[IO-459] Add WindowsLineEndingInputStream and UnixLineEndingInputStream

Submitted by  Kristian Rosenvold



git-svn-id: https://svn.apache.org/repos/asf/commons/proper/io/trunk@1634738 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 110 insertions, 0 deletions

diff --git a/src/main/java/org/apache/commons/io/input/UnixLineEndingInputStream.java b/src/main/java/org/apache/commons/io/input/UnixLineEndingInputStream.java
new file mode 100644
index 00000000..b6ed27e8
--- /dev/null
+++ b/src/main/java/org/apache/commons/io/input/UnixLineEndingInputStream.java
@@ -0,0 +1,110 @@
+package org.apache.commons.io.input;
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * A filtering input stream that ensures the content will have unix-style line endings, LF.
+ * @since 2.5
+ */
+public class UnixLineEndingInputStream
+		extends InputStream {
+
+	private boolean slashNSeen = false;
+
+	private boolean eofSeen = false;
+
+	private final InputStream target;
+
+	private final boolean ensureLineFeedAtEndOfFile;
+
+	/**
+	 * Create an input stream that filters another stream
+	 *
+	 * @param in                        The input stream to wrap
+	 * @param ensureLineFeedAtEndOfFile true to ensure that the file ends with LF
+	 */
+	public UnixLineEndingInputStream(InputStream in, boolean ensureLineFeedAtEndOfFile) {
+		this.target = in;
+		this.ensureLineFeedAtEndOfFile = ensureLineFeedAtEndOfFile;
+	}
+
+	private int readWithUpdate() throws IOException {
+		final int target = this.target.read();
+		eofSeen = target == -1;
+		if (eofSeen) {
+			return target;
+		}
+		slashNSeen = target == '\n';
+		return target;
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+
+	@Override public int read()
+			throws IOException {
+		if (eofSeen) {
+			return eofGame();
+		} else {
+			int target = readWithUpdate();
+			if (eofSeen) {
+				return eofGame();
+			}
+			if (target == '\r') {
+				target = readWithUpdate();
+			}
+			return target;
+		}
+	}
+
+	private int eofGame() {
+		if (!ensureLineFeedAtEndOfFile) {
+			return -1;
+		}
+		if (!slashNSeen) {
+			slashNSeen = true;
+			return '\n';
+		} else {
+			return -1;
+		}
+	}
+
+	/**
+	 * Closes the stream. Also closes the underlying stream.
+	 */
+	@Override
+	public void close()
+			throws IOException {
+		super.close();
+		target.close();
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	@Override
+	public synchronized void mark(int readlimit) {
+		throw new UnsupportedOperationException("Mark notsupported");
+	}
+}