# BufferedReader

public class **BufferedReader** extends [Reader](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/Reader.html)  

|---|---|---|
| Known Direct Subclasses [LineNumberReader](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/LineNumberReader.html) |---|---| | [LineNumberReader](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/LineNumberReader.html) | A buffered character-input stream that keeps track of line numbers. | |||

Reads text from a character-input stream, buffering characters so as to
provide for the efficient reading of characters, arrays, and lines.

The buffer size may be specified, or the default size may be used. The
default is large enough for most purposes.

In general, each read request made of a Reader causes a corresponding
read request to be made of the underlying character or byte stream. It is
therefore advisable to wrap a BufferedReader around any Reader whose read()
operations may be costly, such as FileReaders and InputStreamReaders. For
example,

```
 BufferedReader in
   = new BufferedReader(new FileReader("foo.in"));
 
```
will buffer the input from the specified file. Without buffering, each invocation of read() or readLine() could cause bytes to be read from the file, converted into characters, and then returned, which can be very inefficient.

Programs that use DataInputStreams for textual input can be localized by
replacing each DataInputStream with an appropriate BufferedReader.

##### See Also

- `https://developers.google.com/j2objc/javadoc/jre/reference/java/io/FileReader.html`
- `https://developers.google.com/j2objc/javadoc/jre/reference/java/io/InputStreamReader.html`
- `https://developers.google.com/j2objc/javadoc/jre/reference/java/nio/file/Files.html#newBufferedReader(java.nio.file.Path)`

### Inherited Field Summary

From class [java.io.Reader](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/Reader.html)

|---|---|---|
| protected [Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) | [lock](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/Reader.html#lock) | The object used to synchronize operations on this stream. |

### Public Constructor Summary

|---|---|
|   | [BufferedReader](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/BufferedReader.html#BufferedReader(java.io.Reader,%20int))([Reader](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/Reader.html) in, int sz) Creates a buffering character-input stream that uses an input buffer of the specified size. |
|   | [BufferedReader](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/BufferedReader.html#BufferedReader(java.io.Reader))([Reader](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/Reader.html) in) Creates a buffering character-input stream that uses a default-sized input buffer. |

### Public Method Summary

|---|---|
| void | [close](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/BufferedReader.html#close())() Closes the stream and releases any system resources associated with it. |
| [Stream](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/stream/Stream.html)\<[String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html)\> | [lines](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/BufferedReader.html#lines())() Returns a `Stream`, the elements of which are lines read from this `BufferedReader`. |
| void | [mark](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/BufferedReader.html#mark(int))(int readAheadLimit) Marks the present position in the stream. |
| boolean | [markSupported](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/BufferedReader.html#markSupported())() Tells whether this stream supports the mark() operation, which it does. |
| int | [read](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/BufferedReader.html#read())() Reads a single character. |
| int | [read](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/BufferedReader.html#read(char[],%20int,%20int))(char\[\] cbuf, int off, int len) Reads characters into a portion of an array. |
| [String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) | [readLine](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/BufferedReader.html#readLine())() Reads a line of text. |
| boolean | [ready](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/BufferedReader.html#ready())() Tells whether this stream is ready to be read. |
| void | [reset](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/BufferedReader.html#reset())() Resets the stream to the most recent mark. |
| long | [skip](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/BufferedReader.html#skip(long))(long n) Skips characters. |

### Inherited Method Summary

From class [java.io.Reader](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/Reader.html)

|---|---|
| abstract void | [close](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/Reader.html#close())() Closes the stream and releases any system resources associated with it. |
| void | [mark](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/Reader.html#mark(int))(int readAheadLimit) Marks the present position in the stream. |
| boolean | [markSupported](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/Reader.html#markSupported())() Tells whether this stream supports the mark() operation. |
| int | [read](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/Reader.html#read())() Reads a single character. |
| abstract int | [read](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/Reader.html#read(char[],%20int,%20int))(char\[\] cbuf, int off, int len) Reads characters into a portion of an array. |
| int | [read](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/Reader.html#read(char[]))(char\[\] cbuf) Reads characters into an array. |
| int | [read](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/Reader.html#read(java.nio.CharBuffer))([CharBuffer](https://developers.google.com/j2objc/javadoc/jre/reference/java/nio/CharBuffer.html) target) Attempts to read characters into the specified character buffer. |
| boolean | [ready](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/Reader.html#ready())() Tells whether this stream is ready to be read. |
| void | [reset](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/Reader.html#reset())() Resets the stream. |
| long | [skip](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/Reader.html#skip(long))(long n) Skips characters. |

