Java InputStream to Writer inputStreamToWriter(final InputStream in, final Writer out)

Description

Copies the content of an InputStream to a Writer.

License

Open Source License

Parameter

Parameter	Description
in	<code>InputStream</code> from which data is read.
out	<code>Writer</code> to which data is written.

Exception

Parameter	Description
IOException	an exception

Return

number of bytes read/written.

Declaration

public static long inputStreamToWriter(final InputStream in, final Writer out) throws IOException 

Method Source Code

//package com.java2s;
/*******************************************************************************
 * Copyright (c) 2010-2014 Alexander Kerner. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.//from w w w. j  a v  a2 s.c  o m
 ******************************************************************************/

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

import java.io.Reader;

import java.io.Writer;

public class Main {
    /**
     * The JCL book specifies the default buffer size as 8K characters.
     */
    public static final int DEFAULT_BUFFER = 8192;

    /**
     * Copies the content of an <code>InputStream</code> to a
     * <code>Writer</code>. Will flush the <code>Writer</code>, but won't close
     * <code>InputStream</code> or <code>Writer</code>.
     *
     * @param in
     *            <code>InputStream</code> from which data is read.
     * @param out
     *            <code>Writer</code> to which data is written.
     * @return number of bytes read/written.
     * @throws IOException
     */
    public static long inputStreamToWriter(final InputStream in, final Writer out) throws IOException {
        final InputStreamReader inr = new InputStreamReader(in);
        return readerToWriter(inr, out);
    }

    /**
     * Copies the content of an <code>InputStream</code> to a
     * <code>Writer</code>. Will flush the <code>Writer</code>, but won't close
     * <code>InputStream</code> or <code>Writer</code>.
     *
     * @param in
     *            <code>InputStream</code> from which data is read.
     * @param out
     *            <code>Writer</code> to which data is written.
     * @param buffer
     *            the number of bytes to buffer reading.
     * @return number of bytes read/written.
     * @throws IOException
     */
    public static long inputStreamToWriter(final InputStream in, final Writer out, final int buffer)
            throws IOException {
        final InputStreamReader inr = new InputStreamReader(in);
        return readerToWriter(inr, out, buffer);
    }

    /**
     * Copies the content of a <code>Reader</code> to a <code>Writer</code>.
     * Will flush the <code>Writer</code>, but won't close <code>Reader</code>
     * or <code>Writer</code>.
     *
     * @param reader
     *            <code>Reader</code> from which data is read.
     * @param writer
     *            <code>Writer</code> to which data is written.
     * @return number of bytes read/ written.
     * @throws IOException
     */
    public static long readerToWriter(final Reader reader, final Writer writer) throws IOException {
        return readerToWriter(reader, writer, 0);
    }

    /**
     * Copies the content of a <code>Reader</code> to a <code>Writer</code>.
     * Will flush the <code>Writer</code>, but won't close <code>Reader</code>
     * or <code>Writer</code>.
     *
     * @param reader
     *            <code>Reader</code> from which data is read.
     * @param writer
     *            <code>Writer</code> to which data is written.
     * @param buffer
     *            the number of bytes to buffer reading.
     * @return number of bytes read/written.
     * @throws IOException
     */
    public static long readerToWriter(final Reader reader, final Writer writer, int buffer) throws IOException {
        if (buffer < 1)
            buffer = DEFAULT_BUFFER;
        final char[] charBuffer = new char[buffer];
        long count = 0;
        int n = 0;
        while ((n = reader.read(charBuffer)) != -1) {
            writer.write(charBuffer, 0, n);
            count += n;
        }
        writer.flush();
        return count;
    }
}

Related

1. inputStreamToWriterToFile(InputStream in, File file)