# LineNumberInputStream
Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
Deprecated in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
# LineNumberInputStream
```
open class LineNumberInputStream : FilterInputStream
```
|---|---|---|----------------------------------------------------------------------------------------------------------------|
| [kotlin.Any](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-any/index.html) ||||
| ↳ | [java.io.InputStream](https://developer.android.com/reference/kotlin/java/io/InputStream) |||
| | ↳ | [java.io.FilterInputStream](https://developer.android.com/reference/kotlin/java/io/FilterInputStream) ||
| | | ↳ | [java.io.LineNumberInputStream](https://developer.android.com/reference/kotlin/java/io/LineNumberInputStream#) |
*** ** * ** ***
| **This class was deprecated in API level 1.**
|
| This class incorrectly assumes that bytes adequately represent characters. As of JDK 1.1, the preferred way to operate on character streams is via the new character-stream classes, which include a class for counting line numbers.
This class is an input stream filter that provides the added functionality of keeping track of the current line number.
A line is a sequence of bytes ending with a carriage return character (`'\u005Cr'`), a newline character (`'\u005Cn'`), or a carriage return character followed immediately by a linefeed character. In all three cases, the line terminating character(s) are returned as a single newline character.
The line number begins at `0`, and is incremented by `1` when a `read` returns a newline character.
## Summary
| Public constructors ||
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---|
| [LineNumberInputStream](https://developer.android.com/reference/kotlin/java/io/LineNumberInputStream#LineNumberInputStream(java.io.InputStream))`(`in:` `[InputStream](https://developer.android.com/reference/kotlin/java/io/InputStream)!`)` Constructs a newline number input stream that reads its input from the specified input stream. |
| Public methods ||
|-----------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| open [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html) | [available](https://developer.android.com/reference/kotlin/java/io/LineNumberInputStream#available())`()` Returns the number of bytes that can be read from this input stream without blocking. |
| open [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html) | [getLineNumber](https://developer.android.com/reference/kotlin/java/io/LineNumberInputStream#getLineNumber())`()` Returns the current line number. |
| open [Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [mark](https://developer.android.com/reference/kotlin/java/io/LineNumberInputStream#mark(kotlin.Int))`(`readlimit:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`)` Marks the current position in this input stream. |
| open [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html) | [read](https://developer.android.com/reference/kotlin/java/io/LineNumberInputStream#read())`()` Reads the next byte of data from this input stream. |
| open [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html) | [read](https://developer.android.com/reference/kotlin/java/io/LineNumberInputStream#read(kotlin.ByteArray,%20kotlin.Int,%20kotlin.Int))`(`b:` `[ByteArray](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-byte-array/index.html)!`, `off:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`, `len:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`)` Reads up to `len` bytes of data from this input stream into an array of bytes. |
| open [Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [reset](https://developer.android.com/reference/kotlin/java/io/LineNumberInputStream#reset())`()` Repositions this stream to the position at the time the `mark` method was last called on this input stream. |
| open [Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [setLineNumber](https://developer.android.com/reference/kotlin/java/io/LineNumberInputStream#setLineNumber(kotlin.Int))`(`lineNumber:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`)` Sets the line number to the specified argument. |
| open [Long](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-long/index.html) | [skip](https://developer.android.com/reference/kotlin/java/io/LineNumberInputStream#skip(kotlin.Long))`(`n:` `[Long](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-long/index.html)`)` Skips over and discards `n` bytes of data from this input stream. |
| Inherited functions ||
|---|---|
| From class [FilterInputStream](https://developer.android.com/reference/kotlin/java/io/FilterInputStream) |------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | [Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [close](https://developer.android.com/reference/kotlin/java/io/FilterInputStream#close())`()` Closes this input stream and releases any system resources associated with the stream. This method simply performs `in.close()`.
| | [Boolean](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-boolean/index.html) | [markSupported](https://developer.android.com/reference/kotlin/java/io/FilterInputStream#markSupported())`()` Tests if this input stream supports the `mark` and `reset` methods. This method simply performs `in.markSupported()`.
| | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html) | [read](https://developer.android.com/reference/kotlin/java/io/FilterInputStream#read(kotlin.ByteArray))`(`b:` `[ByteArray](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-byte-array/index.html)!`)` Reads up to `b.length` bytes of data from this input stream into an array of bytes. This method blocks until some input is available. This method simply performs the call `read(b, 0, b.length)` and returns the result. It is important that it does *not* do `in.read(b)` instead; certain subclasses of `FilterInputStream` depend on the implementation strategy actually used.
