09-Java Input Output

Transcription

1 JAVA Programming Language JAVA Input/Output 2

2 (1) (Stream) 2,,,,, 3 (2) InputStream OutputStream, 8 Reader Writer, 16 4

3 (3) Data Source/Dest. (byte stream) InputStream OutputStream Java Internal (byte, byte[ ]) < > Data Source/Dest. (byte stream) Character Encoding Reader Writer < > Unicode Java Internal (char, char[ ], String) 5 (4) OutputStream InputStream 6

4 (5) Reader Writer 7 (6) Reader BufferedReader LineNumberReader CharArrayReader InputStreamReader FileReader FilterReader PushbackReader PipedReader StringReader Writer / /, /, / / / / (pushback) PipedReader/PipedOutputStream InputStream BufferedInputStream LineNumberInputStream ByteArrayInputStream (none) FileInputStream FilterInputStream PushbackInputStream PipedInputStream StringBufferInputStream OutputStream BufferedWriter /, BufferedWriter BufferedOutputStream CharArrayWriter / / ByteArrayOutputStream FiterWriter / FilterOutputStream OutputStreamWriter FileWriter PrintWriter PipedWriter StringWriter / Writer/Streamdp PipedReader/PipedOutputStream (none) FileOutputStream PrintStream PipedOutputStream (none) 8

5 (1) InputStream, abstract int read( ) throws IOException int read(byte b[ ]) throws IOException int read(byte b[ ], int off, int len) throws IOException int available( ) throws IOException long skip(long n) throws IOException synchronized void mark(int readlimit) synchronized void reset( ) throws IOException void close( ) throws IOException 9 (2) InputStream import java.io.*; class InputStreamTest { public static void main(string args[ ]) { int ch; InputStream in = System.in; try { while((ch=in.read())!= -1) { if(ch == 'S') { in.skip(2); System.out.println("Char: "+(char)ch+", Available: "+in.available( )); catch(ioexception e) { System.out.println(e); 10

6 (3) OutputStream, abstract void write(int b) throws IOException void write(byte b[ ]) throws IOException void write(byte b[ ], int off, int len) throws IOException void flush( ) throws IOException void close( ) throws IOException 11 (4) OutputStream import java.io.*; class OutputStreamTest { public static void main(string args[ ]) { OutputStream out = System.out; int ch=0x0fffff00 + 'A'; try { out.write(ch); out.flush( ); // (a) // out.close( ); // (b) catch(ioexception e) { System.out.println(e); 12

7 (5) Reader, boolean ready( ); int read( ); int read(char[ ] cbuf); abstract int read(char[ ] cbuf, int off, int len); boolean marksupported( ); void mark(int readaheadlimit); void reset( ); long skip(long n); abstract void close( ); 13 (6) Writer, void write(int c ); void write(char[ ] cbuf); abstract void write(char[ ] cbuf, int off, int len); void write(string str); void write(string str, int off, int len); abstract void flush( ); abstract void close( ); 14

8 (1) FileInputStream FileInputStream FileInputStream // File FileInputStream(File file); // FileDescriptor FileInputStream(FileDescriptor fdobj); // FileInputStream(String name); 15 (2) FileOutputStream File FileOutputStream // File FileOutputStream(File file); // FileDescriptor FileOutputStream(FileDescriptor fdobj); // FileOutputStream(String name); // append FileOutputStream(String name, boolean append); 16

9 (3) import java.io.*; import java.lang.boolean; class FileInputOutputStreamTest { public staticvoid main(string[] args) { booleanappend = false ; int i, len=0; InputStream in=null; OutputStream out=null; if(args.length < 2) { System.out.println("USAGE: FileInputOutputStreamTest Source_file Destination_file"); System.exit(-1); else if(args.length > 2) { append = newboolean(args[2]).booleanvalue(); System.out.println("args[0]: "+args[0]); System.out.println("args[1]: "+args[1]); System.out.println(" append: "+append); try { in = newfileinputstream(newfile(args[0])); out = newfileoutputstream(args[1], append); catch(filenotfoundexception e) { System.out.println(e); try { while((i=in.read())!= -1) { out.write(i); len++; in.close(); out.close(); System.out.println(len+" bytes are copied..."); catch(ioexception e) { System.out.println(e); 17 (4) FileReader FileWriter // FileReader FileReader(File file); FileReader(FileDescriptor fd); FileReader(String filename); // FileWriter FileWriter(File file); FileWriter(FileDescriptor fd); FileWriter(String filename); FileWriter(String filename, boolean append); 18

