本机查询的休眠异常

Question

我有一个获取大量数据的 Hiberante 原生查询。到现在为止，它一直没有打嗝，但由于某些特定数据的原因，我得到了下面给出的例外。我应该如何尝试找出原因？

我的本​​机查询格式为：

    Query query = entityManager.createNativeQuery(sql);
    query.setParameter(1, foo);
    List<Object[]> results = query.getResultList();

实际查询由两个内连接、多个左外连接、一个 where 条件和三列的 order by 组成。它没有对 sql 函数的任何调用。它确实使用索引，因为它是一个大查询。这个问题发生在 Hibernate 4 beta 5 和 4.1.1 中，使用 MySQL 5.5

还有其他查询，但异常与为该本机查询调用 query.getResultList 的时刻直接相关。会不会是 Hibernate 还强制执行其他一些查询（因为懒惰或其他原因？）

Caused by: java.lang.NullPointerException
    at org.hibernate.engine.jdbc.internal.proxy.ResultSetProxyHandler.getJdbcServices(ResultSetProxyHandler.java:57) [hibernate-core-4.0.0.Beta5.jar:4.0.0.Beta5]
    at org.hibernate.engine.jdbc.internal.proxy.AbstractResultSetProxyHandler.continueInvocation(AbstractResultSetProxyHandler.java:110) [hibernate-core-4.0.0.Beta5.jar:4.0.0.Beta5]
    at org.hibernate.engine.jdbc.internal.proxy.AbstractProxyHandler.invoke(AbstractProxyHandler.java:80) [hibernate-core-4.0.0.Beta5.jar:4.0.0.Beta5]
    at $Proxy305.wasNull(Unknown Source)    at org.hibernate.type.descriptor.sql.BasicExtractor.extract(BasicExtractor.java:66) [hibernate-core-4.0.0.Beta5.jar:4.0.0.Beta5]
    at org.hibernate.type.AbstractStandardBasicType.nullSafeGet(AbstractStandardBasicType.java:269) [hibernate-core-4.0.0.Beta5.jar:4.0.0.Beta5]
    at org.hibernate.type.AbstractStandardBasicType.nullSafeGet(AbstractStandardBasicType.java:265) [hibernate-core-4.0.0.Beta5.jar:4.0.0.Beta5]
    at org.hibernate.type.AbstractStandardBasicType.nullSafeGet(AbstractStandardBasicType.java:243) [hibernate-core-4.0.0.Beta5.jar:4.0.0.Beta5]
    at org.hibernate.loader.custom.CustomLoader$ScalarResultColumnProcessor.extract(CustomLoader.java:549) [hibernate-core-4.0.0.Beta5.jar:4.0.0.Beta5]
    at org.hibernate.loader.custom.CustomLoader$ResultRowProcessor.buildResultRow(CustomLoader.java:499) [hibernate-core-4.0.0.Beta5.jar:4.0.0.Beta5]
    at org.hibernate.loader.custom.CustomLoader$ResultRowProcessor.buildResultRow(CustomLoader.java:478) [hibernate-core-4.0.0.Beta5.jar:4.0.0.Beta5]
    at org.hibernate.loader.custom.CustomLoader.getResultColumnOrRow(CustomLoader.java:375) [hibernate-core-4.0.0.Beta5.jar:4.0.0.Beta5]
    at org.hibernate.loader.Loader.getRowFromResultSet(Loader.java:668) [hibernate-core-4.0.0.Beta5.jar:4.0.0.Beta5]
    at org.hibernate.loader.Loader.doQuery(Loader.java:860) [hibernate-core-4.0.0.Beta5.jar:4.0.0.Beta5]
    at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:289) [hibernate-core-4.0.0.Beta5.jar:4.0.0.Beta5]
    at org.hibernate.loader.Loader.doList(Loader.java:2449) [hibernate-core-4.0.0.Beta5.jar:4.0.0.Beta5]
    at org.hibernate.loader.Loader.doList(Loader.java:2435) [hibernate-core-4.0.0.Beta5.jar:4.0.0.Beta5]
    at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2276) [hibernate-core-4.0.0.Beta5.jar:4.0.0.Beta5]
    at org.hibernate.loader.Loader.list(Loader.java:2271) [hibernate-core-4.0.0.Beta5.jar:4.0.0.Beta5]
    at org.hibernate.loader.custom.CustomLoader.list(CustomLoader.java:331) [hibernate-core-4.0.0.Beta5.jar:4.0.0.Beta5]
    at org.hibernate.internal.SessionImpl.listCustomQuery(SessionImpl.java:1571) [hibernate-core-4.0.0.Beta5.jar:4.0.0.Beta5]
    at org.hibernate.internal.AbstractSessionImpl.list(AbstractSessionImpl.java:224) [hibernate-core-4.0.0.Beta5.jar:4.0.0.Beta5]
    at org.hibernate.internal.SQLQueryImpl.list(SQLQueryImpl.java:156) [hibernate-core-4.0.0.Beta5.jar:4.0.0.Beta5]
    at org.hibernate.ejb.QueryImpl.getResultList(QueryImpl.java:252) [hibernate-entitymanager-4.0.0.Beta5.jar:4.0.0.Beta5]
    at com.foo.bar.getResults(MyResultHandler.java:114) [classes:]
    at sun.reflect.GeneratedMethodAccessor16978.invoke(Unknown Source) [:1.7.0]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [:1.7.0]
    at java.lang.reflect.Method.invoke(Method.java:601) [:1.7.0]
