Two years ago I was working on a project using:
- spring 4.0.3.RELEASE
- jpa 2.0
- hibernate 4.2.7.Final
- java 1.6.X
This project has a maven task hibernate3-maven-plugin which allow us to generate a database schema without any connection to a database (MySQL).
Now we are upgrading this project with:
- java 1.8
- jpa 2.1
- spring 4.2.4.RELEASE
- hibernate 5.0.6.Final
I understand that hibernate3-maven-plugin does not work on JPA 2.1 and hibernate > 4.3.
All the solution I have found need a connection to a database.
For instance: Auto generate data schema from JPA annotated entity classes.
Does anyone know how to generate a database schema offline?
All I have is a persistence.xml with all the Entity classes listed.
I follow your idea of using h2 with Mysql dialect but using JPA Persistence.generateSchema(...).
It does work except all commands are not separated by a semi-column...
How can this been done using JPA 2.1?
Otherwise I will switch to your solution.
import java.util.Properties;
import javax.persistence.Persistence;
import javax.persistence.PersistenceException;
import org.hibernate.jpa.AvailableSettings;
/**
* Generate DDL with hibernate 4+/5:
* http://stackoverflow.com/questions/27314165/generate-ddl-script-at-maven-build-with-hibernate4-jpa-2-1/27314166#27314166
* @author dmary
*
*/
public class Jpa21SchemaExport {
/**
*
*/
public Jpa21SchemaExport() {
// TODO Auto-generated constructor stub
}
/**
* @param args
*/
public static void main(String[] args) {
execute(args[0], args[1]);
System.exit(0);
}
public static void execute(String persistenceUnitName, String destination) {
System.out.println("Generating DDL create script to : " + destination);
final Properties persistenceProperties = new Properties();
// XXX force persistence properties : remove database target
persistenceProperties.setProperty(org.hibernate.cfg.AvailableSettings.HBM2DDL_AUTO, "");
persistenceProperties.setProperty(AvailableSettings.SCHEMA_GEN_DATABASE_ACTION, "none");
// XXX force persistence properties : define create script target from metadata to destination
// persistenceProperties.setProperty(AvailableSettings.SCHEMA_GEN_CREATE_SCHEMAS, "true");
persistenceProperties.setProperty(AvailableSettings.SCHEMA_GEN_SCRIPTS_ACTION, "create");
persistenceProperties.setProperty(AvailableSettings.SCHEMA_GEN_CREATE_SOURCE, "metadata");
persistenceProperties.setProperty(AvailableSettings.SCHEMA_GEN_SCRIPTS_CREATE_TARGET, destination);
persistenceProperties.setProperty(AvailableSettings.JDBC_DRIVER,"org.h2.Driver");
persistenceProperties.setProperty(AvailableSettings.JDBC_URL, "jdbc:h2:mem:export");
persistenceProperties.setProperty(AvailableSettings.JDBC_USER, "sa");
persistenceProperties.setProperty(AvailableSettings.JDBC_PASSWORD, "");
persistenceProperties.setProperty(org.hibernate.cfg.AvailableSettings.DIALECT, "com.wiztivi.sdk.persistence.MySQL5InnoDBUTF8Dialect");
try
{
Persistence.generateSchema(persistenceUnitName, persistenceProperties);
} catch (PersistenceException pe)
{
System.err.println("DDL generation failed: ");
pe.printStackTrace(System.err);
}
}
As the other question, you can use hbm2ddl and an embedded database to provide a connection.
For exemple using H2 database (require h2, scannotation, hibernate and common-io):
package com.stackoverflow;
import java.io.File;
import java.io.FileWriter;
import java.io.InputStream;
import java.net.URL;
import java.util.Set;
import javax.persistence.Entity;
import org.apache.commons.io.IOUtils;
import org.hibernate.cfg.Configuration;
import org.hibernate.cfg.Environment;
import org.hibernate.connection.DriverManagerConnectionProvider;
import org.hibernate.dialect.PostgreSQLDialect;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.scannotation.AnnotationDB;
public class ExportShema {
private static final String OUTPUT_SQL_FILE = "target/database.sql";
private static final String INIT_FILE = "init.sql";
private static final String DB_URL = "jdbc:h2:mem:test;DB_CLOSE_DELAY=-1";
private static final String DB_USERNAME = "sa";
private static final String DB_PASSWORD = "";
private static final File HBM_DIRECTORY = new File("src/main/resources/com/stackoverflow/domain/");
public static void main(final String[] args) throws Exception {
final Configuration cfg = new Configuration();
cfg.setProperty(Environment.CONNECTION_PROVIDER, DriverManagerConnectionProvider.class.getName());
//for postgrest schema
cfg.setProperty(Environment.DIALECT, PostgreSQLDialect.class.getName());
cfg.setProperty(Environment.URL, DB_URL);
cfg.setProperty(Environment.USER, DB_USERNAME);
cfg.setProperty(Environment.PASS, DB_PASSWORD);
//If you have HBM + annotated class
cfg.addDirectory(HBM_DIRECTORY);
final AnnotationDB db = new AnnotationDB();
db.scanArchives(new URL("file:target/classes/"));
final Set<String> clazzNames = db.getAnnotationIndex().get(Entity.class.getName());
for (final String clazzName : clazzNames) {
cfg.addAnnotatedClass(Class.forName(clazzName));
}
final SchemaExport exporter = new SchemaExport(cfg);
exporter.setOutputFile(OUTPUT_SQL_FILE);
exporter.setDelimiter(";");
exporter.setFormat(true);
exporter.create(false, true);
try (final InputStream init_file = ExportShema.class.getResourceAsStream(INIT_FILE)) {
if (init_file != null) {
final File output = new File(OUTPUT_SQL_FILE);
try (final FileWriter fw = new FileWriter(output, true)) {
final String eol = System.getProperty("line.separator");
fw.append(eol + eol);
fw.append(IOUtils.toString(init_file));
}
}
}
}
}
you can do this in a unit test or create an annotation processor.
