xref: /libcore/luni/src/main/java/java/lang/Readable.java

/* Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 java.lang;

import java.io.IOException;
import java.nio.CharBuffer;

/**
 * Represents a sequence of characters that can be incrementally read (copied)
 * into a {@link CharBuffer}.
 */
public interface Readable {

    /**
     * Reads characters into the specified {@code CharBuffer}. The maximum
     * number of characters read is {@code CharBuffer.remaining()}.
     *
     * @param cb
     *            the buffer to be filled with characters read.
     * @return the number of characters actually read, or -1 if this
     *         {@code Readable} reaches its end
     * @throws IOException
     *             if an I/O error occurs.
     */
    int read(CharBuffer cb) throws IOException;
}