java.lang.NoClassDefFoundError：無法初始化類xxx.xxx.xxx.HibernateUtil

Question

我在此添加了web.xml的源代碼

<?xml version="1.0" encoding="UTF-8"?>
<web-app id="WebApp_ID" version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
    <display-name>ussd</display-name>
    <servlet>
        <servlet-name>init</servlet-name>
        <jsp-file>/init.jsp</jsp-file>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <context-param>
        <param-name>javax.ws.rs.core.Application</param-name>
        <param-value>com.dialog.mife.ussd.api.USSDApplication</param-value>
    </context-param>
    <context-param>
        <param-name>resteasy.providers</param-name>
        <param-value>com.dialog.mife.ussd.exception.NotFoundException</param-value>
    </context-param>
    <context-param>
        <param-name>resteasy.servlet.mapping.prefix</param-name>
        <param-value>/</param-value>
    </context-param>
    <listener>
        <listener-class>org.jboss.resteasy.plugins.server.servlet.ResteasyBootstrap</listener-class>
    </listener>
    <servlet>
        <servlet-name>Resteasy</servlet-name>
        <servlet-class>org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher</servlet-class>
    </servlet>
    <servlet>
        <servlet-name>ServletAdaptor</servlet-name>
        <servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>Resteasy</servlet-name>
        <url-pattern>/*</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>ServletAdaptor</servlet-name>
        <url-pattern>/webresources/*</url-pattern>
    </servlet-mapping>
</web-app>

Hibernate.cfg.xml。 我的Web服務項目與Jersey + Hibernate一起使用。

    <!DOCTYPE hibernate-configuration PUBLIC
    "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
    "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>   
        <property name="hibernate.bytecode.use_reflection_optimizer">false</property>
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="hibernate.connection.password">xxx</property>
        <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/USSD</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
        <property name="show_sql">true</property>   
        <property name="hbm2ddl.auto">update</property>
        <property name="hibernate.transaction.factory_class">org.hibernate.transaction.JDBCTransactionFactory</property>
        <property name="connection.pool_size">1</property>
        <property name="hibernate.connection.autocommit">true</property>
        <mapping class="com.xxx.xxx.xxx.xxx.Application" />

    </session-factory>
</hibernate-configuration>

這是HibernateUtil類

public class HibernateUtil {
    private static final SessionFactory sessionFactory;
    static {
        try {
            sessionFactory = new Configuration().configure().buildSessionFactory();
        } catch (Exception ex) {
            ex.printStackTrace();
            throw new ExceptionInInitializerError(ex);
        }
    }

這是我添加了Hibernate最新的jar文件的錯誤。 [ hibernate-core-4.3.7.Final.jar ]

SEVERE: StandardWrapper.Throwable
java.lang.NoClassDefFoundError: Could not initialize class com.dialog.mife.ussd.util.HibernateUtil
    at org.apache.jsp.init_jsp.jspInit(init_jsp.java:23)
    at org.apache.jasper.runtime.HttpJspBase.init(HttpJspBase.java:48)
    at org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:180)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:369)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
    at org.apache.jasper.servlet.JspServlet.init(JspServlet.java:138)
    at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1280)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1193)
    at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1088)
    at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5123)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5407)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
    at java.util.concurrent.FutureTask.run(FutureTask.java:262)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:744)

Nov 11, 2014 2:06:11 PM org.apache.catalina.core.StandardContext loadOnStartup
SEVERE: Servlet /ussd threw load() exception
java.lang.NoClassDefFoundError: Could not initialize class com.dialog.mife.ussd.util.HibernateUtil
    at org.apache.jsp.init_jsp.jspInit(init_jsp.java:23)
    at org.apache.jasper.runtime.HttpJspBase.init(HttpJspBase.java:48)
    at org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:180)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:369)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
    at org.apache.jasper.servlet.JspServlet.init(JspServlet.java:138)
    at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1280)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1193)
    at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1088)
    at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5123)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5407)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
    at java.util.concurrent.FutureTask.run(FutureTask.java:262)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:744)

請幫我解決這個問題謝謝

Answer 1

SessionFactory初始化失敗時，可能會發生這種錯誤。 您已經提到您正在使用hibernate-core-4.3.7 。 初始化SessionFactory方式不適用於此版本。 使用Hibernate 3.x版或更改初始化SessionFactory 。 下面是在Hibernate 4.x +構建會話工廠的正確方法。

Configuration configuration = new Configuration().configure();
StandardServiceRegistryBuilder builder = new StandardServiceRegistryBuilder().
applySettings(configuration.getProperties());
SessionFactory factory = configuration.buildSessionFactory(builder.build());

Answer 2

初始化com.dialog.mife.ussd.util.HibernateUtil類時，缺少某些類（例如，靜態字段或靜態初始化塊）。
運行servlet時，請確保所有庫都位於lib目錄中。

Answer 3

當類在類加載器中出現的次數超過一次時，我通常會收到那些java.lang.NoClassDefFoundError。 檢查jar，因為如果同一類存在於多個類中（可能同時包含在webservice客戶端jar和其他地方），則java類加載器將不知道要加載哪個類，即使它是完全相同的類也是如此。

Answer 4

根據codejava.net ，用於hibernate-core-4.x的HibernateUtil如下所示：

...
import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;

public class HibernateUtil {
    private static SessionFactory sessionFactory;

    public static SessionFactory getSessionFactory() {
        if (sessionFactory == null) {
            // loads configuration and mappings
            Configuration configuration = new Configuration().configure();
            ServiceRegistry serviceRegistry
                = new StandardServiceRegistryBuilder()
                    .applySettings(configuration.getProperties()).build();

            // builds a session factory from the service registry
            sessionFactory = configuration.buildSessionFactory(serviceRegistry);           
        }

        return sessionFactory;
    }
}
....

與上面的示例在光學上略有不同，但是效果相同。 為了確保確實沒有舊字典hibernate-3.x 。

Answer 5

在HibernateUtils中，有“ /hibernate.cfg.xml”文件的參考。 我們必須在其中添加hbm.xml映射。 還確認映射文件存在於資源文件中。