import org.eclipse.persistence.jpa.PersistenceProvider; //导入依赖的package包/类
private void createEntityManagerFactory(String pid, Dictionary<String, ?> configs) {
    EntityManagerFactory emf = null;
    try {
        String unitName = (String) configs.get("unitName");
        LOGGER.info("Creating EntityManagerFactory for PersistenceUnit: [{}]", unitName);
        emf = new PersistenceProvider().createEntityManagerFactory(unitName, this.jpaProperties(configs));
        if (emf == null) {
            LOGGER.warn("Could not initialize EntityManagerFactory, Most probably persistence.xml not found!!");
        } else {
            LOGGER.info("EntityManagerFactory [{}] created for PersistenceUnit: [{}]", emf, unitName);
            this.pidVsUnitNameMapping.put(pid, unitName);
            this.unitNameVsEMFMapping.put(unitName, emf);
            this.repositoryManager.registerJpaCrudRepository(unitName, emf);
            if (LOGGER.isDebugEnabled()) {
                emf.getMetamodel()
                        .getEntities()
                        .forEach(type -> LOGGER.debug("EntityType: [{}]", type.getName()));
            }
        }
    } catch (Exception ex) { // NOSONAR
        LOGGER.error("Exception occurred while creating EntityManagerFactory!!", ex);
        if (emf != null) {
            emf.close();
        }
    }
}
 

import org.eclipse.persistence.jpa.PersistenceProvider; //导入依赖的package包/类
public void generateSchema() throws MojoFailureException
{
    final Map<String, Object> cfg = buildCfg();
    String[] allBasePackages = this.getBasePackages();
    getLog().info("Using base packages " + StringUtils.arrayToDelimitedString(allBasePackages, ", "));
    final PersistenceProvider provider = new PersistenceProvider();
    final DefaultPersistenceUnitManager manager = new DefaultPersistenceUnitManager();
    manager.setDefaultPersistenceUnitRootLocation(null);
    manager.setDefaultPersistenceUnitName("default");
    manager.setPackagesToScan(allBasePackages);
    manager.setPersistenceXmlLocations(new String[0]);
    manager.afterPropertiesSet();

    final SmartPersistenceUnitInfo puInfo = (SmartPersistenceUnitInfo) manager.obtainDefaultPersistenceUnitInfo();
    puInfo.setPersistenceProviderPackageName(provider.getClass().getName());
    getLog().info("Entities found : " + puInfo.getManagedClassNames().size());
    getLog().debug("Managed class names:\n    * " + StringUtils.collectionToDelimitedString(puInfo.getManagedClassNames(), "\n    * "));
    puInfo.getProperties().putAll(cfg);
    provider.generateSchema(new DelegatingPuInfo(puInfo), cfg);
}
 

import org.eclipse.persistence.jpa.PersistenceProvider; //导入依赖的package包/类
@Bean
public FactoryBean<EntityManagerFactory> entityManagerFactory(DataSource dataSource) {
    LocalContainerEntityManagerFactoryBean emf = new LocalContainerEntityManagerFactoryBean();
    emf.setDataSource(dataSource);
    emf.setPersistenceUnitName("PU");
    emf.setPackagesToScan("org.teavm.flavour.example.model");
    emf.setPersistenceProviderClass(PersistenceProvider.class);

    Map<String, String> properties = new HashMap<>();
    properties.put("eclipselink.weaving", "false");
    properties.put("eclipselink.ddl-generation", "create-or-extend-tables");
    emf.setJpaPropertyMap(properties);

    return emf;
}
 

import org.eclipse.persistence.jpa.PersistenceProvider; //导入依赖的package包/类
private void connect() {
	log.trace("connect to database: {}", url);
	Map<Object, Object> map = new HashMap<>();
	map.put("javax.persistence.jdbc.url", url);
	map.put("javax.persistence.jdbc.driver",
			"org.apache.derby.jdbc.EmbeddedDriver");
	map.put("eclipselink.classloader", getClass().getClassLoader());
	map.put("eclipselink.target-database", "Derby");
	entityFactory = new PersistenceProvider().createEntityManagerFactory(
			"openLCA", map);
	initConnectionPool();
}
 

import org.eclipse.persistence.jpa.PersistenceProvider; //导入依赖的package包/类
private void connect() {
	log.trace("Connect to database mysql: {} @ {}", user, url);
	Map<Object, Object> map = new HashMap<>();
	map.put("javax.persistence.jdbc.url", url);
	map.put("javax.persistence.jdbc.user", user);
	map.put("javax.persistence.jdbc.password", password);
	map.put("javax.persistence.jdbc.driver", "com.mysql.jdbc.Driver");
	map.put("eclipselink.classloader", getClass().getClassLoader());
	map.put("eclipselink.target-database", "MySQL");
	entityFactory = new PersistenceProvider().createEntityManagerFactory(
			persistenceUnit, map);
	initConnectionPool();
}
 

import org.eclipse.persistence.jpa.PersistenceProvider; //导入依赖的package包/类
public EclipseLinkProvider(String version){
    super(PersistenceProvider.class.getName(), version); //NOI18N
}
 

import org.eclipse.persistence.jpa.PersistenceProvider; //导入依赖的package包/类
private void connectToDatabase() {
	Job connectDatabaseJob = new Job("Connecting to Timekeeper database") {