From class [java.lang.Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html)

|---|---|
| [Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) | [clone](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#clone())() Creates and returns a copy of this `Object`. |
| boolean | [equals](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#equals(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) obj) Compares this instance with the specified object and indicates if they are equal. |
| void | [finalize](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#finalize())() Invoked when the garbage collector has detected that this instance is no longer reachable. |
| final [Class](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Class.html)\<?\> | [getClass](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#getClass())() Returns the unique instance of `https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Class.html` that represents this object's class. |
| int | [hashCode](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#hashCode())() Returns an integer hash code for this object. |
| final void | [notify](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#notify())() Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up. |
| final void | [notifyAll](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#notifyAll())() Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up. |
| [String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) | [toString](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#toString())() Returns a string containing a concise, human-readable description of this object. |
| final void | [wait](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#wait(long,%20int))(long timeout, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires. |
| final void | [wait](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#wait(long))(long timeout) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires. |
| final void | [wait](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#wait())() Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object. |

From interface [java.lang.Readable](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Readable.html)

|---|---|
| abstract int | [read](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Readable.html#read(java.nio.CharBuffer))([CharBuffer](https://developers.google.com/j2objc/javadoc/jre/reference/java/nio/CharBuffer.html) cb) Attempts to read characters into the specified character buffer. |

From interface [java.io.Closeable](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/Closeable.html)

|---|---|
| abstract void | [close](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/Closeable.html#close())() Closes this stream and releases any system resources associated with it. |

From interface [java.lang.AutoCloseable](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/AutoCloseable.html)

|---|---|
| abstract void | [close](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/AutoCloseable.html#close())() Closes this resource, relinquishing any underlying resources. |

## Public Constructors

#### public
**BufferedReader**
([Reader](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/Reader.html) in, int sz)

Creates a buffering character-input stream that uses an input buffer of
the specified size.

##### Parameters

| in | A Reader |
| sz | Input-buffer size |
|---|---|

##### Throws

| [IllegalArgumentException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/IllegalArgumentException.html) | If `sz <= 0` |
|---|---|

#### public
**BufferedReader**
([Reader](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/Reader.html) in)

Creates a buffering character-input stream that uses a default-sized
input buffer.

##### Parameters

| in | A Reader |
|---|---|

## Public Methods

#### public void
**close**
()

Closes the stream and releases any system resources associated with
it. Once the stream has been closed, further read(), ready(),
mark(), reset(), or skip() invocations will throw an IOException.
Closing a previously closed stream has no effect.

##### Throws

| [IOException](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/IOException.html) |   |
|---|---|

#### public [Stream](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/stream/Stream.html)\<[String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html)\>
**lines**
()

Returns a `Stream`, the elements of which are lines read from
this `BufferedReader`. The `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/stream/Stream.html` is lazily populated,
i.e., read only occurs during the
[terminal
stream operation](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/stream/package-summary.html#StreamOps).

The reader must not be operated on during the execution of the
terminal stream operation. Otherwise, the result of the terminal stream
operation is undefined.

After execution of the terminal stream operation there are no
guarantees that the reader will be at a specific position from which to
read the next character or line.

If an `https://developers.google.com/j2objc/javadoc/jre/reference/java/io/IOException.html` is thrown when accessing the underlying
`BufferedReader`, it is wrapped in an `https://developers.google.com/j2objc/javadoc/jre/reference/java/io/UncheckedIOException.html` which will be thrown from the `Stream`
method that caused the read to take place. This method will return a
Stream if invoked on a BufferedReader that is closed. Any operation on
that stream that requires reading from the BufferedReader after it is
closed, will cause an UncheckedIOException to be thrown.

##### Returns

- a `Stream<String>` providing the lines of text described by this `BufferedReader`

#### public void
**mark**
(int readAheadLimit)

Marks the present position in the stream. Subsequent calls to reset()
will attempt to reposition the stream to this point.

