SpringBoot中的事务处理问题

// 这个类中的public方法如果抛出Exception，则该方法会回滚
@Transactional(rollbackFor = Exception.class)
public class DefaultFooService implements FooService {
 
  public Foo getFoo(String fooName) {
    // do something
  }
 
  // these settings have precedence for this method
  //方法上注解属性会覆盖类注解上的相同属性
  @Transactional(readOnly = false, propagation = Propagation.REQUIRES_NEW)
  public void updateFoo(Foo foo) {
    // do something
  }
}

package org.springframework.transaction.annotation;
 
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Inherited;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
 
import org.springframework.core.annotation.AliasFor;
import org.springframework.transaction.TransactionDefinition;
 
@Target({ElementType.TYPE, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Inherited
@Documented
public @interface Transactional {
 
	@AliasFor("transactionManager")
	String value() default "";
 
	@AliasFor("value")
	String transactionManager() default "";
 
	Propagation propagation() default Propagation.REQUIRED;
 
	Isolation isolation() default Isolation.DEFAULT;
 
	int timeout() default TransactionDefinition.TIMEOUT_DEFAULT;
 
	boolean readOnly() default false;
 
	Class<? extends Throwable>[] rollbackFor() default {};
 
	String[] rollbackForClassName() default {};
 
	Class<? extends Throwable>[] noRollbackFor() default {};
 
	String[] noRollbackForClassName() default {};
}

package org.springframework.transaction.annotation;
 
import org.springframework.transaction.TransactionDefinition;
 
public enum Isolation {
 
	DEFAULT(TransactionDefinition.ISOLATION_DEFAULT),
 
	READ_UNCOMMITTED(TransactionDefinition.ISOLATION_READ_UNCOMMITTED),
 
	READ_COMMITTED(TransactionDefinition.ISOLATION_READ_COMMITTED),
 
	REPEATABLE_READ(TransactionDefinition.ISOLATION_REPEATABLE_READ),
	
	SERIALIZABLE(TransactionDefinition.ISOLATION_SERIALIZABLE);
 
 
	private final int value;
 
	Isolation(int value) {
		this.value = value;
	}
 
	public int value() {
		return this.value;
	}
}

@Transactional
public void contextLoads() {
    try {
        int i = 0;
    }catch (Exception e){
        System.out.println("不可以回滚");
    }
}

@Transactional
public void contextLoads() {
    try {
        int i = 0;
    }catch (Exception e){
        // 手动回滚
        TransactionAspectSupport.currentTransactionStatus().setRollbackOnly();
        System.out.println("可以回滚");
    }
}