IO library
Contents
IO related functions.
Usage
Add the following to your build.gradle file:
dependencies {
include xplibs.io
}Add the import statement to your code:
import ioLib from '/lib/xp/io';You are now ready to use the API.
Functions
getMimeType
Returns the mime-type from a file name or extension.
Parameters
Takes a single name string — the file name or extension to look up.
Returns
string : The mime-type for the given name or extension.
Example
import {getMimeType} from '/lib/xp/io';
// Returns mime-type for a file name.
const type = getMimeType('myfile.txt');
log.info('Mime type is %s', type);getResource
Looks up a resource on the classpath.
Parameters
Takes a single key argument — a string path or a ResourceKey identifying the resource.
Returns
object : (Resource) A resource handle exposing exists(), getSize(), getTimestamp(), and getStream().
Examples
import {getResource} from '/lib/xp/io';
// Returns a file by name.
const res1 = getResource('/lib/xp/examples/io/sample.txt');
const exists = res1.exists();
const size = res1.getSize();
const timestamp = res1.getTimestamp();
const stream = res1.getStream();import {getResource} from '/lib/xp/io';
// Returns a file by reference.
const res2 = getResource(resolve('./sample.txt'));
if (res2.exists()) {
log.info('Resource exists');
}getSize
Returns the size of a stream in bytes.
Parameters
Takes a single stream argument — a ByteSource to measure.
Returns
number : Size of the stream in bytes.
Example
import {getSize} from '/lib/xp/io';
// Returns the size of a stream.
const size = getSize(stream);
log.info('Stream size is %s bytes', size);newStream
Creates a new stream from a string.
Parameters
Takes a single text string — the text to encode as a UTF-8 byte stream.
Returns
object : (ByteSource) A new stream containing the UTF-8 bytes of the input string.
Example
import {newStream} from '/lib/xp/io';
// Creates a new stream from a string.
const stream = newStream('Hello World');processLines
Reads a stream line by line, invoking a callback for each line.
Parameters
Takes two positional arguments: a stream (ByteSource) to read from, and a func callback (line: string) ⇒ void called once per line.
Example
import {processLines} from '/lib/xp/io';
let num = 0;
// Process lines from stream.
processLines(stream, (line) => {
num++;
log.info('Line %s: %s', num, line);
});readLines
Reads all lines from a stream and returns them as an array.
Parameters
Takes a single stream argument — a ByteSource to read from.
Returns
string[] : Lines read from the stream.
Example
import {readLines} from '/lib/xp/io';
// Reads lines from stream.
const lines = readLines(stream);
log.info('Num lines: %s', lines.length);readText
Reads the full text content of a stream.
Parameters
Takes a single stream argument — a ByteSource to read from.
Returns
string : Text read from the stream.
Example
import {readText} from '/lib/xp/io';
// Reads text from stream.
const text = readText(stream);
log.info('Text: %s', text);