不通过WildFly管理数据库，使用JNDI配置PostgreSQL是否可行？

Absolutely! You don’t have to depend on WildFly’s admin console or server-level config files (like standalone.xml/domain.xml) to set up JNDI access for PostgreSQL. Here are two practical, application-controlled approaches to get this done:

1. Embedded JNDI Context with Custom Connection Pooling #

You can spin up your own JNDI context directly within your application and bind a PostgreSQL connection pool to it—no WildFly server configuration required. Libraries like HikariCP or Apache Commons DBCP2 work perfectly here for robust pooling.

Step-by-Step Example: #

• First, add the required dependencies to your build file (Maven example below):

  <!-- PostgreSQL JDBC Driver -->
  <dependency>
      <groupId>org.postgresql</groupId>
      <artifactId>postgresql</artifactId>
      <version>42.6.0</version>
  </dependency>
  <!-- HikariCP Connection Pool -->
  <dependency>
      <groupId>com.zaxxer</groupId>
      <artifactId>HikariCP</artifactId>
      <version>5.0.1</version>
  </dependency>
  <!-- Lightweight JNDI Implementation -->
  <dependency>
      <groupId>org.apache.tomcat</groupId>
      <artifactId>tomcat-jndi</artifactId>
      <version>10.1.10</version>
      <scope>provided</scope>
  </dependency>
  

• Create a startup listener (for web apps) to initialize the JNDI context and bind your data source:

  import com.zaxxer.hikari.HikariConfig;
  import com.zaxxer.hikari.HikariDataSource;
  import javax.naming.Context;
  import javax.naming.InitialContext;
  import javax.naming.NamingException;
  import javax.servlet.ServletContextEvent;
  import javax.servlet.ServletContextListener;
  import javax.servlet.annotation.WebListener;
  
  @WebListener
  public class JndiDataSourceInitializer implements ServletContextListener {
  
      @Override
      public void contextInitialized(ServletContextEvent sce) {
          try {
              // Configure HikariCP pool
              HikariConfig poolConfig = new HikariConfig();
              poolConfig.setJdbcUrl("jdbc:postgresql://localhost:5432/your_database");
              poolConfig.setUsername("your_db_user");
              poolConfig.setPassword("your_db_password");
              poolConfig.setDriverClassName("org.postgresql.Driver");
              poolConfig.setMaximumPoolSize(10); // Adjust based on your needs
  
              HikariDataSource dataSource = new HikariDataSource(poolConfig);
  
              // Set up embedded JNDI context
              System.setProperty(Context.INITIAL_CONTEXT_FACTORY, "org.apache.naming.java.javaURLContextFactory");
              System.setProperty(Context.URL_PKG_PREFIXES, "org.apache.naming");
              InitialContext jndiContext = new InitialContext();
              
              // Create subcontext and bind the data source
              jndiContext.createSubcontext("java:comp/env/jdbc");
              jndiContext.bind("java:comp/env/jdbc/PostgresDS", dataSource);
          } catch (NamingException e) {
              throw new RuntimeException("Failed to initialize JNDI data source", e);
          }
      }
  
      @Override
      public void contextDestroyed(ServletContextEvent sce) {
          // Clean up the pool on app shutdown
          try {
              InitialContext jndiContext = new InitialContext();
              HikariDataSource dataSource = (HikariDataSource) jndiContext.lookup("java:comp/env/jdbc/PostgresDS");
              dataSource.close();
          } catch (NamingException e) {
              e.printStackTrace();
          }
      }
  }
  

• Now you can look up the data source anywhere in your app using standard JNDI syntax:

  InitialContext context = new InitialContext();
  DataSource postgresDS = (DataSource) context.lookup("java:comp/env/jdbc/PostgresDS");
  

2. Application-Level Java EE Resource Configuration #

If you’re using Java EE, you can define the PostgreSQL data source directly in your application’s deployment descriptors. WildFly will recognize these settings without needing any server-level admin changes.

Example Setup: #

• First, either package the PostgreSQL driver in your app’s WEB-INF/lib directory or add it as a WildFly module (the module approach avoids duplicate driver conflicts).
• Add a resource reference to your web.xml:

  <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" version="4.0">
      <resource-ref>
          <description>PostgreSQL Application Data Source</description>
          <res-ref-name>jdbc/PostgresDS</res-ref-name>
          <res-type>javax.sql.DataSource</res-type>
          <res-auth>Container</res-auth>
      </resource-ref>
  </web-app>
  

• Create a jboss-web.xml (WildFly-specific) to map the resource reference to an app-scoped JNDI name:

  <jboss-web xmlns="http://www.jboss.com/xml/ns/javaee" version="8.0">
      <resource-ref>
          <res-ref-name>jdbc/PostgresDS</res-ref-name>
          <jndi-name>java:app/PostgresDS</jndi-name>
      </resource-ref>
  </jboss-web>
  

• Define the data source and connection pool in a glassfish-resources.xml (WildFly supports this standard file):

  <resources xmlns="http://glassfish.org/xmlns/resources">
      <jdbc-resource jndi-name="java:app/PostgresDS" pool-name="PostgresAppPool"/>
      <jdbc-connection-pool name="PostgresAppPool" res-type="javax.sql.DataSource">
          <property name="driverClass" value="org.postgresql.Driver"/>
          <property name="url" value="jdbc:postgresql://localhost:5432/your_database"/>
          <property name="user" value="your_db_user"/>
          <property name="password" value="your_db_password"/>
          <property name="maxPoolSize" value="10"/>
          <property name="minPoolSize" value="2"/>
      </jdbc-connection-pool>
  </resources>
  

• Package all these files with your WAR/EAR, and WildFly will deploy the data source alongside your application automatically.

Quick Tips: #

• For the embedded JNDI approach, you have full control over credentials and pool settings—they’re stored within your app, not in WildFly’s server config.
• If you package the PostgreSQL driver with your app, ensure it’s not conflicting with any driver modules already installed in WildFly.

内容的提问来源于stack exchange，提问作者Igor Gorbunov