创建Jenkins插件以添加参数

Question

I am writing a Jenkins plugin (for the first time) that connects to a nexus repository to pull back a list of artifacts based on a GAV search. The config.jelly allows the user to specify which groups to pull artifacts back from and then the index.jelly populates separate select boxes for groupId, artifactId, and version when the user actually does the build. The idea is that when the user clicks the "Build" button, those artifact coordinates are available during the build process. When I click the "Build" button I get the following error:

javax.servlet.ServletException: java.lang.ClassCastException: net.sf.json.JSONNull cannot be cast to net.sf.json.JSONObject
at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:778)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:858)
at org.kohsuke.stapler.MetaClass$6.doDispatch(MetaClass.java:248)
at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:53)
at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:728)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:858)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:631)
at org.kohsuke.stapler.Stapler.service(Stapler.java:225)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:848)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:686)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1494)
at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:96)
at hudson.util.PluginServletFilter.doFilter(PluginServletFilter.java:88)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1482)
at hudson.security.csrf.CrumbFilter.doFilter(CrumbFilter.java:48)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1482)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:84)
at hudson.security.ChainedServletFilter.doFilter(ChainedServletFilter.java:76)
at hudson.security.HudsonFilter.doFilter(HudsonFilter.java:164)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1482)
at org.kohsuke.stapler.compression.CompressionFilter.doFilter(CompressionFilter.java:46)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1482)
at hudson.util.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:81)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1474)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:499)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:137)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:533)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:231)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1086)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:428)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:193)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1020)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:135)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:116)
at org.eclipse.jetty.server.Server.handle(Server.java:370)
at org.eclipse.jetty.server.AbstractHttpConnection.handleRequest(AbstractHttpConnection.java:489)
at org.eclipse.jetty.server.AbstractHttpConnection.content(AbstractHttpConnection.java:960)
at org.eclipse.jetty.server.AbstractHttpConnection$RequestHandler.content(AbstractHttpConnection.java:1021)
at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:865)
at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:240)
at org.eclipse.jetty.server.AsyncHttpConnection.handle(AsyncHttpConnection.java:82)
at org.eclipse.jetty.io.nio.SelectChannelEndPoint.handle(SelectChannelEndPoint.java:668)
at org.eclipse.jetty.io.nio.SelectChannelEndPoint$1.run(SelectChannelEndPoint.java:52)
at winstone.BoundedExecutorService$1.run(BoundedExecutorService.java:77)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.ClassCastException: net.sf.json.JSONNull cannot be cast to net.sf.json.JSONObject
at hudson.model.ParametersDefinitionProperty._doBuild(ParametersDefinitionProperty.java:132)
at hudson.model.AbstractProject.doBuild(AbstractProject.java:1849)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.kohsuke.stapler.Function$InstanceFunction.invoke(Function.java:298)
at org.kohsuke.stapler.Function.bindAndInvoke(Function.java:161)
at org.kohsuke.stapler.Function.bindAndInvokeAndServeResponse(Function.java:96)
at org.kohsuke.stapler.MetaClass$1.doDispatch(MetaClass.java:120)
at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:53)
at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:728)
... 46 more

---

I realize that JSONNull is not a subclass of JSONObject, but I don't understand why there is a JSONNull in the first place. I haven't gotten Eclipse to bind to the debug port, so I'm just using the jenkins.out.log and jenkins.err.log logs as a way of tracing through the plugin as it runs. Using Fiddler I captured the following transaction with a response code of 500 (Internal server error):

POST http://localhost:8080/job/asdf/build?delay=0sec HTTP/1.1
Host: localhost:8080

Connection: keep-alive
Content-Length: 316
Cache-Control: max-age=0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Origin: http://localhost:8080
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/32.0.1700.107 Safari/537.36
Content-Type: application/x-www-form-urlencoded
Referer: http://localhost:8080/job/asdf/build?delay=0sec
Accept-Encoding: gzip,deflate,sdch
Accept-Language: en-US,en;q=0.8
Cookie: screenResolution=1280x1024; JSESSIONID=fd6xjf3cxhat1mwlhv2vzt17g

groupId=org.test&artifactId=test-service&version=0.0.1-SNAPSHOT&statusCode=303&redirectTo=.&json=%7B%22groupId%22%3A+%22org.test%22%2C+%22artifactId%22%3A+%22test-service%22%2C+%22version%22%3A+%220.0.1-SNAPSHOT%22%2C+%22statusCode%22%3A+%22303%22%2C+%22redirectTo%22%3A+%22.%22%7D&Submit=Build

In my ClassParameterDefinition I am overriding the following method, with the expectation that a "Build" button click will come here:

@Override
    public ParameterValue createValue(StaplerRequest req, JSONObject jo) {
        System.out.println(new Date().toString() + " createValue(" + jo.toString() + ")");
        ClassParameterValue value = req.bindJSON(ClassParameterValue.class, jo);

        value.setGroupId(this.groupId);
        value.setArtifactId(this.artifactId);
        value.setVersion(this.version);
        return value;
    }

and my index.jelly file looks like this:

