RESTful Web Services (JAX-RS) @PathParam Example

In RESTful (JAX-RS) web services @PathParam annotation will be used to bind RESTful URL parameter values to the method arguments. Lets discuss with a simple example.

Note:
If you are new to RESTful web services or if you would like to know complete step by step flow of JAX-RS, Go through this article ‘Jersey Hello World example With Maven in Eclipse Juno‘, then only you will be able to understand this tutorial 🙂 and even further web services tutorials.

Required Files

• pom.xml
• web.xml
• RestServicePathParamJava4s.java

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>RestPathParamAnnotationExample</groupId>
  <artifactId>RestPathParamAnnotationExample</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>war</packaging>
 
  <repositories>
        <repository>
            <id>maven2-repository.java.net</id>
            <name>Java.net Repository for Maven</name>
            <url>http://download.java.net/maven/2/</url>
            <layout>default</layout>
        </repository>
    </repositories>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.8.2</version>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>com.sun.jersey</groupId>
            <artifactId>jersey-server</artifactId>
            <version>1.8</version>
        </dependency>
        
    </dependencies>
 
      <build>
        <finalName>RestPathParamAnnotationExample</finalName>
        <plugins>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <compilerVersion>1.5</compilerVersion>
                    <source>1.5</source>
                    <target>1.5</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
 
</project>

 web.xml

<web-app id="WebApp_ID" version="2.4"
    xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
    http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
    <display-name>RestPathParamAnnotationExample</display-name>

    <servlet>
        <servlet-name>jersey-serlvet</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>com.java4s</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>jersey-serlvet</servlet-name>
        <url-pattern>/rest/*</url-pattern>
    </servlet-mapping>

</web-app>
<!-- www.Java4s.com -->

RestServicePathParamJava4s.java

package com.java4s;
 
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.core.Response;
 
@Path("/customers")
public class RestServicePathParamJava4s {
    
    @GET
    @Path("{name}/{country}")
    @Produces("text/html")
    public Response getResultByPassingValue(
                    @PathParam("name") String name,
                    @PathParam("country") String country) {
        
        String output = "Customer name - "+name+", Country - "+country+"";
        return Response.status(200).entity(output).build();
 
    }
}

Explanation

• Right click on your project > Run As > Run on Server
• By default eclipse will open http://localhost:2013/RestPathParamAnnotationExample/ with  HTTP 404 Error
• In web.xml we have specified URL pattern as /rest/* (line number 19) and in RestServicePathParamJava4s.java we specified class level @path as /customers [ line number 9 ] and method level @path as  {name}/{country} [ line number 13 ]
• So the final URL should be http://localhost:2013/RestPathParamAnnotationExample/rest/customers/Java4s/USA
• Once you hit the URL,  http://localhost:2013/……/rest/../Java4s/USA  , last two parameters in this URL ‘Java4s‘ and ‘USA‘ are retrieved by @PathParam(“name”), @PathParam(“country”) annotations in RestServicePathParamJava4s.java and will copy into String name, String country respectively.
  
• Check the output

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.