无法使用Hibernate和Maven运行JPA2

Question

一整天都在努力,用网络搜索****......徒劳无功.你是我最后的希望:

这是我的代码:

实体:

package sas.test.model;

import javax.persistence.Entity;
import javax.persistence.Id;

@Entity
public class Employee {
    @Id private int id;
    private String name;
    private long salary;
    public Employee() {}
    public Employee(int id) { this.id = id; }
    public int getId() { return id; }
    public void setId(int id) { this.id = id; }
    public String getName() { return name; }
    public void setName(String name) { this.name = name; }
    public long getSalary() { return salary; }
    public void setSalary (long salary) { this.salary = salary; }
}

服务类:

package sas.test.dao;

import sas.test.model.Employee;

import javax.persistence.*;
import java.util.List;

public class EmployeeService {

    protected EntityManager em;

    public EmployeeService(EntityManager em) {
        this.em = em;
    }
    public Employee createEmployee(int id, String name, long salary) {
        Employee emp = new Employee(id);

      emp.setName(name);
  emp.setSalary(salary);
  em.persist(emp);
  return emp;
}
  public void removeEmployee(int id) {
      Employee emp = findEmployee(id);
      if (emp != null) {
          em.remove(emp);
      }
  }
  public Employee raiseEmployeeSalary(int id, long raise) {
      Employee emp = em.find(Employee.class, id);
      if (emp != null) {
          emp.setSalary(emp.getSalary() + raise);
      }
      return emp;
  }
  public Employee findEmployee(int id) {
      return em.find(Employee.class, id);
  }

}

而主要课程:

package sas.test.main;

import javax.persistence.*;
import java.util.List;
import sas.test.model.Employee;
import sas.test.dao.EmployeeService;


public class ExecuteMe {
    public static void main(String[] args) {
        EntityManagerFactory emf =
                Persistence.createEntityManagerFactory("EmployeeService");
        EntityManager em = emf.createEntityManager();
        EmployeeService service = new EmployeeService(em);

          // create and persist an employee
          em.getTransaction().begin();
          Employee emp = service.createEmployee(158, "John Doe", 45000);
          em.getTransaction().commit();
          System.out.println("Persisted " + emp);
          // find a specific employee
          emp = service.findEmployee(158);
          System.out.println("Found " + emp);
          // find all employees
     //     List<Employee> emps = service.findAllEmployees();
         // for (Employee e : emps)
         //      System.out.println("Found employee: " + e);
          // update the employee
          em.getTransaction().begin();
          emp = service.raiseEmployeeSalary(158, 1000);
          em.getTransaction().commit();
          System.out.println("Updated " + emp);
          // remove an employee
          em.getTransaction().begin();
          service.removeEmployee(158);
          em.getTransaction().commit();
          System.out.println("Removed Employee 158");
          // close the EM and EMF when done
          em.close();
          emf.close();
    }
}

最后我的confs.

pom.xml中:

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>Test_JPA_CRUD</groupId>
    <artifactId>Test_JPA_CRUD</artifactId>
    <packaging>jar</packaging>
    <version>1.0</version>
    <name>Test_JPA_CRUD</name>
    <url>http://maven.apache.org</url>
    <repositories>


        <repository>
            <id>maven2-repository.dev.java.net</id>
            <name>Java.net Repository for Maven</name>
            <url>http://download.java.net/maven/2/
            </url>
            <layout>default</layout>
        </repository>


        <repository>
            <id>maven.org</id>
            <name>maven.org Repository</name>
            <url>http://repo1.maven.org/maven2</url>
            <releases>
                <enabled>true</enabled>
            </releases>
            <snapshots>
                <enabled>true</enabled>
            </snapshots>
        </repository>
    </repositories>
    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.8.1</version>
            <scope>test</scope>
        </dependency>

        <!--

                <dependency>
                    <groupId>javax</groupId>
                    <artifactId>javaee-api</artifactId>
                    <version>6.0</version>
                </dependency>
        -->
        <!--
        <dependency>
            <groupId>javax.persistence</groupId>
            <artifactId>persistence-api</artifactId>
            <version>1.0</version>
        </dependency>
                                      -->
        <!-- JPA2 provider -->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-entitymanager</artifactId>
            <version>3.4.0.GA</version>
        </dependency>

        <!-- JDBC driver -->
        <dependency>
            <groupId>org.apache.derby</groupId>
            <artifactId>derby</artifactId>
            <version>10.5.3.0_1</version>
        </dependency>


