Package org.apache.commons.net.io
Class DotTerminatedMessageReader
- java.lang.Object
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- java.io.Reader
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- org.apache.commons.net.io.DotTerminatedMessageReader
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- All Implemented Interfaces:
java.io.Closeable
,java.lang.AutoCloseable
,java.lang.Readable
public final class DotTerminatedMessageReader extends java.io.Reader
DotTerminatedMessageReader is a class used to read messages from 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.This class handles stripping of the duplicate period at the beginning of lines starting with a period, converts NETASCII newlines to the local line separator format, truncates the end of message indicator, and ensures you cannot read past the end of the message.
- Version:
- $Id: DotTerminatedMessageReader.java 165675 2005-05-02 20:09:55Z rwinston $
- Author:
- Daniel F. Savarese
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Constructor Summary
Constructors Constructor Description DotTerminatedMessageReader(java.io.Reader reader)
Creates a DotTerminatedMessageReader that wraps an existing Reader input source.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
close()
Closes the message for reading.int
read()
Reads and returns the next character in the message.int
read(char[] buffer)
Reads the next characters from the message into an array and returns the number of characters read.int
read(char[] buffer, int offset, int length)
Reads the next characters from the message into an array and returns the number of characters read.boolean
ready()
Determines if the message is ready to be read.
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Method Detail
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read
public int read() throws java.io.IOException
Reads and returns the next character in the message. If the end of the message has been reached, returns -1. Note that a call to this method may result in multiple reads from the underlying input stream to decode the message properly (removing doubled dots and so on). All of this is transparent to the programmer and is only mentioned for completeness.- Overrides:
read
in classjava.io.Reader
- Returns:
- The next character in the message. Returns -1 if the end of the message has been reached.
- Throws:
java.io.IOException
- If an error occurs while reading the underlying stream.
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read
public int read(char[] buffer) throws java.io.IOException
Reads the next characters from the message into an array and returns the number of characters read. Returns -1 if the end of the message has been reached.- Overrides:
read
in classjava.io.Reader
- Parameters:
buffer
- The character array in which to store the characters.- Returns:
- The number of characters read. Returns -1 if the end of the message has been reached.
- Throws:
java.io.IOException
- If an error occurs in reading the underlying stream.
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read
public int read(char[] buffer, int offset, int length) throws java.io.IOException
Reads the next characters from the message into an array and returns the number of characters read. Returns -1 if the end of the message has been reached. The characters are stored in the array starting from the given offset and up to the length specified.- Specified by:
read
in classjava.io.Reader
- Parameters:
buffer
- The character array in which to store the characters.offset
- The offset into the array at which to start storing characters.length
- The number of characters to read.- Returns:
- The number of characters read. Returns -1 if the end of the message has been reached.
- Throws:
java.io.IOException
- If an error occurs in reading the underlying stream.
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ready
public boolean ready() throws java.io.IOException
Determines if the message is ready to be read.- Overrides:
ready
in classjava.io.Reader
- Returns:
- True if the message is ready to be read, false if not.
- Throws:
java.io.IOException
- If an error occurs while checking the underlying stream.
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close
public void close() throws java.io.IOException
Closes the message for reading. This doesn't actually close the underlying stream. The underlying stream may still be used for communicating with the server and therefore is not closed.If the end of the message has not yet been reached, this method will read the remainder of the message until it reaches the end, so that the underlying stream may continue to be used properly for communicating with the server. If you do not fully read a message, you MUST close it, otherwise your program will likely hang or behave improperly.
- Specified by:
close
in interfacejava.lang.AutoCloseable
- Specified by:
close
in interfacejava.io.Closeable
- Specified by:
close
in classjava.io.Reader
- Throws:
java.io.IOException
- If an error occurs while reading the underlying stream.
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