try{
     con.setAutoCommit(false);//開(kāi)啟事務(wù)
     ......
     con.commit();//try的最后提交事務(wù)      
} catch（） {
    con.rollback();//回滾事務(wù)
}

Connection.getTransactionIsolation()

con.setTransactionIsolation(Connection.TRANSACTION_REPEATABLE_READ);

public interface PlatformTransactionManager {
    // 通過(guò)Transation定義 獲取Transation
    TransactionStatus getTransaction(@Nullable TransactionDefinition var1) throws TransactionException;
    // 提交事務(wù)
    void commit(TransactionStatus var1) throws TransactionException;
    // 回滾事務(wù)
    void rollback(TransactionStatus var1) throws TransactionException;
}

public interface TransactionDefinition {
    // 傳播機(jī)制
    int PROPAGATION_REQUIRED = 0;
    int PROPAGATION_SUPPORTS = 1;
    int PROPAGATION_MANDATORY = 2;
    int PROPAGATION_REQUIRES_NEW = 3;
    int PROPAGATION_NOT_SUPPORTED = 4;
    int PROPAGATION_NEVER = 5;
    int PROPAGATION_NESTED = 6;
    // 隔離級(jí)別
    int ISOLATION_DEFAULT = -1;
    int ISOLATION_READ_UNCOMMITTED = 1;
    int ISOLATION_READ_COMMITTED = 2;
    int ISOLATION_REPEATABLE_READ = 4;
    int ISOLATION_SERIALIZABLE = 8;
    int TIMEOUT_DEFAULT = -1;

    int getPropagationBehavior();
    // 獲取隔離級(jí)別
    int getIsolationLevel();

    int getTimeout();
    
    boolean isReadOnly();

    @Nullable
    String getName();
}

public interface TransactionStatus extends SavepointManager, Flushable {
    boolean isNewTransaction();

    boolean hasSavepoint();

    void setRollbackOnly();

    boolean isRollbackOnly();

    void flush();

    boolean isCompleted();
}

@Autowired
private PlatformTransactionManager transactionManager;
public void testTX(){
    DefaultTransactionDefinition definition = new DefaultTransactionDefinition();
    TransactionStatus status = transactionManager.getTransaction(definition);
    try {
        // 業(yè)務(wù)邏輯
        // ...
        
        // 提交事務(wù)
        transactionManager.commit(status);
    }catch (Exception e){
        // 發(fā)生異常，事務(wù)回滾
        transactionManager.rollback(status);
    }
}

@Transactional
void testTX2(){
    // 業(yè)務(wù)邏輯 ...
}

@Target({ElementType.METHOD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Inherited
@Documented
public @interface Transactional {

    //指定使用的事務(wù)管理器
    @AliasFor("transactionManager")
    String value() default "";

    @AliasFor("value")
    String transactionManager() default "";
    // 可選的事務(wù)傳播行為設(shè)置
    Propagation propagation() default Propagation.REQUIRED;
    // 可選的事務(wù)隔離級(jí)別設(shè)置
    Isolation isolation() default Isolation.DEFAULT;
    // 事務(wù)超時(shí)時(shí)間設(shè)置
    int timeout() default -1;
    // 讀寫(xiě)或只讀事務(wù)，默認(rèn)讀寫(xiě)
    boolean readOnly() default false;
    // 導(dǎo)致事務(wù)回滾的異常類(lèi)數(shù)組 
    Class<? extends Throwable>[] rollbackFor() default {};
    // 導(dǎo)致事務(wù)回滾的異常類(lèi)名字?jǐn)?shù)組
    String[] rollbackForClassName() default {};
    // 不會(huì)導(dǎo)致事務(wù)回滾的異常類(lèi)數(shù)組
    Class<? extends Throwable>[] noRollbackFor() default {};
    // 不會(huì)導(dǎo)致事務(wù)回滾的異常類(lèi)名字?jǐn)?shù)組
    String[] noRollbackForClassName() default {};
}

public void delUser(Integer userId) {
    // 刪除和用戶(hù)相關(guān)的信息
     otherRepository.deleteByUserId(userId); 
    // 刪除用戶(hù)
     userRepository.deleteById(userId);
}

public void delUser(Integer userId) {
    // 刪除和用戶(hù)相關(guān)的信息
    otherRepository.deleteByUserId();
    if (true) {
        throw new RuntimeException("xxx");
    }
    // 刪除用戶(hù)
     userRepository.deleteById(userId);
}

@Transactional
public void delUser(Integer userId) {
    // 刪除和用戶(hù)相關(guān)的信息
    otherRepository.deleteByUserId();
    if (true) {
        throw new RuntimeException("xxx");
    }
    // 刪除用戶(hù)
     userRepository.deleteById(userId);
}

@Bean
public ConnectionFactory connectionFactory() {
    CachingConnectionFactory connectionFactory = new CachingConnectionFactory();
    return connectionFactory;
}

@Bean
public RabbitTransactionManager rabbitTransactionManager(ConnectionFactory connectionFactory) {
    return new RabbitTransactionManager(connectionFactory);
}