1. Provide a mechanism by which filter readers recognized by Ant's core (FilterreaderSet) can have a better syntax.

2.  Remove double-quotes from javadoc and replace with "


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@271584 13f79535-47bb-0310-9956-ffa450edef68

proposal/sandbox/filterreaders/src/main/org/apache/tools/ant/filters/HeadFilter.java

@@ -67,12 +67,12 @@ import org.apache.tools.ant.types.Parameterizable;
  * Example:
  * =======
  *
- * <headfilter lines="3"/>
+ * <headfilter lines="3"/>
  *
  * Or:
  *
- * <filterreader classname="org.apache.tools.ant.filters.HeadFilter">
- *    <param name="lines" value="3"/>
+ * <filterreader classname="org.apache.tools.ant.filters.HeadFilter">
+ *    <param name="lines" value="3"/>
  * </filterreader>
  *
  * @author <a href="mailto:umagesh@apache.org">Magesh Umasankar</a>
@@ -180,15 +180,15 @@ public final class HeadFilter
         this.lines = lines;
     }
 
-    public final long getLines() {
+    private final long getLines() {
         return lines;
     }
 
-    public final void setInitialized(final boolean initialized) {
+    private final void setInitialized(final boolean initialized) {
         this.initialized = initialized;
     }
 
-    public final boolean getInitialized() {
+    private final boolean getInitialized() {
         return initialized;
     }
 

proposal/sandbox/filterreaders/src/main/org/apache/tools/ant/filters/LineContains.java

@@ -3,6 +3,7 @@ package org.apache.tools.ant.filters;
 import java.io.FilterReader;
 import java.io.IOException;
 import java.io.Reader;
+import java.io.StringReader;
 import java.util.Vector;
 
 import org.apache.tools.ant.types.Parameter;
@@ -15,6 +16,13 @@ import org.apache.tools.ant.types.Parameterizable;
  * Example:
  * =======
  *
+ * <linecontains>
+ *   <contains value="foo">
+ *   <contains value="bar">
+ * </linecontains>
+ *
+ * Or:
+ *
  * <filterreader classname="org.apache.tools.ant.filters.LineContains">
  *    <param type="contains" value="foo"/>
  *    <param type="contains" value="bar"/>
@@ -26,7 +34,7 @@ import org.apache.tools.ant.types.Parameterizable;
  */
 public final class LineContains
     extends FilterReader
-    implements Parameterizable
+    implements Parameterizable, CloneableReader
 {
     private static final String CONTAINS_KEY = "contains";
 
@@ -34,12 +42,26 @@ public final class LineContains
 
     private boolean initialized = false;
 
-    private final Vector contains = new Vector();
-
-    private int containsSize = 0;
+    private Vector contains = new Vector();
 
     private String line = null;
 
+    /**
+     * This constructor is a dummy constructor and is
+     * not meant to be used by any class other than Ant's
+     * introspection mechanism. This will close the filter
+     * that is created making it useless for further operations.
+     */
+    public LineContains() {
+        // Dummy constructor to be invoked by Ant's Introspector
+        super(new StringReader(new String()));
+        try {
+            close();
+        } catch (IOException  ioe) {
+            // Ignore
+        }
+    }
+
     /**
      * Create a new filtered reader.
      *
@@ -78,9 +100,11 @@ public final class LineContains
             }
 
             if (line != null) {
+                int containsSize = contains.size();
                 for (int i = 0; i < containsSize; i++) {
                     String containsStr = (String) contains.elementAt(i);
                     if (line.indexOf(containsStr) == -1) {
+                        System.out.println("Hello");
                         line = null;
                         break;
                     }
@@ -116,6 +140,33 @@ public final class LineContains
         return n;
     }
 
+    public final void addConfiguredContains(final Contains contains) {
+        this.contains.addElement(contains.getValue());
+    }
+
+    private void setContains(final Vector contains) {
+        this.contains = contains;
+    }
+
+    private final Vector getContains() {
+        return contains;
+    }
+
+    private final void setInitialized(final boolean initialized) {
+        this.initialized = initialized;
+    }
+
+    private final boolean getInitialized() {
+        return initialized;
+    }
+
+    public final Reader clone(final Reader rdr) {
+        LineContains newFilter = new LineContains(rdr);
+        newFilter.setContains(getContains());
+        newFilter.setInitialized(true);
+        return newFilter;
+    }
+
     /**
      * Set Parameters
      */
@@ -131,7 +182,18 @@ public final class LineContains
                     contains.addElement(parameters[i].getValue());
                 }
             }
-            containsSize = contains.size();
+        }
+    }
+
+    public static class Contains {
+        private String value;
+
+        public final void setValue(String contains) {
+            value = contains;
+        }
+
+        public final String getValue() {
+            return value;
         }
     }
 }

proposal/sandbox/filterreaders/src/main/org/apache/tools/ant/filters/PrefixLines.java

