是否有使用 mysql 的项目的框架，一些以 RESOURCE_LOCAL 作为连接类型的 eclipse/top 链接？最好使用maven。我正在搜索它几个小时，但即使是最简单的例子也无法运行。因此，如果您已准备好并运行它，请发布 :-)。即使像这两个类这样简单的东西。

@Entity
public class Message implements Serializable{
    public Message() {}
    public Message(String s){
        this.s = s;
    }
    @Id
    String s;
    public String getS(){
        return s;
    }
}
public class App {
    static private EntityManagerFactory emf;
    static private EntityManager em;
    public static void main( String[] args ) {
        emf = Persistence.createEntityManagerFactory("persistence");
        em = emf.createEntityManager();
        Message m = new Message("abc");
        em.persist(m);
    }
}<p></p>

<p></p>

最佳答案

Maven 有一个 JPA 应用程序原型(prototype)，可以从内部目录中获得

$ mvn archetype:generate 
[INFO] Scanning for projects...
[INFO] Searching repository for plugin with prefix: 'archetype'.
[INFO] ------------------------------------------------------------------------
[INFO] Building Maven Default Project
[INFO]    task-segment: [archetype:generate] (aggregator-style)
[INFO] ------------------------------------------------------------------------
[INFO] Preparing archetype:generate
[INFO] No goals needed for project - skipping
[INFO] Setting property: classpath.resource.loader.class => 'org.codehaus.plexus.velocity.ContextClassLoaderResourceLoader'.
[INFO] Setting property: velocimacro.messages.on => 'false'.
[INFO] Setting property: resource.loader => 'classpath'.
[INFO] Setting property: resource.manager.logwhenfound => 'false'.
[INFO] [archetype:generate {execution: default-cli}]
[INFO] Generating project in Interactive mode
[INFO] No archetype defined. Using maven-archetype-quickstart (org.apache.maven.archetypes:maven-archetype-quickstart:1.0)
Choose archetype:
...
23: internal -> jpa-maven-archetype (JPA application)
...
Choose a number:  (1/2/3/4/5/6/7/8/9/10/11/12/13/14/15/16/17/18/19/20/21/22/23/24/25/26/27/28/29/30/31/32/33/34/35/36/37/38/39/40/41) 15: : 

Or more directly:

mvn archetype:generate \
  -DgroupId=com.mycompany.myproject \
  -DartifactId=my-project-domain \
  -DpackageName=com.mycompany.myproject.domain \
  -DarchetypeGroupId=com.rfc.maven.archetypes \
  -DarchetypeArtifactId=jpa-maven-archetype  \
  -DarchetypeVersion=1.0.0 \
  -DremoteRepositories=http://maven.rodcoffin.com/repo \
  -DinteractiveMode=false

这将使用 Hibernate、HSQLDB 和 DbUnit 测试生成一个不错的项目。现在，cd 进入创建的目录进行一些更改。

首先，编辑pom.xml。删除与 Hibernate 相关的工件并用 EclipseLink 替换它们(您将需要一个额外的存储库):

<project>
  ...
  <repositories>
    <repository>
      <id>eclipselink</id>
      <url>http://www.eclipse.org/downloads/download.php?r=1&amp;nf=1&amp;file=/rt/eclipselink/maven.repo/</url>
    </repository>
  </repositories>
  <dependencies>
    <!-- See http://wiki.eclipse.org/EclipseLink/Maven -->
    <dependency>
      <groupId>org.eclipse.persistence</groupId>
      <artifactId>eclipselink</artifactId>
      <version>2.0.0</version>
    </dependency>
    <!-- optional - only needed if you are using JPA outside of a Java EE container-->
    <dependency>
      <groupId>org.eclipse.persistence</groupId>
      <artifactId>javax.persistence</artifactId>
      <version>2.0.0</version>
      <scope>provided</scope>
    </dependency>
    ...
  </dependencies>
  ...
</project>

然后修改persistence.xml(注意下面有2个persistence unit，填充的那个用于测试):

<?xml version="1.0"?>
<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_2_0.xsd"
  version="2.0">
  <persistence-unit name="my-project-domain"/>
  <persistence-unit name="my-project-domain-test" transaction-type="RESOURCE_LOCAL">
    <class>com.mycompany.myproject.User</class>
    <properties>
      <property name="eclipselink.target-database" value="HSQL"/>
      <property name="javax.persistence.jdbc.driver" value="org.hsqldb.jdbcDriver"/>
      <property name="javax.persistence.jdbc.user" value="sa"/>
      <property name="javax.persistence.jdbc.password" value=""/>
      <property name="javax.persistence.jdbc.url" value="jdbc:hsqldb:mem:my-project-test"/>
      <property name="eclipselink.ddl-generation" value="create-tables"/>
    </properties>
  </persistence-unit>
</persistence>

就是这样。我已经在 pastebin.com 上发布了修改后的 pom.xml .要使用 MySQL，请将 JDBC 驱动程序添加为 pom.xml 中的依赖项并复制 EclipseLink 配置。这应该很容易，留给读者作为练习:) 如果遇到阻塞问题，请发表评论，我会看看是否可以提供帮助。

如果你想让测试再次通过，你必须替换 UserTest.java 中的以下行:

HibernateEntityManager em = (HibernateEntityManager) emf.createEntityManager();

DbUnitDataLoader loader = new DbUnitDataLoader(testData, em.getSession().connection());

通过

EntityManager em = emf.createEntityManager();
Connection conn = em.unwrap(java.sql.Connection.class);
conn.setAutoCommit(true);

DbUnitDataLoader loader = new DbUnitDataLoader(testData, conn);

关于java - Mysql maven jpa框架，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/2844200/