Question

Spring批处理无法跳过异常。任何人都可以建议我在这里错过了什么吗？

<batch:job id="runPromotion">   
        <batch:step id="readPromotionStep">
            <batch:tasklet ref="processPromotion"></batch:tasklet>
            <batch:next on="SUCCESS" to="getPromotionalPoints" />
            <batch:end on="FAILED"></batch:end> 
            <batch:listeners>
                <batch:listener ref="queryProvider"/>           
            </batch:listeners>          
        </batch:step>
        <batch:step id="getPromotionalPoints">      
            <batch:tasklet >            
                <batch:chunk reader="transactionDataReader" writer="userPromotionWriter" commit-interval="100" skip-limit="100">                
                <batch:skippable-exception-classes >
                    <batch:include class="org.hibernate.exception.ConstraintViolationException"/>
                    <batch:include class="javax.persistence.PersistenceException"/>
                </batch:skippable-exception-classes>
                </batch:chunk>
            </batch:tasklet>
            <batch:listeners>
                <batch:listener ref="queryProvider"/>           
            </batch:listeners>


        </batch:step>   

    </batch:job>

运行批处理时

以下是错误：

2013-08-24 14：43：16,451 - [main] WARN：org.hibernate.engine.jdbc.spi.SqlExceptionHelper：143 - SQL错误：1062，SQLState：23000 2013-08-24 14：43：16,451 - [main]错误：org.hibernate.engine.jdbc.spi.SqlExceptionHelper：144 - 键'promotion_id'重复输入'1' javax.persistence.PersistenceException：org.hibernate.exception.ConstraintViolationException：键'promotion_id'的重复条目'1' 在org.hibernate.ejb.AbstractEntityManagerImpl.convert（AbstractEntityManagerImpl.java:1377）

Answer 1

如果您查看错误

javax.persistence.PersistenceException：org.hibernate.exception.ConstraintViolationException

您会注意到， PersistenceException 是引发的实际错误，而 ConstraintViolationException 是原因。这就是为什么向 skippable-exception-classes 中添加 ConstraintViolationException 无效的原因，但令我惊讶的是，甚至 PersistenceException 都不适合您。它对我有用（但是我顺便使用了Java配置）。此外，由于您还将 PersistenceException （这是 ConstraintViolationException 的超类）添加到 skippable-exception-classes ，因此添加了 ConstraintViolationException 似乎是多余的。

我假设您只希望跳过 ConstraintViolationException 。我尝试了两种解决方案（但使用Java配置）：

实施SkipPolicy以创建自定义的船长。注意我们如何检查引发异常的原因是否是 ConstraintViolationException ：

package pkg;

import javax.persistence.PersistenceException;
import org.hibernate.exception.ConstraintViolationException;
import org.springframework.batch.core.step.skip.SkipLimitExceededException;
import org.springframework.batch.core.step.skip.SkipPolicy;
import org.springframework.stereotype.Component;

public class ConstraintViolationExceptionSkipper implements SkipPolicy {

    private int skipLimit;

    @Override
    public boolean shouldSkip(Throwable t, int skipCount) throws SkipLimitExceededException {
      if(t instanceof PersistenceException && 
          t.getCause() instanceof ConstraintViolationException) {
        return true;
      }
      return false;
    }

    public void setSkipLimit(int skipLimit) {
      this.skipLimit = skipLimit;
    }
}

并将上面的船长设置为块中的 skip-policy ，并摆脱 skippable-exception-class 块。还要注意在此处设置 skip-limit 的方法：

<batch:chunk reader="transactionDataReader" writer="userPromotionWriter" commit-interval="100" 
    skip-policy="skipPolicy" />

<bean id="skipPolicy" class=pkg.ConstraintViolationExceptionSkipper">
  <property name="skipLimit" value="100" />
</bean>

修改您的编写器以捕获PersistenceException并将其作为ConstraintVioaltionException重新抛出。我不确定您是如何实现 userPromotionWriter 的，但是下面是一个示例实现。它使用JPA进行持久化，显式刷新EntityManager并捕获并引发一个新异常，如我刚才所说：

package pkg;

import java.util.List;

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;

import org.hibernate.exception.ConstraintViolationException;
import org.springframework.batch.item.ItemWriter;
import org.springframework.stereotype.Component;

@Component("userPromotionWriter")
public class UserPromotionWriter implements ItemWriter<User> {

  @PersistenceContext
  private EntityManager entityManger;

  @Override
  public void write(List<? extends User> users) throws Exception {
      for(User user : users) {
        entityManger.persist(user);
        try {
            entityManger.flush();
        } catch(Exception e) {
            if(e.getCause() instanceof ConstraintViolationException) {
                throw new ConstraintViolationException("Tried to insert a User record with a non-unique user_id of " + user.getUserId(), null, null);
            }
            throw e;
        }
        finally {
          entityManger.clear();
        }
      }
   }
}

现在，由于抛出的异常是ConstraintViolationException（而不是PersistenceException），因此以下方法可以正常工作：

<batch:chunk reader="transactionDataReader" writer="userPromotionWriter" commit-interval="100" skip-limit="100"> <batch:skippable-exception-classes > <batch:include class="org.hibernate.exception.ConstraintViolationException"/> </batch:skippable-exception-classes> </batch:chunk>

不在Spring批处理中跳过异常

1 个答案: