Jersey jdbc @resource not working

问题

I'm trying to have a simple Jersey based jaxrs listener, running on my existing tomcat 7.0.57. Tomcat has a global config in its context.xml for a jdbc datasource, which I want to use.

My problem is that I can't get the resource to resolve via the @Resource annotation.

Heres a simple test example

@Path("/")
public class TestJersey {
    @Resource(name = "jdbc/default")
    private DataSource dsA;

    @Resource(name = "java:comp/env/jdbc/default")
    private DataSource dsB;

    @Resource(lookup = "java:comp/env/jdbc/default")
    private DataSource dsC;

    @Resource(mappedName="jdbc/default")
    private DataSource dsD;

    @GET
    @Produces("text/plain")
    public String test() throws NamingException {
        StringBuffer ret = new StringBuffer();
        ret.append("A: " + dsA + "\n");
        ret.append("B: " + dsB + "\n");
        ret.append("C: " + dsC + "\n");
        ret.append("D: " + dsD + "\n");        
        DataSource ds1 = 
              (DataSource) InitialContext.doLookup("java:comp/env/jdbc/default");
        ret.append("1: " + ds1 + "\n");
        return ret.toString();
    }
}

This test app returns the following

A: null
B: null
C: null
D: null
1: org.apache.tomcat.jdbc.pool.DataSource@1518c95{ConnectionPool[d.....

So the jdbc connection is configured, and can be accessed with an explicit doLookup, so why can't I get it working with a @Resource annotation?

My apps web.xml contains

<servlet>
    <servlet-name>test</servlet-name>
    <servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
    <init-param>
        <param-name>jersey.config.server.provider.packages</param-name>
        <param-value>com.test</param-value>
    </init-param>
</servlet>

<servlet-mapping>
    <servlet-name>test</servlet-name>
    <url-pattern>/*</url-pattern>
</servlet-mapping>

I've spend some time searching for what I'm doing wrong but I can't find it. I've read posts suggesting adding things like the following web.xml snippets, but they haven't helped

  <resource-ref>
      <description>DB Connection</description>
      <res-ref-name>jdbc/default</res-ref-name>
      <res-type>javax.sql.DataSource</res-type>
      <res-auth>Container</res-auth>
  </resource-ref>

For completeness, my maven dependencies are simply jersey:

<dependency>
    <groupId>org.glassfish.jersey.containers</groupId>
    <artifactId>jersey-container-servlet</artifactId>
    <version>2.19</version>
</dependency>

回答1:

It looks like peeskillet was right about needing some level of CDI.

I'll explain what I had to add, as it kind of jumps away from a lot of the instructions I found.

First, you need a CDI manager, weld is one of those so we need a dependency in our pom for that

<dependency>
    <groupId>org.jboss.weld.servlet</groupId>
    <artifactId>weld-servlet</artifactId>
    <version>2.2.15.Final</version>
</dependency>

It will also need a logging dependency, to avoid warnings or get any logging, so something like this will get the logs going to normal java util logging

<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-jdk14</artifactId>
    <version>1.7.12</version>
</dependency>

Only that isn't enough, as jersey apparently uses hk, not cdi so you need an adapter.

<dependency>
    <groupId>org.glassfish.jersey.containers.glassfish</groupId>
    <artifactId>jersey-gf-cdi</artifactId>
    <version>2.6</version>
</dependency>

Then that adapter seems to have a broken dependency so we need to add one more to avoid a two page stack trace each request.

<dependency>
    <groupId>javax.transaction</groupId>
    <artifactId>javax.transaction-api</artifactId>
    <version>1.2</version>
</dependency>

So now you have all the code in place, you need to do one last thing to make it actually work.

You need an empty WEB-INF/beans.xml. I don't quite follow why though.

Some sites also state that you need a META-INF/context.xml entry, but I didn't find I needed that, perhaps it is for injecting custom classes?

Hopefully this helps someone else

来源：https://stackoverflow.com/questions/31831611/jersey-jdbc-resource-not-working