Question

所以我想在heroku上部署我的java应用程序。部署后，它会设置一个环境变量DATABASE_URL。我想用它作为我的hibernate网址。我目前有hibernate.cfg.xml，并在那里设置了url jdbc：postgresql：// localhost：port / db。如何更改它以获取DATABASE_URL？

Answer 1

其中一种方法是在创建SessionFactory之前使用setProperty(String propertyName, String value) Configuration显式覆盖hibernate.connection.url的值。

要获取环境变量，您可以使用System.getenv(String name)。

/**Load the hibernate.cfg.xml from the classpath**/
Configuration cfg = new Configuration();
cfg.setProperty("hibernate.connection.url", System.getenv("DATABASE_URL"));
SessionFactory sessionFactory = cfg.buildSessionFactory();

Answer 2

我在java本身没有编程任何编程的情况下搜索了很多其他解决方案。我得出了以下结论

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
                                     "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
    <property name="hibernate.check_nullability">false</property>
    <property name="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</property>
    <property name="hibernate.connection.driver_class">org.postgresql.Driver</property>
    <property name="hibernate.connection.username">${hibernate_username}</property>
    <property name="hibernate.connection.password">${hibernate_password}</property>
    <property name="hibernate.connection.url">jdbc:postgresql://${hibernate_db_host}/${hibernate_db_name}</property>
    <property name="hibernate.search.autoregister_listeners">false</property>
    <property name="hibernate.hbm2ddl.auto">update</property>
    <property name="hibernate.show_sql">${hibernate_show_sql}</property>
</session-factory>
</hibernate-configuration>

我使用以下vmargs启动我的应用程序：

-Dhibernate_username=test-Dhibernate_password=testpassword -Dhibernate_db_host=localhost -Dhibernate_db_name=test -Dhibernate_show_sql=true

我将此解决方案发布到这个旧帖子，因为我在一个旧的论坛帖子（Google Search Side 3+ ^^）中找到了这个。我认为这非常有用。

Answer 3

愿这对你有帮助，

我正在使用Jboss AS 5.x和hibernate的HSQL DB来动态创建表并使用以下* .cfg.xml文件。

使用$ JBOSS_HOME作为环境变量。

<?xml version="1.0" encoding="UTF-8"?>

    <session-factory>

            <!-- Database connection settings -->

            <property name="connection.driver_class">org.hsqldb.jdbcDriver</property>
            <property name="connection.url">jdbc:hsqldb:$JBOSS_HOME/server/test/data/hypersonic/localDB</property>
            <property name="connection.username">sa</property>

            <property name="connection.password"></property>

            <!-- JDBC connection pool (use the built-in) -->
            <property name="connection.pool_size">1</property>

            <!-- SQL dialect -->
            <property name="dialect">org.hibernate.dialect.HSQLDialect</property>

            <!-- Enable Hibernate's automatic session context management -->
            <property name="current_session_context_class">thread</property>

            <!-- Disable the second-level cache -->
            <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>

            <!-- Echo all executed SQL to stdout -->
            <property name="show_sql">true</property>
            <!-- Drop and re-create the database schema on startup -->

            <property name="hbm2ddl.auto">update</property>
            <!--  Mapping files  -->
            <mapping resource="friends_presence_log.hbm.xml" />
            <mapping resource="profileuuid.hbm.xml" />
    </session-factory>

所以，这意味着如果你想将环境变量用于Jboss配置，那么你可以正常使用，后来由内部hibernate.jar实用程序使用，你可以像java程序一样得到连接或事物。

Answer 4

如果使用诸如gradle之类的构建工具，则可以使用@ ... @括起来的占位符，如下所示：

<?xml version = "1.0" encoding = "utf-8"?>
<!DOCTYPE hibernate-configuration SYSTEM 
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
   <session-factory>
      <property name = "hibernate.dialect">
         @db_dialect@
      </property>

      <property name = "hibernate.connection.driver_class">
         @db_driver@
      </property>

      <!-- Assume test is the database name -->

      <property name = "hibernate.connection.url">
         @db_url@
      </property>

      <property name = "hibernate.connection.username">
         @db_user@
      </property>

      <property name = "hibernate.connection.password">
         @db_password@
      </property>

      <!-- Cannot use anything other than "validate" in production. --> 
      <property name="hibernate.hbm2ddl.auto">validate</property>

      <!-- Connection pooling -->
      <property name="hibernate.connection.provider_class">org.hibernate.c3p0.internal.C3P0ConnectionProvider</property>
      <property name="hibernate.c3p0.min_size">1</property>
      <property name="hibernate.c3p0.max_size">500</property>
      <property name="hibernate.c3p0.timeout">120</property>
      <property name="hibernate.c3p0.max_statements">1024</property>

      <!-- Your mappings -->
   </session-factory>
</hibernate-configuration>

然后在 build.gradle 中，您将遇到类似这样的事情：

def db_driver = System.getenv('MYAPP_DB_DRIVER')
def db_url = System.getenv('MYAPP_DB_URL')
def db_dialect = System.getenv('MYAPP_DB_DIALECT')

processResources {
    filesMatching(['**/*.xml', '**/*.properties', '**/*.json']) {
        filter ReplaceTokens, tokens: [
            'db_driver': db_driver,
            'db_url': db_url,
            'db_dialect': db_dialect,
        ]
    }
}

如何使用环境变量配置Hibernate

4 个答案: