throw ex.getCause();
}
catch (TransactionSystemException ex2) {
if (throwableHolder.throwable != null) {
logger.error("Application exception overridden by commit exception", throwableHolder.throwable);
ex2.initApplicationException(throwableHolder.throwable);
}
throw ex2;
}
catch (Throwable ex2) {
if (throwableHolder.throwable != null) {
logger.error("Application exception overridden by commit exception", throwableHolder.throwable);
}
throw ex2;
}
// Check result state: It might indicate a Throwable to rethrow.
if (throwableHolder.throwable != null) {
throw throwableHolder.throwable;
}
return result;
}
}
/**
* 建立事務的邏輯
*/
protected TransactionInfo createTransactionIfNecessary(@Nullable PlatformTransactionManager tm,
@Nullable TransactionAttribute txAttr, final String joinpointIdentification) {
// If no name specified, apply method identification as transaction name.
// name為空,取方法名字
if (txAttr != null && txAttr.getName() == null) {
txAttr = new DelegatingTransactionAttribute(txAttr) {
@Override
public String getName() {
return joinpointIdentification;
}
};
}
// 每個邏輯事務都會建立一個TransactionStatus,但是TransactionStatus中有一個屬性代表當前邏輯事務底層的物理事務是不是新的
TransactionStatus status = null;
if (txAttr != null) {
if (tm != null) {
// 開啟事務!
status = tm.getTransaction(txAttr);
}
else {
if (logger.isDebugEnabled()) {
logger.debug("Skipping transactional joinpoint [" + joinpointIdentification +
"] because no transaction manager has been configured");
}
}
}
// 返回一個TransactionInfo物件,表示得到了一個事務,可能是新建立的一個事務,也可能是拿到的已有的事務
return prepareTransactionInfo(tm, txAttr, joinpointIdentification, status);
}
獲取(開啟)事務的邏輯
/**
* 獲取事務的邏輯
* 原始碼位置:org.springframework.transaction.support.AbstractPlatformTransactionManager.getTransaction(TransactionDefinition)
* definition:Transaction註解的資訊的物件
*/
public final TransactionStatus getTransaction(@Nullable TransactionDefinition definition)
throws TransactionException {
// Use defaults if no transaction definition given.
TransactionDefinition def = (definition != null ? definition : TransactionDefinition.withDefaults());
// 從ThreadLocal中拿到txObject物件
Object transaction = doGetTransaction();
boolean debugEnabled = logger.isDebugEnabled();
// transaction.getConnectionHolder().isTransactionActive()
// 判斷是不是存在一個事務
if (isExistingTransaction(transaction)) {
// Existing transaction found -> check propagation behavior to find out how to behave.
return handleExistingTransaction(def, transaction, debugEnabled);
}
// Check definition settings for new transaction.
// 配置的資料庫返回的超時時間小於-1,拋異常。
if (def.getTimeout() < TransactionDefinition.TIMEOUT_DEFAULT) {
throw new InvalidTimeoutException("Invalid transaction timeout", def.getTimeout());
}
// No existing transaction found -> check propagation behavior to find out how to proceed.
// 當前不存在事務,並且配置的傳播機制為PROPAGATION_MANDATORY(支援當前事務,如果沒有事務丟擲異常),拋異常
if (def.getPropagationBehavior() == TransactionDefinition.PROPAGATION_MANDATORY) {
throw new IllegalTransactionStateException(
"No existing transaction found for transaction marked with propagation 'mandatory'");
}
// 在當前Thread中沒有事務的前提下,以下三個是等價的。
// PROPAGATION_REQUIRED :支援當前事務,如果沒有事務會建立一個新的事務
// PROPAGATION_REQUIRES_NEW :建立一個新的事務並掛起當前事務
// PROPAGATION_NESTED: 如果當前存在事務,則在巢狀事務內執行。如果當前沒有事務,則建立一個事務。
else if (def.getPropagationBehavior() == TransactionDefinition.PROPAGATION_REQUIRED ||
def.getPropagationBehavior() == TransactionDefinition.PROPAGATION_REQUIRES_NEW ||
def.getPropagationBehavior() == TransactionDefinition.PROPAGATION_NESTED) {
// 沒有事務需要掛起,不過TransactionSynchronization有可能需要掛起。直接呼叫TransactionSynchronizationManager.initSynchronization方法會有需要被掛起的。
// suspendedResources表示當前執行緒被掛起的資源持有物件(資料庫連線、TransactionSynchronization)
SuspendedResourcesHolder suspendedResources = suspend(null);
if (debugEnabled) {
logger.debug("Creating new transaction with name [" + def.getName() + "]: " + def);
}
try {
// 開啟事務方法
// 開啟事務後,transaction中就會有資料庫連線了,並且isTransactionActive為true
// 並返回TransactionStatus物件,該物件儲存了很多資訊,包括被掛起的資源
return startTransaction(def, transaction, debugEnabled, suspendedResources);
}
catch (RuntimeException | Error ex) {
resume(null, suspendedResources);
throw ex;
}
}
else {
// Create "empty" transaction: no actual transaction, but potentially synchronization.
