framework/java/android/bluetooth/BluetoothInputStream.java

/*
 * Copyright (C) 2009 The Android Open Source Project
 *
 * 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.
 */

package android.bluetooth;

import android.annotation.Hide;
import android.annotation.RequiresNoPermission;

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

/** Used to write to a Bluetooth socket. */
@Hide
final class BluetoothInputStream extends InputStream {
    private final BluetoothSocket mSocket;

    /*package*/ BluetoothInputStream(BluetoothSocket s) {
        mSocket = s;
    }

    /** Return number of bytes available before this stream will block. */
    @RequiresNoPermission // Permission is checked when creating the stream
    public int available() throws IOException {
        return mSocket.available();
    }

    public void close() throws IOException {
        mSocket.close();
    }

    /**
     * Reads a single byte from this stream and returns it as an integer in the range from 0 to 255.
     * Returns -1 if the end of the stream has been reached. Blocks until one byte has been read,
     * the end of the source stream is detected or an exception is thrown.
     *
     * @return the byte read or -1 if the end of stream has been reached.
     * @throws IOException if the stream is closed or another IOException occurs.
     * @since Android 1.5
     */
    @RequiresNoPermission // Permission is checked when creating the stream
    public int read() throws IOException {
        byte[] b = new byte[1];
        int ret = mSocket.read(b, 0, 1);
        if (ret == 1) {
            return (int) b[0] & 0xff;
        } else {
            return -1;
        }
    }

    /**
     * Reads at most {@code length} bytes from this stream and stores them in the byte array {@code
     * b} starting at {@code offset}.
     *
     * @param b the byte array in which to store the bytes read.
     * @param offset the initial position in {@code buffer} to store the bytes read from this
     *     stream.
     * @param length the maximum number of bytes to store in {@code b}.
     * @return the number of bytes actually read or -1 if the end of the stream has been reached.
     * @throws IndexOutOfBoundsException if {@code offset < 0} or {@code length < 0}, or if {@code
     *     offset + length} is greater than the length of {@code b}.
     * @throws IOException if the stream is closed or another IOException occurs.
     * @since Android 1.5
     */
    @RequiresNoPermission // Permission is checked when creating the stream
    public int read(byte[] b, int offset, int length) throws IOException {
        if (b == null) {
            throw new NullPointerException("byte array is null");
        }
        if ((offset | length) < 0 || length > b.length - offset) {
            throw new ArrayIndexOutOfBoundsException("invalid offset or length");
        }
        return mSocket.read(b, offset, length);
    }
}