diff options
Diffstat (limited to 'app/src/main/java/org/apache/commons/net/io/DotTerminatedMessageWriter.java')
| -rw-r--r-- | app/src/main/java/org/apache/commons/net/io/DotTerminatedMessageWriter.java | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/app/src/main/java/org/apache/commons/net/io/DotTerminatedMessageWriter.java b/app/src/main/java/org/apache/commons/net/io/DotTerminatedMessageWriter.java new file mode 100644 index 0000000..853e42f --- /dev/null +++ b/app/src/main/java/org/apache/commons/net/io/DotTerminatedMessageWriter.java @@ -0,0 +1,215 @@ +/*
+ * 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.
+ */
+
+package org.apache.commons.net.io;
+
+import java.io.IOException;
+import java.io.Writer;
+
+/***
+ * DotTerminatedMessageWriter is a class used to write messages to a
+ * server that are terminated by a single dot followed by a
+ * <CR><LF>
+ * sequence and with double dots appearing at the begining of lines which
+ * do not signal end of message yet start with a dot. Various Internet
+ * protocols such as NNTP and POP3 produce messages of this type.
+ * <p>
+ * This class handles the doubling of line-starting periods,
+ * converts single linefeeds to NETASCII newlines, and on closing
+ * will send the final message terminator dot and NETASCII newline
+ * sequence.
+ * <p>
+ * <p>
+ * @author Daniel F. Savarese
+ ***/
+
+public final class DotTerminatedMessageWriter extends Writer
+{
+ private static final int __NOTHING_SPECIAL_STATE = 0;
+ private static final int __LAST_WAS_CR_STATE = 1;
+ private static final int __LAST_WAS_NL_STATE = 2;
+
+ private int __state;
+ private Writer __output;
+
+
+ /***
+ * Creates a DotTerminatedMessageWriter that wraps an existing Writer
+ * output destination.
+ * <p>
+ * @param output The Writer output destination to write the message.
+ ***/
+ public DotTerminatedMessageWriter(Writer output)
+ {
+ super(output);
+ __output = output;
+ __state = __NOTHING_SPECIAL_STATE;
+ }
+
+
+ /***
+ * Writes a character to the output. Note that a call to this method
+ * may result in multiple writes to the underling Writer in order to
+ * convert naked linefeeds to NETASCII line separators and to double
+ * line-leading periods. This is transparent to the programmer and
+ * is only mentioned for completeness.
+ * <p>
+ * @param ch The character to write.
+ * @exception IOException If an error occurs while writing to the
+ * underlying output.
+ ***/
+ @Override
+ public void write(int ch) throws IOException
+ {
+ synchronized (lock)
+ {
+ switch (ch)
+ {
+ case '\r':
+ __state = __LAST_WAS_CR_STATE;
+ __output.write('\r');
+ return ;
+ case '\n':
+ if (__state != __LAST_WAS_CR_STATE)
+ __output.write('\r');
+ __output.write('\n');
+ __state = __LAST_WAS_NL_STATE;
+ return ;
+ case '.':
+ // Double the dot at the beginning of a line
+ if (__state == __LAST_WAS_NL_STATE)
+ __output.write('.');
+ // Fall through
+ default:
+ __state = __NOTHING_SPECIAL_STATE;
+ __output.write(ch);
+ return ;
+ }
+ }
+ }
+
+
+ /***
+ * Writes a number of characters from a character array to the output
+ * starting from a given offset.
+ * <p>
+ * @param buffer The character array to write.
+ * @param offset The offset into the array at which to start copying data.
+ * @param length The number of characters to write.
+ * @exception IOException If an error occurs while writing to the underlying
+ * output.
+ ***/
+ @Override
+ public void write(char[] buffer, int offset, int length) throws IOException
+ {
+ synchronized (lock)
+ {
+ while (length-- > 0)
+ write(buffer[offset++]);
+ }
+ }
+
+
+ /***
+ * Writes a character array to the output.
+ * <p>
+ * @param buffer The character array to write.
+ * @exception IOException If an error occurs while writing to the underlying
+ * output.
+ ***/
+ @Override
+ public void write(char[] buffer) throws IOException
+ {
+ write(buffer, 0, buffer.length);
+ }
+
+
+ /***
+ * Writes a String to the output.
+ * <p>
+ * @param string The String to write.
+ * @exception IOException If an error occurs while writing to the underlying
+ * output.
+ ***/
+ @Override
+ public void write(String string) throws IOException
+ {
+ write(string.toCharArray());
+ }
+
+
+ /***
+ * Writes part of a String to the output starting from a given offset.
+ * <p>
+ * @param string The String to write.
+ * @param offset The offset into the String at which to start copying data.
+ * @param length The number of characters to write.
+ * @exception IOException If an error occurs while writing to the underlying
+ * output.
+ ***/
+ @Override
+ public void write(String string, int offset, int length) throws IOException
+ {
+ write(string.toCharArray(), offset, length);
+ }
+
+
+ /***
+ * Flushes the underlying output, writing all buffered output.
+ * <p>
+ * @exception IOException If an error occurs while writing to the underlying
+ * output.
+ ***/
+ @Override
+ public void flush() throws IOException
+ {
+ synchronized (lock)
+ {
+ __output.flush();
+ }
+ }
+
+
+ /***
+ * Flushes the underlying output, writing all buffered output, but doesn't
+ * actually close the underlying stream. The underlying stream may still
+ * be used for communicating with the server and therefore is not closed.
+ * <p>
+ * @exception IOException If an error occurs while writing to the underlying
+ * output or closing the Writer.
+ ***/
+ @Override
+ public void close() throws IOException
+ {
+ synchronized (lock)
+ {
+ if (__output == null)
+ return ;
+
+ if (__state == __LAST_WAS_CR_STATE)
+ __output.write('\n');
+ else if (__state != __LAST_WAS_NL_STATE)
+ __output.write("\r\n");
+
+ __output.write(".\r\n");
+
+ __output.flush();
+ __output = null;
+ }
+ }
+
+}
|