SeamForge Reference Guide

$ exampleplugin 

@Alias("example")
public class ExamplePlugin implements Plugin {
   // commands
}

$ example 

Take the 'grep' command itself, for example, which supports two methods of invocation: Invocation on one or more Resource<?> objects, or invocation on a piped InputStream.

@Alias("grep")
@Topic("File & Resources")
@Help("print lines matching a pattern")
public class GrepPlugin implements Plugin
{
   @DefaultCommand
   public void run(
         @PipeIn final InputStream pipeIn,
         @Option(name = "ignore-case", shortName = "i", flagOnly = true) boolean ignoreCase,
         @Option(name = "regexp", shortName = "e") String regExp,
         @Option(description = "PATTERN") String pattern,
         @Option(description = "FILE ...") Resource<?>[] resources, 
         final PipeOut pipeOut
   ) throws IOException 
   {
      Pattern matchPattern = /* determine pattern (omitted for space) */;

      if (resources != null) {
      
         /* User passed file(s) on the command line; grep those. */
      
         for (Resource<?> r : resources) {
            InputStream inputStream = r.getResourceInputStream();
            try {
               match(inputStream, matchPattern, pipeOut, ignoreCase);
            }
            finally {
               inputStream.close();
            }
         }
      }
      else if (pipeIn != null) {
      
         /* No files were passed on the command line; check for a 
          * piped InputStream and use that.
          */
      
         match(pipeIn, matchPattern, pipeOut, ignoreCase);
      }
      else {
      
         /* No input was passed to the plugin. */
      
         throw new RuntimeException("Error: arguments required");
      }
   }

   private void match(InputStream instream, Pattern pattern, PipeOut pipeOut, boolean caseInsensitive) throws IOException {
      StringAppender buf = new StringAppender();

      int c;
      while ((c = instream.read()) != -1) { /* Read from the given stream. */
         switch (c) {
         case '\r':
         case '\n':
            String s = caseInsensitive ? buf.toString().toLowerCase() : buf.toString();

            if (pattern.matcher(s).matches()) {
               pipeOut.println(s); /* Write to the output pipe. */
            }
            buf.reset();
            break;
         default:
            buf.append((char) c);
            break;
         }
      }
   }
}

It it also recommended, however, to relocate shaded class files to a new package. Your code will access the bundled code at this new location, and will prevent version conflicts if another plugin bundles a different version of the same library. For this, we use the following command.

$ shade relocate --pattern {ORIGINAL PGK} --shadedPattern {NEW PKG} --excludes {EXCLUDED PKGS...}

For the purposes of this example, let us assume that our Plugin depends on the Apache Commons Collections library (org.apache.commons.collections), and we want to make sure that no conflicts occur.

[example-plugin] example-plugin $ shade relocate --pattern org.apache.commons.collections --shadedPattern ~.shaded.apache.collections
***SUCCESS*** Relocating [org.apache.commons.collections] to [com.example.forge.plugin.shaded.apache.collections]
[example-plugin] example-plugin $ 
      	

This should be repeated for each dependency as necessary. Notice that our POM has been updated with the configuration:

   <plugin>
     <artifactId>maven-shade-plugin</artifactId>
     <version>1.4</version>
     <executions>
       <execution>
         <phase>package</phase>
         <goals>
           <goal>shade</goal>
         </goals>
         <configuration>
           <artifactSet>
             <includes>
               <include>commons-collections:commons-collections</include>
             </includes>
           </artifactSet>
           <relocations>
             <relocation>
               <pattern>org.apache.commons.collections</pattern>
               <shadedPattern>com.example.forge.plugin.shaded.apache.collections</shadedPattern>
             </relocation>
           </relocations>
         </configuration>
       </execution>
     </executions>
   </plugin>

[INFO] --- maven-shade-plugin:1.4:shade (default) @ example-plugin ---
[INFO] Excluding org.jboss.seam.forge:forge-shell-api:jar:{version} from the shaded jar.
[INFO] Excluding org.jboss.seam.forge:forge-parser-java-api:jar:{version} from the shaded jar.
[INFO] Excluding org.jboss.seam.forge:forge-parser-xml:jar:{version} from the shaded jar.
[INFO] Excluding org.jboss.shrinkwrap.descriptors:shrinkwrap-descriptors-api:jar:{version} from the shaded jar.
[INFO] Excluding javax.enterprise:cdi-api:jar:{version} from the shaded jar.
[INFO] Excluding org.jboss.spec.javax.interceptor:jboss-interceptors-api:jar:{version} from the shaded jar.
[INFO] Excluding javax.annotation:jsr250-api:jar:{version} from the shaded jar.
[INFO] Excluding javax.inject:javax.inject:jar:{version} from the shaded jar.

[INFO] Including commons-collections:commons-collections:jar:3.2.1 in the shaded jar.

[INFO] Replacing original artifact with shaded artifact.
[INFO] Replacing ~/Desktop/example-plugin/target/example-plugin-1.0.0-SNAPSHOT.jar 
   with ~/Desktop/example-plugin/target/example-plugin-1.0.0-SNAPSHOT-shaded.jar
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------