JPA在JSF Project中没有为JDBC PostgreSQL找到合适的驱动程序

Question

我在与Maven的JSF项目中使用JPA（EclipseLink）。在运行时期间，抛出以下异常：No suitable driver found for jdbc:postgresql://localhost:5432/project

之后必须重新启动GlassFish Server。

Caused by: com.sun.appserv.connectors.internal.api.PoolingException: Connection could not be allocated because: No suitable driver found for jdbc:postgresql://localhost:5432/project?loginTimeout=0&socketTimeout=0&prepareThreshold=5&unknownLength=2147483647&loglevel=0&tcpkeepalive=false&binaryTransfer=true
    at com.sun.enterprise.resource.pool.datastructure.RWLockDataStructure.addResource(RWLockDataStructure.java:103)
    at com.sun.enterprise.resource.pool.ConnectionPool.addResource(ConnectionPool.java:282)
    at com.sun.enterprise.resource.pool.ConnectionPool.createResourceAndAddToPool(ConnectionPool.java:1512)
    at com.sun.enterprise.resource.pool.ConnectionPool.createResources(ConnectionPool.java:944)
    at com.sun.enterprise.resource.pool.ConnectionPool.resizePoolAndGetNewResource(ConnectionPool.java:792)
    at com.sun.enterprise.resource.pool.ConnectionPool.getResourceFromPool(ConnectionPool.java:760)
    at com.sun.enterprise.resource.pool.ConnectionPool.getUnenlistedResource(ConnectionPool.java:632)
    at com.sun.enterprise.resource.pool.ConnectionPool.internalGetResource(ConnectionPool.java:526)
    at com.sun.enterprise.resource.pool.ConnectionPool.getResource(ConnectionPool.java:381)
    at com.sun.enterprise.resource.pool.PoolManagerImpl.getResourceFromPool(PoolManagerImpl.java:245)
    at com.sun.enterprise.resource.pool.PoolManagerImpl.getResource(PoolManagerImpl.java:170)
    at com.sun.enterprise.connectors.ConnectionManagerImpl.getResource(ConnectionManagerImpl.java:360)
    at com.sun.enterprise.connectors.ConnectionManagerImpl.internalGetConnection(ConnectionManagerImpl.java:307)
    ... 53 more

我已经尝试了一切。我找了好几个小时来解决这个问题。我的假设是连接池配置不正确或者事务Scoped（容器管理）EntityManager没有正确关闭连接。

以下是该项目的一些代码片段：

的persistence.xml

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
  <persistence-unit name="projectPU" transaction-type="JTA">
    <jta-data-source>jdbc/project_customer_pool</jta-data-source>
    <exclude-unlisted-classes>false</exclude-unlisted-classes>
    <properties/>
  </persistence-unit>
</persistence>

的glassfish-resources.xml中

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE resources PUBLIC "-//GlassFish.org//DTD GlassFish Application Server 3.1 Resource Definitions//EN" "http://glassfish.org/dtds/glassfish-resources_1_5.dtd">
<resources>
  <jdbc-resource enabled="true" 
                 jndi-name="jdbc/project_customer_pool" 
                 object-type="user" 
                 pool-name="project_customer_pool">
    <description>Project Customer Pool</description>
  </jdbc-resource>
  <jdbc-connection-pool allow-non-component-callers="false" 
                        associate-with-thread="false" 
                        connection-creation-retry-attempts="0" 
                        connection-creation-retry-interval-in-seconds="10" 
                        connection-leak-reclaim="true" 
                        connection-leak-timeout-in-seconds="15"
                        statement-timeout-in-seconds="8"
                        statement-leak-timeout-in-seconds="4"
                        connection-validation-method="auto-commit" 
                        datasource-classname="org.postgresql.ds.PGConnectionPoolDataSource" 
                        fail-all-connections="false" 
                        idle-timeout-in-seconds="300" 
                        is-connection-validation-required="false" 
                        is-isolation-level-guaranteed="true" 
                        lazy-connection-association="false" 
                        lazy-connection-enlistment="false" 
                        match-connections="false"
                        max-connection-usage-count="0" 
                        max-pool-size="32" 
                        max-wait-time-in-millis="60000" 
                        name="project_customer_pool" 
                        non-transactional-connections="false" 
                        pool-resize-quantity="2" 
                        res-type="javax.sql.ConnectionPoolDataSource" 
                        steady-pool-size="8" 
                        validate-atmost-once-period-in-seconds="0" 
                        wrap-jdbc-objects="false">
    <description>project db</description>
    <property name="serverName" value="localhost"/>
    <property name="portNumber" value="5432"/>
    <property name="databaseName" value="project"/>
    <property name="URL" value="jdbc:postgresql://localhost:5432/project"/>
    <property name="User" value="admin"/>
    <property name="Password" value="admin"/>
  </jdbc-connection-pool>
</resources>

数据库访问对象（DAO）：

@Stateless
public class DAO implements IDAO, Serializable {

    @PersistenceContext(unitName = "projectPU")
    private EntityManager em;

    // Example for a method
    @Override
    public Benutzer login(String email) {
        if (email.isEmpty()) {
            return null;
        }

        try {
            TypedQuery<User> qu = em.createQuery("FROM User u WHERE u.email = :email AND u.valid_to IS null", User.class);
            qu.setParameter("email", email);
            return qu.getSingleResult();
        } catch (Exception ex) {
            System.err.println(ex.getMessage());
        }
        return null;
    }
}

我希望有人可以帮我解决这个问题，或者知道如何解决这个问题。我不知道该怎么办了。

谢谢！