Java InputStream to Char Array getInputStreamAsCharArray(InputStream stream, int length, String encoding)

Description

Returns the given input stream's contents as a character array.

License

Open Source License

Exception

Parameter	Description
IOException	if a problem occured reading the stream.

Declaration

public static char[] getInputStreamAsCharArray(InputStream stream,
        int length, String encoding) throws IOException 

Method Source Code

//package com.java2s;
/*******************************************************************************
 * Copyright (c) 2002, 2016 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * //from  w ww .j  av a 2  s  .com
 * Contributors:
 *     Rational Software - Initial API and implementation
 *     Markus Schorn (Wind River Systems)
 *     Anton Leherbauer (Wind River Systems)
 *     IBM Corporation - EFS support
 *     Marc-Andre Laperle (Ericsson)
 *******************************************************************************/

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

public class Main {
    /**
     * Returns the given input stream's contents as a character array. If a
     * length is specified (ie. if length != -1), only length chars are
     * returned. Otherwise all chars in the stream are returned. Closes the stream.
     * 
     * @throws IOException
     *             if a problem occured reading the stream.
     */
    public static char[] getInputStreamAsCharArray(InputStream stream,
            int length, String encoding) throws IOException {
        final InputStreamReader reader = encoding == null ? new InputStreamReader(
                stream) : new InputStreamReader(stream, encoding);
        try {
            char[] contents;
            if (length == -1) {
                contents = new char[0];
                int contentsLength = 0;
                int charsRead = -1;
                do {
                    int available = stream.available();
                    // resize contents if needed
                    if (contentsLength + available > contents.length) {
                        System.arraycopy(contents, 0,
                                contents = new char[contentsLength
                                        + available], 0, contentsLength);
                    }
                    // read as many chars as possible
                    charsRead = reader.read(contents, contentsLength,
                            available);
                    if (charsRead > 0) {
                        // remember length of contents
                        contentsLength += charsRead;
                    }
                } while (charsRead > 0);
                // resize contents if necessary
                if (contentsLength < contents.length) {
                    System.arraycopy(contents, 0,
                            contents = new char[contentsLength], 0,
                            contentsLength);
                }
            } else {
                contents = new char[length];
                int len = 0;
                int readSize = 0;
                while ((readSize != -1) && (len != length)) {
                    // See PR 1FMS89U
                    // We record first the read size. In this case len is the
                    // actual read size.
                    len += readSize;
                    readSize = reader.read(contents, len, length - len);
                }
                // See PR 1FMS89U
                // Now we need to resize in case the default encoding used more
                // than one byte for each
                // character
                if (len != length)
                    System.arraycopy(contents, 0,
                            (contents = new char[len]), 0, len);
            }
            return contents;
        } finally {
            reader.close();
        }
    }
}

Related

1. getInputStreamAsCharArray(InputStream stream, int length, String encoding)