10 (5) import java.io.*; import java.lang.boolean; class FileReaderWriterTest { public staticvoid main(string[] args) { booleanappend = false ; int i, len=0; FileReaderin=null; FileWriterout=null; if(args.length < 2) { System.out.println("USAGE: FileReaderWriterTest Source_file Destination_file"); System.exit(-1); else if(args.length > 2) { append = newboolean(args[2]).booleanvalue(); System.out.println("args[0]: "+args[0]); System.out.println("args[1]: "+args[1]); System.out.println(" append: "+append); try { in = newfilereader(newfile(args[0])); out = newfilewriter(args[1], append); catch(filenotfoundexception e) { System.out.println(e); catch(ioexception e) { System.out.println(e); try { while((i=in.read())!= -1) { out.write(i); len++; in.close(); out.close(); System.out.println(len+" bytes are copied..."); catch(ioexception e) { System.out.println(e); 19 (1) SequenceInputStream SequenceInputStream // Enumeration SequenceInputStream(Enumeration) // 2 SequenceInputStream(InputStream s1, InputStream s2) 20

11 (2) SequenceInputStream import java.io.*; class SequenceInputTest { public static void main(string[] args) throws IOException { int ch; byte arr1[] = { (byte )'H',(byte )'e',(byte )'l',(byte )'l',(byte )'o' ; byte arr2[] = { (byte )',',(byte )' ' ; ByteArrayInputStream in1 = new ByteArrayInputStream(arr1); ByteArrayInputStream in2 = new ByteArrayInputStream(arr2); FileInputStream in3 = new FileInputStream("SequenceInputTest.txt"); java.util.vector v = new java.util.vector(); v.add(in1); v.add(in2); v.add(in3); in3.reset(); SequenceInputStream in = new SequenceInputStream(v.elements()); while((ch=in.read())!= -1) { System.out.write(ch); System.out.flush(); System.out.println(); in1.reset(); if(in3.marksupported()) { System.out.println("reset()"); else { in3 = new FileInputStream("SequenceInputTest.txt"); System.out.println("newFileInputStream(\"SequenceInputTest.txt\")"); in = newsequenceinputstream(in1, in3); while((ch=in.read())!= -1) { System.out.print((char)ch); System.out.println(); 21 (3) PipedInputStream, PipedOutputStream 22

12 (4) PipedInputStream PipedOutputStream Java Program (Producer) PipedOutputStream PIPE PipedInputStream Java Program (Consumer) <Pipe > //PipedInputStream PipedInputStream( ); PipedInputStream(PipedOutputStream src); void connect(pipedoutputstream src); // PipedOutputStream PipedOutputStream( ); PipedOutputStream(PipedInputStream snk); void connect(pipedinputstream snk); 23 (5) PipedReaderStream PipedWriterStream //PipedReaderStream PipedReader( ); PipedReader(PipedWriter src); void connect(pipedwriter src); // PipedWriterStream PipedWriter( ); PipedWriter(PipedReader snk); void connect(pipedreader snk); 24

13 (6) PipedInputStream PipedOutputStream public PipedOutputStream getpipedoutput() { import java.io.*; class PipedInputThread extends Thread {... PipedInputThread () { public PipedInputStream getpipedinput() { public void connect(pipedoutputstream pout) { try { public void run() { class PipedOutputThread extends Thread {... PipedOutputThread() { pout = new PipedOutputStream();... public void connect(pipedinputstream pin) {... public void run() { try {... catch(ioexception e) { System.out. println(tostring() + ": "+e); public class PipedInputOutputTest { public static void main(string args[]) { PipedInputThread pin = null; PipedOutputThread pout = null; pin = new PipedInputThread(); pout = new PipedOutputThread(); pin.connect(pout. getpipedoutput()); pin.start(); pout.start(); 25 (1), ByteArrayInputStream ByteArrayOutputStream CharArrayReader CharArrayWriter StringBufferInputStream StringReader StringWriter 26

14 (2) ByteArrayInputStream (protected byte[ ] buf) ByteArrayOutputStream // ByteArrayInputStream ByteArrayInputStream(byte[ ] buf); ByteArrayInputStream(byte[ ] buf, int offset, int length); // ByteArrayOutputStream ByteArrayOutputStream( ); ByteArrayOutputStream(int size); String tostring( ); String tostring(string enc); 27 (3) ByteArrayInputStream ByteArrayOutputStream import java.io.*; class ByteArrayInputOutputTest { public staticvoid main(string[] args) throws IOException { int ch; byte arr[] = { (byte)'j',(byte)'a',(byte)'v',(byte)'a',(byte)'!' ; ByteArrayInputStream in = new ByteArrayInputStream(arr); ByteArrayOutputStream out = newbytearrayoutputstream(); FileOutputStream outfile = newfileoutputstream("bytearrayinputoutputtest.txt"); while((ch=in.read())!= -1) { out.write(ch); System.out.println(" read: ["+(char)ch+"]" +", write: ["+out.tostring () +"]"+out.size()); System.out.println("String: "+out.tostring()); out.writeto(outfile); 28

