我的理解呢， 一:java io中的重要概念就是流，基本的就是InputStream,OutputStream,其他的都是基于这两个的，看下面两段话 1 Class InputStream java.lang.Object | +-java.io.InputStreamDirect Known Subclasses: AudioInputStream, ByteArrayInputStream, FileInputStream, FilterInputStream, InputStream, ObjectInputStream, PipedInputStream, SequenceInputStream, StringBufferInputStream 2 Class OutputStream java.lang.Object | +-java.io.OutputStream Direct Known Subclasses: ByteArrayOutputStream, FileOutputStream, FilterOutputStream, ObjectOutputStream, OutputStream, PipedOutputStream 二：为了在网络中更好了利用流，缓冲，还引入了新的io概念，放在新的package中叫nio Package java.nio Defines buffers, which are containers for data, and provides an overview of the other NIO packages. See: Description Class Summary Buffer A container for data of a specific primitive type. ByteBuffer A byte buffer. ByteOrder A typesafe enumeration for byte orders. CharBuffer A character buffer. DoubleBuffer A double buffer. FloatBuffer A float buffer. IntBuffer An int buffer. LongBuffer A long buffer. MappedByteBuffer A direct byte buffer whose content is a memory-mapped region of a file. ShortBuffer A short buffer. Exception Summary BufferOverflowException Unchecked exception thrown when a relative put operation reaches the target buffer's limit. BufferUnderflowException Unchecked exception thrown when a relative get operation reaches the source buffer's limit. InvalidMarkException Unchecked exception thrown when an attempt is made to reset a buffer when its is not defined. ReadOnlyBufferException Unchecked exception thrown when a content-mutation method such as put or compact is invoked upon a read-only buffer.
Package java.nio Description Defines buffers, which are containers for data, and provides an overview of the other NIO packages. The central abstractions of the NIO APIs are: Buffers, which are containers for data; Charsets and their associated decoders and encoders, which translate between bytes and Unicode characters; Channels of various types, which represent connections to entities capable of performing I/O operations; and Selectors and selection keys, which together with selectable channels define a multiplexed, non-blocking I/O facility. The java.nio package defines the buffer classes, which are used throughout the NIO APIs. The charset API is defined in the java.nio.charset package, and the channel and selector APIs are defined in the java.nio.channels package. Each of these subpackages has its own service-provider (SPI) subpackage, the contents of which can be used to extend the platform's default implementations or to construct alternative implementations. Buffers Buffer Position, limit, and capacity; clear, flip, rewind, and /reset ByteBuffer Get/put, compact, views; allocate, wrap MappedByteBuffer A byte buffer mapped to a file CharBuffer Get/put, compact; allocate, wrap DoubleBuffer ' ' FloatBuffer ' ' IntBuffer ' ' LongBuffer ' ' ShortBuffer ' ' ByteOrder Typesafe enumeration for byte orders A buffer is a container for a fixed amount of data of a specific primitive type. In addition to its content a buffer has a position, which is the index of the next element to be read or written, and a limit, which is the index of the first element that should not be read or written. The base Buffer class defines these properties as well as methods for clearing, flipping, and rewinding, for ing the current position, and for resetting the position to the previous . There is a buffer class for each non-boolean primitive type. Each class defines a family of get and put methods for moving data out of and in to a buffer, methods for compacting, duplicating, and slicing a buffer, and static methods for allocating a new buffer as well as for wrapping an existing array into a buffer. Byte buffers are distinguished in that they can be used as the sources and targets of I/O operations. They also support several features not found in the other buffer classes: A byte buffer can be allocated as a direct buffer, in which case the Java virtual machine will make a best effort to perform native I/O operations directly upon it. A byte buffer can be created by mapping a region of a file directly into memory, in which case a few additional file-related operations defined in the MappedByteBuffer class are available. A byte buffer provides access to its content as either a heterogenous or homogeneous sequence of binary data of any non-boolean primitive type, in either big-endian or little-endian byte order. Since: 1.4
filterInputStream
<!--有进-->OutputStream
FilterOutputStream
<!--才有出-->
一:java io中的重要概念就是流，基本的就是InputStream,OutputStream,其他的都是基于这两个的，看下面两段话
1
Class InputStream
java.lang.Object
|
+-java.io.InputStreamDirect Known Subclasses:
AudioInputStream, ByteArrayInputStream, FileInputStream, FilterInputStream, InputStream, ObjectInputStream, PipedInputStream, SequenceInputStream, StringBufferInputStream 2
Class OutputStream
java.lang.Object
|
+-java.io.OutputStream
Direct Known Subclasses:
ByteArrayOutputStream, FileOutputStream, FilterOutputStream, ObjectOutputStream, OutputStream, PipedOutputStream 二：为了在网络中更好了利用流，缓冲，还引入了新的io概念，放在新的package中叫nio
Package java.nio
Defines buffers, which are containers for data, and provides an overview of the other NIO packages.
