调用getNextException以查看原因:如何使Hibernate/JPA显示数据库服务器消息以查找异常

Question

我正在使用Postgresql,Hibernate和JPA.每当数据库中出现异常时,我都会得到类似这样的东西,因为它没有显示DB服务器上真正出错的地方.

Caused by: java.sql.BatchUpdateException: Batch entry 0 update foo set ALERT_FLAG='3' was aborted.  Call getNextException to see the cause.
    at org.postgresql.jdbc2.AbstractJdbc2Statement$BatchResultHandler.handleError(AbstractJdbc2Statement.java:2621)
    at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1837)
    at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:407)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.executeBatch(AbstractJdbc2Statement.java:2754)
    at com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.executeBatch(NewProxyPreparedStatement.java:1723)
    at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:70)
    at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:268)
    ... 82 more

我希望数据库中的异常消息出现在应用程序的日志中.

我遇到过这篇文章,它使用一个Aspect来填充异常链,否则在SQLExceptions的情况下不能正确填充.

有没有办法解决这个问题,而无需使用Aspects或任何自定义代码.理想的解决方案只涉及配置文件更改.

Answer 1

这对我有用,可以获得导致问题的异常消息(Hibernate 3.2.5.ga):

catch (JDBCException jdbce) {
    jdbce.getSQLException().getNextException().printStackTrace();
}

Answer 2

无需编写任何自定义代码即可实现此目的 - Hibernate将默认记录异常原因.如果您看不到这一点,则不能正确设置Hibernate日志记录.这是slf4j + log4j的示例,并使用Maven进行依赖关系管理.

的src /主/爪哇/ pgextest/PGExceptionTest.java

public class PGExceptionTest {

    public static void main(String[] args) throws Exception {

        EntityManagerFactory entityManagerFactory = Persistence.createEntityManagerFactory(
                "pgextest");
        EntityManager entityManager = entityManagerFactory.createEntityManager();
        entityManager.getTransaction().begin();
        // here I attempt to persist an object with an ID that is already in use
        entityManager.persist(new PGExceptionTestBean(1));
        entityManager.getTransaction().commit();
        entityManager.close();
    }
}

SRC /主/资源/ log4j.properties

log4j.rootLogger=ERROR, stdout

log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n

SRC /主/资源/ META-INF/persistence.xml中

<persistence xmlns="http://java.sun.com/xml/ns/persistence"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
        version="2.0">
    <persistence-unit name="pgextest">
        <properties>
            <property name="javax.persistence.jdbc.driver" value="org.postgresql.Driver"/>
            <property name="javax.persistence.jdbc.url" value="jdbc:postgresql://localhost/pgextest"/>
            <property name="javax.persistence.jdbc.user" value="postgres"/>
            <property name="javax.persistence.jdbc.password" value="postgres"/>
            <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect"/>
            <property name="hibernate.jdbc.batch_size" value="5"/>
        </properties>
    </persistence-unit>
</persistence>

的pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

    <modelVersion>4.0.0</modelVersion>

    <groupId>pgextest</groupId>
    <artifactId>pgextest</artifactId>
    <version>0.0.1-SNAPSHOT</version>

    <build>
        <plugins>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.6</source>
                    <target>1.6</target>
                </configuration>
            </plugin>
        </plugins>
    </build>

    <dependencies>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-entitymanager</artifactId>
            <version>3.6.9.Final</version>
        </dependency>   

        <dependency>
            <groupId>postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <version>9.1-901.jdbc4</version>
            <scope>runtime</scope>
        </dependency>

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.6.1</version>
            <scope>runtime</scope>
        </dependency>

        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.15</version>
            <scope>runtime</scope>
        </dependency>
    </dependencies>
</project>

执行main方法将记录以下内容:

ERROR [main] - Batch entry 0 insert into PGExceptionTestBean (label, id) values (NULL, '1') was aborted.  Call getNextException to see the cause.
ERROR [main] - ERROR: duplicate key value violates unique constraint "pgexceptiontestbean_pkey"

这也许值得一提的是,您可以禁用JDBC批处理,通过属性设置包装原始异常hibernate.jdbc.batch_size到0(不用说了你可能不希望这样做生产.)

Answer 3

我认为 Aspect Programming 是解决此类问题的更好方法。

但是，如果您想编写自定义代码来执行此操作，您可以捕获 SqlException 并循环遍历它并记录每个异常。像这样的事情应该有效。

try {
 // whatever your code is
} catch (SQLException e) {
    while(e!= null) {
      logger.log(e);
      e = e.getNextException();
    }
}