if (def.getIsolationLevel() != TransactionDefinition.ISOLATION_DEFAULT && logger.isWarnEnabled()) {
logger.warn("Custom isolation level specified but no actual transaction initiated; " +
"isolation level will effectively be ignored: " + def);
}
boolean newSynchronization = (getTransactionSynchronization() == SYNCHRONIZATION_ALWAYS);
return prepareTransactionStatus(def, null, true, newSynchronization, debugEnabled, null);
}
}
/**
* 開啟Transaction事務
*/
private TransactionStatus startTransaction(TransactionDefinition definition, Object transaction,
boolean debugEnabled, @Nullable SuspendedResourcesHolder suspendedResources) {
// 是否開啟一個新的TransactionSynchronization
boolean newSynchronization = (getTransactionSynchronization() != SYNCHRONIZATION_NEVER);
// 開啟的這個事務的狀態資訊:
// 事務的定義、用來儲存資料庫連線的物件、是否是新事務,是否是新的TransactionSynchronization
DefaultTransactionStatus status = newTransactionStatus(
definition, transaction, true, newSynchronization, debugEnabled, suspendedResources);
// 開啟事務
doBegin(transaction, definition);
// 如果需要新開一個TransactionSynchronization,就把新建立的事務的一些狀態資訊設定到TransactionSynchronizationManager中
prepareSynchronization(status, definition);
return status;
}
/**
* 開啟事務!DataSource層面
* 原始碼位置:org.springframework.jdbc.datasource.DataSourceTransactionManager.doBegin(Object, TransactionDefinition)
*/
protected void doBegin(Object transaction, TransactionDefinition definition) {
DataSourceTransactionObject txObject = (DataSourceTransactionObject) transaction;
Connection con = null;
try {
// 如果當前執行緒中所使用的DataSource還沒有建立過資料庫連線,就獲取一個新的資料庫連線
if (!txObject.hasConnectionHolder() ||
txObject.getConnectionHolder().isSynchronizedWithTransaction()) {
// 得到連線物件
Connection newCon = obtainDataSource().getConnection();
if (logger.isDebugEnabled()) {
logger.debug("Acquired Connection [" + newCon + "] for JDBC transaction");
}
// 設定到DataSourceTransactionObject。注意這裡設定的true,表示txObject的連結一個新的
txObject.setConnectionHolder(new ConnectionHolder(newCon), true);
}
txObject.getConnectionHolder().setSynchronizedWithTransaction(true);
// 得到連線物件
con = txObject.getConnectionHolder().getConnection();
// 根據@Transactional註解中的設定,設定Connection的readOnly與隔離級別
Integer previousIsolationLevel = DataSourceUtils.prepareConnectionForTransaction(con, definition);
txObject.setPreviousIsolationLevel(previousIsolationLevel);
txObject.setReadOnly(definition.isReadOnly());
// Switch to manual commit if necessary. This is very expensive in some JDBC drivers,
// so we don't want to do it unnecessarily (for example if we've explicitly
// configured the connection pool to set it already).