    at org.jboss.as.ee.component.ManagedReferenceMethodInterceptor.processInvocation(ManagedReferenceMethodInterceptor.java:51)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:287) [jboss-invocation-1.1.0.Final.jar:1.1.0.Final]
    at org.jboss.invocation.InterceptorContext$Invocation.proceed(InterceptorContext.java:370) [jboss-invocation-1.1.0.Final.jar:1.1.0.Final]
    at org.jboss.as.weld.ejb.Jsr299BindingsInterceptor.doMethodInterception(Jsr299BindingsInterceptor.java:114) [jboss-as-weld-7.0.1.Final.jar:7.0.1.Final]
    at org.jboss.as.weld.ejb.Jsr299BindingsInterceptor.processInvocation(Jsr299BindingsInterceptor.java:122) [jboss-as-weld-7.0.1.Final.jar:7.0.1.Final]
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:287) [jboss-invocation-1.1.0.Final.jar:1.1.0.Final]
    at org.jboss.invocation.WeavedInterceptor.processInvocation(WeavedInterceptor.java:53) [jboss-invocation-1.1.0.Final.jar:1.1.0.Final]
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:287) [jboss-invocation-1.1.0.Final.jar:1.1.0.Final]
    at org.jboss.as.jpa.interceptor.SBInvocationInterceptor.processInvocation(SBInvocationInterceptor.java:45) [jboss-as-jpa-7.0.1.Final.jar:7.0.1.Final]
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:287) [jboss-invocation-1.1.0.Final.jar:1.1.0.Final]
    at org.jboss.as.ejb3.component.stateful.StatefulSessionSynchronizationInterceptor.processInvocation(StatefulSessionSynchronizationInterceptor.java:132)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:287) [jboss-invocation-1.1.0.Final.jar:1.1.0.Final]
    at org.jboss.as.ee.component.NamespaceContextInterceptor.processInvocation(NamespaceContextInterceptor.java:44)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:287) [jboss-invocation-1.1.0.Final.jar:1.1.0.Final]
    at org.jboss.as.ee.component.TCCLInterceptor.processInvocation(TCCLInterceptor.java:45)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:287) [jboss-invocation-1.1.0.Final.jar:1.1.0.Final]
    at org.jboss.invocation.InitialInterceptor.processInvocation(InitialInterceptor.java:21) [jboss-invocation-1.1.0.Final.jar:1.1.0.Final]
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:287) [jboss-invocation-1.1.0.Final.jar:1.1.0.Final]
    at org.jboss.invocation.ChainedInterceptor.processInvocation(ChainedInterceptor.java:61) [jboss-invocation-1.1.0.Final.jar:1.1.0.Final]
    at org.jboss.as.ee.component.ViewDescription$ComponentDispatcherInterceptor.processInvocation(ViewDescription.java:202)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:287) [jboss-invocation-1.1.0.Final.jar:1.1.0.Final]
    at org.jboss.as.jpa.interceptor.SFSBInvocationInterceptor.processInvocation(SFSBInvocationInterceptor.java:58) [jboss-as-jpa-7.0.1.Final.jar:7.0.1.Final]
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:287) [jboss-invocation-1.1.0.Final.jar:1.1.0.Final]
    at org.jboss.as.ejb3.component.stateful.StatefulComponentInstanceInterceptor.processInvocation(StatefulComponentInstanceInterceptor.java:61)
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:287) [jboss-invocation-1.1.0.Final.jar:1.1.0.Final]
    at org.jboss.as.ejb3.component.session.SessionInvocationContextInterceptor$CustomSessionInvocationContext.proceed(SessionInvocationContextInterceptor.java:126)
    at org.jboss.ejb3.tx2.impl.CMTTxInterceptor.invokeInCallerTx(CMTTxInterceptor.java:233)
    ... 93 more

Answer 1

您可能期望来自可空列的原语。

Hibernate 使用反射来创建对象。

public class A {
    private long id;

    private int n;

    public void setN(int n) { this.n = n; }
    public int getN() { return this.n; }

    // id
}

如果您使用DAO.get(id, A.class) 检索A 对象，它将像这样安装：

select a_.id, a_.n from A a_ where a_id = ? /* Where ? is the id */

然后它会这样做（注意，这只是为了说明我的例子）：

A a = new A();

a.setId([a_.id])
a.setN([a_.n])

如果检索两行：

id     n
 1     1
 2     NULL

它会尝试实例化一个A 对象并将其n 属性设置为setN(null)。由于签名是原语，这会引发错误。

查看表描述以查看是否有任何可为空的列。如果是这样，请在 setter 中寻找不期望任何原语。

这意味着当hibernate 执行setPrimitive(null) // signature setPrimitive(long l) 失败。