"Java Foundation" IO stream

Package Com.pachira.c;import Java.io.bufferedreader;import Java.io.file;import java.io.fileinputstream;import                                               Java.io.ioexception;import Java.io.inputstreamreader;import java.util.scanner;/* * +----> [c] bufferedreader------> [c] LineNumberReader * | | ---> [c] inputstreamreader------> [c] filereader * |----> [c] Str                        Ingreader * +---> [c] Reader-------+----> [c] Pipedreader * |                        |----> [C] CharArrayReader * |              +----> [c] filterreader------> [C] pushbackreader * +---> Character stream--+ * |                        |              +----> [C] bufferedwriter * |                        |              |----> [c] outputstreamwriter------> [c] FileWriter * |              |          |----> [C] printerwriter * |                                       +---> [c] Writer-------+----> [c] StringWriter * |                                       |----> [C] pipedwriter * |                                       |----> [C] chararraywriter * |                                       +----> [C] filterwriter * IO--+ * |                                       +----> [c] fileinputstream +----> [c] Bufferedinputstream * |                                       |----> [c] filterinputstream--|----> [c] DataInputStream * |              |----> [c] objectinputstream +----> [c] Pushbackinputstream * |              +---> [c] inputstream--+----> [c] PipedInputStream * |                        |              |----> [C] Sequenceinputstream * |                        |              |----> [C] StringBufferInputStream * |                        | +----[C] Bytearrayinputstream * +---> Byte stream--+ * |                        +----> [c] fileoutputstream +----> [c] Bufferedoutputstream * | |----> [c] filteroutputstream--|----> [c] dataoutputstream * +---> [c] outputstream-+----& Gt [C] ObjectOutputStream +----> [c] printstream * |----> [c] Pipedoutpu TStream * +----> [C] bytearrayoutputstream * * *io Stream Classification * *). Data type: Character stream and byte flow). Data flow: input stream and Output stream * * character stream and Byte stream * *). The origin of the character stream: Because the data is encoded differently, there is a stream object that efficiently operates on the character. The essence is actually based on the byte stream reading, to check the specified code table. *). The difference between a byte stream and a character stream: * Read and write units are different: bytes stream in bits (8bit), character stream in characters, according to the Code table mapping characters, can read multiple bytes at a time. * Processing objects are different: the byte stream can handle all types of data (slices, audio, etc.), whereas a character stream can only handle data of the type of characters. * Conclusion: As long as the processing of plain text data, the use of character streams is preferred, in addition to the use of byte stream.  * * Input stream and output stream * Only read the input stream, only write to the output stream, the program needs to use different streams according to the different characteristics of the data to be transmitted. * *inputstream). InputStream is the parent class of all input byte streams, which is an abstract class; Bytearrayinputstream, StrinGbufferinputstream, FileInputStream are three basic media streams that read data from byte arrays, StringBuffer, and local files, respectively. PipedInputStream is the data read from a pipeline shared with other threads; ObjectInputStream and all FilterInputStream subclasses are decorative streams (the protagonist of the adorner pattern); * *outputstream). OutputStream is the parent class of all output byte streams, which is an abstract class; Bytearrayoutputstream and FileOutputStream are two basic media streams, which write data to byte array and local file respectively; ). PipedOutputStream is writing data to a pipeline that is shared with other threads; ObjectOutputStream and all filteroutputstream subclasses are decorative streams; * *reader). Reader is the parent class of all the input character streams, which is an abstract class; Charreader, StringReader, are two basic media streams that read data from a char array, a string, and a different one. Pipedreader is the data read from a pipeline shared with other threads; BufferedReader is obviously an adorner, and its subclasses are responsible for decorating other reader objects; FilterReader is the parent of all custom concrete adornment streams whose subclasses pushbackreader the reader object, adding a line number; *6). InputStreamReader is a bridge between the byte stream and the character stream, which transforms the stream of bytes into character streams. FileReader can be said to achieve this function, commonly used tool class, * in its source code is clearly used to convert FileInputStream to reader method; * *writer). Writer is the parent of all the streams of output characters, which is an abstract class; Chararraywriter, StringWriter are two basic media streams, which write data to a char array, a string, respectively. PipedWriter is writing data to a pipeline that is shared with other threads; BufferedWriter is an adorner that provides buffering function for writer; PrintWriter and PrintStream PolesThey are similar in function and use very similar; *6). OutputStreamWriter is outputstream to writer Transformation Bridge, its subclass filewriter is actually a concrete class to implement this function; * */public class IO {public static void Main (string[] args) throws IOException {//character stream string path = "Data/data"; BufferedReader br = new BufferedReader (new InputStreamReader (New FileInputStream (path), "Utf-8")); String line = "", while (line = Br.readline ())! = null) {System.out.println (line);} Br.close ();/* Byte stream * UTF-8: is a variable-length encoding that can represent a symbol using 1~4 bytes; * gbk:a character is encoded as 1 or 2 bytes */path = "Data/data2"; FileInputStream fis = new FileInputStream (path); byte[] bs = new Byte[2];while (fis.available () > 0) {fis.read (BS); string tmp = new string (BS, "GBK"); for (byte b:bs) {System.out.print (b + "");} SYSTEM.OUT.PRINTLN (tmp + ""); bs = new byte[2];} Fis.close ();/* * Common Tools * This ((Readablebytechannel) (new FileInputStream (source). Getchannel ()), charsetname); */scanner sc = new Scanner (new File (path), "GBK"), while (Sc.hasnext ()) {String tline = Sc.nextline (); System.out.println (Tline);}}}

　　

"Java Foundation" IO stream