@@ -3,6 +3,7 @@ package org.apache.tools.ant.filters;
 import java.io.FilterReader;
 import java.io.IOException;
 import java.io.Reader;
+import java.io.StringReader;
 
 import org.apache.tools.ant.types.Parameter;
 import org.apache.tools.ant.types.Parameterizable;
@@ -10,11 +11,22 @@ import org.apache.tools.ant.types.Parameterizable;
 /**
  * Attach a prefix to every line
  *
+ * Example:
+ * =======
+ *
+ * <prefixlines prefix="Foo"/>
+ *
+ * Or:
+ *
+ * <filterreader classname="org.apache.tools.ant.filters.PrefixLines">
+ *    <param name="prefix" value="Foo"/>
+ * </filterreader>
+ *
  * @author <a href="mailto:umagesh@apache.org">Magesh Umasankar</a>
  */
 public final class PrefixLines
     extends FilterReader
-    implements Parameterizable
+    implements Parameterizable, CloneableReader
 {
     /**
      * prefix key
@@ -29,6 +41,22 @@ public final class PrefixLines
 
     private String queuedData = null;
 
+    /**
+     * This constructor is a dummy constructor and is
+     * not meant to be used by any class other than Ant's
+     * introspection mechanism. This will close the filter
+     * that is created making it useless for further operations.
+     */
+    public PrefixLines() {
+        // Dummy constructor to be invoked by Ant's Introspector
+        super(new StringReader(new String()));
+        try {
+            close();
+        } catch (IOException  ioe) {
+            // Ignore
+        }
+    }
+
     /**
      * Create a new filtered reader.
      *
@@ -39,9 +67,9 @@ public final class PrefixLines
     }
 
     public final int read() throws IOException {
-        if (!initialized) {
+        if (!getInitialized()) {
             initialize();
-            initialized = true;
+            setInitialized(true);
         }
 
         int ch = -1;
@@ -101,12 +129,35 @@ public final class PrefixLines
         return n;
     }
 
+    public final void setPrefix(final String prefix) {
+        this.prefix = prefix;
+    }
+
+    private final String getPrefix() {
+        return prefix;
+    }
+
+    private final void setInitialized(final boolean initialized) {
+        this.initialized = initialized;
+    }
+
+    private final boolean getInitialized() {
+        return initialized;
+    }
+
+    public final Reader clone(final Reader rdr) {
+        PrefixLines newFilter = new PrefixLines(rdr);
+        newFilter.setPrefix(getPrefix());
+        newFilter.setInitialized(true);
+        return newFilter;
+    }
+
     /**
      * Set Parameters
      */
     public final void setParameters(final Parameter[] parameters) {
         this.parameters = parameters;
-        initialized = false;
+        setInitialized(false);
     }
 
     private final void initialize() {

proposal/sandbox/filterreaders/src/main/org/apache/tools/ant/filters/ReplaceTokens.java

@@ -56,6 +56,7 @@ package org.apache.tools.ant.filters;
 import java.io.FilterReader;
 import java.io.IOException;
 import java.io.Reader;
+import java.io.StringReader;
 import java.util.Hashtable;
 
 import org.apache.tools.ant.types.Parameter;
@@ -66,17 +67,24 @@ import org.apache.tools.ant.types.Parameterizable;
  *
  * Example Usage:
  * =============
+ *
+ * <replacetokens begintoken="#" endtoken="#">
+ *   <token key="DATE" value="${TODAY}"/>
+ * </replacetokens>
+ *
+ * Or:
+ *
  * <filterreader classname="org.apache.tools.ant.filters.ReplaceTokens">
  *    <param type="tokenchar" name="begintoken" value="#"/>
  *    <param type="tokenchar" name="endtoken" value="#"/>
- *    <param type="token" name="DATE" value="${DATE}"/>
+ *    <param type="token" name="DATE" value="${TODAY}"/>
  * </filterreader>
  *
  * @author <a href="mailto:umagesh@apache.org">Magesh Umasankar</a>
  */
 public final class ReplaceTokens
     extends FilterReader
-    implements Parameterizable
+    implements Parameterizable, CloneableReader
 {
     private static final char DEFAULT_BEGIN_TOKEN = '@';
 
