Created a OutputStream that redirected to an appropriate handler

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@270552 13f79535-47bb-0310-9956-ffa450edef68

proposal/myrmidon/src/java/org/apache/myrmidon/framework/exec/impl/LogOutputStream.java

@@ -0,0 +1,93 @@
+/*
+ * Copyright (C) The Apache Software Foundation. All rights reserved.
+ *
+ * This software is published under the terms of the Apache Software License
+ * version 1.1, a copy of which has been included with this distribution in
+ * the LICENSE.txt file.
+ */
+package org.apache.myrmidon.framework.exec.impl;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import org.apache.myrmidon.framework.exec.ExecOutputHandler;
+import org.apache.avalon.framework.logger.Logger;
+
+/**
+ * Logs each line written to this stream to the specified
+ * <code>ExecOutputHandler</code>. Tries to be smart about
+ * line separators.
+ *
+ * @author <a href="mailto:peter@apache.org">Peter Donald</a>
+ * @version $Revision$ $Date$
+ */
+class LogOutputStream
+    extends OutputStream
+{
+    private final boolean m_isError;
+    private final ExecOutputHandler m_handler;
+
+    private final ByteArrayOutputStream m_buffer = new ByteArrayOutputStream();
+    private boolean m_skip;
+
+    public LogOutputStream( final ExecOutputHandler handler,
+                            final boolean isError )
+    {
+        m_handler = handler;
+        m_isError = isError;
+    }
+
+    /**
+     * Writes all remaining
+     */
+    public void close()
+        throws IOException
+    {
+        if( m_buffer.size() > 0 )
+        {
+            processBuffer();
+        }
+        super.close();
+    }
+
+    /**
+     * Write the data to the buffer and flush the buffer, if a line separator is
+     * detected.
+     *
+     * @param ch data to log (byte).
+     */
+    public void write( final int ch )
+        throws IOException
+    {
+        if( ( ch == '\n' ) || ( ch == '\r' ) )
+        {
+            if( !m_skip )
+            {
+                processBuffer();
+            }
+        }
+        else
+        {
+            m_buffer.write( (byte)ch );
+        }
+
+        m_skip = ( ch == '\r' );
+    }
+
+    /**
+     * Converts the buffer to a string and sends it to <code>ExecOutputHandler</code>
+     */
+    private void processBuffer()
+    {
+        final String line = m_buffer.toString();
+        if( m_isError )
+        {
+            m_handler.stderr( line );
+        }
+        else
+        {
+            m_handler.stdout( line );
+        }
+        m_buffer.reset();
+    }
+}