Spring Boot-Tomcat JNDI在服务bean中失败

Question

@RestController
public class TestController {

  @Autowired
  private DataSource dataSource;

  @RequestMapping("/test")
  @ResponseBody
  public String test() {

  // Gets object instance... everything is OK...
  System.out.println(this.dataSource); 
  }

@Service
public class TestService {

  @Autowired
  private DataSource dataSource;

  @PostConstruct
  private void init() {

    // Throws exception...
    System.out.println(this.dataSource);

}

Caused by: javax.naming.NameNotFoundException: Name [java:comp/env/jdbc/myDataSource] is not bound in this Context. Unable to find [java:comp].
    at org.apache.naming.NamingContext.lookup(NamingContext.java:819)
    at org.apache.naming.NamingContext.lookup(NamingContext.java:167)
    at javax.naming.InitialContext.lookup(InitialContext.java:411)
    at org.springframework.jndi.JndiTemplate$1.doInContext(JndiTemplate.java:155)
    at org.springframework.jndi.JndiTemplate.execute(JndiTemplate.java:87)
    at org.springframework.jndi.JndiTemplate.lookup(JndiTemplate.java:152)
    at org.springframework.jndi.JndiTemplate.lookup(JndiTemplate.java:179)
    at org.springframework.jndi.JndiLocatorSupport.lookup(JndiLocatorSupport.java:95)
    at org.springframework.jndi.JndiObjectLocator.lookup(JndiObjectLocator.java:106)
    at org.springframework.jndi.JndiObjectTargetSource.getTarget(JndiObjectTargetSource.java:135)
    ... 11 more

我想知道为什么JNDI数据源bean不能从@service class访问？有什么想法吗？

Answer 1

实际问题是您试图在PostConstruct中获取数据源，而不是在服务bean中失败。

默认情况下，Tomcat使用线程上下文类加载器来确定应该对哪个JNDI上下文执行查找。因此，在将资源绑定到web应用程序的JNDI上下文中时，需要确保在web应用程序的类加载器（即org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedWebAppClassLoader)是线程上下文类加载器时执行查找。

下面是执行上述检查的org.apache.naming.ContextBindings.GetClassLoader的代码片段：

/**
 * Retrieves the naming context bound to a class loader.
 */
public static Context getClassLoader()
    throws NamingException {
    ClassLoader cl = Thread.currentThread().getContextClassLoader();
    Context context = null;
    do {
        context = clBindings.get(cl);
        if (context != null) {
            return context;
        }
    } while ((cl = cl.getParent()) != null);
    throw new NamingException
        (sm.getString("contextBindings.noContextBoundToCL"));
}