java - 资源未从 web.xml 注入数据源 - Java 框架 - Payara Micro - NullPointerException
问题描述
我的 Payara REST API 在没有 DB 连接的情况下工作正常,并且 Postgres localhost 连接也通过 DriverManager 工作正常,即:
Connection connection = DriverManager.getConnection("jdbc:postgresql://localhost:5432/postgres", "postgres", "pass@123")
但是,web.xml & Resource 中 postgresql 的数据源在下面的代码中抛出 NullPointerException:
public class AppService {
@Resource(name="java:global/esWf")
DataSource ds;
public Response test (
...
Connection conn = ds.getConnection();
...
WEB-INF/web.xml:-
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
version="3.1">
<session-config>
<session-timeout>
30
</session-timeout>
</session-config>
<display-name>PG-DataSource</display-name>
<data-source>
<name>java:global/esWf</name>
<class-name>org.postgresql.ds.PGSimpleDataSource</class-name>
<url>jdbc:postgresql://localhost:5432/postgres</url>
<user>postgres</user>
<password>pass@123</password>
<property>
<name>fish.payara.slow-query-threshold-in-seconds</name>
<value>5</value>
</property>
</data-source>
</web-app>
我还尝试用服务器、端口、数据库名称的单独元素替换 url!
这是我第一次尝试通过数据源和资源进行连接,可能会遗漏一些小东西!
参考链接:- https://blog.payara.fish/setting-up-a-data-source-in-payara-micro, https://dzone.com/articles/easy-java-ee-microservices-with- payara-micro , Payara DB 示例等
错误: -
java.lang.NullPointerException
at es.dms.DmsSrv.test(DmsSrv.java:65)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.glassfish.jersey.server.model.internal.ResourceMethodInvocationHandlerFactory.lambda$static$0(ResourceMethodInvocationHandlerFactory.java:52)
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher$1.run(AbstractJavaResourceMethodDispatcher.java:124)
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.invoke(AbstractJavaResourceMethodDispatcher.java:167)
at org.glassfish.jersey.server.model.internal.JavaResourceMethodDispatcherProvider$ResponseOutInvoker.doDispatch(JavaResourceMethodDispatcherProvider.java:176)
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.dispatch(AbstractJavaResourceMethodDispatcher.java:79)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:469)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:391)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:80)
at org.glassfish.jersey.server.ServerRuntime$1.run(ServerRuntime.java:253)
at org.glassfish.jersey.internal.Errors$1.call(Errors.java:248)
at org.glassfish.jersey.internal.Errors$1.call(Errors.java:244)
at org.glassfish.jersey.internal.Errors.process(Errors.java:292)
at org.glassfish.jersey.internal.Errors.process(Errors.java:274)
at org.glassfish.jersey.internal.Errors.process(Errors.java:244)
at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:265)
at org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:232)
at org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:680)
at org.glassfish.jersey.servlet.WebComponent.serviceImpl(WebComponent.java:394)
at org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:346)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:366)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:319)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:205)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1636)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:259)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:161)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:757)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:577)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:158)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:371)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:238)
at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:520)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:217)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:182)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:156)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:218)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:95)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:260)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:177)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:109)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:88)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:53)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:524)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:89)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:94)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:33)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:114)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:569)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:549)
at java.lang.Thread.run(Thread.java:748)
解决方案
这看起来与cdi bean 中的资源注入中的问题相同。
使用注入@Resource
在普通 CDI bean 和 JAX-RS 资源中不起作用。它仅适用于企业 bean。
您有 2 个选项:
- 将您的 bean 变成无状态的 EJB - 只需
@Stateless
在类中添加注释:
@Stateless
@RequestScoped
@Path("app")
public class AppService {
@Resource(name="java:global/esWf")
DataSource ds;
public Response test (
- 创建一个 CDI 生产者,然后将数据源作为 CDI bean 注入。最佳做法是使用限定符来标记您要注入的 DS(如果应用程序中有多个数据源):
@Qualifier
@Retention(RUNTIME)
@Target({METHOD, FIELD, PARAMETER, TYPE})
public @interface Eswf {
}
---------------
@RequestScoped
public DsProducer {
@Produces
@Resource(name="java:global/esWf")
@Eswf
Datasource eswfDatasource;
}
------------------
@RequestScoped
@Path("app")
public class AppService {
@Inject
@Eswf
DataSource ds;
public Response test (
PS 我认为您还需要更改 JNDI 名称以使用java:app/
命名空间 instad,java:global/
因为 DS 应该仅对已部署的应用程序可用。您可以使用`new InitialContext().lookup("java:global/esWf") 测试是否可以通过 JNDI 名称检索 DS。这应该可以在您的应用程序中的任何地方工作,而不仅仅是在 EJB 中。
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