// 保證autocommit是false。autocommit為true的時候設定autocommit為false
if (con.getAutoCommit()) {
txObject.setMustRestoreAutoCommit(true);
if (logger.isDebugEnabled()) {
logger.debug("Switching JDBC Connection [" + con + "] to manual commit");
}
con.setAutoCommit(false);
}
prepareTransactionalConnection(con, definition);
txObject.getConnectionHolder().setTransactionActive(true);
// 設定資料庫連線的過期時間
int timeout = determineTimeout(definition);
if (timeout != TransactionDefinition.TIMEOUT_DEFAULT) {
txObject.getConnectionHolder().setTimeoutInSeconds(timeout);
}
// Bind the connection holder to the thread.
// 把新建的資料庫連線設定到resources中,resources就是一個ThreadLocal<Map<Object, Object>>,事務管理器中的設定的DataSource物件為key,資料庫連線物件為value
if (txObject.isNewConnectionHolder()) {
TransactionSynchronizationManager.bindResource(obtainDataSource(), txObject.getConnectionHolder());
}
}
catch (Throwable ex) {
if (txObject.isNewConnectionHolder()) {
DataSourceUtils.releaseConnection(con, obtainDataSource());
txObject.setConnectionHolder(null, false);
}
throw new CannotCreateTransactionException("Could not open JDBC Connection for transaction", ex);
}
}
掛起相關流程
/**
* 掛起相關流程
* 原始碼位置:org.springframework.transaction.support.AbstractPlatformTransactionManager.suspend(Object)
*/
protected final SuspendedResourcesHolder suspend(@Nullable Object transaction) throws TransactionException {
// synchronizations是一個ThreadLocal<Set<TransactionSynchronization>>
// 我們可以在任何地方通過TransactionSynchronizationManager給當前執行緒新增TransactionSynchronization,
// 這裡判斷有沒有開啟事務。在prepareSynchronization方法中開啟!
if (TransactionSynchronizationManager.isSynchronizationActive()) {
// 呼叫TransactionSynchronization的suspend方法,並清空和返回當前執行緒中所有的TransactionSynchronization物件
List<TransactionSynchronization> suspendedSynchronizations = doSuspendSynchronization();
try {
Object suspendedResources = null;
if (transaction != null) {
// 掛起事務,把transaction中的Connection清空,並把resources中的key-value進行移除,並返回資料庫連線Connection物件
suspendedResources = doSuspend(transaction);
}
// 獲取並清空當前執行緒中關於TransactionSynchronizationManager的設定
String name = TransactionSynchronizationManager.getCurrentTransactionName();
TransactionSynchronizationManager.setCurrentTransactionName(null);
boolean readOnly = TransactionSynchronizationManager.isCurrentTransactionReadOnly();
TransactionSynchronizationManager.setCurrentTransactionReadOnly(false);
Integer isolationLevel = TransactionSynchronizationManager.getCurrentTransactionIsolationLevel();
TransactionSynchronizationManager.setCurrentTransactionIsolationLevel(null);
boolean wasActive = TransactionSynchronizationManager.isActualTransactionActive();
TransactionSynchronizationManager.setActualTransactionActive(false);
// 將當前執行緒中的資料庫連線物件、TransactionSynchronization物件、TransactionSynchronizationManager中的設定構造成一個物件
// 表示被掛起的資源持有物件,持有了當前執行緒中的事務物件、TransactionSynchronization物件
// suspendedResources資料庫連線、suspendedSynchronizations自己定義的同步器、name事務的名稱、readOnly事務是不是隻讀、isolationLevel事務隔離級別、wasActive切面的Active
return new SuspendedResourcesHolder(
suspendedResources, suspendedSynchronizations, name, readOnly, isolationLevel, wasActive);
}
catch (RuntimeException | Error ex) {
// doSuspend failed - original transaction is still active...
doResumeSynchronization(suspendedSynchronizations);
throw ex;
}
}
else if (transaction != null) {
// Transaction active but no synchronization active.