15 (4) CharArrayReader CharArrayWriter // CharArrayReader CharArrayReader(char[ ] buf); CharArrayReader(char[ ] buf, int offset, int length); //CharArrayWriter CharArrayWriter( ); CharArrayWriter(int initialsize); int size( ); void writeto(write out); (5) CharArrayReader CharArrayWriter import java.io.*; class CharArrayReaderWriterTest { public static voidmain(string[ ] args) throws IOException { int ch; chararr[ ] = { 'H','e','l','l','o',',',' ','J','a','v','a','!' ; CharArrayReaderin; CharArrayWriter out; in = new CharArrayReader(arr, 7, 5); out = newchararraywriter( ); while((ch=in.read( ))!= -1) { out.write(ch); System.out.println("read: ["+(char)ch+"]"+", write: ["+out.tostring()+"]"+out.size( )); System.out.println(" String: "+out.tostring()); 30

16 (6) StringBufferInputStream 1. StringBufferInputStream // StringBufferInputStream(String s); 31 (7) StringBufferInputStream import java.io.*; class StringBufferInputTest { public static void main(string[ ] args) throws IOException { int ch; String s = "Hi~"; StringBufferInputStream in = new StringBufferInputStream(s); while((ch=in.read())!= -1) { System.out.println("read: ["+(char)ch+","+ch+"]"+in.available( )); 32

17 (8) StringReader StringWriter // StringReader StringReader(String s); // StringWriter StringWriter( ); StringWriter(int initialsize); StringBuffer getbuffer( ); String tostring( ); 33 (9) StringReader StringWriter import java.io.*; class StringReaderWriterTest{ publicstatic void main(string[]args) throws IOException { int ch; String s = "Hello, Java!"; StringReader in = newstringreader(s); StringWriter out = newstringwriter(s.length()/2); in.skip(7); while((ch=in.read())!= -1) { out.write(ch); System.out.println("read: ["+(char)ch+"]" +", write: ["+out.tostring()+"]" +out.getbuffer().length()); System.out.println(" out: "+out.tostring()); System.out.println(" out: "+out.getbuffer().reverse()); in = newstringreader(out.tostring()); CharArrayWriterout2 = newchararraywriter(); while((ch=in.read())!= -1) { out2.write(ch); System.out.println("read: ["+(char)ch+"]"+", write: ["+out2.tostring()+"]"+out2.size() out2.writeto(out); System.out.println(" out: "+out.tostring()); System.out.println("out2: "+out2.tostring()); 34

18 (1) 1. : FilterInputStream / FilterOutputStream FilterReader / FilterWriter 2. : BufferedInputStream / BufferedOutputStream, BufferedReader / BufferedWriter 3. : DataInputStream / DataOutputStream 4. : LineNumberInputStream / LineNumberReader 5. : PushbackInputStream / PushbackReader 6. : PrintStream / PrintWriter Java Program FilterInputStream FilterOutputStream InputStream OutputStream <Filter > Data Source / Destination 35 (2) FilterInputStream FilterOutputStream FilterReader FilterWriter 36

19 (3) BufferedInputStream mark reset BufferedOutputStream BufferedReader BufferedWriter 37 (4) DataInputStream, DataOutputStream 38

20 (5) LineNumberInputStream JDK1.1 LineNumberReader LineNumberReader LineNumberInputStream 39 (5) import java.io.*; class LineNumberInputTest { public static voidmain(string[]args) { int ch, i=-1; LineNumberInputStream in=null; try { FileInputStream fin = newfileinputstream("test.java"); in = new LineNumberInputStream(fin); catch(filenotfoundexceptione) { System.out.println(e); try { while((ch=in.read())!= -1) { if(i!= in.getlinenumber()) { i = in.getlinenumber(); if(i >= 10) { in.setlinenumber(0); i = in.getlinenumber(); System.out.print("currline: "+i+", "); System.out.println(); catch(ioexceptione) { System.out.println(e); 40

21 (6) PushbackInputStream PushbackReader 41 (6) import java.io.*; class PushbackInputTest { public static int readnum(pushbackinputstream in) { int i, ch; i=0; try { while(((ch=in.read())!= -1)&((ch >= '0')&&(ch <= '9'))) { i = (i * 10) + (ch - '0'); in.unread(ch); catch(ioexception e) { System.out.println(e); return(i); 42

