Tomcat RESTful Web 服务部署

Question

I'm writing a simple RESTful web service using Java, tomcat7, jersey and the IDE eclipse.

When I launched the web service using eclipse (Servers), it works well. I tested the GET and POST method. But when I export the application in WAR file and deployed with tomcat manage UI. It returns status 404 not found.

Here is the example:

@Path("/webservice")
public class WebService {

    @POST
    @Path("/post")
    @Produces(MediaType.APPLICATION_JSON)
    public Response helloWorld(String inputJson) {
        return Response.ok().entity("Hello World").build();
    }

    @GET  
    @Path("/{param}")  
    public Response getMessage(@PathParam("param") String message) {  
        String output = "Jersey say Hello World!!! : " + message;  
        return Response.status(200).entity(output).build();  
    }
}

Here is the web.xml:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
  <display-name>WebService</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
  </welcome-file-list>

  <servlet>
    <servlet-name>jersey-servlet</servlet-name>
    <servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer</servlet-class>
    <init-param>
        <param-name>com.sun.jersey.config.property.packages</param-name>
        <param-value>package.webservice</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>jersey-servlet</servlet-name>
    <url-pattern>/*</url-pattern>
  </servlet-mapping>
</web-app>

Can anybody explain what's the difference between the launch the service in eclipse and deploy in localhost (OR remote host)? And how can I debug or get some traces about this?

Answer 1

there are 2 suggestion for you to get rid from this problem 1) in your resource file make a default method so that if no url match then it will invoke otherwise it may give 404

@GET
@Produces({ MediaType.TEXT_HTML, MediaType.TEXT_PLAIN })
public String default() {
    return "Hello Rest Api";
}

you can see -> Rest api resource example

2) set a default rest api path in your web.xml lke below

<servlet-mapping>
    <servlet-name>Jersey</servlet-name>
    <url-pattern>/rest/*</url-pattern>
</servlet-mapping>

you can see -> Rest api default path set

so that when you call your api like -> http://something.com/project/rest then your default method of the resource file will fire. so no 404 happen.

Answer 2

I finally get it working. I set the context-root in the properties of the eclipse project. The URL accessible will be something like: localhost:8080/context-root/rest/... But when I deploy this with WAR file in Tomcat, this configuration is not taken into account. The correct URL is still: localhost:8080/project/rest/...

I have to find how to set the context-root in web.xml or somewhere else.

Answer 3

The web.xml settings for running REST Api's using Jersey is best explained in following URL.

http://www.vogella.com/tutorials/REST/article.html#jerseyprojectsetup_gradle

I am developing REST Api's and following is the web.xml setting.

<servlet>
    <servlet-name>BOARDWALK REST Service</servlet-name>
    <servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
    <!-- Register resources and providers under com.vogella.jersey.first package. -->
    <init-param>
        <param-name>jersey.config.server.provider.packages</param-name>
        <param-value>io.swagger.api</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
</servlet>

<servlet-mapping>
    <servlet-name>BOARDWALK REST Service</servlet-name>
    <url-pattern>/bae/*</url-pattern>
</servlet-mapping>

All REST API Service classes are stored under classes/io/swagger/api folder. When I call a REST api, I use following URL and it works.

http://localhost:8080/bae4_3_release/bae/bcpInstance

where http://localhost:8080/bae4_3_release is the context. /bae/bcpInstance is pointing to a class in classes/io/swagger/api/BcpInstanceApi.class that has PATH as @bcpInstance defined in it.

    <init-param>
        <param-name>jersey.config.server.provider.packages</param-name>
        <param-value>io.swagger.api</param-value>
    </init-param>

Denotes location of REST APIs deployment.

Answer 4

I've fixed it by putting the right JDK on env variables. Setting up JAVA_HOME to point to Java 11 instead of Java 8.

I had the same issue with Tomcat 9 and IntelliJ. When deployed via IntelliJ it all would work, but deploying that same.war coming from project/target/project.war to tomcat by copying it into $CATALINA_HOME/webapps would result in a successful deployment but with 404 on all my requests.

It was just a simple hello world restful app using jersey and my /api/hello-world never worked. I need to keep both java versions on my machine, so IntelliJ was using 11 and the rest of the system was using 8.

All working now.