Object suspendedResources = doSuspend(transaction);
return new SuspendedResourcesHolder(suspendedResources);
}
else {
// Neither transaction nor synchronization active.
return null;
}
}
/**
* 呼叫TransactionSynchronization的suspend方法,並清空和返回當前執行緒中所有的TransactionSynchronization物件
*/
private List<TransactionSynchronization> doSuspendSynchronization() {
// 從synchronizations(一個ThreadLocal)中拿到所設定的TransactionSynchronization物件
List<TransactionSynchronization> suspendedSynchronizations =
TransactionSynchronizationManager.getSynchronizations();
// 呼叫TransactionSynchronization物件的suspend()
for (TransactionSynchronization synchronization : suspendedSynchronizations) {
synchronization.suspend();
}
// 清空synchronizations
TransactionSynchronizationManager.clearSynchronization();
// 把獲取到的TransactionSynchronization返回
return suspendedSynchronizations;
}
之前存在事務的執行邏輯
/**
* 之前存在事務的執行邏輯
* 原始碼位置:org.springframework.transaction.support.AbstractPlatformTransactionManager.handleExistingTransaction(TransactionDefinition, Object, boolean)
*/
private TransactionStatus handleExistingTransaction(
TransactionDefinition definition, Object transaction, boolean debugEnabled)
throws TransactionException {
// PROPAGATION_NEVER:以非事務方式進行,如果存在事務則丟擲異常
if (definition.getPropagationBehavior() == TransactionDefinition.PROPAGATION_NEVER) {
throw new IllegalTransactionStateException(
"Existing transaction found for transaction marked with propagation 'never'");
}
// PROPAGATION_NOT_SUPPORTED:以非事務方式執行,如果當前存在事務則將當前事務掛起
if (definition.getPropagationBehavior() == TransactionDefinition.PROPAGATION_NOT_SUPPORTED) {
if (debugEnabled) {
logger.debug("Suspending current transaction");
}
// 把當前事務掛起,其中就會把資料庫連線物件從ThreadLocal中移除
Object suspendedResources = suspend(transaction);
boolean newSynchronization = (getTransactionSynchronization() == SYNCHRONIZATION_ALWAYS);
return prepareTransactionStatus(
definition, null, false, newSynchronization, debugEnabled, suspendedResources);
}
// PROPAGATION_REQUIRES_NEW:建立一個新的事務並掛起當前事務
if (definition.getPropagationBehavior() == TransactionDefinition.PROPAGATION_REQUIRES_NEW) {
if (debugEnabled) {
logger.debug("Suspending current transaction, creating new transaction with name [" +
definition.getName() + "]");
}
// 呼叫掛起的邏輯
SuspendedResourcesHolder suspendedResources = suspend(transaction);
// 開啟新事務的邏輯
try {
return startTransaction(definition, transaction, debugEnabled, suspendedResources);
}
catch (RuntimeException | Error beginEx) {
resumeAfterBeginException(transaction, suspendedResources, beginEx);
throw beginEx;
}
}
// PROPAGATION_NESTED:果當前存在事務,則在巢狀事務內執行。如果當前沒有事務,則建立一個事務。
if (definition.getPropagationBehavior() == TransactionDefinition.PROPAGATION_NESTED) {
if (!isNestedTransactionAllowed()) {
throw new NestedTransactionNotSupportedException(
"Transaction manager does not allow nested transactions by default - " +
"specify 'nestedTransactionAllowed' property with value 'true'");
}
if (debugEnabled) {
logger.debug("Creating nested transaction with name [" + definition.getName() + "]");
}
if (useSavepointForNestedTransaction()) {
// Create savepoint within existing Spring-managed transaction,
// through the SavepointManager API implemented by TransactionStatus.
// Usually uses JDBC 3.0 savepoints. Never activates Spring synchronization.
DefaultTransactionStatus status =
prepareTransactionStatus(definition, transaction, false, false, debugEnabled, null);
// 建立一個savepoint
status.createAndHoldSavepoint();
return status;
}
else {
// Nested transaction through nested begin and commit/rollback calls.