		@Override
		protected IStatus run(IProgressMonitor monitor) {
			Map<String, Object> props = new HashMap<String, Object>();
			// default, default location
			String jdbc_url = "jdbc:h2:~/.timekeeper/h2db";
			try {
				
				String location = Platform.getPreferencesService().getString(BUNDLE_ID, DATABASE_LOCATION, DATABASE_LOCATION_SHARED,new IScopeContext[] { InstanceScope.INSTANCE });
				switch (location){
					case DATABASE_LOCATION_SHARED:
						jdbc_url = getSharedLocation();
						// Fix https://github.com/turesheim/eclipse-timekeeper/issues/107
						System.setProperty("h2.bindAddress", "localhost");
					break;
					case DATABASE_LOCATION_WORKSPACE:
						jdbc_url = getWorkspaceLocation();
					break;
					case DATABASE_LOCATION_URL:
					jdbc_url = getSpecifiedLocation();
					break;
				}					
				// baseline the database
		        Flyway flyway = new Flyway();
		        flyway.setDataSource(jdbc_url, "sa", "");
		        flyway.setLocations("classpath:/db/");
		        flyway.setBaselineOnMigrate(true);
		        flyway.migrate();
				// https://www.eclipse.org/forums/index.php?t=msg&goto=541155&
				props.put(PersistenceUnitProperties.CLASSLOADER, TimekeeperPlugin.class.getClassLoader());
				
				// ensure only a in-memory database is used when testing
				if (Thread.currentThread().getName().equals("WorkbenchTestable")) {
					jdbc_url = "jdbc:h2:mem:test_mem";
				}
				props.put(PersistenceUnitProperties.JDBC_URL, jdbc_url);
				props.put(PersistenceUnitProperties.JDBC_DRIVER, "org.h2.Driver");
				props.put(PersistenceUnitProperties.JDBC_USER, "sa");
				props.put(PersistenceUnitProperties.JDBC_PASSWORD, "");
				props.put(PersistenceUnitProperties.LOGGING_LEVEL, "fine");
				// we want Flyway to create the database, it gives us better control over migrating
				props.put(PersistenceUnitProperties.DDL_GENERATION, "none");
				entityManager = new PersistenceProvider()	
					.createEntityManagerFactory("net.resheim.eclipse.timekeeper.db", props)
					.createEntityManager();
			} catch (Exception e) {
				return new Status(IStatus.ERROR, BUNDLE_ID,
						"Could not connect to Timekeeper database at " + jdbc_url, e);
			}
	        cleanTaskActivities();
			notifyListeners();
			return Status.OK_STATUS;			}

	};
	connectDatabaseJob.setSystem(false);
	connectDatabaseJob.schedule();
}
 

import org.eclipse.persistence.jpa.PersistenceProvider; //导入依赖的package包/类
public static void main(String[] args) {

		try {

			Map<Object, Object> config = new HashMap<>();

			// set the connection data to the database
			// you should already have an existing database (in this case
			// olca_test_db)
			String url = "jdbc:mysql://localhost:3306/olca_test_db";
			String user = "root";
			String pw = "";
			config.put("javax.persistence.jdbc.url", url);
			config.put("javax.persistence.jdbc.user", user);
			config.put("javax.persistence.jdbc.password", pw);

			// change the driver and database type if you want to create the
			// database schema for another database type than MySQL
			config.put("javax.persistence.jdbc.driver", "com.mysql.jdbc.Driver");
			config.put("eclipselink.target-database", "MySQL");

			// specify the location where the schema files should be written
			String folder = Files.createTempDir().getAbsolutePath();
			String createDllFile = "olca_schema_create.sql";
			String dropDllFile = "olca_schema_drop.sql";

			// see
			// http://eclipse.org/eclipselink/documentation/2.4/jpa/extensions/p_ddl_generation_output_mode.htm
			// for more configuration details
			config.put("eclipselink.ddl-generation", "drop-and-create-tables");
			config.put("eclipselink.ddl-generation.output-mode", "both");
			config.put("eclipselink.create-ddl-jdbc-file-name", createDllFile);
			config.put("eclipselink.drop-ddl-jdbc-file-name", dropDllFile);
			config.put("eclipselink.application-location", folder);

			// now we create an entity manager which will generate the database
			// schema
			new PersistenceProvider()
					.createEntityManagerFactory("openLCA", config)
					.createEntityManager().close();

			System.out.println("DDL files should be created now in: " + folder);

		} catch (Exception e) {
			e.printStackTrace();
		}

	}