Don't let the garbage collector close System.in

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@274946 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/input/DefaultInputHandler.java

@@ -59,6 +59,7 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.util.Enumeration;
 import org.apache.tools.ant.BuildException;
+import org.apache.tools.ant.util.KeepAliveInputStream;
 
 /**
  * Prompts on System.err, reads input from System.in
@@ -81,7 +82,10 @@ public class DefaultInputHandler implements InputHandler {
      */
     public void handleInput(InputRequest request) throws BuildException {
         String prompt = getPrompt(request);
-        DataInputStream in = new DataInputStream(getInputStream());
+        DataInputStream in = null;
+        try {
+            in = 
+                new DataInputStream(new KeepAliveInputStream(getInputStream()));
         do {
             System.err.println(prompt);
             try {
@@ -92,6 +96,15 @@ public class DefaultInputHandler implements InputHandler {
                                          e);
             }
         } while (!request.isInputValid());
+        } finally {
+            if (in != null) {
+                try {
+                    in.close();
+                } catch (IOException e) {
+                    throw new BuildException("Failed to close input.", e);
+                }
+            }
+        }
     }
 
     /**

src/main/org/apache/tools/ant/util/KeepAliveInputStream.java

@@ -0,0 +1,87 @@
+/*
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 2003 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 "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.util;
+
+import java.io.FilterInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * Class that can be used to wrap <tt>System.in</tt> 
+ * without getting anxious about any client closing the stream.
+ *
+ * <p>
+ * In code-language it means that it is not necessary to do:
+ * <pre>
+ * if (out != System.in) {
+ *   in.close();
+ * }
+ * </pre>
+ * </p>
+ *
+ * @author <a href="mailto:sbailliez@apache.org">Stephane Bailliez</a>
+ * @since Ant 1.6
+ */
+public class KeepAliveInputStream extends FilterInputStream {
+
+    public KeepAliveInputStream(InputStream in) {
+        super(in);
+    }
+
+    /** this method does nothing */
+    public void close() throws IOException {
+        //
+    }
+}
+