Performance JPA Hibernate工作非常慢

我正在学习JPA。 我尝试了Spring JPA Hibernate组合。 应用程序运行正常，我得到了结果。 但是，尽管数据库中只有一条记录，但加载页面大约需要4到5分钟。 不太清楚我做错了什么。 我在谷歌上搜索了同样的结果，但我得到的只是性能优化建议，但我认为我缺少了一些更基本的东西，因为我的表中只有一条记录

详情如下:

Persistence.xml

<?xml version="1.0" encoding="UTF-8" ?>
<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" xmlns="http://java.sun.com/xml/ns/persistence">
  <persistence-unit name="bike_unit" transaction-type="RESOURCE_LOCAL">
  <provider>org.hibernate.ejb.HibernatePersistence</provider>
  <jta-data-source>java:comp/env/jdbc/testdb123</jta-data-source>
    <class>bike.Bike</class>
    <class>bike.Company</class>
    <properties>
        <property name="hibernate.dialect" value="org.hibernate.dialect.DerbyDialect"/>
        <property name="javax.persistence.jdbc.driver" value="org.apache.derby.jdbc.ClientDriver"/>
        <property name="javax.persistence.jdbc.url" value="jdbc:derby://localhost:1527/bike"/>
        <property name="javax.persistence.jdbc.user" value="abc"/>
        <property name="javax.persistence.jdbc.password" value="abc"/>
    </properties>

  </persistence-unit>
</persistence>

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
     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"
     version="3.0">
    <servlet>
        <servlet-name>bikeDispatcher</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>bikeDispatcher</servlet-name>
        <url-pattern>*.html</url-pattern>
    </servlet-mapping>

    <welcome-file-list>
        <welcome-file>/home.html</welcome-file>
    </welcome-file-list>

    <session-config>
        <session-timeout>30</session-timeout>
    </session-config>

    <resource-env-ref>
        <resource-env-ref-name>jdbc/testdb123</resource-env-ref-name>
        <resource-env-ref-type>javax.sql.DataSource</resource-env-ref-type>
    </resource-env-ref>

</web-app>

<?xml version="1.0" encoding="UTF-8"?>
<Context>
<Resource name="jdbc/testdb123" auth="Container" 
    type="javax.sql.DataSource"
    username="abc" password="abc" 
    driverClassName="org.apache.derby.jdbc.ClientDriver" 
    url="jdbc:derby://localhost:1527/bike" />
</Context> 

org.hibernate.ejb.HibernatePersistence
java:comp/env/jdbc/testdb123
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web.xml

<?xml version="1.0" encoding="UTF-8" ?>
<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" xmlns="http://java.sun.com/xml/ns/persistence">
  <persistence-unit name="bike_unit" transaction-type="RESOURCE_LOCAL">
  <provider>org.hibernate.ejb.HibernatePersistence</provider>
  <jta-data-source>java:comp/env/jdbc/testdb123</jta-data-source>
    <class>bike.Bike</class>
    <class>bike.Company</class>
    <properties>
        <property name="hibernate.dialect" value="org.hibernate.dialect.DerbyDialect"/>
        <property name="javax.persistence.jdbc.driver" value="org.apache.derby.jdbc.ClientDriver"/>
        <property name="javax.persistence.jdbc.url" value="jdbc:derby://localhost:1527/bike"/>
        <property name="javax.persistence.jdbc.user" value="abc"/>
        <property name="javax.persistence.jdbc.password" value="abc"/>
    </properties>

  </persistence-unit>
</persistence>

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
     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"
     version="3.0">
    <servlet>
        <servlet-name>bikeDispatcher</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>bikeDispatcher</servlet-name>
        <url-pattern>*.html</url-pattern>
    </servlet-mapping>

    <welcome-file-list>
        <welcome-file>/home.html</welcome-file>
    </welcome-file-list>

    <session-config>
        <session-timeout>30</session-timeout>
    </session-config>

    <resource-env-ref>
        <resource-env-ref-name>jdbc/testdb123</resource-env-ref-name>
        <resource-env-ref-type>javax.sql.DataSource</resource-env-ref-type>
    </resource-env-ref>