// Usually only for JTA: Spring synchronization might get activated here
// in case of a pre-existing JTA transaction.
return startTransaction(definition, transaction, debugEnabled, null);
}
}
// Assumably PROPAGATION_SUPPORTS or PROPAGATION_REQUIRED.
if (debugEnabled) {
logger.debug("Participating in existing transaction");
}
if (isValidateExistingTransaction()) {
if (definition.getIsolationLevel() != TransactionDefinition.ISOLATION_DEFAULT) {
Integer currentIsolationLevel = TransactionSynchronizationManager.getCurrentTransactionIsolationLevel();
if (currentIsolationLevel == null || currentIsolationLevel != definition.getIsolationLevel()) {
Constants isoConstants = DefaultTransactionDefinition.constants;
throw new IllegalTransactionStateException("Participating transaction with definition [" +
definition + "] specifies isolation level which is incompatible with existing transaction: " +
(currentIsolationLevel != null ?
isoConstants.toCode(currentIsolationLevel, DefaultTransactionDefinition.PREFIX_ISOLATION) :
"(unknown)"));
}
}
if (!definition.isReadOnly()) {
if (TransactionSynchronizationManager.isCurrentTransactionReadOnly()) {
throw new IllegalTransactionStateException("Participating transaction with definition [" +
definition + "] is not marked as read-only but existing transaction is");
}
}
}
// 如果依然是Propagation.REQUIRED
boolean newSynchronization = (getTransactionSynchronization() != SYNCHRONIZATION_NEVER);
return prepareTransactionStatus(definition, transaction, false, newSynchronization, debugEnabled, null);
}
事務的提交邏輯
/**
* 事務的提交
*/
protected void commitTransactionAfterReturning(@Nullable TransactionInfo txInfo) {
if (txInfo != null && txInfo.getTransactionStatus() != null) {
if (logger.isTraceEnabled()) {
logger.trace("Completing transaction for [" + txInfo.getJoinpointIdentification() + "]");
}
txInfo.getTransactionManager().commit(txInfo.getTransactionStatus());
}
}
/**
* 事務提交的準備邏輯
*/
public final void commit(TransactionStatus status) throws TransactionException {
if (status.isCompleted()) {
throw new IllegalTransactionStateException(
"Transaction is already completed - do not call commit or rollback more than once per transaction");
}
DefaultTransactionStatus defStatus = (DefaultTransactionStatus) status;
// 可以通過TransactionAspectSupport.currentTransactionStatus().setRollbackOnly();來設定
// 事務本來是可以要提交的,但是可以強制回滾。比如報錯後更有好的提示。
if (defStatus.isLocalRollbackOnly()) {
if (defStatus.isDebug()) {
logger.debug("Transactional code has requested rollback");
}
processRollback(defStatus, false);
return;
}
// 判斷此事務在之前是否設定了需要回滾,跟globalRollbackOnParticipationFailure有關
if (!shouldCommitOnGlobalRollbackOnly() && defStatus.isGlobalRollbackOnly()) {
if (defStatus.isDebug()) {
logger.debug("Global transaction is marked as rollback-only but transactional code requested commit");
}
processRollback(defStatus, true);
return;
}
// 提交
processCommit(defStatus);
}
/**
* 提交外部邏輯
*/
private void processCommit(DefaultTransactionStatus status) throws TransactionException {
try {
boolean beforeCompletionInvoked = false;
try {
boolean unexpectedRollback = false;
// 空方法,無任何子類的實現
prepareForCommit(status);
// 呼叫同步器提交前的邏輯(回滾的時候不呼叫這個)
triggerBeforeCommit(status);
// 呼叫同步器完成前的邏輯
triggerBeforeCompletion(status);
beforeCompletionInvoked = true;
if (status.hasSavepoint()) {
if (status.isDebug()) {
logger.debug("Releasing transaction savepoint");
}
unexpectedRollback = status.isGlobalRollbackOnly();
status.releaseHeldSavepoint();
}
// 新的事務,直接呼叫提交
else if (status.isNewTransaction()) {
if (status.isDebug()) {
logger.debug("Initiating transaction commit");
}
unexpectedRollback = status.isGlobalRollbackOnly();
// 呼叫提交方法
doCommit(status);
}
else if (isFailEarlyOnGlobalRollbackOnly()) {
unexpectedRollback = status.isGlobalRollbackOnly();
}
// Throw UnexpectedRollbackException if we have a global rollback-only
// marker but still didn't get a corresponding exception from commit.
