replacing the reference to channel via checkChannel()

core/src/main/java/hudson/cli/CLICommand.java

@@ -131,6 +131,10 @@ public abstract class CLICommand implements ExtensionPoint, Cloneable {
      * <p>
      * Starting 1.445, CLI transports are not required to provide a channel
      * (think of sshd, telnet, etc), so in such a case this field is null.
+     * 
+     * <p>
+     * See {@link #checkChannel()} to get a channel and throw an user-friendly
+     * exception
      */
     public transient Channel channel;
 
@@ -214,6 +218,12 @@ public abstract class CLICommand implements ExtensionPoint, Cloneable {
             sc.setAuthentication(old); // restore
         }
     }
+    
+    public Channel checkChannel() throws AbortException {
+        if (channel==null)
+            throw new AbortException("This command can only run with Jenkins CLI. See https://wiki.jenkins-ci.org/display/JENKINS/Jenkins+CLI");
+        return channel;
+    }
 
     /**
      * Loads the persisted authentication information from {@link ClientAuthenticationCache}
@@ -309,7 +319,7 @@ public abstract class CLICommand implements ExtensionPoint, Cloneable {
      * Convenience method for subtypes to obtain the system property of the client.
      */
     protected String getClientSystemProperty(String name) throws IOException, InterruptedException {
-        return channel.call(new GetSystemProperty(name));
+        return checkChannel().call(new GetSystemProperty(name));
     }
 
     private static final class GetSystemProperty implements Callable<String, IOException> {
@@ -327,7 +337,7 @@ public abstract class CLICommand implements ExtensionPoint, Cloneable {
     }
 
     protected Charset getClientCharset() throws IOException, InterruptedException {
-        String charsetName = channel.call(new GetCharset());
+        String charsetName = checkChannel().call(new GetCharset());
         try {
             return Charset.forName(charsetName);
         } catch (UnsupportedCharsetException e) {
@@ -348,7 +358,7 @@ public abstract class CLICommand implements ExtensionPoint, Cloneable {
      * Convenience method for subtypes to obtain environment variables of the client.
      */
     protected String getClientEnvironmentVariable(String name) throws IOException, InterruptedException {
-        return channel.call(new GetEnvironmentVariable(name));
+        return checkChannel().call(new GetEnvironmentVariable(name));
     }
 
     private static final class GetEnvironmentVariable implements Callable<String, IOException> {

core/src/main/java/hudson/cli/CommandDuringBuild.java

@@ -46,7 +46,7 @@ public abstract class CommandDuringBuild extends CLICommand {
         try {
             CLICommand c = CLICommand.getCurrent();
             if (c==null)    throw new IllegalStateException("Not executing a CLI command");
-            String[] envs = c.channel.call(new GetCharacteristicEnvironmentVariables());
+            String[] envs = c.checkChannel().call(new GetCharacteristicEnvironmentVariables());
 
             if (envs[0]==null || envs[1]==null)
                 throw new CmdLineException("This CLI command works only when invoked from inside a build");

core/src/main/java/hudson/cli/GroovyCommand.java

@@ -103,7 +103,7 @@ public class GroovyCommand extends CLICommand implements Serializable {
         if (script.equals("="))
             return IOUtils.toString(stdin);
 
-        return channel.call(new Callable<String,IOException>() {
+        return checkChannel().call(new Callable<String,IOException>() {
             public String call() throws IOException {
                 File f = new File(script);
                 if(f.exists())

core/src/main/java/hudson/cli/InstallPluginCommand.java

@@ -76,15 +76,17 @@ public class InstallPluginCommand extends CLICommand {
 
         for (String source : sources) {
             // is this a file?
-            FilePath f = new FilePath(channel, source);
-            if (f.exists()) {
-                stdout.println(Messages.InstallPluginCommand_InstallingPluginFromLocalFile(f));
-                if (name==null)
-                    name = f.getBaseName();
-                f.copyTo(getTargetFilePath());
-                if (dynamicLoad)
-                    pm.dynamicLoad(getTargetFile());
-                continue;
+            if (channel!=null) {
+                FilePath f = new FilePath(channel, source);
+                if (f.exists()) {
+                    stdout.println(Messages.InstallPluginCommand_InstallingPluginFromLocalFile(f));
+                    if (name==null)
+                        name = f.getBaseName();
+                    f.copyTo(getTargetFilePath());
+                    if (dynamicLoad)
+                        pm.dynamicLoad(getTargetFile());
+                    continue;
+                }
             }
 
             // is this an URL?

core/src/main/java/hudson/cli/InstallToolCommand.java

@@ -68,7 +68,7 @@ public class InstallToolCommand extends CLICommand {
         h.checkPermission(Jenkins.READ);
 
         // where is this build running?
-        BuildIDs id = channel.call(new BuildIDs());
+        BuildIDs id = checkChannel().call(new BuildIDs());
 
         if (!id.isComplete())
             throw new AbortException("This command can be only invoked from a build executing inside Hudson");
@@ -129,7 +129,7 @@ public class InstallToolCommand extends CLICommand {
         }
         if (t instanceof EnvironmentSpecific) {
             EnvironmentSpecific e = (EnvironmentSpecific) t;
-            t = (ToolInstallation)e.forEnvironment(EnvVars.getRemote(channel));
+            t = (ToolInstallation)e.forEnvironment(EnvVars.getRemote(checkChannel()));
         }
         stdout.println(t.getHome());
         return 0;

core/src/main/java/hudson/cli/LoginCommand.java

@@ -33,7 +33,7 @@ public class LoginCommand extends CLICommand {
         if (a== Jenkins.ANONYMOUS)
             throw new CmdLineException("No credentials specified."); // this causes CLI to show the command line options.
 
