org.apache.poi.poifs.filesystem

Class DocumentInputStream

java.lang.Object

java.io.InputStream

org.apache.poi.poifs.filesystem.DocumentInputStream

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, LittleEndianInput

public final class DocumentInputStream
extends java.io.InputStream
implements LittleEndianInput

This class provides methods to read a DocumentEntry managed by a POIFSFileSystem instance. (此类提供读取由 POIFSFileSystem 实例管理的 DocumentEntry 的方法。)

Constructor Summary

Constructors

Constructor and Description
DocumentInputStream(DocumentEntry document) Create an InputStream from the specified DocumentEntry
DocumentInputStream(POIFSDocument document) Create an InputStream from the specified Document

Method Summary

Modifier and Type	Method and Description
int	available()
void	close()
void	mark(int ignoredReadlimit)
boolean	markSupported() Tests if this input stream supports the mark and reset methods. (测试此输入流是否支持 mark 和 reset 方法。)
int	read()
int	read(byte[] b)
int	read(byte[] b, int off, int len)
byte	readByte()
double	readDouble()
void	readFully(byte[] buf)
void	readFully(byte[] buf, int off, int len)
int	readInt()
long	readLong()
void	readPlain(byte[] buf, int off, int len) Usually acts the same as LittleEndianInput.readFully(byte[], int, int), but for an encrypted stream the raw (unencrypted) data is filled (通常行为与 LittleEndianInput.readFully(byte[], int, int) 相同，但对于加密流，原始（未加密）数据被填充)
short	readShort()
int	readUByte()
long	readUInt()
int	readUShort()
void	reset() Repositions this stream to the position at the time the mark() method was last called on this input stream. (将此流重新定位到最后一次在此输入流上调用 mark() 方法时的位置。)
long	skip(long n)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DocumentInputStream

public DocumentInputStream(DocumentEntry document)
                    throws java.io.IOException

Create an InputStream from the specified DocumentEntry (从指定的 DocumentEntry 创建一个 InputStream)

Parameters:

document - the DocumentEntry to be read (document - 要读取的 DocumentEntry)

Throws:

java.io.IOException - if the DocumentEntry cannot be opened (like, maybe it has been deleted?) (java.io.IOException - 如果 DocumentEntry 无法打开（例如，它可能已被删除？）)

DocumentInputStream

public DocumentInputStream(POIFSDocument document)

Create an InputStream from the specified Document (从指定的 Document 创建一个 InputStream)

Parameters:

document - the Document to be read (document - 要阅读的文档)

Method Detail

available

public int available()

Specified by:

available in interface LittleEndianInput (在接口 LittleEndianInput 中可用)

Overrides:

available in class java.io.InputStream

close

public void close()

Specified by:

close in interface java.io.Closeable (在接口 java.io.Closeable 中关闭)

Specified by:

close in interface java.lang.AutoCloseable (在接口 java.lang.AutoCloseable 中关闭)

Overrides:

close in class java.io.InputStream

markSupported

public boolean markSupported()

Tests if this input stream supports the mark and reset methods. (测试此输入流是否支持 mark 和 reset 方法。)

Overrides:

markSupported in class java.io.InputStream

Returns:

true always (永远真实)

mark

public void mark(int ignoredReadlimit)

Overrides:

mark in class java.io.InputStream

read

public int read()
         throws java.io.IOException

Specified by:

read in class java.io.InputStream (读入类 java.io.InputStream)

Throws:

java.io.IOException (java.io.IOException)

read

public int read(byte[] b)
         throws java.io.IOException

Overrides:

read in class java.io.InputStream

Throws:

java.io.IOException (java.io.IOException)

read

public int read(byte[] b,
                int off,
                int len)
         throws java.io.IOException

Overrides:

read in class java.io.InputStream

Throws:

java.io.IOException (java.io.IOException)

reset

public void reset()

Repositions this stream to the position at the time the mark() method was last called on this input stream. If mark() has not been called this method repositions the stream to its beginning. (将此流重新定位到最后一次在此输入流上调用 mark() 方法时的位置。如果尚未调用 mark()，则此方法将流重新定位到其开头。)

Overrides:

reset in class java.io.InputStream

skip

public long skip(long n)
          throws java.io.IOException

Overrides:

skip in class java.io.InputStream

Throws:

java.io.IOException (java.io.IOException)

readFully

public void readFully(byte[] buf)

Specified by:

readFully in interface LittleEndianInput (接口 LittleEndianInput 中的 readFully)

readFully

public void readFully(byte[] buf,
                      int off,
                      int len)

Specified by:

readFully in interface LittleEndianInput (接口 LittleEndianInput 中的 readFully)

readPlain

public void readPlain(byte[] buf,
                      int off,
                      int len)

Description copied from interface: LittleEndianInput

Usually acts the same as LittleEndianInput.readFully(byte[], int, int), but for an encrypted stream the raw (unencrypted) data is filled (通常行为与 LittleEndianInput.readFully(byte[], int, int) 相同，但对于加密流，原始（未加密）数据被填充)

Specified by:

readPlain in interface LittleEndianInput (接口 LittleEndianInput 中的 readPlain)

Parameters:

buf - the byte array to receive the bytes (buf - 接收字节的字节数组)

off - the start offset into the byte array (off - 字节数组的起始偏移量)

len - the amount of bytes to fill (len - 要填充的字节数)

readByte

public byte readByte()

Specified by:

readByte in interface LittleEndianInput (接口 LittleEndianInput 中的 readByte)

readDouble

public double readDouble()

Specified by:

readDouble in interface LittleEndianInput (接口 LittleEndianInput 中的 readDouble)

readLong

public long readLong()

Specified by:

readLong in interface LittleEndianInput (接口 LittleEndianInput 中的 readLong)

readShort

public short readShort()

Specified by:

readShort in interface LittleEndianInput (接口 LittleEndianInput 中的 readShort)

readInt

public int readInt()

Specified by:

readInt in interface LittleEndianInput (接口 LittleEndianInput 中的 readInt)

readUInt

public long readUInt()

readUShort

public int readUShort()

Specified by:

readUShort in interface LittleEndianInput (接口 LittleEndianInput 中的 readUShort)

readUByte

public int readUByte()

Specified by:

readUByte in interface LittleEndianInput (接口 LittleEndianInput 中的 readUByte)