22 (6) ( ) public static voidmain(string[ ] args) { int ch, i=-1; int op1, op2; charopr='\u0000'; PushbackInputStream in=new PushbackInputStream(System.in); op1 = readnum (in); try { opr = (char)in.read( ); catch(ioexception e) { System.out.println(e); op2 = readnum (in); switch(opr) { case '+': System.out.println(op1+" "+opr+" "+op2+" = "+(op1+op2)); break; case '-': System.out.println(op1+" "+opr+" "+op2+" = "+(op1-op2)); break; case '*': System.out.println(op1+" "+opr+" "+op2+" = "+(op1*op2)); break; case '/': System.out.println(op1+" "+opr+" "+op2+" = "+(op1/op2)); break; 43. ObjectInputStream ObjectOutputStream 44

23 ObjectInputStream / ObjectOutputStream, ObjectInput / ObjectOutput 45 ObjectInput DataInout // ObjectInput int available( ); int read( ); int read(byte[ ] b); // //. //. int read(byte[ ] b, int off, int len); //. Object readobject( ); //. long skip(long n); void close( ); //. //. 46

24 ObjectOutput DataOutput // ObjectOutput void write(byte[ ] b); void write(byte[ ] b, int off, int len); void write(int b); // // void writeobject(object obj); // void flush( ); void close( ); // flush //. // 47 ObjectInputStream ObjectOutputStream // ObjectInputStream FileInputStream istream = new FileInputStream( t.tmp ); ObjectInputStream p = new ObjectInputStream(istream); int i = p.readint( ); String today = (String)p.readObject( ); Date data = (Date)p.readObject( ); istream.close( ); 48

25 ObjectOutputStream // ObjectOutputStream FileOutputStream ostream = new FileOutputStream( t.tmp ); ObjectOutputStream p = new ObjectOutputStream(ostream); p.writeint(12345); p.writeobject( Today ); p.writeobject(new Date( )); p.flush( ); ostream.close( ); 49 Serializable. Serializable wirteobject readobject Externalizable Serializable writeexternal readexternal 50

26 import java.io.*; class ObjectData implements Serializable { String name; int age; float height; private void readobject(objectinputstream stream) throws IOException, ClassNotFoundException { stream.defaultreadobject(); System.out.print(" readobject: "); public ObjectData () { this("noname", 0, 0.0f); public ObjectData (String name, int age, float height) { this.name = name; this.age = age; this.height = height; public String tostring() { return("name: "+name+", age: "+age+", height: " + height); class ObjectInputOutputTest { public static void main(string[] args) { ObjectData [] data = new ObjectData [3]; private void writeobject(objectoutputstream stream) throws IOException { stream.defaultwriteobject(); System.out.print("writeObject: "); data[0] = new ObjectData ("Yongwoo", 26, 168f); data[1] = new ObjectData ("Kildong ", 19, 174.8f); data[2] = new ObjectData ("Dongsoo ", 30, 169.4f); try { FileOutputStream outf = new FileOutputStream("ObjectInputOutputTest.txt"); ObjectOutput out = newobjectoutputstream(outf); 51 ( ) out.writeint(data.length); System.out.println("Number: "+data.length); for(int i=0;i<data.length;i++) { out.writeobject(data[i]); System.out.println(data[i]); out.close(); FileInputStream inf = new FileInputStream("ObjectInputOutputTest.txt"); ObjectInput in = new ObjectInputStream(inf); int numberofdata ; ObjectData objdata ; numberofdata = in.readint(); System.out.println("Number: "+numberofdata ); for(int i=0;i<numberofdata ;i++) { objdata = (ObjectData )in.readobject(); System.out.println(objData); in.close(); catch(exception e) { e.printstacktrace(); 52

27 RandomAccessFile,.., RandomAccessFile 53 RandomAccessFile // RandomAccessFile RandomAccessFile(String name, String mode); RandomAccessFile(File file, String mode); void seek(long pos); // long getfilepointer( ); // long length( ); // 54

28 RandomAccessFile import java.io.*; publicclass RandomAccessFileTest { public staticvoid main(string[ ] args)throws IOException { RandomAccessFile f; f = newrandomaccessfile("randomaccessfile.txt", "rw"); for(int i=0;i<100;i++) { f.writeint(i); for(int i=0;i<10;i++) { int accpointer= (int)(math.random( )*100); f.seek(accpointer* 4); System.out.print("Current FP: " + f.getfilepointer( )); System.out.println(", Data: " + f.readint( )); f.close(); C:\>javac RandomAccessFileTest.java C:\>java RandomAccessFileTest Current FP: 20, Data: 5 Current FP: 72, Data: 18 Current FP: 256, Data: 64 Current FP: 104, Data: 26 Current FP: 304, Data: 76 Current FP: 40, Data: 10 Current FP: 96, Data: 24 Current FP: 168, Data: 42 Current FP: 96, Data: 24 Current FP: 324, Data: 81 C:\> 55