| ||
| From class [InputStream](https://developer.android.com/reference/kotlin/java/io/InputStream) |------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | [InputStream](https://developer.android.com/reference/kotlin/java/io/InputStream)! | [nullInputStream](https://developer.android.com/reference/kotlin/java/io/InputStream#nullInputStream())`()` Returns a new `InputStream` that reads no bytes. The returned stream is initially open. The stream is closed by calling the `close()` method. Subsequent calls to `close()` have no effect. While the stream is open, the `available()`, `read()`, `read(byte[])`, `read(byte[], int, int)`, `readAllBytes()`, `readNBytes(byte[], int, int)`, `readNBytes(int)`, `skip(long)`, `skipNBytes(long)`, and `transferTo()` methods all behave as if end of stream has been reached. After the stream has been closed, these methods all throw `IOException`. The `markSupported()` method returns `false`. The `mark()` method does nothing, and the `reset()` method throws `IOException`.
| | [ByteArray](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-byte-array/index.html)! | [readAllBytes](https://developer.android.com/reference/kotlin/java/io/InputStream#readAllBytes())`()` Reads all remaining bytes from the input stream. This method blocks until all remaining bytes have been read and end of stream is detected, or an exception is thrown. This method does not close the input stream. When this stream reaches end of stream, further invocations of this method will return an empty byte array. Note that this method is intended for simple cases where it is convenient to read all bytes into a byte array. It is not intended for reading input streams with large amounts of data. The behavior for the case where the input stream is *asynchronously closed*, or the thread interrupted during the read, is highly input stream specific, and therefore not specified. If an I/O error occurs reading from the input stream, then it may do so after some, but not all, bytes have been read. Consequently the input stream may not be at end of stream and may be in an inconsistent state. It is strongly recommended that the stream be promptly closed if an I/O error occurs.
| | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html) | [readNBytes](https://developer.android.com/reference/kotlin/java/io/InputStream#readNBytes(kotlin.ByteArray,%20kotlin.Int,%20kotlin.Int))`(`b:` `[ByteArray](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-byte-array/index.html)!`, `off:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`, `len:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`)` Reads the requested number of bytes from the input stream into the given byte array. This method blocks until `len` bytes of input data have been read, end of stream is detected, or an exception is thrown. The number of bytes actually read, possibly zero, is returned. This method does not close the input stream. In the case where end of stream is reached before `len` bytes have been read, then the actual number of bytes read will be returned. When this stream reaches end of stream, further invocations of this method will return zero. If `len` is zero, then no bytes are read and `0` is returned; otherwise, there is an attempt to read up to `len` bytes. The first byte read is stored into element `b[off]`, the next one in to `b[off+1]`, and so on. The number of bytes read is, at most, equal to `len`. Let *k* be the number of bytes actually read; these bytes will be stored in elements `b[off]` through `b[off+`*k* `-1]`, leaving elements `b[off+`*k* `]` through `b[off+len-1]` unaffected. The behavior for the case where the input stream is *asynchronously closed*, or the thread interrupted during the read, is highly input stream specific, and therefore not specified. If an I/O error occurs reading from the input stream, then it may do so after some, but not all, bytes of `b` have been updated with data from the input stream. Consequently the input stream and `b` may be in an inconsistent state. It is strongly recommended that the stream be promptly closed if an I/O error occurs.
| | [ByteArray](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-byte-array/index.html)! | [readNBytes](https://developer.android.com/reference/kotlin/java/io/InputStream#readNBytes(kotlin.Int))`(`len:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`)` Reads up to a specified number of bytes from the input stream. This method blocks until the requested number of bytes has been read, end of stream is detected, or an exception is thrown. This method does not close the input stream. The length of the returned array equals the number of bytes read from the stream. If `len` is zero, then no bytes are read and an empty byte array is returned. Otherwise, up to `len` bytes are read from the stream. Fewer than `len` bytes may be read if end of stream is encountered. When this stream reaches end of stream, further invocations of this method will return an empty byte array. Note that this method is intended for simple cases where it is convenient to read the specified number of bytes into a byte array. The total amount of memory allocated by this method is proportional to the number of bytes read from the stream which is bounded by `len`. Therefore, the method may be safely called with very large values of `len` provided sufficient memory is available. The behavior for the case where the input stream is *asynchronously closed*, or the thread interrupted during the read, is highly input stream specific, and therefore not specified. If an I/O error occurs reading from the input stream, then it may do so after some, but not all, bytes have been read. Consequently the input stream may not be at end of stream and may be in an inconsistent state. It is strongly recommended that the stream be promptly closed if an I/O error occurs.