<?jelly escape-by-default='true'?>
<j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define"
    xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form"
    xmlns:i="jelly:fmt" xmlns:p="/lib/hudson/project">

    <!-- This is the input form when a user does a build. -->

    <j:invokeStatic className="org.test.ClassParameterDefinition" method="getFullArtifactList" var="fullArtifactList" />
    <j:invokeStatic className="org.test.ClassParameterDefinition" method="fetchGroupList" var="groupList" />

    <![CDATA[
    <script type="text/javascript">
        var artifactList = [];
        var versionList = [];

        function createArtifactList(fullArtifactList, groupId) {
            artifactList = [];
            for(var a = 0; a < fullArtifactList.length; a++) {
                var found = false;
                for(var l = 0; l < artifactList.length; l++) {
                    if(fullArtifactList[a].groupId == groupId) {
                        if(fullArtifactList[a].artifactId == artifactList[l]) {
                            found = true
                            break
                        }
                    }
                }
                if(fullArtifactList[a].groupId == groupId) {
                    if(!found) {
                        artifactList.push(fullArtifactList[a].artifactId)
                    }
                }
            }
            artifactList.sort(function (a, b) {
                return a.toLowerCase().localeCompare(b.toLowerCase())
            })
            populateArtifactSelect(artifactList)
        }

        function populateArtifactSelect(artifactList) {
            console.log('Populating the artifactId drop down')
            document.getElementById('artifactIdSelect').innerHTML = ""
            for(var a = 0; a < artifactList.length; a++) {
                opt = document.createElement("option")
                opt.value = artifactList[a]
                opt.text = artifactList[a]
                document.getElementById('artifactIdSelect').appendChild(opt)
            }
            createVersionList(${fullArtifactList}, document.getElementById('groupIdSelect').value, document.getElementById('artifactIdSelect').value)
        }

        function createVersionList(fullArtifactList, groupId, artifactId) {
            versionList = [];
            for(var a = 0; a < fullArtifactList.length; a++) {
                if(fullArtifactList[a].groupId == groupId) {
                    if(fullArtifactList[a].artifactId == artifactId) {
                        versionList.push(fullArtifactList[a].version)
                    }
                }
            }
            populateVersionSelect(versionList)
        }

        function populateVersionSelect(versionList) {
            console.log('Populating the version drop down')
            document.getElementById('versionIdSelect').innerHTML = ""
            for(var v = 0; v < versionList.length; v++) {
                opt = document.createElement("option")
                opt.value = versionList[v]
                opt.text = versionList[v]
                document.getElementById('versionIdSelect').appendChild(opt)
            }
        }
    </script>
    ]]>

    <j:set var="it" value="${it.build}" />
    <f:entry title="Group ID" description="${%group.id.description}" field="groupId">
        <select id="groupIdSelect" name="groupId" onchange="createArtifactList(${fullArtifactList}, this.value)">
            <j:forEach var="group" items="${groupList}">
                <option value="${group}">${group}</option>
            </j:forEach>
        </select>
    </f:entry>

    <f:entry title="Artifact ID" description="${%artifact.id.description}" field="artifactId">
        <select id="artifactIdSelect" name="artifactId" onchange="createVersionList(${fullArtifactList}, document.getElementById('groupIdSelect').value, this.value)"></select>
    </f:entry>

    <f:entry title="Version" description="${%version.description}" field="version">
        <select name="version" id="versionIdSelect"></select>
    </f:entry>

    <![CDATA[
        <script type="text/javascript">
            createArtifactList(${fullArtifactList}, document.getElementById('groupIdSelect').value)
        </script>
    ]]>

</j:jelly>

• Why am I getting a JSONNull object created when the "Build" button submits the form?
• Is the code in fact trying to go to the createValue method I am overriding?

Answer 1

After quite a bit of reading through plugins and trial and error I found the issue. Hope this helps someone else.

My index.jelly file was missing a name field, and my ClassParameterDescription was expecting it in the constructor and calling super(name);

That said the only way I was able to make the parameters usable, and I'm sure there are better ways to do this but since it's my first plugin I'm satisfied with a working product at the moment, was to add the following section into my index.jelly:

<div name="parameter">
        <input type="hidden" name="name" value="${it.name}" />
        <input type="hidden" id="groupIdValue" name="groupId" value="document.getElementById('groupIdSelect').value" />
        <input type="hidden" id="artifactIdValue" name="artifactId" value="document.getElementById('artifactIdSelect').value" />
        <input type="hidden" id="versionValue" name="version" value="document.getElementById('versionSelect').value" />
    </div>

The values had to be updated as well in the select onchange method.

The variables were then put into the environment variables in the ClassParameterValue.java class and they were accessible by $groupId, $artifactId, and $version. Or on the windows batch file as %groupId%, %artifactId%, and %version%

I got the hint from the Label Parameter plugin for Jenkins source code ( https://wiki.jenkins-ci.org/display/JENKINS/NodeLabel+Parameter+Plugin )