Class Reader

dw.io

Class Reader

Object

dw.io.Reader

The class supports reading characters from a stream.

All Known Subclasses

FileReader

lines : List (Read Only)

The method reads the whole input stream, parses it and returns a list of strings.

Using this method on large feeds is inherently unsafe and may lead to an out-of-memory condition. Instead use method readLine() and process one line at a time.

Deprecated:

Use readLines()

string : String (Read Only)

The method reads the whole input stream as one string and returns it.

Using this method is unsafe if the length of the input stream is not known and may lead to an out-of-memory condition. Instead use method readN(Number).

Deprecated:

Use readString()

Reader(source : String)

Creates a reader from a string.

Reader(stream : InputStream)

Create a reader from a stream using UTF-8 character encoding.

Reader(stream : InputStream, encoding : String)

Create a reader from a stream using the specified character encoding.

close() : void

Closes the reader.

getLines() : List

The method reads the whole input stream, parses it and returns a list of strings.

getString() : String

The method reads the whole input stream as one string and returns it.

read() : String

Reads a single character from the stream.

read(length : Number) : String

Reads multiple characters from the stream as string.

readLine() : String

Reads the next line.

readLines() : List

The method reads the whole input stream, parses it and returns a list of strings.

readN(n : Number) : String

Reads n characters from the stream as string.

readString() : String

The method reads the whole input stream as one string and returns it.

ready() : boolean

Identifies if this stream is ready to be read.

skip(n : Number) : void

Skips the specified number of characters in the stream.

Methods inherited from class Object

assign, create, create, defineProperties, defineProperty, entries, freeze, fromEntries, getOwnPropertyDescriptor, getOwnPropertyNames, getOwnPropertySymbols, getPrototypeOf, hasOwnProperty, is, isExtensible, isFrozen, isPrototypeOf, isSealed, keys, preventExtensions, propertyIsEnumerable, seal, setPrototypeOf, toLocaleString, toString, valueOf, values

Reader

public Reader(source : String)

Creates a reader from a string.

Parameters:

source - the source string.

Reader

public Reader(stream : InputStream)

Create a reader from a stream using UTF-8 character encoding.

Parameters:

stream - the input stream to use.

Reader

public Reader(stream : InputStream, encoding : String)

Create a reader from a stream using the specified character encoding.

Parameters:

stream - the input stream to use.

encoding - the encoding to use.

close() : void

Closes the reader.

getLines

getLines() : List

The method reads the whole input stream, parses it and returns a list of strings.

Using this method on large feeds is inherently unsafe and may lead to an out-of-memory condition. Instead use method readLine() and process one line at a time.

Deprecated:

Use readLines()

Returns:

a list of strings

getString

getString() : String

The method reads the whole input stream as one string and returns it.

Using this method is unsafe if the length of the input stream is not known and may lead to an out-of-memory condition. Instead use method readN(Number).

Deprecated:

Use readString()

Returns:

a string, which represents the whole content of the InputStream

Throws:

IOException - if something went wrong while reading from the underlying stream

read

read() : String

Reads a single character from the stream. The method returns null if the end of the stream is reached.

Returns:

a single character in a string, or null if the end of the stream is reached

read

read(length : Number) : String

Reads multiple characters from the stream as string. The actual number of characters that were read can be determined from the length of the returned string. If the end of the stream is reached and no more characters can be read, the method exits with an exception.

Deprecated:

use readN(Number) instead which does not throw an exception if the stream is exhausted

Parameters:

length - the number of characters to read.

Returns:

a string whose length is controlled by the length parameter. The actual number of characters that were read can be determined from the length of the returned string.

Throws:

an - exception if the stream is exhausted

readLine

readLine() : String

Reads the next line.

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.

readLines

readLines() : List

The method reads the whole input stream, parses it and returns a list of strings.

Using this method on large feeds is inherently unsafe and may lead to an out-of-memory condition. Instead use method readLine() and process one line at a time.

Returns:

a list of strings

readN

readN(n : Number) : String

Reads n characters from the stream as string. The actual number of characters that were read can be determined from the length of the returned string. If the end of the stream is reached and no more characters can be read, the method returns null.

Parameters:

n - the number of characters to read

Returns:

a string whose maximum length is controlled by the n parameter, or null if the end of the stream is reached and no more characters can be read

readString

readString() : String

The method reads the whole input stream as one string and returns it.

Using this method is unsafe if the length of the input stream is not known and may lead to an out-of-memory condition. Instead use method readN(Number).

Returns:

a string, which represents the whole content of the InputStream

Throws:

IOException - if something went wrong while reading from the underlying stream

ready

ready() : boolean

Identifies if this stream is ready to be read.

Returns:

true guarantees that the stream is ready to read without waiting for input. A false response means that the stream may or may not block to wait for input. Note that returning false does not guarantee that the next read() will block.

skip

skip(n : Number) : void

Skips the specified number of characters in the stream.

Parameters:

n - the number of characters to skip.