How to use #PathParam? - json

Question

I am following simple steps of tutorial and till now I cant figure out why it displays error.
I am trying to return simple JSON using a simple JAX-RS application.
The following is my code and web.xml settings:
package ws;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.UriInfo;
import javax.ws.rs.PathParam;
import javax.ws.rs.Consumes;
import javax.ws.rs.PUT;
import javax.ws.rs.Path;
import javax.ws.rs.GET;
import javax.ws.rs.Produces;
#Path("/employee/{empno}")
public class EmployeeResource {
#Context
private UriInfo context;
public EmployeeResource() {
}
#GET
#Produces("application/json")
public String getJson( #PathParam("empno") int empno) {
switch(empno) {
case 1 :
return "{'name':'George Koch', 'age':58}";
case 2:
return "{'name':'Peter Norton', 'age':50}";
default:
return "{'name':'unknown', 'age':-1}";
}
}
#PUT
#Consumes("application/json")
public void putJson(String content) {
}
}
web.xml is as follows:
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
version="3.0">
<servlet>
<servlet-name>Jersey REST Service</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>ws</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>Jersey REST Service</servlet-name>
<url-pattern>/resources/*</url-pattern>
</servlet-mapping>
<session-config>
<session-timeout>30</session-timeout>
</session-config>
</web-app>
And then I use address:
localhost:8084/restdemo/resources/employee/empno=1
but it shows 404 error.

Answer 1

Call
localhost:8084/restdemo/resources/employee/1
A #PathParam is not a #QueryParam. Its name is derived from its position in the query path, not by a give name like empno=1. Since your #Path is
#Path("/employee/{empno}")
the element of your URL path that is at the position of {empno} is automatically assigned to your #PathParam empno.
Edit:
If you want to call a URL like
localhost:8084/restdemo/resources/employee?empno=1
you must use
#Path("/employee")
public String getJson(#QueryParam("empno") int empno)
Note the ? that is the border between the URL path left of it and the query on the right of it.
Hint:
Your JSON is not valid. You must use double quotes " instead of single quotes ':
return "{\"name\":\"George Koch\", \"age\":58}";