Use a forked exec-maven-plugin instead of maven-antrun-plugin

Motivation:

maven-antrun-plugin does not redirect stdin, and thus it's impossible to
run interactive examples such as securechat-client and telnet-client.
org.codehaus.mojo:exec-maven-plugin redirects stdin, but it buffers
stdout and stderr, and thus an application output is not flushed timely.

Modifications:

Deploy a forked version of exec-maven-plugin which flushes output
buffers in a timely manner.

Result:

Interactive examples work.  Launches faster than maven-antrun-plugin.

pom.xml

@@ -502,12 +502,6 @@
       <plugin>
         <artifactId>maven-antrun-plugin</artifactId>
         <version>1.7</version>
-        <configuration>
-          <target>
-            <property name="runtime_classpath" refid="maven.runtime.classpath"/>
-            <ant antfile="${antfile}"/>
-          </target>
-        </configuration>
         <executions>
           <execution>
             <id>write-version</id>
@@ -515,7 +509,7 @@
             <goals>
               <goal>run</goal>
             </goals>
-            <configuration combine.self="override">
+            <configuration>
               <target>
                 <taskdef resource="net/sf/antcontrib/antlib.xml" />
                 <exec executable="git" outputproperty="gitOutput" resultproperty="gitExitCode" failonerror="false" failifexecutionfails="false">
@@ -545,7 +539,7 @@
             <goals>
               <goal>run</goal>
             </goals>
-            <configuration combine.self="override">
+            <configuration>
               <target>
                 <taskdef resource="net/sf/antcontrib/antlib.xml" />
                 <if>
@@ -736,6 +730,20 @@
           </dependency>
         </dependencies>
       </plugin>
+      <!-- run-example.sh invokes this plugin to launch an example. -->
+      <plugin>
+        <groupId>kr.motd.maven</groupId>
+        <artifactId>exec-maven-plugin</artifactId>
+        <version>1.0.0.Final</version>
+        <configuration>
+          <executable>${java.home}/bin/java</executable>
+          <commandlineArgs>
+            -classpath %classpath
+            ${argLine.example}
+            ${exampleClass}
+          </commandlineArgs>
+        </configuration>
+      </plugin>
     </plugins>
   </build>
 </project>

run-example.sh

@@ -83,5 +83,5 @@ fi
 
 cd "`dirname "$0"`"
 echo "[INFO] Running: $EXAMPLE ($EXAMPLE_CLASS $EXAMPLE_ARGS)"
-exec mvn -nsu compile antrun:run -Dcheckstyle.skip=true -Dantfile=src/antrun/run-example.xml -DargLine.example="$EXAMPLE_ARGS" -DexampleClass="$EXAMPLE_CLASS"
+exec mvn -q -nsu compile exec:exec -Dcheckstyle.skip=true -DargLine.example="$EXAMPLE_ARGS" -DexampleClass="$EXAMPLE_CLASS"
 

src/antrun/run-example.xml

@@ -1,9 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project default="run-example">
-  <target name="run-example">
-    <java classname="${exampleClass}" classpath="${runtime_classpath}" fork="true">
-      <jvmarg line="${argLine.example}" />
-    </java>
-  </target>
-</project>
-