        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>3.3.2.GA</version>
        </dependency>
        <dependency>
          <groupId>org.hibernate</groupId>
          <artifactId>ejb3-persistence</artifactId>
          <version>3.3.2.Beta1</version>
        </dependency>

        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-annotations</artifactId>
            <version>3.4.0.GA</version>
        </dependency>

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.5.2</version>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.14</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <!-- compile with mvn assembly:assembly -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-jar-plugin</artifactId>
                <version>2.2</version>
            </plugin>
            <!-- compile with mvn assembly:assembly -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-assembly-plugin</artifactId>
                <version>2.2-beta-2</version>
                <configuration>
                    <descriptorRefs>
                        <descriptorRef>jar-with-dependencies</descriptorRef>
                    </descriptorRefs>
                    <archive>
                        <manifest>
                            <mainClass>sas.test.main.ExecuteMe</mainClass>
                        </manifest>
                    </archive>
                </configuration>
                <executions>
                    <execution>
                        <phase>package</phase>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <!-- Force UTF-8 & Java-Version 1.6 -->
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.6</source>
                    <target>1.6</target>
                    <!--<encoding>utf-8</encoding>-->
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

和persistence.xml,我保证,它位于目标的类路径中:

<?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
http://java.sun.com/xml/ns/persistence ">
    <persistence-unit name="EmployeeService" transaction-type="RESOURCE_LOCAL">
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <class>sas.test.model.Employee</class>
        <properties>

            <property name="javax.persistence.jdbc.driver" value="org.apache.derby.jdbc.EmbeddedDriver"/>
            <property name="hibernate.dialect" value="org.hibernate.dialect.DerbyDialect"/>
            <property name="hibernate.show_sql" value="true"/>
            <property name="javax.persistence.jdbc.url" value="jdbc:derby:webdb;create=true"/>


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

正如您可能从一些注释代码中注意到的那样,我尝试了两者,即JPA2.0的Hibernate和J2EE 6实现,但都失败了.上述代码最终会出现以下错误:

log4j:WARN No appenders could be found for logger (org.hibernate.cfg.annotations.Version).
log4j:WARN Please initialize the log4j system properly.
Exception in thread "main" java.lang.UnsupportedOperationException: The user must supply a JDBC connection
 at org.hibernate.connection.UserSuppliedConnectionProvider.getConnection(UserSuppliedConnectionProvider.java:54)
 at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:446)
 at org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:167)
 at org.hibernate.jdbc.JDBCContext.connection(JDBCContext.java:142)

知道出了什么问题吗？实际运行的任何"Hello World"maven/JPA2演示？我无法获得谷歌搜索运行提供的任何内容.

Thanx提前.

Answer 1

Hibernate EntityManager 3.4.0.GA 不是 JPA 2.0实现,因此它不支持标准化javax.persistence.*属性persistence.xml(因此没有提供JDBC连接的例外).对于JPA 2.0,您需要Hibernate EM 3.5.1-Final.在具有正确依赖性的简单POM下面:

<project>
  ...
  <repositories>
    <repository>
      <id>jboss</id>
      <name>JBoss repository</name>
      <url>http://repository.jboss.org/maven2</url>
    </repository>
  </repositories>

  <dependencies>
    <!-- JPA API and Hibernate -->
    <dependency>
      <groupId>org.hibernate</groupId>
      <artifactId>hibernate-entitymanager</artifactId>
      <version>3.5.1-Final</version>
    </dependency>

    <!-- Logging -->
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-simple</artifactId>
      <version>1.5.8</version>
    </dependency>

    ...
  </dependencies>
  ...
</project>

这就是你所需要的,其他依赖关系将被传递.只需将我正在使用的slf4j绑定替换为您最喜欢的绑定.

如果要使用Bean Validation(JSR-303)API和RI,请添加(根据您的需要调整范围):

<!-- Bean Validation API and RI -->
<dependency>
    <groupId>javax.validation</groupId>
    <artifactId>validation-api</artifactId>
    <version>1.0.0.GA</version>
    <scope>compile</scope>
</dependency>
<dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-validator</artifactId>
    <version>4.0.2.GA</version>
    <scope>runtime</scope>
</dependency>

我没有测试你的代码,但这至少会修复你的POM.

PS:persistence.xml如果类路径中只有一个,则不需要指定持久性提供程序,也不需要指定方言.但这不应该受到伤害.

PPS:注意,这javax.persistence:persistence-api:jar:1.0是一个API,而不是一个实现,它本身不会做任何事情(我的意思是,它不是Hibernate,EclipseLink等的替代品).