@@ -94,6 +102,22 @@ public final class ReplaceTokens
 
     private char endToken = DEFAULT_END_TOKEN;
 
+    /**
+     * This constructor is a dummy constructor and is
+     * not meant to be used by any class other than Ant's
+     * introspection mechanism. This will close the filter
+     * that is created making it useless for further operations.
+     */
+    public ReplaceTokens() {
+        // Dummy constructor to be invoked by Ant's Introspector
+        super(new StringReader(new String()));
+        try {
+            close();
+        } catch (IOException  ioe) {
+            // Ignore
+        }
+    }
+
     /**
      * Create a new filtered reader.
      *
@@ -107,9 +131,9 @@ public final class ReplaceTokens
      * Replace tokens with values.
      */
     public final int read() throws IOException {
-        if (!initialized) {
+        if (!getInitialized()) {
             initialize();
-            initialized = true;
+            setInitialized(true);
         }
 
         if (queuedData != null && queuedData.length() > 0) {
@@ -177,12 +201,57 @@ public final class ReplaceTokens
         return n;
     }
 
+    public final void setBeginToken(final char beginToken) {
+        this.beginToken = beginToken;
+    }
+
+    private final char getBeginToken() {
+        return beginToken;
+    }
+
+    public final void setEndToken(final char endToken) {
+        this.endToken = endToken;
+    }
+
+    private final char getEndToken() {
+        return endToken;
+    }
+
+    public final void addConfiguredToken(final Token token) {
+        hash.put(token.getKey(), token.getValue());
+    }
+
+    private void setTokens(final Hashtable hash) {
+        this.hash = hash;
+    }
+
+    private final Hashtable getTokens() {
+        return hash;
+    }
+
+    private final void setInitialized(final boolean initialized) {
+        this.initialized = initialized;
+    }
+
+    private final boolean getInitialized() {
+        return initialized;
+    }
+
+    public final Reader clone(final Reader rdr) {
+        ReplaceTokens newFilter = new ReplaceTokens(rdr);
+        newFilter.setBeginToken(getBeginToken());
+        newFilter.setEndToken(getEndToken());
+        newFilter.setTokens(getTokens());
+        newFilter.setInitialized(true);
+        return newFilter;
+    }
+
     /**
      * Set Parameters
      */
     public final void setParameters(final Parameter[] parameters) {
         this.parameters = parameters;
-        initialized = false;
+        setInitialized(false);
     }
 
     /**
@@ -209,4 +278,26 @@ public final class ReplaceTokens
             }
         }
     }
+
+    public static class Token {
+        private String key;
+
+        private String value;
+
+        public final void setKey(String key) {
+            this.key = key;
+        }
+
+        public final void setValue(String value) {
+            this.value = value;
+        }
+
+        public final String getKey() {
+            return key;
+        }
+
+        public final String getValue() {
+            return value;
+        }
+    }
 }

proposal/sandbox/filterreaders/src/main/org/apache/tools/ant/filters/StripJavaComments.java

@@ -56,6 +56,7 @@ package org.apache.tools.ant.filters;
 import java.io.FilterReader;
 import java.io.IOException;
 import java.io.Reader;
+import java.io.StringReader;
 
 /**
  * This is a java comment and string stripper reader that filters
@@ -64,7 +65,25 @@ import java.io.Reader;
  * Since this class heavily relies on the single char read function,
  * you are reccomended to make it work on top of a buffered reader.
  */
-public final class StripJavaComments extends FilterReader {
+public final class StripJavaComments
+    extends FilterReader
+    implements CloneableReader
+{
+    /**
+     * This constructor is a dummy constructor and is
+     * not meant to be used by any class other than Ant's
+     * introspection mechanism. This will close the filter
+     * that is created making it useless for further operations.
+     */
+    public StripJavaComments() {
+        // Dummy constructor to be invoked by Ant's Introspector
+        super(new StringReader(new String()));
+        try {
+            close();
+        } catch (IOException  ioe) {
+            // Ignore
+        }
+    }
 