| | [Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [skipNBytes](https://developer.android.com/reference/kotlin/java/io/InputStream#skipNBytes(kotlin.Long))`(`n:` `[Long](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-long/index.html)`)` Skips over and discards exactly `n` bytes of data from this input stream. If `n` is zero, then no bytes are skipped. If `n` is negative, then no bytes are skipped. Subclasses may handle the negative value differently. This method blocks until the requested number of bytes has been skipped, end of file is reached, or an exception is thrown. If end of stream is reached before the stream is at the desired position, then an `EOFException` is thrown. If an I/O error occurs, then the input stream may be in an inconsistent state. It is strongly recommended that the stream be promptly closed if an I/O error occurs.
| | [Long](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-long/index.html) | [transferTo](https://developer.android.com/reference/kotlin/java/io/InputStream#transferTo(java.io.OutputStream))`(`out:` `[OutputStream](https://developer.android.com/reference/kotlin/java/io/OutputStream)!`)` Reads all bytes from this input stream and writes the bytes to the given output stream in the order that they are read. On return, this input stream will be at end of stream. This method does not close either stream. This method may block indefinitely reading from the input stream, or writing to the output stream. The behavior for the case where the input and/or output stream is *asynchronously closed*, or the thread interrupted during the transfer, is highly input and output stream specific, and therefore not specified. If an I/O error occurs reading from the input stream or writing to the output stream, then it may do so after some bytes have been read or written. Consequently the input stream may not be at end of stream and one, or both, streams may be in an inconsistent state. It is strongly recommended that both streams be promptly closed if an I/O error occurs.
| ||
| Inherited properties ||
|---|---|
| From class [FilterInputStream](https://developer.android.com/reference/kotlin/java/io/FilterInputStream) |------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------| | [InputStream](https://developer.android.com/reference/kotlin/java/io/InputStream)! | [in](https://developer.android.com/reference/kotlin/java/io/FilterInputStream#in:java.io.InputStream) The input stream to be filtered.
| ||
## Public constructors
### LineNumberInputStream
Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
LineNumberInputStream(in: InputStream!)
```
Constructs a newline number input stream that reads its input from the specified input stream.
| Parameters ||
|------|------------------------------------------------------------------------------------------------------------------|
| `in` | [InputStream](https://developer.android.com/reference/kotlin/java/io/InputStream)!: the underlying input stream. |
## Public methods
### available
Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun available(): Int
```
**Deprecated:** *Deprecated in Java.*
Returns the number of bytes that can be read from this input stream without blocking.
Note that if the underlying input stream is able to supply *k* input characters without blocking, the `LineNumberInputStream` can guarantee only to provide *k* /2 characters without blocking, because the *k* characters from the underlying input stream might consist of *k* /2 pairs of `'\u005Cr'` and `'\u005Cn'`, which are converted to just *k* /2 `'\u005Cn'` characters.
| Return ||
|----------------------------------------------------------------------------|-------------------------------------------------------------------------------|
| [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html) | the number of bytes that can be read from this input stream without blocking. |
| Exceptions ||
|-----------------------|-------------------------|
| `java.io.IOException` | if an I/O error occurs. |
| `java.io.IOException` | if an I/O error occurs. |
**See Also**
- [java.io.FilterInputStream#in](https://developer.android.com/reference/kotlin/java/io/FilterInputStream#in:java.io.InputStream)
### getLineNumber
Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun getLineNumber(): Int
```
**Deprecated:** *Deprecated in Java.*
Returns the current line number.
| Return ||
|----------------------------------------------------------------------------|--------------------------|
| [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html) | the current line number. |
**See Also**
- [#setLineNumber](https://developer.android.com/reference/kotlin/java/io/LineNumberInputStream#setLineNumber(kotlin.Int))
### mark
Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun mark(readlimit: Int): Unit
```
**Deprecated:** *Deprecated in Java.*
Marks the current position in this input stream. A subsequent call to the `reset` method repositions this stream at the last marked position so that subsequent reads re-read the same bytes.
The `mark` method of `LineNumberInputStream` remembers the current line number in a private variable, and then calls the `mark` method of the underlying input stream.
| Parameters ||
|-------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `readlimit` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html): the maximum limit of bytes that can be read before the mark position becomes invalid. |
**See Also**
- [java.io.FilterInputStream#in](https://developer.android.com/reference/kotlin/java/io/FilterInputStream#in:java.io.InputStream)
### read
Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun read(): Int
```
**Deprecated:** *Deprecated in Java.*
Reads the next byte of data from this input stream. The value byte is returned as an `int` in the range `0` to `255`. If no byte is available because the end of the stream has been reached, the value `-1` is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.