##### Parameters

| readAheadLimit | Limit on the number of characters that may be read while still preserving the mark. An attempt to reset the stream after reading characters up to this limit or beyond may fail. A limit value larger than the size of the input buffer will cause a new buffer to be allocated whose size is no smaller than limit. Therefore large values should be used with care. |
|---|---|

##### Throws

| [IllegalArgumentException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/IllegalArgumentException.html) | If `readAheadLimit < 0` |
| [IOException](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/IOException.html) | If an I/O error occurs |
|---|---|

#### public boolean
**markSupported**
()

Tells whether this stream supports the mark() operation, which it does.

##### Returns

- true if and only if this stream supports the mark operation.

#### public int
**read**
()

Reads a single character.

##### Returns

- The character read, as an integer in the range 0 to 65535 (0x00-0xffff), or -1 if the end of the stream has been reached

##### Throws

| [IOException](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/IOException.html) | If an I/O error occurs |
|---|---|

#### public int
**read**
(char\[\] cbuf, int off, int len)

Reads characters into a portion of an array.

This method implements the general contract of the corresponding
`` `https://developers.google.com/j2objc/javadoc/jre/reference/java/io/Reader.html#read(char[],%20int,%20int)` `` method of the
`` `https://developers.google.com/j2objc/javadoc/jre/reference/java/io/Reader.html` `` class. As an additional convenience, it
attempts to read as many characters as possible by repeatedly invoking
the `read` method of the underlying stream. This iterated
`read` continues until one of the following conditions becomes
true:

- The specified number of characters have been read,
- The `read` method of the underlying stream returns `-1`, indicating end-of-file, or
- The `ready` method of the underlying stream returns `false`, indicating that further input requests would block.

If the first `read` on the underlying stream returns `-1` to indicate end-of-file then this method returns `-1`. Otherwise this method returns the number of characters actually read.

Subclasses of this class are encouraged, but not required, to
attempt to read as many characters as possible in the same fashion.

Ordinarily this method takes characters from this stream's character
buffer, filling it from the underlying stream as necessary. If,
however, the buffer is empty, the mark is not valid, and the requested
length is at least as large as the buffer, then this method will read
characters directly from the underlying stream into the given array.
Thus redundant `BufferedReader`s will not copy data
unnecessarily.

##### Parameters

| cbuf | Destination buffer |
| off | Offset at which to start storing characters |
| len | Maximum number of characters to read |
|---|---|

##### Returns

- The number of characters read, or -1 if the end of the stream has been reached

##### Throws

| [IOException](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/IOException.html) | If an I/O error occurs |
|---|---|

#### public [String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html)
**readLine**
()

Reads a line of text. A line is considered to be terminated by any one
of a line feed ('\\n'), a carriage return ('\\r'), or a carriage return
followed immediately by a linefeed.

##### Returns

- A String containing the contents of the line, not including any line-termination characters, or null if the end of the stream has been reached

##### Throws

| [IOException](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/IOException.html) | If an I/O error occurs |
|---|---|

##### See Also

- `https://developers.google.com/j2objc/javadoc/jre/reference/java/nio/file/Files.html#readAllLines(java.nio.file.Path)`

#### public boolean
**ready**
()

Tells whether this stream is ready to be read. A buffered character
stream is ready if the buffer is not empty, or if the underlying
character stream is ready.

##### Returns

- True if the next read() is guaranteed not to block for input, false otherwise. Note that returning false does not guarantee that the next read will block.

##### Throws

| [IOException](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/IOException.html) | If an I/O error occurs |
|---|---|

#### public void
**reset**
()

Resets the stream to the most recent mark.

##### Throws

| [IOException](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/IOException.html) | If the stream has never been marked, or if the mark has been invalidated |
|---|---|

#### public long
**skip**
(long n)

Skips characters.

##### Parameters

| n | The number of characters to skip |
|---|---|

##### Returns

- The number of characters actually skipped

##### Throws

| [IllegalArgumentException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/IllegalArgumentException.html) | If `n` is negative. |
| [IOException](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/IOException.html) | If an I/O error occurs |
|---|---|