RESTful Web Services (JAX-RS) @QueryParam Example

In RESTful web services (JAX-RS) @QueryParam annotation will be used to get the query parameters from the URL, Observe carefully, i am saying we will retrieve the parameters only not their values.  But in case of @PathParam we will get parameter values directly.

Query Parameters Syntax

Consider this URL:
http://localhost:2013/RestPathAnnotationExample/rest/customers?nameKey=Java4s&countryKey=USA
Here query parameters are nameKey, countryKey and their values are Java4s, USA respectively, hope you understood.

Required Files

• pom.xml & web.xml are similar to previous article no changes 🙂
• RestServiceQueryParamJava4s.java

RestServiceQueryParamJava4s.java

package com.java4s;
 
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.QueryParam;
import javax.ws.rs.core.Response;
 
@Path("/customers")
public class RestServiceQueryParamJava4s {
    
    @GET
    @Produces("text/html")
    public Response getResultByPassingValue(
                    @QueryParam("nameKey") String name,
                    @QueryParam("countryKey") String country) {
        
        String output = "Customer name - "+name+", Country - "+country+"";
        return Response.status(200).entity(output).build();
 
    }
}

Explanation

• Right click on your project folder > Run As > Run on Server
• Eclipse will open http://localhost:2013/RestQueryParamAnnotationExample/ with  HTTP 404 Error
• In web.xml we have specified the url pattern as /rest/* (line number 19) and in RestServiceQueryParamJava4s.java we specified class level @path as /customers [ line number 9 ] and we are retrieving 2 query parameters [ Line number 15,16 ], so our final URL should be the http://localhost:2013/RestQueryParamAnnotationExample/rest/customers?nameKey=java4s&countryKey=USA
• Check the output by hitting the above URL

Output

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• Spring Boot – RESTful Web Service with POST Request in JSON Example
• Spring Boot – Example of RESTful Web Service with XML Response
• Spring Boot – Creating a RESTful Web Service Example
• Exception Handling in RESTful Web Services (JAX-RS) with Jersey
• JAX-RS Example of Multiple Resource Formats

::. About the Author .::
		Sivateja Kandula - Java/J2EE Full Stack Developer Founder of Java4s - Get It Yourself, A popular Java/J2EE Programming Blog, Love Java and UI frameworks. You can sign-up for the Email Newsletter for your daily dose of Java tutorials.