See:
Description Class Summary
Buffer A container for data of a specific primitive type.
ByteBuffer A byte buffer.
ByteOrder A typesafe enumeration for byte orders.
CharBuffer A character buffer.
DoubleBuffer A double buffer.
FloatBuffer A float buffer.
IntBuffer An int buffer.
LongBuffer A long buffer.
MappedByteBuffer A direct byte buffer whose content is a memory-mapped region of a file.
ShortBuffer A short buffer.
Exception Summary
BufferOverflowException Unchecked exception thrown when a relative put operation reaches the target buffer's limit.
BufferUnderflowException Unchecked exception thrown when a relative get operation reaches the source buffer's limit.
InvalidMarkException Unchecked exception thrown when an attempt is made to reset a buffer when its is not defined.
ReadOnlyBufferException Unchecked exception thrown when a content-mutation method such as put or compact is invoked upon a read-only buffer.
Package java.nio Description
Defines buffers, which are containers for data, and provides an overview of the other NIO packages. The central abstractions of the NIO APIs are: Buffers, which are containers for data; Charsets and their associated decoders and encoders,
which translate between bytes and Unicode characters; Channels of various types, which represent connections
to entities capable of performing I/O operations; and Selectors and selection keys, which together with
selectable channels define a multiplexed, non-blocking
I/O facility. The java.nio package defines the buffer classes, which are used throughout the NIO APIs. The charset API is defined in the java.nio.charset package, and the channel and selector APIs are defined in the java.nio.channels package. Each of these subpackages has its own service-provider (SPI) subpackage, the contents of which can be used to extend the platform's default implementations or to construct alternative implementations. Buffers
Buffer Position, limit, and capacity;
clear, flip, rewind, and /reset
ByteBuffer Get/put, compact, views; allocate, wrap
MappedByteBuffer A byte buffer mapped to a file
CharBuffer Get/put, compact; allocate, wrap
DoubleBuffer ' '
FloatBuffer ' '
IntBuffer ' '
LongBuffer ' '
ShortBuffer ' '
ByteOrder Typesafe enumeration for byte orders A buffer is a container for a fixed amount of data of a specific primitive type. In addition to its content a buffer has a position, which is the index of the next element to be read or written, and a limit, which is the index of the first element that should not be read or written. The base Buffer class defines these properties as well as methods for clearing, flipping, and rewinding, for ing the current position, and for resetting the position to the previous . There is a buffer class for each non-boolean primitive type. Each class defines a family of get and put methods for moving data out of and in to a buffer, methods for compacting, duplicating, and slicing a buffer, and static methods for allocating a new buffer as well as for wrapping an existing array into a buffer. Byte buffers are distinguished in that they can be used as the sources and targets of I/O operations. They also support several features not found in the other buffer classes: A byte buffer can be allocated as a direct buffer, in which case the Java virtual machine will make a best effort to perform native I/O operations directly upon it. A byte buffer can be created by mapping a region of a file directly into memory, in which case a few additional file-related operations defined in the MappedByteBuffer class are available. A byte buffer provides access to its content as either a heterogenous or homogeneous sequence of binary data of any non-boolean primitive type, in either big-endian or little-endian byte order. Since:
1.4