</web-app>

<?xml version="1.0" encoding="UTF-8"?>
<Context>
<Resource name="jdbc/testdb123" auth="Container" 
    type="javax.sql.DataSource"
    username="abc" password="abc" 
    driverClassName="org.apache.derby.jdbc.ClientDriver" 
    url="jdbc:derby://localhost:1527/bike" />
</Context> 

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org.springframework.web.servlet.DispatcherServlet
1.
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*.html
/home.html
30
jdbc/testdb123
javax.sql.DataSource

context.xml

<?xml version="1.0" encoding="UTF-8" ?>
<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" xmlns="http://java.sun.com/xml/ns/persistence">
  <persistence-unit name="bike_unit" transaction-type="RESOURCE_LOCAL">
  <provider>org.hibernate.ejb.HibernatePersistence</provider>
  <jta-data-source>java:comp/env/jdbc/testdb123</jta-data-source>
    <class>bike.Bike</class>
    <class>bike.Company</class>
    <properties>
        <property name="hibernate.dialect" value="org.hibernate.dialect.DerbyDialect"/>
        <property name="javax.persistence.jdbc.driver" value="org.apache.derby.jdbc.ClientDriver"/>
        <property name="javax.persistence.jdbc.url" value="jdbc:derby://localhost:1527/bike"/>
        <property name="javax.persistence.jdbc.user" value="abc"/>
        <property name="javax.persistence.jdbc.password" value="abc"/>
    </properties>

  </persistence-unit>
</persistence>

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
     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"
     version="3.0">
    <servlet>
        <servlet-name>bikeDispatcher</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>bikeDispatcher</servlet-name>
        <url-pattern>*.html</url-pattern>
    </servlet-mapping>

    <welcome-file-list>
        <welcome-file>/home.html</welcome-file>
    </welcome-file-list>

    <session-config>
        <session-timeout>30</session-timeout>
    </session-config>

    <resource-env-ref>
        <resource-env-ref-name>jdbc/testdb123</resource-env-ref-name>
        <resource-env-ref-type>javax.sql.DataSource</resource-env-ref-type>
    </resource-env-ref>

</web-app>

<?xml version="1.0" encoding="UTF-8"?>
<Context>
<Resource name="jdbc/testdb123" auth="Container" 
    type="javax.sql.DataSource"
    username="abc" password="abc" 
    driverClassName="org.apache.derby.jdbc.ClientDriver" 
    url="jdbc:derby://localhost:1527/bike" />
</Context> 

我正在使用Spring3和Hibernate3JAR文件。 我尝试用Eclipselink替换Hibernate，应用程序运行得非常完美。只有当我将JPA与Hibernate一起使用时，我才有慢度问题

以下是我与Eclipselink和Hibernate一起使用的罐子：

日食：

• 日食罐
• javax.persistence_2.1.0.v201304241213.jar
• javax.persistence.source_2.1.0.v201304241213.jar

休眠：

• ejb3-persistence.jar
• hibernate-annotations.jar
• hibernate-commons-annotations.jar

使用Eclipselink，我的persistence.xml就是这样的：

<?xml version="1.0" encoding="UTF-8" ?>
<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" xmlns="http://java.sun.com/xml/ns/persistence">
  <persistence-unit name="bike_unit" transaction-type="RESOURCE_LOCAL">
    <class>bike.Bike</class>
    <class>bike.Company</class>
    <properties>
      <property name="javax.persistence.jdbc.driver" value="org.apache.derby.jdbc.ClientDriver" />
      <property name="javax.persistence.jdbc.url" value="jdbc:derby://localhost:1527/bike" />
      <property name="javax.persistence.jdbc.user" value="abc" />
      <property name="javax.persistence.jdbc.password" value="abc" />
    </properties>

  </persistence-unit>
</persistence>

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不确定我遗漏了什么。

我在Windows 7桌面上遇到了这个性能问题。 然而，当我在Windows8机器上使用相同的代码和数据库进行测试时，我并没有遇到这个问题

---

没有找到根本原因，但现在解决了我的问题。

很难确定确切的原因，但是我建议启用hibernate日志记录，看看是否可以找到一些线索。同样值得使用的还有VisualVM。认识到它是一直在消耗时间的Persistence.createEntityManagerFactory（Persistence\u UNIT\u NAME）方法。谢谢@Shailendra为我指路。很高兴能帮忙！通常，对于web应用程序，将为每个数据库创建一次entity manager工厂，每个请求都将创建自己的entity manager实例。