I was able to mix your Hibernate solution with JPA2.1:
I am now able to add the entity classes from the persistence.xml
This way I can generate the SQl file outside the jar where the entities are located.
This is a temporary solution till hibernate fix this bug
Thanks for your help.
/**
*
*/
package com.stackoverflow.common.util.schema;
import java.io.IOException;
import java.util.Properties;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;
import javax.persistence.metamodel.ManagedType;
import javax.persistence.metamodel.Metamodel;
import org.hibernate.boot.MetadataBuilder;
import org.hibernate.boot.MetadataSources;
import org.hibernate.boot.registry.BootstrapServiceRegistry;
import org.hibernate.boot.registry.BootstrapServiceRegistryBuilder;
import org.hibernate.boot.registry.StandardServiceRegistry;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.boot.spi.MetadataImplementor;
import org.hibernate.cfg.Environment;
import org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl;
import org.hibernate.jpa.AvailableSettings;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.hibernate.dialect.MySQL5InnoDBDialect;
/**
*
*/
public class JPA21Hibernate5ExportSchema {
private static final String JDBC_DRIVER = "org.h2.Driver";
private static final String JDBC_URL = "jdbc:h2:mem:export;DB_CLOSE_DELAY=-1";
private static final String JDBC_USERNAME = "sa";
private static final String JDBC_PASSWORD = "";
/**
*
*/
public JPA21Hibernate5ExportSchema() {
}
public static void main(String[] args) {
try {
JPA21Hibernate5ExportSchema hes = new JPA21Hibernate5ExportSchema();
hes.export(args[0], args[1]);
System.exit(0);
} catch (Exception e) {
e.printStackTrace();
System.exit(1);
}
}
public void export(String persistenceUnitName, String sqlFile) throws IOException, ClassNotFoundException {
final BootstrapServiceRegistry bsr = new BootstrapServiceRegistryBuilder().build();
final MetadataSources metadataSources = new MetadataSources(bsr);
final StandardServiceRegistryBuilder srrBuilder = new StandardServiceRegistryBuilder(bsr)
.applySetting(Environment.CONNECTION_PROVIDER, DriverManagerConnectionProviderImpl.class.getName())
.applySetting(Environment.DIALECT, MySQL5InnoDBDialect.class.getName())
.applySetting(Environment.URL, JDBC_URL).applySetting(Environment.USER, JDBC_USERNAME)
.applySetting(Environment.PASS, JDBC_PASSWORD);
// Use the persistence metamodel to retrieve the Entities classes
Metamodel metamodel = this.getMetamodel(persistenceUnitName);
for (final ManagedType<?> managedType : metamodel.getManagedTypes()) {
metadataSources.addAnnotatedClass(managedType.getJavaType());
}
final StandardServiceRegistry ssr = (StandardServiceRegistry) srrBuilder.build();
final MetadataBuilder metadataBuilder = metadataSources.getMetadataBuilder(ssr);
final SchemaExport exporter = new SchemaExport((MetadataImplementor) metadataBuilder.build());
exporter.setOutputFile(sqlFile);
exporter.setDelimiter(";");
exporter.setFormat(true);
exporter.create(false, true);
}
/**
* Retrieve the JPA metamodel from the persistence unit name
*
* @param persistenceUnitName
* @return
*/
private Metamodel getMetamodel(String persistenceUnitName) {
final Properties persistenceProperties = new Properties();
persistenceProperties.setProperty(AvailableSettings.JDBC_DRIVER, JDBC_DRIVER);
persistenceProperties.setProperty(AvailableSettings.JDBC_URL, JDBC_URL);
persistenceProperties.setProperty(AvailableSettings.JDBC_USER, "sa");
persistenceProperties.setProperty(AvailableSettings.JDBC_PASSWORD, "");
persistenceProperties.setProperty(org.hibernate.cfg.AvailableSettings.DIALECT,
MySQL5InnoDBDialect.class.getName());
final EntityManagerFactory emf = Persistence.createEntityManagerFactory(persistenceUnitName,
persistenceProperties);
return emf.getMetamodel();
}
}