     /**
      * Create a new filtered reader.
@@ -147,4 +166,9 @@ public final class StripJavaComments extends FilterReader {
         }
         return n;
     }
+
+    public final Reader clone(final Reader rdr) {
+        StripJavaComments newFilter = new StripJavaComments(rdr);
+        return newFilter;
+    }
 }

proposal/sandbox/filterreaders/src/main/org/apache/tools/ant/filters/StripLineBreaks.java

@@ -56,6 +56,7 @@ package org.apache.tools.ant.filters;
 import java.io.FilterReader;
 import java.io.IOException;
 import java.io.Reader;
+import java.io.StringReader;
 
 import org.apache.tools.ant.types.Parameter;
 import org.apache.tools.ant.types.Parameterizable;
@@ -63,12 +64,18 @@ import org.apache.tools.ant.types.Parameterizable;
 /**
  * Filter to flatten the stream to a single line.
  *
+ * <striplinebreaks/>
+ *
+ * Or:
+ *
+ * <filterreader classname="org.apache.tools.ant.filters.StripLineBreaks"/>
+ *
  * @author Steve Loughran
  * @author <a href="mailto:umagesh@apache.org">Magesh Umasankar</a>
  */
 public final class StripLineBreaks
     extends FilterReader
-    implements Parameterizable
+    implements Parameterizable, CloneableReader
 {
     /**
      * Linebreaks. What do to on funny IBM mainframes with odd line endings?
@@ -87,6 +94,22 @@ public final class StripLineBreaks
 
     private boolean initialized = false;
 
+    /**
+     * This constructor is a dummy constructor and is
+     * not meant to be used by any class other than Ant's
+     * introspection mechanism. This will close the filter
+     * that is created making it useless for further operations.
+     */
+    public StripLineBreaks() {
+        // Dummy constructor to be invoked by Ant's Introspector
+        super(new StringReader(new String()));
+        try {
+            close();
+        } catch (IOException  ioe) {
+            // Ignore
+        }
+    }
+
     /**
      * Create a new filtered reader.
      *
@@ -98,21 +121,8 @@ public final class StripLineBreaks
 
     public final int read() throws IOException {
         if (!initialized) {
-            String userDefinedLineBreaks = null;
-            if (parameters != null) {
-                for (int i = 0; i < parameters.length; i++) {
-                    if (LINE_BREAKS_KEY.equals(parameters[i].getName())) {
-                        userDefinedLineBreaks = parameters[i].getValue();
-                        break;
-                    }
-                }
-            }
-
-            if (userDefinedLineBreaks != null) {
-                lineBreaks = userDefinedLineBreaks;
-            }
-
-            initialized = true;
+            initialize();
+            setInitialized(true);
         }
 
         int ch = in.read();
@@ -151,11 +161,49 @@ public final class StripLineBreaks
         return n;
     }
 
+    public final void setLineBreaks(final String lineBreaks) {
+        this.lineBreaks = lineBreaks;
+    }
+
+    private final String getLineBreaks() {
+        return lineBreaks;
+    }
+
+    private final void setInitialized(final boolean initialized) {
+        this.initialized = initialized;
+    }
+
+    private final boolean getInitialized() {
+        return initialized;
+    }
+
+    public final Reader clone(final Reader rdr) {
+        StripLineBreaks newFilter = new StripLineBreaks(rdr);
+        newFilter.setLineBreaks(getLineBreaks());
+        newFilter.setInitialized(true);
+        return newFilter;
+    }
+
     /**
      * Set Parameters
      */
     public final void setParameters(final Parameter[] parameters) {
         this.parameters = parameters;
-        initialized = false;
+        setInitialized(false);
+    }
+
+    private final void initialize() {
+        String userDefinedLineBreaks = null;
+        if (parameters != null) {
+            for (int i = 0; i < parameters.length; i++) {
+                if (LINE_BREAKS_KEY.equals(parameters[i].getName())) {
+                    userDefinedLineBreaks = parameters[i].getValue();
+                    break;
+                }
+            }
+        }
+        if (userDefinedLineBreaks != null) {
+            lineBreaks = userDefinedLineBreaks;
+        }
     }
 }

proposal/sandbox/filterreaders/src/main/org/apache/tools/ant/filters/StripLineComments.java

