Java rest API returns HTTP status 404

Question

I have a simple REST API i am trying to get running and it's giving me a HTTP 404 error. AFAICS it looks right but obv not ... Tomcat is running and i get the Eclipse browser come up with HTTP404. Tomcat doesnt help with all its errors but they are all just warnings but i can pop them in here if needed, will clutter the question though.

I think its to do with the jersey format, the xml or both but not sure.

*****Updated the question to include a xml update and a tomcat error.******

My class is thus:

package WS;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;

//annotations
@Path("/book")
public class Book{
    @GET
    @Produces(MediaType.TEXT_XML)
    public String sayHelloXML(){
        String response = "<?xml version='1.0'?><hello>Hello there</hello>";
        return response;
    }
}

My Xml is thus: (note i think im using jersey 2.0 so i dont have to have anything here right?)

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
  <display-name>RestApi</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>



  <servlet>
    <servlet-name>MyApplication</servlet-name>
    <servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
    <init-param>
        <param-name>jersey.config.server.provider.packages</param-name>
        <!-- The package where your resource classes are -->
        <param-value>WS</param-value>
    </init-param>
</servlet>
<servlet-mapping>
    <servlet-name>MyApplication</servlet-name>
    <url-pattern>/api/*</url-pattern>
</servlet-mapping>
</web-app>

... and my libs imported is thus:

SEVERE: Allocate exception for servlet MyApplication java.lang.ClassNotFoundException: org.glassfish.jersey.servlet.ServletContainer at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1333) at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1167) at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:520) at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:501) at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:120) at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1095) at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:817) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:135) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:673) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456) at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Unknown Source)

Error i get back in browser when i hit http://localhost:8080/PK_WS/api/

javax.servlet.ServletException: Error instantiating servlet class org.glassfish.jersey.servlet.ServletContainer org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502) org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616) org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518) org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091) org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:673) org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500) org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456) java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) java.lang.Thread.run(Unknown Source)

root cause java.lang.ClassNotFoundException: org.glassfish.jersey.servlet.ServletContainer org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1333) org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1167) org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502) org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616) org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518) org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091) org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:673) org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500) org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456) java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) java.lang.Thread.run(Unknown Source)

Answer 1

That's not enough in the web.xml. You still need to configure Jersey, as it's the runtime that handle the JAX-RS processing. You can either do it with web.xml

<servlet>
    <servlet-name>MyApplication</servlet-name>
    <servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
    <init-param>
        <param-name>jersey.config.server.provider.packages</param-name>
        <!-- The package where your resource classes are -->
        <param-value>WS</param-value>
    </init-param>
</servlet>
<servlet-mapping>
    <servlet-name>MyApplication</servlet-name>
    <url-pattern>/api/*</url-pattern>
</servlet-mapping>

Or without web.xml

@ApplicationPath("/api")
public class MyApplication extends ResourceConfig {
    public MyApplication() {
        packages("WS");
    }
}

With both options, /api will be the app url prefix. You can change it.

For more information check out Servlet Based Deployment from the Jersey User Guide.