task: add parameter comparator

Author: mbtaylor

task/src/main/uk/ac/starlink/task/Parameter.java

@@ -3,6 +3,7 @@
 import java.lang.reflect.Array;
 import java.lang.reflect.Constructor;
 import java.util.Collection;
+import java.util.Comparator;
 
 /**
  * A Parameter describes the function of one of a task's parameters.
@@ -38,6 +39,14 @@ public abstract class Parameter<T> {
     private T objectValue_;
     private boolean gotValue_;
 
+    /** Compares parameters alphabetically by parameter name. */
+    public static final Comparator<Parameter> BY_NAME =
+            new Comparator<Parameter>() {
+        public int compare( Parameter p1, Parameter p2 ) {
+            return p1.getName().compareTo( p2.getName() );
+        }
+    };
+
     /**
      * Constructs a parameter with a given name.  This name should be unique
      * within a given Task.

ttools/src/main/uk/ac/starlink/ttools/build/UsageWriter.java

@@ -6,7 +6,6 @@
 import java.io.IOException;
 import java.io.OutputStream;
 import java.util.Arrays;
-import java.util.Comparator;
 import java.util.Iterator;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -62,14 +61,7 @@ private void writeXml() throws IOException {
             outln( "</p>" );
             outln( "<p>" );
             outln( "<dl>" );
-            Arrays.sort( params, new Comparator() {
-                public int compare( Object o1, Object o2 ) {
-                    Parameter p1 = (Parameter) o1;
-                    Parameter p2 = (Parameter) o2;
-                    return ((Parameter) o1).getName()
-                          .compareTo( ((Parameter) o2).getName() );
-                }
-            } );
+            Arrays.sort( params, Parameter.BY_NAME );
             for ( int i = 0; i < params.length; i++ ) {
                 outln( xmlItem( params[ i ], false ) );
             }

ttools/src/main/uk/ac/starlink/ttools/server/TaskServlet.java

@@ -6,7 +6,6 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.Comparator;
 import java.util.HashSet;
 import java.util.List;
 import javax.servlet.ServletConfig;
@@ -303,14 +302,7 @@ private void writeTaskHelp( String baseUrl, ServletOutputStream out,
 
         out.println( "<h3>Parameters</h3>" );
         out.println( "<dl>" );
-        Arrays.sort( params, new Comparator() {
-            public int compare( Object o1, Object o2 ) {
-                Parameter p1 = (Parameter) o1;
-                Parameter p2 = (Parameter) o2;
-                return ((Parameter) o1).getName()
-                      .compareTo( ((Parameter) o2).getName() ); 
-            }
-        } );
+        Arrays.sort( params, Parameter.BY_NAME );
         for ( int i = 0; i < params.length; i++ ) {
             Parameter param = params[ i ];
             out.println( "<dt><b><a name='" + param.getName() + "'>"