休眠状态在调用query.list方法

时间：2019-04-05 13:43:26

标签： java sql hibernate hql

我试图通过使用hibernate运行查询从数据库中获取一些数据。然后，使用query.list方法将数据存储在List中。问题是运行query.list方法时出现nullPointerException，我认为这是因为查询不返回任何要列出的数据。

这是产生兴奋的方法

public static void getDataForMonth(int yearCount ,int monthCount){
        try {
            session.beginTransaction();
            LocalDate date = LocalDate.of(yearCount, monthCount, 1);

            Query query = session.createQuery("select t from Task t where month(t.date) = month(:date)  and year(t.date) = year(:date)");

            query.setParameter("date", dtf.format(date));
            taskList = query.list();
            session.getTransaction().commit();

            } finally {
            session.close();
        }
    }

这是日志：

Exception in Application constructor
java.lang.reflect.InvocationTargetException
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:564)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:473)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:372)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:564)
    at java.base/sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:941)
Caused by: java.lang.RuntimeException: Unable to construct Application instance: class tadej.Main
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:963)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication$2(LauncherImpl.java:198)
    at java.base/java.lang.Thread.run(Thread.java:844)
Caused by: java.lang.reflect.InvocationTargetException
    at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:488)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$8(LauncherImpl.java:875)
    at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runAndWait$11(PlatformImpl.java:449)
    at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$9(PlatformImpl.java:418)
    at java.base/java.security.AccessController.doPrivileged(Native Method)
    at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(PlatformImpl.java:417)
    at javafx.graphics/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:96)
    at javafx.graphics/com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at javafx.graphics/com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(WinApplication.java:175)
    ... 1 more
Caused by: java.lang.NullPointerException
    at org.hibernate.query.sqm.consume.spi.BaseSqmToSqlAstConverter.visitGenericFunction(BaseSqmToSqlAstConverter.java:1184)
    at org.hibernate.query.sqm.tree.expression.function.SqmGenericFunction.accept(SqmGenericFunction.java:49)
    at org.hibernate.query.sqm.consume.spi.BaseSqmToSqlAstConverter.visitRelationalPredicate(BaseSqmToSqlAstConverter.java:1774)
    at org.hibernate.query.sqm.consume.spi.BaseSqmToSqlAstConverter.visitRelationalPredicate(BaseSqmToSqlAstConverter.java:213)
    at org.hibernate.query.sqm.tree.predicate.RelationalSqmPredicate.accept(RelationalSqmPredicate.java:72)
    at org.hibernate.query.sqm.consume.spi.BaseSqmToSqlAstConverter.visitAndPredicate(BaseSqmToSqlAstConverter.java:1752)
    at org.hibernate.query.sqm.consume.spi.BaseSqmToSqlAstConverter.visitAndPredicate(BaseSqmToSqlAstConverter.java:213)
    at org.hibernate.query.sqm.tree.predicate.AndSqmPredicate.accept(AndSqmPredicate.java:33)
    at org.hibernate.query.sqm.consume.spi.BaseSqmToSqlAstConverter.visitQuerySpec(BaseSqmToSqlAstConverter.java:417)
    at org.hibernate.sql.ast.produce.sqm.spi.SqmSelectToSqlAstConverter.visitSelectStatement(SqmSelectToSqlAstConverter.java:189)
    at org.hibernate.sql.ast.produce.sqm.spi.SqmSelectToSqlAstConverter.interpret(SqmSelectToSqlAstConverter.java:113)
    at org.hibernate.query.sqm.internal.ConcreteSqmSelectQueryPlan.performList(ConcreteSqmSelectQueryPlan.java:162)
    at org.hibernate.query.sqm.internal.QuerySqmImpl.doList(QuerySqmImpl.java:275)
    at org.hibernate.query.internal.AbstractQuery.list(AbstractQuery.java:1302)
    at tadej.TaskManager.<init>(TaskManager.java:129)
    at tadej.ChartPanel.sortDataByDay(ChartPanel.java:47)
    at tadej.ChartPanel.<init>(ChartPanel.java:31)
    at tadej.PanelManager.<init>(PanelManager.java:12)
    at tadej.Main.<init>(Main.java:10)
    ... 13 more
Exception running application tadej.Main

我有一堆类似的方法，它们以相同的原理工作，但查询不同，而且效果很好。

例如：

public static void getDataByDescriptionAndDate(String description, String date) {
        try {
            session.beginTransaction();

            Query query = session.createQuery("select c.id, c.description, c.completion, c.date from Task c where c.description = :desc and c.date = :dt");

            query.setParameter("desc", description).setParameter("dt", date);
            taskList = query.list();
            session.getTransaction().commit();

        } finally {
            Main.getFactory().getCurrentSession().close();
        }
    }

我尝试以String格式传递date参数，但是发生相同的问题，我也尝试在MySQL工作台中进行查询，并且该查询工作正常，因此我很困惑为什么它在程序中不起作用。我坚持使用此查询，因为这是我发现的唯一一个将基于从日期参数收集的月份和年份返回数据的查询，如果有人知道查询也会返回我所需的数据，请告诉我。 / p>

1 个答案:

答案 0 :(得分：0)

问题解决了。显然，最新版本的hibernate不支持month（）和year（）函数，因此我将不得不从数据库中获取的所有数据的列表中选择Java中所需的数据，或者使用其他查询。

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