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Explore the source code of the class FilteringInputStream.java

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 * and Distribution License("CDDL") (collectively, the "License").  You
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 * obtain a copy of the License at
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package org.glassfish.jersey.media.json.internal;

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

/**
 * Abstract filtering input stream.
 *
 * @author Jakub Podlesak
 */
public abstract class FilteringInputStream extends InputStream {

    private byte[] currentBuffer;
    private int cursor;

    /**
     * Get the next available chunk of bytes.
     * @return the next available chunk of bytes.
     * @throws IOException
     */
    protected abstract byte[] nextBytes() throws IOException;

    @Override
    public int available() throws IOException {

        if (currentBuffer == null) {
            return 0;
        }

        return currentBuffer.length - cursor;
    }

    @Override
    public synchronized void mark(int readlimit) {
        throw new UnsupportedOperationException();
    }

    @Override
    public boolean markSupported() {
        return false;
    }

    private void getNextBytesIfNothingAvailable() throws IOException {
        if (available() < 1) {
            currentBuffer = nextBytes();
            cursor = 0;
        }

    }

    @Override
    public int read() throws IOException {

        getNextBytesIfNothingAvailable();

        if ((currentBuffer == null) || (currentBuffer.length == 0)) {
            return -1;
        }

        return currentBuffer[cursor++];
    }

    @Override
    public int read(byte[] b) throws IOException {
        return this.read(b, 0, b.length);
    }

    @Override
    public int read(byte[] b, int off, int len) throws IOException {

        getNextBytesIfNothingAvailable();

        if (currentBuffer == null) {
            return -1;
        }

        int availableBytes = currentBuffer.length - cursor;

        if (len >= availableBytes) {
            System.arraycopy(currentBuffer, cursor, b, off, availableBytes);
            currentBuffer = null;
            return availableBytes;
        } else {
            System.arraycopy(currentBuffer, cursor, b, off, len);
            cursor += len;
            return len;
        }
    }

    @Override
    public synchronized void reset() throws IOException {
        throw new IOException();
    }

    @Override
    public long skip(long n) throws IOException {
        return super.skip(n);
    }

    @Override
    public String toString() {
        return super.toString();
    }
}