if (unexpectedRollback) {
throw new UnexpectedRollbackException(
"Transaction silently rolled back because it has been marked as rollback-only");
}
}
catch (UnexpectedRollbackException ex) {
// can only be caused by doCommit
triggerAfterCompletion(status, TransactionSynchronization.STATUS_ROLLED_BACK);
throw ex;
}
catch (TransactionException ex) {
// can only be caused by doCommit
if (isRollbackOnCommitFailure()) {
doRollbackOnCommitException(status, ex);
}
else {
triggerAfterCompletion(status, TransactionSynchronization.STATUS_UNKNOWN);
}
throw ex;
}
catch (RuntimeException | Error ex) {
if (!beforeCompletionInvoked) {
triggerBeforeCompletion(status);
}
doRollbackOnCommitException(status, ex);
throw ex;
}
// Trigger afterCommit callbacks, with an exception thrown there
// propagated to callers but the transaction still considered as committed.
try {
// 呼叫同步器提交後的邏輯
triggerAfterCommit(status);
}
finally {
// 呼叫同步器完成後的邏輯
triggerAfterCompletion(status, TransactionSynchronization.STATUS_COMMITTED);
}
}
finally {
// 恢復被掛起的資源到當前執行緒中
cleanupAfterCompletion(status);
}
}
/**
* 提交的核心邏輯,直接呼叫Connection的提交方法
*/
protected void doCommit(DefaultTransactionStatus status) {
DataSourceTransactionObject txObject = (DataSourceTransactionObject) status.getTransaction();
Connection con = txObject.getConnectionHolder().getConnection();
if (status.isDebug()) {
logger.debug("Committing JDBC transaction on Connection [" + con + "]");
}
try {
con.commit();
}
catch (SQLException ex) {
throw translateException("JDBC commit", ex);
}
}
/**
* 恢復被掛起的資源到當前執行緒中
*/
private void cleanupAfterCompletion(DefaultTransactionStatus status) {
status.setCompleted();
if (status.isNewSynchronization()) {
TransactionSynchronizationManager.clear();
}
// 判斷當前事務執行的方法,是不是建立這個事務的方法
if (status.isNewTransaction()) {
// 這裡會去關閉資料庫連線
doCleanupAfterCompletion(status.getTransaction());
}
// 恢復被掛起的資源到當前執行緒中
if (status.getSuspendedResources() != null) {
if (status.isDebug()) {
logger.debug("Resuming suspended transaction after completion of inner transaction");
}
Object transaction = (status.hasTransaction() ? status.getTransaction() : null);
// 恢復
resume(transaction, (SuspendedResourcesHolder) status.getSuspendedResources());
}
}
回滾事務的邏輯
protected void completeTransactionAfterThrowing(@Nullable TransactionInfo txInfo, Throwable ex) {
if (txInfo != null && txInfo.getTransactionStatus() != null) {
if (logger.isTraceEnabled()) {
logger.trace("Completing transaction for [" + txInfo.getJoinpointIdentification() +
"] after exception: " + ex);
}
// transactionAttribute的實現類為RuleBasedTransactionAttribute,父類為DefaultTransactionAttribute
// 判斷配置的rollBackFor的異常資訊
if (txInfo.transactionAttribute != null && txInfo.transactionAttribute.rollbackOn(ex)) {
try {
txInfo.getTransactionManager().rollback(txInfo.getTransactionStatus());
}
catch (TransactionSystemException ex2) {
logger.error("Application exception overridden by rollback exception", ex);
ex2.initApplicationException(ex);
throw ex2;
}
catch (RuntimeException | Error ex2) {
logger.error("Application exception overridden by rollback exception", ex);
throw ex2;
}
}
else {
// We don't roll back on this exception.
