◆◆有以下问题，请大伙拉小弟一把！
本文导语: j2me中，用以下方法取得一文件的内容： InputStream eBookStream = getClass().getResourceAsStream("dao.book"); 请问在eBookStream中的数据是什么形式的？如何知道其长度？ 谢谢！ | 是二进制流吧 | 自...
InputStream eBookStream = getClass().getResourceAsStream("dao.book");
请问在eBookStream中的数据是什么形式的？如何知道其长度？
谢谢！
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/*
* @(#)InputStream.java 1.37 00/07/18
*
* Copyright 1994-2000 Sun Microsystems, Inc. All Rights Reserved.
*
* This software is the proprietary information of Sun Microsystems, Inc.
* Use is subject to license terms.
*
*/
package java.io;
/**
* This abstract class is the superclass of all classes representing
* an input stream of bytes.
*
*
Applications that need to define a subclass of InputStream
* must always provide a method that returns the next byte of input.
*
* @author Arthur van Hoff
* @version 1.37, 07/18/00
* @see java.io.BufferedInputStream
* @see java.io.ByteArrayInputStream
* @see java.io.DataInputStream
* @see java.io.FilterInputStream
* @see java.io.InputStream#read()
* @see java.io.OutputStream
* @see java.io.PushbackInputStream
* @since JDK1.0
*/
public abstract class InputStream {
// SKIP_BUFFER_SIZE is used to determine the size of skipBuffer
private static final int SKIP_BUFFER_SIZE = 2048;
// skipBuffer is initialized in skip(long), if needed.
private static byte[] skipBuffer;
/**
* Reads the next byte of data from the input stream. The value byte is
* returned as an int in the range 0 to
* 255. If no byte is available because the end of the stream
* has been reached, the value -1 is returned. This method
* blocks until input data is available, the end of the stream is detected,
* or an exception is thrown.
*
*
A subclass must provide an implementation of this method.
*
* @return the next byte of data, or -1 if the end of the
* stream is reached.
* @exception IOException if an I/O error occurs.
*/
public abstract int read() throws IOException;
/**
* Reads some number of bytes from the input stream and stores them into
* the buffer array b. The number of bytes actually read is
* returned as an integer. This method blocks until input data is
* available, end of file is detected, or an exception is thrown.
*
*
If b is null, a
* NullPointerException is thrown. If the length of
* b is zero, then no bytes are read and 0 is
* returned; otherwise, there is an attempt to read at least one byte. If
* no byte is available because the stream is at end of file, the value
* -1 is returned; otherwise, at least one byte is read and
* stored into b.
*
*
The first byte read is stored into element b[0], the
* next one into b[1], and so on. The number of bytes read is,
* at most, equal to the length of b. Let k be the
* number of bytes actually read; these bytes will be stored in elements
* b[0] through b[k-1],
* leaving elements b[k] through
* b[b.length-1] unaffected.
*
*
If the first byte cannot be read for any reason other than end of
* file, then an IOException is thrown. In particular, an
* IOException is thrown if the input stream has been closed.
*
*
The read(b) method for class InputStream
* has the same effect as:
read(b, 0, b.length)
*
* @param b the buffer into which the data is read.
* @return the total number of bytes read into the buffer, or
* -1 is there is no more data because the end of
* the stream has been reached.
* @exception IOException if an I/O error occurs.
* @see java.io.InputStream#read(byte[], int, int)
*/
public int read(byte b[]) throws IOException {
return read(b, 0, b.length);
}
/**
* Reads up to len bytes of data from the input stream into
* an array of bytes. An attempt is made to read as many as
* len bytes, but a smaller number may be read, possibly
* zero. The number of bytes actually read is returned as an integer.
*
*
This method blocks until input data is available, end of file is
* detected, or an exception is thrown.
*
*
If b is null, a
* NullPointerException is thrown.
*
*
If off is negative, or len is negative, or
* off+len is greater than the length of the array
* b, then an IndexOutOfBoundsException is
* thrown.
*
*
If len is zero, then no bytes are read and
* 0 is returned; otherwise, there is an attempt to read at
* least one byte. If no byte is available because the stream is at end of
* file, the value -1 is returned; otherwise, at least one
* byte is read and stored into b.
*
*
The first byte read is stored into element b[off], the
* next one into b[off+1], and so on. The number of bytes read
* is, at most, equal to len. Let k be the number of
* bytes actually read; these bytes will be stored in elements
* b[off] through b[off+k-1],
* leaving elements b[off+k] through
* b[off+len-1] unaffected.
*
*
In every case, elements b[0] through
* b[off] and elements b[off+len] through
* b[b.length-1] are unaffected.
*
*
If the first byte cannot be read for any reason other than end of
* file, then an IOException is thrown. In particular, an
* IOException is thrown if the input stream has been closed.
*
*
The read(b, off, len) method
* for class InputStream simply calls the method
* read() repeatedly. If the first such call results in an
* IOException, that exception is returned from the call to
* the read(b, off, len) method. If
* any subsequent call to read() results in a
* IOException, the exception is caught and treated as if it
* were end of file; the bytes read up to that point are stored into
* b and the number of bytes read before the exception
* occurred is returned. Subclasses are encouraged to provide a more
* efficient implementation of this method.
*
* @param b the buffer into which the data is read.
* @param off the start offset in array b
* at which the data is written.
* @param len the maximum number of bytes to read.
* @return the total number of bytes read into the buffer, or
* -1 if there is no more data because the end of
* the stream has been reached.
* @exception IOException if an I/O error occurs.
* @see java.io.InputStream#read()
*/
public int read(byte b[], int off, int len) throws IOException {
if (b == null) {
throw new NullPointerException();
} else if ((off b.length) || (len b.length) || ((off + len)
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