ReaderInputStream (The Adobe AEM Quickstart and Web Application.)

java.lang.Object
- java.io.InputStream
- - org.apache.commons.io.input.ReaderInputStream

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable
```
public class ReaderInputStream
extends java.io.InputStream
```
InputStream implementation that reads a character stream from a Reader and transforms it to a byte stream using a specified charset encoding. The stream is transformed using a CharsetEncoder object, guaranteeing that all charset encodings supported by the JRE are handled correctly. In particular for charsets such as UTF-16, the implementation ensures that one and only one byte order marker is produced.
Since in general it is not possible to predict the number of characters to be read from the Reader to satisfy a read request on the ReaderInputStream, all reads from the Reader are buffered. There is therefore no well defined correlation between the current position of the Reader and that of the ReaderInputStream. This also implies that in general there is no need to wrap the underlying Reader in a BufferedReader.

ReaderInputStream implements the inverse transformation of InputStreamReader; in the following example, reading from in2 would return the same byte sequence as reading from in (provided that the initial byte sequence is legal with respect to the charset encoding):

To build an instance, see ReaderInputStream.Builder.
```
 InputStream inputStream = ...
 Charset cs = ...
 InputStreamReader reader = new InputStreamReader(inputStream, cs);
 ReaderInputStream in2 = ReaderInputStream.builder()
   .setReader(reader)
   .setCharset(cs)
   .get();
 
```
ReaderInputStream implements the same transformation as OutputStreamWriter, except that the control flow is reversed: both classes transform a character stream into a byte stream, but OutputStreamWriter pushes data to the underlying stream, while ReaderInputStream pulls it from the underlying stream.

Note that while there are use cases where there is no alternative to using this class, very often the need to use this class is an indication of a flaw in the design of the code. This class is typically used in situations where an existing API only accepts an InputStream, but where the most natural way to produce the data is as a character stream, i.e. by providing a Reader instance. An example of a situation where this problem may appear is when implementing the javax.activation.DataSource interface from the Java Activation Framework.

The InputStream.available() method of this class always returns 0. The methods InputStream.mark(int) and InputStream.reset() are not supported.

Instances of ReaderInputStream are not thread safe.
Since:

2.0

See Also:

WriterOutputStream

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class ReaderInputStream.Builder
Builds a new ReaderInputStream instance.

Nested Classes
Modifier and Type	Class and Description
`static class`	`ReaderInputStream.Builder` Builds a new `ReaderInputStream` instance.

Constructor Summary

Constructors
Constructor and Description
`ReaderInputStream(java.io.Reader reader)` Deprecated. Use `builder()` instead
`ReaderInputStream(java.io.Reader reader, java.nio.charset.Charset charset)` Deprecated. Use `builder()` instead, will be protected for subclasses.
`ReaderInputStream(java.io.Reader reader, java.nio.charset.CharsetEncoder charsetEncoder)` Deprecated. Use `builder()` instead
`ReaderInputStream(java.io.Reader reader, java.nio.charset.CharsetEncoder charsetEncoder, int bufferSize)` Deprecated. Use `builder()` instead
`ReaderInputStream(java.io.Reader reader, java.nio.charset.Charset charset, int bufferSize)` Deprecated. Use `builder()` instead
`ReaderInputStream(java.io.Reader reader, java.lang.String charsetName)` Deprecated. Use `builder()` instead
`ReaderInputStream(java.io.Reader reader, java.lang.String charsetName, int bufferSize)` Deprecated. Use `builder()` instead

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`static ReaderInputStream.Builder`	`builder()` Constructs a new `ReaderInputStream.Builder`.
`void`	`close()` Closes the stream.
`int`	`read()` Reads a single byte.
`int`	`read(byte[] b)` Reads the specified number of bytes into an array.
`int`	`read(byte[] array, int off, int len)` Reads the specified number of bytes into an array.

Methods inherited from class java.io.InputStream
available, mark, markSupported, reset, skip

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - ReaderInputStream
```
@Deprecated
public ReaderInputStream(java.io.Reader reader)
```
    Deprecated. Use builder() instead
    
    Constructs a new ReaderInputStream that uses the default character encoding with a default input buffer size of characters.
    
    Parameters:
    
    reader - the target Reader
  - ReaderInputStream
```
@Deprecated
public ReaderInputStream(java.io.Reader reader,
                                     java.nio.charset.Charset charset)
```
    Deprecated. Use builder() instead, will be protected for subclasses.
    
    Constructs a new ReaderInputStream with a default input buffer size of characters.
    The encoder created for the specified charset will use CodingErrorAction.REPLACE for malformed input and unmappable characters.
    
