New filter reader that gets those lines that match a regular expression pattern.

Requested by: Adam Murdoch


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@271621 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -0,0 +1,208 @@
+/*
+ *  The Apache Software License, Version 1.1
+ *
+ *  Copyright (c) 2002 The Apache Software Foundation.  All rights
+ *  reserved.
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *  notice, this list of conditions and the following disclaimer.
+ *
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *  notice, this list of conditions and the following disclaimer in
+ *  the documentation and/or other materials provided with the
+ *  distribution.
+ *
+ *  3. The end-user documentation included with the redistribution, if
+ *  any, must include the following acknowlegement:
+ *  "This product includes software developed by the
+ *  Apache Software Foundation (http://www.apache.org/)."
+ *  Alternately, this acknowlegement may appear in the software itself,
+ *  if and wherever such third-party acknowlegements normally appear.
+ *
+ *  4. The names "The Jakarta Project", "Ant", and "Apache Software
+ *  Foundation" must not be used to endorse or promote products derived
+ *  from this software without prior written permission. For written
+ *  permission, please contact apache@apache.org.
+ *
+ *  5. Products derived from this software may not be called "Apache"
+ *  nor may "Apache" appear in their names without prior written
+ *  permission of the Apache Group.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ *  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ *  ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ *  USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ *  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ *  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ *  OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ *  SUCH DAMAGE.
+ *  ====================================================================
+ *
+ *  This software consists of voluntary contributions made by many
+ *  individuals on behalf of the Apache Software Foundation.  For more
+ *  information on the Apache Software Foundation, please see
+ *  <http://www.apache.org/>.
+ */
+package org.apache.tools.ant.filters;
+
+import java.io.IOException;
+import java.io.Reader;
+import java.util.Vector;
+
+import org.apache.tools.ant.types.Parameter;
+import org.apache.tools.ant.types.RegularExpression;
+import org.apache.tools.ant.util.regexp.Regexp;
+
+/**
+ * Filter Reader to fetch only those lines that contain user specified
+ * regular expression matching strings.
+ *
+ * Example:
+ * =======
+ *
+ * &lt;linecontainsregexp&gt;
+ *   &lt;regexp pattern=&quot;foo*&quot;&gt;
+ * &lt;/linecontainsregexp&gt;
+ *
+ * Or:
+ *
+ * &lt;filterreader classname=&quot;org.apache.tools.ant.filters.LineContainsRegExp&quot;&gt;
+ *    &lt;param type=&quot;regexp&quot; value=&quot;foo*&quot;/&gt;
+ * &lt;/filterreader&gt;
+ *
+ * This will fetch all those lines that contain the pattern foo
+ *
+ * @author <a href="mailto:umagesh@apache.org">Magesh Umasankar</a>
+ */
+public final class LineContainsRegExp
+    extends BaseParamFilterReader
+    implements ChainableReader
+{
+    /** contains key */
+    private static final String REGEXP_KEY = "regexp";
+
+    /** Vector that holds the strings that input lines must contain. */
+    private Vector regexps = new Vector();
+
+    /** Currently read in line. */
+    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 LineContainsRegExp() {
+        super();
+    }
+
+    /**
+     * Create a new filtered reader.
+     *
+     * @param in  a Reader object providing the underlying stream.
+     */
+    public LineContainsRegExp(final Reader in) {
+        super(in);
+    }
+
+    /**
+     * Choose only those lines that contains
+     * user defined values.
+     */
+    public final int read() throws IOException {
+        if (!getInitialized()) {
+            initialize();
+            setInitialized(true);
+        }
+
+        int ch = -1;
+
+        if (line != null) {
+            ch = line.charAt(0);
+            if (line.length() == 1) {
+                line = null;
+            } else {
+                line = line.substring(1);
+            }
+        } else {
+            line = readLine();
+            if (line == null) {
+                ch = -1;
+            } else {
+                final int regexpsSize = regexps.size();
+                for (int i = 0; i < regexpsSize; i++) {
+                    RegularExpression regexp = (RegularExpression)
+                                                        regexps.elementAt(i);
+                    Regexp re = regexp.getRegexp(getProject());
+                    boolean matches = re.matches(line);
+                    if (!matches) {
+                        line = null;
+                        break;
+                    }
+                }
+
+                return read();
+            }
+        }
+
+        return ch;
+    }
+
+    /**
+     * Add a contains element.
+     */
+    public final void addConfiguredRegexp(final RegularExpression regExp) {
+        this.regexps.addElement(regExp);
+    }
+
+    /**
+     * Set regexps vector.
+     */
+    private void setRegexps(final Vector regexps) {
+        this.regexps = regexps;
+    }
+
+    /**
+     * Get regexps vector.
+     */
+    private final Vector getRegexps() {
+        return regexps;
+    }
+
+    /**
+     * Create a new LineContainsRegExp using the passed in
+     * Reader for instantiation.
+     */
+    public final Reader chain(final Reader rdr) {
+        LineContainsRegExp newFilter = new LineContainsRegExp(rdr);
+        newFilter.setRegexps(getRegexps());
+        newFilter.setInitialized(true);
+        return newFilter;
+    }
+
+    /**
+     * Parse params to add user defined contains strings.
+     */
+    private final void initialize() {
+        Parameter[] params = getParameters();
+        if (params != null) {
+            for (int i = 0; i < params.length; i++) {
+                if (REGEXP_KEY.equals(params[i].getType())) {
+                    String pattern = params[i].getValue();
+                    RegularExpression regexp = new RegularExpression();
+                    regexp.setPattern(pattern);
+                    regexps.addElement(regexp);
+                }
+            }
+        }
+    }
+}

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

@@ -58,6 +58,7 @@ import java.util.Vector;
 import org.apache.tools.ant.filters.ExpandProperties;
 import org.apache.tools.ant.filters.HeadFilter;
 import org.apache.tools.ant.filters.LineContains;
+import org.apache.tools.ant.filters.LineContainsRegExp;
 import org.apache.tools.ant.filters.PrefixLines;
 import org.apache.tools.ant.filters.ReplaceTokens;
 import org.apache.tools.ant.filters.StripJavaComments;
@@ -95,6 +96,11 @@ public final class FilterChain {
         filterReaders.addElement(lineContains);
     }
 
+    public final void addLineContainsRegExp(final LineContainsRegExp
+                                                lineContainsRegExp) {
+        filterReaders.addElement(lineContainsRegExp);
+    }
+
     public final void addPrefixLines(final PrefixLines prefixLines) {
         filterReaders.addElement(prefixLines);
     }