DefaultServlet.java 文件源码

/**
 * Copy the contents of the specified input stream to the specified
 * output stream, and ensure that both streams are closed before returning
 * (even in the face of an exception).
 *
 * @param istream The input stream to read from
 * @param ostream The output stream to write to
 * @return Exception which occurred during processing
 */
private IOException copyRange(InputStream istream,
                              ServletOutputStream ostream) {

    // Copy the input stream to the output stream
    IOException exception = null;
    byte buffer[] = new byte[input];
    int len = buffer.length;
    while (true) {
        try {
            len = istream.read(buffer);
            if (len == -1)
                break;
            ostream.write(buffer, 0, len);
        } catch (IOException e) {
            exception = e;
            len = -1;
            break;
        }
    }
    return exception;

}