The `read` method of `LineNumberInputStream` calls the `read` method of the underlying input stream. It checks for carriage returns and newline characters in the input, and modifies the current line number as appropriate. A carriage-return character or a carriage return followed by a newline character are both converted into a single newline character.
| Return ||
|----------------------------------------------------------------------------|----------------------------------------------------------------------|
| [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html) | the next byte of data, or `-1` if the end of this stream is reached. |
| Exceptions ||
|-----------------------|-------------------------|
| `java.io.IOException` | if an I/O error occurs. |
| `java.io.IOException` | if an I/O error occurs. |
**See Also**
- [java.io.FilterInputStream#in](https://developer.android.com/reference/kotlin/java/io/FilterInputStream#in:java.io.InputStream)
- [java.io.LineNumberInputStream#getLineNumber()](https://developer.android.com/reference/kotlin/java/io/LineNumberInputStream#getLineNumber())
### read
Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun read(
b: ByteArray!,
off: Int,
len: Int
): Int
```
**Deprecated:** *Deprecated in Java.*
Reads up to `len` bytes of data from this input stream into an array of bytes. This method blocks until some input is available.
The `read` method of `LineNumberInputStream` repeatedly calls the `read` method of zero arguments to fill in the byte array.
| Parameters ||
|-------|-----------------------------------------------------------------------------------------------------------------------------------|
| `b` | [ByteArray](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-byte-array/index.html)!: the buffer into which the data is read. |
| `off` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html): the start offset of the data. |
| `len` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html): the maximum number of bytes read. |
| Return ||
|----------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------|
| [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html) | the total number of bytes read into the buffer, or `-1` if there is no more data because the end of this stream has been reached. |
| Exceptions ||
|---------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------|
| `java.io.IOException` | If the first byte cannot be read for any reason other than end of file, or if the input stream has been closed, or if some other I/O error occurs. |
| `java.lang.NullPointerException` | If `b` is `null`. |
| `java.lang.IndexOutOfBoundsException` | If `off` is negative, `len` is negative, or `len` is greater than `b.length - off` |
| `java.io.IOException` | if an I/O error occurs. |
**See Also**
### reset
Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun reset(): Unit
```
**Deprecated:** *Deprecated in Java.*
Repositions this stream to the position at the time the `mark` method was last called on this input stream.
The `reset` method of `LineNumberInputStream` resets the line number to be the line number at the time the `mark` method was called, and then calls the `reset` method of the underlying input stream.
Stream marks are intended to be used in situations where you need to read ahead a little to see what's in the stream. Often this is most easily done by invoking some general parser. If the stream is of the type handled by the parser, it just chugs along happily. If the stream is not of that type, the parser should toss an exception when it fails, which, if it happens within readlimit bytes, allows the outer code to reset the stream and try another parser.
| Exceptions ||
|-----------------------|-------------------------------------------------------------------------|
| `java.io.IOException` | if this stream has not been marked or if the mark has been invalidated. |
| `java.io.IOException` | if an I/O error occurs. |
**See Also**
- [java.io.FilterInputStream#in](https://developer.android.com/reference/kotlin/java/io/FilterInputStream#in:java.io.InputStream)
### setLineNumber
Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun setLineNumber(lineNumber: Int): Unit
```
**Deprecated:** *Deprecated in Java.*
Sets the line number to the specified argument.
| Parameters ||
|--------------|--------------------------------------------------------------------------------------------------|
| `lineNumber` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html): the new line number. |
**See Also**
- [#getLineNumber](https://developer.android.com/reference/kotlin/java/io/LineNumberInputStream#getLineNumber())
### skip
Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun skip(n: Long): Long
```
**Deprecated:** *Deprecated in Java.*
Skips over and discards `n` bytes of data from this input stream. The `skip` method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly `0`. The actual number of bytes skipped is returned. If `n` is negative, no bytes are skipped.
The `skip` method of `LineNumberInputStream` creates a byte array and then repeatedly reads into it until `n` bytes have been read or the end of the stream has been reached.
| Parameters ||
|-----|------------------------------------------------------------------------------------------------------------------|
| `n` | [Long](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-long/index.html): the number of bytes to be skipped. |
| Return ||
|------------------------------------------------------------------------------|-------------------------------------|
| [Long](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-long/index.html) | the actual number of bytes skipped. |
| Exceptions ||
|-----------------------|----------------------------------------|
| `java.io.IOException` | if `in.skip(n)` throws an IOException. |
| `java.io.IOException` | if an I/O error occurs. |
**See Also**
- [java.io.FilterInputStream#in](https://developer.android.com/reference/kotlin/java/io/FilterInputStream#in:java.io.InputStream)