是否需要文件persistence.xml？

时间：2012-05-23 06:51:02

标签： java xml java-ee websphere-8 ibm-rad

我的开发环境（IBM RAD 8 + WAS 8）抱怨我的项目没有persistence.xml文件。似乎我仍然可以构建和运行我的项目。是否需要该文件，如果添加一个这样的文件以使我的项目通过验证，该文件应该包含什么内容？

该项目是一个使用会话bean和来自其他项目的实体bean的Web项目，这个persistence.xml错误是项目中唯一的错误，所以我很乐意摆脱它。

感谢您的帮助

更新

我搜索了我的文件中的persistence.xml，它出现在EJB项目的src /和bin /中，而带有servlets和jsp的web项目没有persistence.xml，据我的同事说，web项目正在使用来自EJB项目的persistence.xml，即：

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="1.0" 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_1_0.xsd">

    <persistence-unit name="PandoraArendeWeb" transaction-type="JTA">

        <jta-data-source>jdbc/Mainframe_TEST_ADBUTV2</jta-data-source>
        <class>se.prv.pandora.arendeprocess.entity.PRVNummer</class>
        <class>se.prv.pandora.arendeprocess.entity.Ansokan</class>
        <class>se.prv.pandora.arendeprocess.entity.NatAnsokan</class>
        <class>se.prv.pandora.arendeprocess.entity.PctAnsokan</class>
        <class>se.prv.pandora.arendeprocess.entity.ArendePerson</class>
        <class>se.prv.pandora.arendeprocess.entity.Nyregistrering</class>
        <class>se.prv.pandora.arendeprocess.entity.Anstalld</class>
        <class>se.prv.pandora.arendeprocess.entity.Handlaggare</class>
        <class>se.prv.pandora.arendeprocess.entity.OrgElement</class>
        <class>se.prv.pandora.arendeprocess.entity.FysiskHandlaggare</class>
        <class>se.prv.pandora.arendeprocess.entity.AnsvarigHandlaggare</class>
        <class>se.prv.pandora.arendeprocess.entity.AnsvarigFysiskHandlaggare</class>
        <class>se.prv.pandora.arendeprocess.entity.TeknikOmrade</class>
        <class>se.prv.pandora.arendeprocess.entity.Person</class>
        <class>se.prv.pandora.arendeprocess.entity.PRVNummerPerson</class>
        <class>se.prv.pandora.arendeprocess.entity.Notering</class>
        <class>se.prv.pandora.arendeprocess.entity.Lock</class>
        <class>se.prv.pandora.arendeprocess.entity.LandKod</class>
        <class>se.prv.pandora.arendeprocess.entity.ArbetsMomentLog</class>
        <class>se.prv.pandora.arendeprocess.entity.SystemTypDel</class>
        <class>se.prv.pandora.arendeprocess.entity.ArbetsMoment</class>
        <class>se.prv.pandora.arendeprocess.entity.UnderStatus</class>
        <class>se.prv.pandora.arendeprocess.entity.PatPers</class>
        <class>se.prv.pandora.arendeprocess.entity.PrvLandP</class>
        <class>se.prv.pandora.arendeprocess.entity.PkaPerln</class>
        <class>se.prv.pandora.arendeprocess.entity.PctnPerl</class>
        <class>se.prv.pandora.arendeprocess.entity.PersonToPatPersKoppl</class>
        <class>se.prv.pandora.arendeprocess.entity.PRVNummerPersonKoppl</class>
        <class>se.prv.pandora.arendeprocess.entity.Region</class>
        <class>se.prv.pandora.arendeprocess.entity.Historik</class>
        <class>se.prv.pandora.arendeprocess.entity.Egenskap</class>
        <exclude-unlisted-classes>true</exclude-unlisted-classes>

    </persistence-unit>

<!-- <persistence-unit name="PandoraArendeWeb_MSSQL" transaction-type="JTA">

        <jta-data-source>jdbc/MSSQL_TEST_XA</jta-data-source>
        <class>se.prv.pandora.arendeprocess.entity.PersonSearch</class>
        <exclude-unlisted-classes>true</exclude-unlisted-classes>

    </persistence-unit>
 -->    
</persistence>

enter image description here

3 个答案:

答案 0 :(得分：9)

persistence.xml文件通常包含与数据库相关的详细信息，例如连接字符串及其各自的用户名和密码，包括其他ORM相关信息。这些细节可以放在其他位置，因此您不需要明确地拥有一个，虽然拥有这样的文件通常会在一个地方提供所有与持久性相关的信息，这使得查找某些设置和配置更容易。

这是一个示例persistence.xml文件：

<?xml version="1.0" encoding="UTF-8"?>
<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_1_0.xsd"
    version="1.0">
    <persistence-unit name="<PERSISTENCE UNIT NAME>">
        <properties>
            <!--
            <property name="hibernate.ejb.cfgfile" value="/hibernate.cfg.xml"/>
            <property name="hibernate.hbm2ddl.auto" value="create"/>
            -->
            <property name="hibernate.archive.autodetection" value="class, hbm"/>
            <property name="hibernate.show_sql" value="true"/>
            <property name="hibernate.connection.driver_class" value="com.mysql.jdbc.Driver"/>
            <property name="hibernate.connection.password" value="<PASSWORD>"/>
            <property name="hibernate.connection.url" value="jdbc:mysql://<HOST IP ADDRESS>/<DB NAME>"/>
            <property name="hibernate.connection.username" value="<USERNAME>"/>
            <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect"/>
            <property name="hibernate.c3p0.min_size" value="5"/>
            <property name="hibernate.c3p0.max_size" value="20"/>
            <property name="hibernate.c3p0.timeout" value="300"/>
            <property name="hibernate.c3p0.max_statements" value="50"/>
            <property name="hibernate.c3p0.idle_test_period" value="3000"/>
        </properties>
    </persistence-unit>
</persistence>

