如何在@Transactional处于课堂级别时使用readonly [英] How to use readonly when @Transactional is on class level

问题描述

我在服务类中调用 DAO @Transactional c $ c>方法
我想知道如何使用只读特定服务方法。

我必须定义额外的 @Transactional readonly = true ，或者有另外一种方法？ >

从Spring API 此处。

当评估方法的事务设置时，派生最多的位置优先。在以下示例中，DefaultFooService类在类级别使用只读事务的设置进行注释，但同一类中updateFoo（Foo）方法的@Transactional注释优先于定义的事务设置

$ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $'

public Foo getFoo（String fooName）{
//做某事
}

//这些设置优先于此方法
@Transactional（readOnly = false，propagation = Propagation.REQUIRES_NEW）
public void updateFoo（Foo foo）{
//做某事
}
}

传播设置为PROPAGATION_REQUIRED。

隔离级别为ISOLATION_DEFAULT。

/ b>

交易是读/写的。

交易超时默认为底层交易系统的默认超时，

任何RuntimeException都会触发回滚，而任何检查过的异常都不会。

I am using @Transactional on my service class which call DAO methods and I was wondering how can I use read only on specific service method.
Do I have to define extra @Transactional with readonly=true on this service method, or there's another way?

解决方案

From the Spring API here.

The most derived location takes precedence when evaluating the transactional settings for a method. In the case of the following example, the DefaultFooService class is annotated at the class level with the settings for a read-only transaction, but the @Transactional annotation on the updateFoo(Foo) method in the same class takes precedence over the transactional settings defined at the class level.

@Transactional(readOnly = true)
public class DefaultFooService implements FooService {

  public Foo getFoo(String fooName) {
    // do something
  }

  // these settings have precedence for this method
  @Transactional(readOnly = false, propagation = Propagation.REQUIRES_NEW)
  public void updateFoo(Foo foo) {
    // do something
  }
}

The @Transactional annotation is metadata that specifies that an interface, class, or method must have transactional semantics; for example, "start a brand new read-only transaction when this method is invoked, suspending any existing transaction". The default @Transactional settings are as follows:

Propagation setting is PROPAGATION_REQUIRED.

Isolation level is ISOLATION_DEFAULT.

Transaction is read/write.

Transaction timeout defaults to the default timeout of the underlying transaction system, or to none if timeouts are not supported.

Any RuntimeException triggers rollback, and any checked Exception does not.

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