    Parameters:
    
    reader - the target Reader
    
    charset - the charset encoding
  - ReaderInputStream
```
@Deprecated
public ReaderInputStream(java.io.Reader reader,
                                     java.nio.charset.Charset charset,
                                     int bufferSize)
```
    Deprecated. Use builder() instead
    
    Constructs a new ReaderInputStream.
    The encoder created for the specified charset will use CodingErrorAction.REPLACE for malformed input and unmappable characters.
    
    Parameters:
    
    reader - the target Reader.
    
    charset - the charset encoding.
    
    bufferSize - the size of the input buffer in number of characters.
  - ReaderInputStream
```
@Deprecated
public ReaderInputStream(java.io.Reader reader,
                                     java.nio.charset.CharsetEncoder charsetEncoder)
```
    Deprecated. Use builder() instead
    
    Constructs a new ReaderInputStream.
    This constructor does not call reset on the provided encoder. The caller of this constructor should do this when providing an encoder which had already been in use.
    
    Parameters:
    
    reader - the target Reader
    
    charsetEncoder - the charset encoder
    
    Since:
    
    2.1
  - ReaderInputStream
```
@Deprecated
public ReaderInputStream(java.io.Reader reader,
                                     java.nio.charset.CharsetEncoder charsetEncoder,
                                     int bufferSize)
```
    Deprecated. Use builder() instead
    
    Constructs a new ReaderInputStream.
    This constructor does not call reset on the provided encoder. The caller of this constructor should do this when providing an encoder which had already been in use.
    
    Parameters:
    
    reader - the target Reader
    
    charsetEncoder - the charset encoder, null defaults to the default Charset encoder.
    
    bufferSize - the size of the input buffer in number of characters
    
    Since:
    
    2.1
  - ReaderInputStream
```
@Deprecated
public ReaderInputStream(java.io.Reader reader,
                                     java.lang.String charsetName)
```
    Deprecated. Use builder() instead
    
    Constructs a new ReaderInputStream with a default input buffer size of characters.
    The encoder created for the specified charset will use CodingErrorAction.REPLACE for malformed input and unmappable characters.
    
    Parameters:
    
    reader - the target Reader
    
    charsetName - the name of the charset encoding
  - ReaderInputStream
```
@Deprecated
public ReaderInputStream(java.io.Reader reader,
                                     java.lang.String charsetName,
                                     int bufferSize)
```
    Deprecated. Use builder() instead
    
    Constructs a new ReaderInputStream.
    The encoder created for the specified charset will use CodingErrorAction.REPLACE for malformed input and unmappable characters.
    
    Parameters:
    
    reader - the target Reader
    
    charsetName - the name of the charset encoding, null maps to the default Charset.
    
    bufferSize - the size of the input buffer in number of characters
- Method Detail
  - builder
```
public static ReaderInputStream.Builder builder()
```
    Constructs a new ReaderInputStream.Builder.
    
    Returns:
    
    a new ReaderInputStream.Builder.
    
    Since:
    
    2.12.0
  - close
```
public void close()
           throws java.io.IOException
```
    Closes the stream. This method will cause the underlying Reader to be closed.
    
    Specified by:
    
    close in interface java.io.Closeable
    
    Specified by:
    
    close in interface java.lang.AutoCloseable
    
    Overrides:
    
    close in class java.io.InputStream
    
    Throws:
    
    java.io.IOException - if an I/O error occurs.
  - read
```
public int read()
         throws java.io.IOException
```
    Reads a single byte.
    
    Specified by:
    
    read in class java.io.InputStream
    
    Returns:
    
    either the byte read or -1 if the end of the stream has been reached
    
    Throws:
    
    java.io.IOException - if an I/O error occurs.
  - read
```
public int read(byte[] b)
         throws java.io.IOException
```
    Reads the specified number of bytes into an array.
    
    Overrides:
    
    read in class java.io.InputStream
    
    Parameters:
    
    b - the byte array to read into
    
    Returns:
    
    the number of bytes read or -1 if the end of the stream has been reached
    
    Throws:
    
    java.io.IOException - if an I/O error occurs.
  - read
```
public int read(byte[] array,
                int off,
                int len)
         throws java.io.IOException
```
    Reads the specified number of bytes into an array.
    
    Overrides:
    
    read in class java.io.InputStream
    
    Parameters:
    
    array - the byte array to read into
    
    off - the offset to start reading bytes into
    
    len - the number of bytes to read
    
    Returns:
    
    the number of bytes read or -1 if the end of the stream has been reached
    
    Throws:
    
    java.io.IOException - if an I/O error occurs.

Class ReaderInputStream

Nested Class Summary

Constructor Summary

Method Summary

Methods inherited from class java.io.InputStream

Methods inherited from class java.lang.Object

Constructor Detail

ReaderInputStream

ReaderInputStream

ReaderInputStream

ReaderInputStream

ReaderInputStream

ReaderInputStream

ReaderInputStream

Method Detail

builder

close

read

read

read