以上内容取自here。

答案 1 :(得分：0)

<?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="AINS" transaction-type="RESOURCE_LOCAL">
        <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>

        <class>com.tridenthyundai.ains.domainobject.AccessoriesDO</class>
        <class>com.tridenthyundai.ains.domainobject.BranchDO</class>
        <class>com.tridenthyundai.ains.domainobject.ContactDO</class>
        <class>com.tridenthyundai.ains.domainobject.CustomerDO</class>
        <class>com.tridenthyundai.ains.domainobject.FinanceDO</class>
        <class>com.tridenthyundai.ains.domainobject.InsuranceDO</class>
        <class>com.tridenthyundai.ains.domainobject.MessageDO</class>
        <class>com.tridenthyundai.ains.domainobject.NotificationDO</class>
        <class>com.tridenthyundai.ains.domainobject.ProductDO</class>
        <class>com.tridenthyundai.ains.domainobject.ProductPriceDO</class>
        <class>com.tridenthyundai.ains.domainobject.ProductSpecDO</class>
        <class>com.tridenthyundai.ains.domainobject.ProductVariantDO</class>
        <class>com.tridenthyundai.ains.domainobject.PurchaseDO</class>
        <class>com.tridenthyundai.ains.domainobject.ServiceCentreDO</class>
        <class>com.tridenthyundai.ains.domainobject.ServiceDO</class>
        <class>com.tridenthyundai.ains.domainobject.ServiceTypeDO</class>
        <class>com.tridenthyundai.ains.domainobject.UserDO</class>
        <class>com.tridenthyundai.ains.domainobject.VisitorDO</class>


        <!-- shouldn't be valid for java SE per specification, but it works for  EclipseLink ... -->
        <exclude-unlisted-classes>false</exclude-unlisted-classes>

        <!-- For Local Testing -->
        <!-- <properties>
            <property name="javax.persistence.jdbc.url" value="jdbc:mysql://saptalabs:3306/tridenthyundai" />
            <property name="javax.persistence.jdbc.user" value="adminuser" />
            <property name="javax.persistence.jdbc.password" value="adminuser" />
            <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver" />

            <property name="eclipselink.cache.shared.default" value="false"/>
            <property name="eclipselink.ddl-generation" value="create-tables" />
            <property name="eclipselink.ddl-generation.output-mode" value="database" />
            <property name="eclipselink.logging.level" value="SEVERE" />        
        </properties> -->

        <!-- For Production -->

    </persistence-unit>
</persistence>

答案 2 :(得分：0)

<?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="saptalabs" transaction-type="RESOURCE_LOCAL">
        <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>

        <class>com.sapta.hr.domainobject.UserDO</class>
        <class>com.sapta.hr.domainobject.EmployeeDO</class>
        <class>com.sapta.hr.domainobject.AddressDO</class>
        <class>com.sapta.hr.domainobject.EmpDetailDO</class>
        <class>com.sapta.hr.domainobject.EmpAccDetailDO</class>
        <class>com.sapta.hr.domainobject.ProjectDO</class>
        <class>com.sapta.hr.domainobject.CustomerDO</class>
        <class>com.sapta.hr.domainobject.EmpAssignmentDO</class>
        <class>com.sapta.hr.domainobject.EmpAboutDO</class>
        <class>com.sapta.hr.domainobject.EmpAchievementsDO</class>
        <class>com.sapta.hr.domainobject.EmpEmploymentHistoryDO</class>
        <class>com.sapta.hr.domainobject.EmpSportsDO</class>
        <class>com.sapta.hr.domainobject.EmpCulturalsDO</class>
        <class>com.sapta.hr.domainobject.EmpEducationDO</class>
        <class>com.sapta.hr.domainobject.EmpLanguageKnownDO</class>
        <class>com.sapta.hr.domainobject.EmpReferencesDO</class>
        <class>com.sapta.hr.domainobject.EmpSkillSetDO</class>
        <class>com.sapta.hr.domainobject.EmpFamilyBackgroundDO</class>
        <class>com.sapta.hr.domainobject.AssetDO</class>
        <class>com.sapta.hr.domainobject.AssetTypeDO</class>
        <class>com.sapta.hr.domainobject.EmpCTCDO</class>
        <class>com.sapta.hr.domainobject.ExpenseDO</class>
        <class>com.sapta.hr.domainobject.ExpTypeDO</class>
        <class>com.sapta.hr.domainobject.InvoiceDO</class>
        <class>com.sapta.hr.domainobject.PayrollDO</class>
        <class>com.sapta.hr.domainobject.ProfessionalTaxDO</class>
        <class>com.sapta.hr.domainobject.TDSDO</class>
        <class>com.sapta.hr.domainobject.VendorDO</class>
        <class>com.sapta.hr.domainobject.BillsDO</class>
        <class>com.sapta.hr.domainobject.EmpLoseOfPayDO</class>

        <!-- shouldn't be valid for java SE per specification, but it works for 
            EclipseLink ... -->
        <exclude-unlisted-classes>false</exclude-unlisted-classes>

        <!-- For Local Testing -->
        <properties>
            <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/hrportal" />
            <property name="javax.persistence.jdbc.user" value="root" />
            <property name="javax.persistence.jdbc.password" value="root" />
            <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver" />
            <property name="eclipselink.cache.shared.default" value="false" />
            <property name="eclipselink.ddl-generation" value="create-tables" />
            <property name="eclipselink.ddl-generation.output-mode"
                value="database" />
            <property name="eclipselink.logging.level" value="SEVERE" />
        </properties>
    </persistence-unit>
</persistence>
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