-        ClientAuthenticationCache store = new ClientAuthenticationCache(channel);
+        ClientAuthenticationCache store = new ClientAuthenticationCache(checkChannel());
         store.set(a);
 
         return 0;

core/src/main/java/hudson/cli/LogoutCommand.java

@@ -17,7 +17,7 @@ public class LogoutCommand extends CLICommand {
 
     @Override
     protected int run() throws Exception {
-        ClientAuthenticationCache store = new ClientAuthenticationCache(channel);
+        ClientAuthenticationCache store = new ClientAuthenticationCache(checkChannel());
         store.remove();
         return 0;
     }

core/src/main/java/hudson/cli/SetBuildDescriptionCommand.java

-package hudson.cli;
-
-import hudson.Extension;
-import hudson.model.AbstractProject;
-import hudson.model.Run;
-import hudson.remoting.Callable;
-
-import java.io.IOException;
-import java.io.Serializable;
-
-import org.apache.commons.io.IOUtils;
-import org.kohsuke.args4j.Argument;
-
-@Extension
-public class SetBuildDescriptionCommand extends CLICommand implements Serializable {
-
-    @Override
-    public String getShortDescription() {
-        return Messages.SetBuildDescriptionCommand_ShortDescription();
-     }
-
-    @Argument(metaVar="JOB",usage="Name of the job to build",required=true,index=0)
-    public transient AbstractProject<?,?> job;
-
-    @Argument(metaVar="BUILD#",usage="Number of the build",required=true,index=1)
-    public int number;
-    
-    @Argument(metaVar="DESCRIPTION",required=true,usage="Description to be set. '=' to read from stdin.", index=2)
-    public String description;
-
-    protected int run() throws Exception {
-    	Run run = job.getBuildByNumber(number);
-        run.checkPermission(Run.UPDATE);
-
-        if ("=".equals(description)) {
-        	description = channel.call(new Callable<String,IOException>() {
-				public String call() throws IOException {
-					return IOUtils.toString(System.in);
-				}
-        	});
-        }
-        
-        run.setDescription(description);
-        
-        return 0;
-    }
-    
-}
+package hudson.cli;
+
+import hudson.Extension;
+import hudson.model.AbstractProject;
+import hudson.model.Run;
+import hudson.remoting.Callable;
+
+import java.io.IOException;
+import java.io.Serializable;
+
+import org.apache.commons.io.IOUtils;
+import org.kohsuke.args4j.Argument;
+
+@Extension
+public class SetBuildDescriptionCommand extends CLICommand implements Serializable {
+
+    @Override
+    public String getShortDescription() {
+        return Messages.SetBuildDescriptionCommand_ShortDescription();
+     }
+
+    @Argument(metaVar="JOB",usage="Name of the job to build",required=true,index=0)
+    public transient AbstractProject<?,?> job;
+
+    @Argument(metaVar="BUILD#",usage="Number of the build",required=true,index=1)
+    public int number;
+    
+    @Argument(metaVar="DESCRIPTION",required=true,usage="Description to be set. '=' to read from stdin.", index=2)
+    public String description;
+
+    protected int run() throws Exception {
+    	Run run = job.getBuildByNumber(number);
+        run.checkPermission(Run.UPDATE);
+
+        if ("=".equals(description)) {
+        	description = IOUtils.toString(stdin);
+        }
+        
+        run.setDescription(description);
+        
+        return 0;
+    }
+    
+}

core/src/main/java/hudson/cli/SetBuildDisplayNameCommand.java

@@ -32,11 +32,7 @@ public class SetBuildDisplayNameCommand extends CLICommand implements Serializab
         run.checkPermission(Run.UPDATE);
 
         if ("-".equals(displayName)) {
-            displayName = channel.call(new Callable<String, IOException>() {
-                public String call() throws IOException {
-                    return IOUtils.toString(System.in);
-                }
-            });
+            displayName = IOUtils.toString(stdin);
         }
 
         run.setDisplayName(displayName);

core/src/main/java/hudson/cli/declarative/CLIRegisterer.java

@@ -120,7 +120,6 @@ public class CLIRegisterer extends ExtensionFinder {
                             this.stdout = stdout;
                             this.stderr = stderr;
                             this.locale = locale;
-                            this.channel = Channel.current();
 
                             registerOptionHandlers();
                             CmdLineParser parser = new CmdLineParser(null);

core/src/main/java/hudson/model/FileParameterDefinition.java

@@ -75,7 +75,7 @@ public class FileParameterDefinition extends ParameterDefinition {
     @Override
     public ParameterValue createValue(CLICommand command, String value) throws IOException, InterruptedException {
         // capture the file to the server
-        FilePath src = new FilePath(command.channel,value);
+        FilePath src = new FilePath(command.checkChannel(),value);
         File local = File.createTempFile("hudson","parameter");
         src.copyTo(new FilePath(local));
 

core/src/main/java/hudson/model/ParameterDefinition.java

@@ -173,7 +173,7 @@ public abstract class ParameterDefinition implements
      * Create a parameter value from the string given in the CLI.
      *
      * @param command
-     *      This is the command that got the parameter. You can use its {@link CLICommand#channel}
+     *      This is the command that got the parameter. You can use its {@link CLICommand#checkChannel()}
      *      for interacting with the CLI JVM.
      * @throws AbortException
      *      If the CLI processing should be aborted. Hudson will report the error message