// Will still roll back if TransactionStatus.isRollbackOnly() is true.
try {
txInfo.getTransactionManager().commit(txInfo.getTransactionStatus());
}
catch (TransactionSystemException ex2) {
logger.error("Application exception overridden by commit exception", ex);
ex2.initApplicationException(ex);
throw ex2;
}
catch (RuntimeException | Error ex2) {
logger.error("Application exception overridden by commit exception", ex);
throw ex2;
}
}
}
}
/**
* 判斷回滾條件是否滿足
* 原始碼位置:org.springframework.transaction.interceptor.RuleBasedTransactionAttribute.rollbackOn(Throwable)
*/
public boolean rollbackOn(Throwable ex) {
RollbackRuleAttribute winner = null;
int deepest = Integer.MAX_VALUE;
if (this.rollbackRules != null) {
// 遍歷所有的RollbackRuleAttribute,判斷現在丟擲的異常ex是否匹配RollbackRuleAttribute中指定的異常型別的子類或本身
for (RollbackRuleAttribute rule : this.rollbackRules) {
int depth = rule.getDepth(ex);
if (depth >= 0 && depth < deepest) {
deepest = depth;
winner = rule;
}
}
}
// User superclass behavior (rollback on unchecked) if no rule matches.
// 沒有匹配的規則,呼叫父類判斷是不是執行時異常
if (winner == null) {
return super.rollbackOn(ex);
}
// ex所匹配的RollbackRuleAttribute,可能是NoRollbackRuleAttribute,如果是匹配的NoRollbackRuleAttribute,那就表示現在這個異常ex不用回滾
return !(winner instanceof NoRollbackRuleAttribute);
}
/**
* 回滾前的準備邏輯
* 原始碼位置:org.springframework.transaction.support.AbstractPlatformTransactionManager.rollback(TransactionStatus)
*/
public final void rollback(TransactionStatus status) throws TransactionException {
// 不完整的,沒有執行完拋異常
if (status.isCompleted()) {
throw new IllegalTransactionStateException(
"Transaction is already completed - do not call commit or rollback more than once per transaction");
}
DefaultTransactionStatus defStatus = (DefaultTransactionStatus) status;
processRollback(defStatus, false);
}
/**
* 回滾
*/
private void processRollback(DefaultTransactionStatus status, boolean unexpected) {
try {
boolean unexpectedRollback = unexpected;
try {
// 只會觸發完成前的同步器邏輯
triggerBeforeCompletion(status);
// 比如mysql中的savepoint
if (status.hasSavepoint()) {
if (status.isDebug()) {
logger.debug("Rolling back transaction to savepoint");
}
// 回滾到上一個savepoint位置
status.rollbackToHeldSavepoint();
}
else if (status.isNewTransaction()) {
if (status.isDebug()) {
logger.debug("Initiating transaction rollback");
}
// 如果當前執行的方法是新開了一個事務,那麼就直接回滾
doRollback(status);
}
else {
// Participating in larger transaction
// 如果當前執行的方法,是公用了一個已存在的事務,而當前執行的方法拋了異常,則要判斷整個事務到底要不要回滾,看具體配置
if (status.hasTransaction()) {
// 如果一個事務中有兩個方法,第二個方法拋異常了,那麼第二個方法就相當於執行失敗需要回滾,如果globalRollbackOnParticipationFailure為true,那麼第一個方法在沒有拋異常的情況下也要回滾
if (status.isLocalRollbackOnly() || isGlobalRollbackOnParticipationFailure()) {
if (status.isDebug()) {
logger.debug("Participating transaction failed - marking existing transaction as rollback-only");
}
// 直接將rollbackOnly設定到ConnectionHolder中去,表示整個事務的sql都要回滾
doSetRollbackOnly(status);
}
else {
if (status.isDebug()) {
logger.debug("Participating transaction failed - letting transaction originator decide on rollback");
}
}
}
else {
logger.debug("Should roll back transaction but cannot - no transaction available");
}
// Unexpected rollback only matters here if we're asked to fail early
if (!isFailEarlyOnGlobalRollbackOnly()) {
unexpectedRollback = false;
}
}
}
catch (RuntimeException | Error ex) {
triggerAfterCompletion(status, TransactionSynchronization.STATUS_UNKNOWN);
throw ex;
}
triggerAfterCompletion(status, TransactionSynchronization.STATUS_ROLLED_BACK);
// Raise UnexpectedRollbackException if we had a global rollback-only marker
if (unexpectedRollback) {
throw new UnexpectedRollbackException(
"Transaction rolled back because it has been marked as rollback-only");
}
}
finally {
cleanupAfterCompletion(status);
}
}
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