@@ -3,6 +3,7 @@ package org.apache.tools.ant.filters;
 import java.io.FilterReader;
 import java.io.IOException;
 import java.io.Reader;
+import java.io.StringReader;
 import java.util.Vector;
 
 import org.apache.tools.ant.types.Parameter;
@@ -14,19 +15,29 @@ import org.apache.tools.ant.types.Parameterizable;
  * Example:
  * =======
  *
- * <filterreader classname="org.apache.tools.ant.filters.StripLineComments">
- *    <param type="comment" value="#"/>
- *    <param type="comment" value="--"/>
- *    <param type="comment" value="REM "/>
- *    <param type="comment" value="rem "/>
- *    <param type="comment" value="//"/>
+ * <striplinecomments>
+ *   <comment value="#"/>
+ *   <comment value="--"/>
+ *   <comment value="REM "/>
+ *   <comment value="rem "/>
+ *   <comment value="//"/>
+ * </striplinecomments>
+ *
+ * Or:
+ *
+ * <filterreader classname="org.apache.tools.ant.filters.StripLineComments">
+ *    <param type="comment" value="#"/>
+ *    <param type="comment" value="--"/>
+ *    <param type="comment" value="REM "/>
+ *    <param type="comment" value="rem "/>
+ *    <param type="comment" value="//"/>
  * </filterreader>
  *
  * @author <a href="mailto:umagesh@apache.org">Magesh Umasankar</a>
  */
 public final class StripLineComments
     extends FilterReader
-    implements Parameterizable
+    implements Parameterizable, CloneableReader
 {
     private static final String COMMENTS_KEY = "comment";
 
@@ -34,12 +45,26 @@ public final class StripLineComments
 
     private boolean initialized = false;
 
-    private final Vector comments = new Vector();
-
-    private int commentsSize = 0;
+    private Vector comments = new Vector();
 
     private String line = null;
 
+    /**
+     * This constructor is a dummy constructor and is
+     * not meant to be used by any class other than Ant's
+     * introspection mechanism. This will close the filter
+     * that is created making it useless for further operations.
+     */
+    public StripLineComments() {
+        // Dummy constructor to be invoked by Ant's Introspector
+        super(new StringReader(new String()));
+        try {
+            close();
+        } catch (IOException  ioe) {
+            // Ignore
+        }
+    }
+
     /**
      * Create a new filtered reader.
      *
@@ -50,9 +75,9 @@ public final class StripLineComments
     }
 
     public final int read() throws IOException {
-        if (!initialized) {
+        if (!getInitialized()) {
             initialize();
-            initialized = true;
+            setInitialized(true);
         }
 
         int ch = -1;
@@ -78,6 +103,7 @@ public final class StripLineComments
             }
 
             if (line != null) {
+                int commentsSize = comments.size();
                 for (int i = 0; i < commentsSize; i++) {
                     String comment = (String) comments.elementAt(i);
                     if (line.startsWith(comment)) {
@@ -115,12 +141,39 @@ public final class StripLineComments
         return n;
     }
 
+    public final void addConfiguredComment(final Comment comment) {
+        comments.addElement(comment.getValue());
+    }
+
+    private void setComments(final Vector comments) {
+        this.comments = comments;
+    }
+
+    private final Vector getComments() {
+        return comments;
+    }
+
+    private final void setInitialized(final boolean initialized) {
+        this.initialized = initialized;
+    }
+
+    private final boolean getInitialized() {
+        return initialized;
+    }
+
+    public final Reader clone(final Reader rdr) {
+        StripLineComments newFilter = new StripLineComments(rdr);
+        newFilter.setComments(getComments());
+        newFilter.setInitialized(true);
+        return newFilter;
+    }
+
     /**
      * Set Parameters
      */
     public final void setParameters(final Parameter[] parameters) {
         this.parameters = parameters;
-        initialized = false;
+        setInitialized(false);
     }
 
     private final void initialize() {
@@ -130,7 +183,18 @@ public final class StripLineComments
                     comments.addElement(parameters[i].getValue());
                 }
             }
-            commentsSize = comments.size();
+        }
+    }
+
+    public static class Comment {
+        private String value;
+
+        public final void setValue(String comment) {
+            value = comment;
+        }
+
+        public final String getValue() {
+            return value;
         }
     }
 }

proposal/sandbox/filterreaders/src/main/org/apache/tools/ant/filters/TabsToSpaces.java

