Apache Commons Text 1.15.0 · org.apache.commons.text.io.StringSubstitutorReader

A Reader that performs string substitution on a source Reader using a StringSubstitutor.

Using this Reader avoids reading a whole file into memory as a String to perform string substitution, for example, when a Servlet filters a file to a client.

This class is not thread-safe.

Field Summary

Modifier and Type	Field and Description
private final TextStringBuilder	buffer References Deprecated `TextStringBuilder` is deprecated or references (maybe indirectly) at least one deprecated element. Our internal buffer.
private static final int	EOS The end-of-stream character marker.
private boolean	eos End-of-Stream flag.
private final StringMatcher	prefixEscapeMatcher Matches escaped variable starts.
private final char[]	read1CharBuffer Internal buffer for `read()` method.
private final StringSubstitutor	stringSubstitutor The underlying StringSubstitutor.
private int	toDrain We don't always want to drain the whole buffer.

Inherited from java.io.FilterReader:: in

Constructor Summary

Access	Constructor and Description
public	StringSubstitutorReader(final Reader the underlying reader containing the template text known to the given `StringSubstitutor`. reader, final StringSubstitutor How to replace as we read. stringSubstitutor) Constructs a new instance.

Method Summary

Modifier and Type	Method and Description
private int	buffer(final int requestReadCount) Buffers the requested number of characters if available.
private int	bufferOrDrainOnEos(final int requestReadCount, final char[] target, final int targetIndex, final int targetLength) Reads a requested number of chars from the underlying reader into the buffer.
private int	drain(final char[] target, final int targetIndex, final int targetLength) Drains characters from our buffer to the given `target`.
private int	drainOnEos(final int readCountOrEos, final char[] target, final int targetIndex, final int targetLength) Drains from the buffer to the target only if we are at EOS per the input count.
private boolean	isBufferMatchAt(final StringMatcher stringMatcher, final int pos) Tests if our buffer matches the given string matcher at the given position in the buffer.
private boolean	isDraining() Tests if we are draining.
public int	Returns: a character as an `int` or `-1` for end-of-stream. read() Overrides java.io.FilterReader.read. Reads a single character.
public int	Returns: The number of characters read, or -1 on end of stream. read(final char[] Target buffer. target, final int Index in the target at which to start storing characters. targetIndexIn, final int Maximum number of characters to read. targetLengthIn) Overrides java.io.FilterReader.read. Reads characters into a portion of an array.
private int	readCount(final int count, final int pos) Returns how many chars to attempt reading to have room in the buffer for `count` chars starting at position `pos`.

Inherited from java.io.FilterReader:: close mark markSupported ready reset skip

Field Detail

buffer	back to summary
private final TextStringBuilder buffer References Deprecated `TextStringBuilder` is deprecated or references (maybe indirectly) at least one deprecated element. See corresponding docs for further information. Our internal buffer.

EOS	back to summary
private static final int EOS The end-of-stream character marker.

eos	back to summary
private boolean eos End-of-Stream flag.

prefixEscapeMatcher	back to summary
private final StringMatcher prefixEscapeMatcher Matches escaped variable starts.

read1CharBuffer	back to summary
private final char[] read1CharBuffer Internal buffer for `read()` method.

stringSubstitutor	back to summary
private final StringSubstitutor stringSubstitutor The underlying StringSubstitutor.

toDrain	back to summary
private int toDrain We don't always want to drain the whole buffer.

Constructor Detail

StringSubstitutorReader back to summary

StringSubstitutorReader	back to summary
public StringSubstitutorReader(final Reader reader, final StringSubstitutor stringSubstitutor) Constructs a new instance. Parameters reader:Reader the underlying reader containing the template text known to the given `StringSubstitutor`. stringSubstitutor:StringSubstitutor How to replace as we read. Exceptions NullPointerException: if `reader` is `null`. if `stringSubstitutor` is `null`.

public StringSubstitutorReader(final Reader reader, final StringSubstitutor stringSubstitutor)

Constructs a new instance.

Parameters

reader:Reader: the underlying reader containing the template text known to the given StringSubstitutor.
stringSubstitutor:StringSubstitutor: How to replace as we read.

Exceptions

NullPointerException:

if reader is null.
if stringSubstitutor is null.

Method Detail

buffer	back to summary
private int buffer(final int requestReadCount) throws IOException Buffers the requested number of characters if available.

bufferOrDrainOnEos	back to summary
private int bufferOrDrainOnEos(final int requestReadCount, final char[] target, final int targetIndex, final int targetLength) throws IOException Reads a requested number of chars from the underlying reader into the buffer. On EOS, set the state is DRAINING, drain, and return a drain count, otherwise, returns the actual read count.

drain	back to summary
private int drain(final char[] target, final int targetIndex, final int targetLength) Drains characters from our buffer to the given `target`.

drainOnEos	back to summary
private int drainOnEos(final int readCountOrEos, final char[] target, final int targetIndex, final int targetLength) Drains from the buffer to the target only if we are at EOS per the input count. If input count is EOS, drain and returns the drain count, otherwise return the input count. If draining, the state is set to DRAINING.

isBufferMatchAt	back to summary
private boolean isBufferMatchAt(final StringMatcher stringMatcher, final int pos) Tests if our buffer matches the given string matcher at the given position in the buffer.

isDraining	back to summary
private boolean isDraining() Tests if we are draining.

read back to summary

read	back to summary
public int read() throws IOException Overrides java.io.FilterReader.read. Reads a single character. Returns:int a character as an `int` or `-1` for end-of-stream. Annotations @Override Exceptions IOException: If an I/O error occurs.

public int read() throws IOException

Overrides java.io.FilterReader.read.

Reads a single character.

Returns:int

a character as an int or -1 for end-of-stream.

Annotations

@Override

Exceptions

IOException:: If an I/O error occurs.

read	back to summary
public int read(final char[] target, final int targetIndexIn, final int targetLengthIn) throws IOException Overrides java.io.FilterReader.read. Reads characters into a portion of an array. Parameters target:char[] Target buffer. targetIndexIn:int Index in the target at which to start storing characters. targetLengthIn:int Maximum number of characters to read. Returns:int The number of characters read, or -1 on end of stream. Annotations @Override Exceptions IOException: If an I/O error occurs.

read

back to summary

public int read(final char[] target, final int targetIndexIn, final int targetLengthIn) throws IOException

Overrides java.io.FilterReader.read.

Reads characters into a portion of an array.

Parameters

target:char[]: Target buffer.
targetIndexIn:int: Index in the target at which to start storing characters.
targetLengthIn:int: Maximum number of characters to read.

Returns:int

The number of characters read, or -1 on end of stream.

Annotations

@Override

Exceptions

IOException:: If an I/O error occurs.

readCount	back to summary
private int readCount(final int count, final int pos) Returns how many chars to attempt reading to have room in the buffer for `count` chars starting at position `pos`.

public Class StringSubstitutorReader

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail