REST Invocation With Maven

Recently I had to invoke some REST service in one of my Maven builds.

I had never did it before but I was expecting to find some ready to use component that could allow me to do all the things that I needed directly from configuration but it wasn't the case.

I did the typical search to see what was available and I have found some good tip here and there.

But the conclusion is that there is not a ready "off the shelf" component.

The 2 most practical options seem to be:

- use an Ant GET Task
- embed Groovy code in you r script

Since the first option work only with the verb GET I decided to use the Groovy approach.

Let's say that we want to invoke a service via POST like this:

 

?

1 2 3 4

pantinor@pantinor maven_rest$     curl -d appid=YahooDemo -d query=madonna -d \     context="renaissance favored the Virgin Mary for inspiration" \     http://search.yahooapis.com/ContentAnalysisService/V1/termExtraction

Produces this output:

?

1 2 3 4 5 6 7

<resultset xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="urn:yahoo:cate" xsi:schemalocation="urn:yahoo:cate http://search.yahooapis.com/ContentAnalysisService/V1/TermExtractionResponse.xsd"> <result>virgin mary</result> <result>renaissance</result> <result>inspiration</result> </resultset> <!-- ws03.ydn.ac4.yahoo.com uncompressed/chunked Thu Nov  8 23:04:36 PST 2012 -->

An example taken from http://developer.yahoo.com/search/content/V1/termExtraction.html


This is one way to do that in Maven

Add some useful dependency

?

1 2 3 4 5 6 7

<dependencies>         <dependency>             <groupid>org.codehaus.groovy.modules.http-builder</groupid>             <artifactid>http-builder</artifactid>             <version>0.5.1</version>         </dependency> </dependencies>

Specify the Groovy plugin

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

<plugin>  <groupid>org.codehaus.groovy.maven</groupid>  <artifactid>gmaven-plugin</artifactid>  <version>1.0</version>  <executions>   <execution>    <phase>generate-resources</phase>    <goals>     <goal>execute</goal>    </goals>    <configuration>     <source>     ...          </configuration>   </execution>  </executions> </plugin>

Add add the proper Groovy code

?

1 2 3 4 5 6 7 8 9 10 11 12 13

import groovyx.net.http.RESTClient import groovy.util.slurpersupport.GPathResult import static groovyx.net.http.ContentType.URLENC import static groovyx.net.http.ContentType.XML   yahoo = new RESTClient('http://search.yahooapis.com/ContentAnalysisService/V1/termExtraction')   def response = yahoo.post(     contentType: XML,     requestContentType: URLENC,     body: [appid:"YahooDemo", query:"madonna", context:"renaissance favored the Virgin Mary for inspiration"] ) log.info "yahoo response data: ${response.data}"

This is the full pom.xml file

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56

<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0" 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>test</groupid>  <artifactid>maven-rest</artifactid>  <version>1.0.0</version>    <name>Maven Rest Example</name>    <dependencies>         <dependency>             <groupid>org.codehaus.groovy.modules.http-builder</groupid>             <artifactid>http-builder</artifactid>             <version>0.5.1</version>         </dependency>     </dependencies>  <build>   <plugins>        <plugin>     <groupid>org.codehaus.groovy.maven</groupid>     <artifactid>gmaven-plugin</artifactid>     <version>1.0</version>     <executions>      <execution>       <phase>generate-resources</phase>       <goals>        <goal>execute</goal>       </goals>       <configuration>        <source>         <![CDATA[ import groovyx.net.http.RESTClient import groovy.util.slurpersupport.GPathResult import static groovyx.net.http.ContentType.URLENC import static groovyx.net.http.ContentType.XML   yahoo = new RESTClient('http://search.yahooapis.com/ContentAnalysisService/V1/termExtraction')   def response = yahoo.post(     contentType: XML,     requestContentType: URLENC,     body: [appid:"YahooDemo", query:"madonna", context:"renaissance favored the Virgin Mary for inspiration"] ) log.info "yahoo response data: ${response.data}"         ]]>                </configuration>      </execution>     </executions>    </plugin>   </plugins>  </build>     </project>

That will produce the following output:

?

1 2 3

pantinor@pantinor maven_rest$     mvn install | grep -i "yahoo"     [INFO]  yahoo response data: virgin maryrenaissanceinspiration