@@ -56,7 +56,7 @@ package org.apache.tools.ant.filters;
 import java.io.FilterReader;
 import java.io.IOException;
 import java.io.Reader;
-import java.util.Hashtable;
+import java.io.StringReader;
 
 import org.apache.tools.ant.types.Parameter;
 import org.apache.tools.ant.types.Parameterizable;
@@ -66,15 +66,20 @@ import org.apache.tools.ant.types.Parameterizable;
  *
  * Example Usage:
  * =============
- * <filterreader classname="org.apache.tools.ant.filters.TabsToSpaces">
- *    <param name="tablength" value="8"/>
+ *
+ * &lt;tabtospaces tablength=&quot;8&quot;/&gt;
+ *
+ * Or:
+ *
+ * <filterreader classname=&quot;org.apache.tools.ant.filters.TabsToSpaces&quot;>
+ *    <param name=&quot;tablength&quot; value=&quot;8&quot;/>
  * </filterreader>
  *
  * @author <a href="mailto:umagesh@apache.org">Magesh Umasankar</a>
  */
 public final class TabsToSpaces
     extends FilterReader
-    implements Parameterizable
+    implements Parameterizable, CloneableReader
 {
     private static final int DEFAULT_TAB_LENGTH = 8;
 
@@ -88,6 +93,22 @@ public final class TabsToSpaces
 
     private int spacesRemaining = 0;
 
+    /**
+     * This constructor is a dummy constructor and is
+     * not meant to be used by any class other than Ant's
+     * introspection mechanism. This will close the filter
+     * that is created making it useless for further operations.
+     */
+    public TabsToSpaces() {
+        // Dummy constructor to be invoked by Ant's Introspector
+        super(new StringReader(new String()));
+        try {
+            close();
+        } catch (IOException  ioe) {
+            // Ignore
+        }
+    }
+
     /**
      * Create a new filtered reader.
      *
@@ -101,9 +122,9 @@ public final class TabsToSpaces
      * Convert tabs with spaces
      */
     public final int read() throws IOException {
-        if (!initialized) {
+        if (!getInitialized()) {
             initialize();
-            initialized = true;
+            setInitialized(true);
         }
 
         int ch = -1;
@@ -146,16 +167,39 @@ public final class TabsToSpaces
         return n;
     }
 
+    public final void setTablength(final int tabLength) {
+        this.tabLength = tabLength;
+    }
+
+    private final int getTablength() {
+        return tabLength;
+    }
+
+    private final void setInitialized(final boolean initialized) {
+        this.initialized = initialized;
+    }
+
+    private final boolean getInitialized() {
+        return initialized;
+    }
+
+    public final Reader clone(final Reader rdr) {
+        TabsToSpaces newFilter = new TabsToSpaces(rdr);
+        newFilter.setTablength(getTablength());
+        newFilter.setInitialized(true);
+        return newFilter;
+    }
+
     /**
      * Set Parameters
      */
     public final void setParameters(final Parameter[] parameters) {
         this.parameters = parameters;
-        initialized = false;
+        setInitialized(false);
     }
 
     /**
-     * Initialize tokens and load the replacee-replacer hashtable.
+     * Initialize tokens
      */
     private final void initialize() {
         if (parameters != null) {

proposal/sandbox/filterreaders/src/main/org/apache/tools/ant/filters/TailFilter.java

@@ -56,6 +56,7 @@ package org.apache.tools.ant.filters;
 import java.io.FilterReader;
 import java.io.IOException;
 import java.io.Reader;
+import java.io.StringReader;
 
 import org.apache.tools.ant.types.Parameter;
 import org.apache.tools.ant.types.Parameterizable;
@@ -66,15 +67,19 @@ import org.apache.tools.ant.types.Parameterizable;
  * Example:
  * =======
  *
- * <filterreader classname="org.apache.tools.ant.filters.TailFilter">
- *    <param name="lines" value="3"/>
+ * <tailfilter lines="3"/>
+ *
+ * Or:
+ *
+ * <filterreader classname="org.apache.tools.ant.filters.TailFilter">
+ *    <param name="lines" value="3"/>
  * </filterreader>
  *
  * @author <a href="mailto:umagesh@apache.org">Magesh Umasankar</a>
  */
 public final class TailFilter
     extends FilterReader
-    implements Parameterizable
+    implements Parameterizable, CloneableReader
 {
     private static final String LINES_KEY = "lines";
 
@@ -96,6 +101,22 @@ public final class TailFilter
 
     private int bufferPos = 0;
 
+    /**
+     * This constructor is a dummy constructor and is
+     * not meant to be used by any class other than Ant's
+     * introspection mechanism. This will close the filter
+     * that is created making it useless for further operations.
+     */
+    public TailFilter() {
+        // Dummy constructor to be invoked by Ant's Introspector
+        super(new StringReader(new String()));
+        try {
+            close();
+        } catch (IOException  ioe) {
+            // Ignore
+        }
+    }
+
     /**
      * Create a new filtered reader.
      *
@@ -110,9 +131,9 @@ public final class TailFilter
      * point.  Grow buffer as needed.
      */
     public final int read() throws IOException {
-        if (!initialized) {
+        if (!getInitialized()) {
             initialize();
-            initialized = true;
+            setInitialized(true);
         }
 
         if (!completedReadAhead) {
@@ -200,19 +221,42 @@ public final class TailFilter
         return n;
     }
 
+    public final void setLines(final long lines) {
+        this.lines = lines;
+    }
+
+    private final long getLines() {
+        return lines;
+    }
+
+    private final void setInitialized(final boolean initialized) {
+        this.initialized = initialized;
+    }
+
+    private final boolean getInitialized() {
+        return initialized;
+    }
+
+    public final Reader clone(final Reader rdr) {
+        TailFilter newFilter = new TailFilter(rdr);
+        newFilter.setLines(getLines());
+        newFilter.setInitialized(true);
+        return newFilter;
+    }
+
     /**
      * Set Parameters
      */
     public final void setParameters(final Parameter[] parameters) {
         this.parameters = parameters;
-        initialized = false;
+        setInitialized(false);
     }
 
     private final void initialize() {
         if (parameters != null) {
             for (int i = 0; i < parameters.length; i++) {
                 if (LINES_KEY.equals(parameters[i].getName())) {
-                    lines = new Long(parameters[i].getValue()).longValue();
+                    setLines(new Long(parameters[i].getValue()).longValue());
                     break;
                 }
             }

proposal/sandbox/filterreaders/src/main/org/apache/tools/ant/types/FilterReaderSet.java

@@ -56,6 +56,14 @@ package org.apache.tools.ant.types;
 import java.util.Vector;
 
 import org.apache.tools.ant.filters.HeadFilter;
+import org.apache.tools.ant.filters.LineContains;
+import org.apache.tools.ant.filters.PrefixLines;
+import org.apache.tools.ant.filters.ReplaceTokens;
+import org.apache.tools.ant.filters.StripJavaComments;
+import org.apache.tools.ant.filters.StripLineBreaks;
+import org.apache.tools.ant.filters.StripLineComments;
+import org.apache.tools.ant.filters.TabsToSpaces;
+import org.apache.tools.ant.filters.TailFilter;
 
 /**
  * Set of FilterReaders
@@ -77,4 +85,39 @@ public final class FilterReaderSet {
     public final void addHeadFilter(final HeadFilter headFilter) {
         filterReaders.addElement(headFilter);
     }
+
+    public final void addLineContains(final LineContains lineContains) {
+        filterReaders.addElement(lineContains);
+    }
+
+    public final void addPrefixLines(final PrefixLines prefixLines) {
+        filterReaders.addElement(prefixLines);
+    }
+
+    public final void addReplaceTokens(final ReplaceTokens replaceTokens) {
+        filterReaders.addElement(replaceTokens);
+    }
+
+    public final void addStripJavaComments(final StripJavaComments
+                                                stripJavaComments) {
+        filterReaders.addElement(stripJavaComments);
+    }
+
+    public final void addStripLineBreaks(final StripLineBreaks
+                                                stripLineBreaks) {
+        filterReaders.addElement(stripLineBreaks);
+    }
+
+    public final void addStripLineComments(final StripLineComments
+                                                stripLineComments) {
+        filterReaders.addElement(stripLineComments);
+    }
+
+    public final void addTabsToSpaces(final TabsToSpaces tabsToSpaces) {
+        filterReaders.addElement(tabsToSpaces);
+    }
+
+    public final void addTailFilter(final TailFilter tailFilter) {
+        filterReaders.addElement(tailFilter);
+    }
 }