Java IO. Streams
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alexey-bovanenko -
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Presentation about java streams. Byte streams, character streams and etc.
Transcript of Java IO. Streams
- 1. Java java.io
2.
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- , ( ), ( )
3. java.io
- java.io
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- InputStream / OutputStream
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- FileInputStream / FileOutputStream
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- BufferedInputStream / BufferedOutputStream
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- InputStreamReader / OutputStreamWriter
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- FileReader / FileWriter
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- BufferedReader / BufferedWriter
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- StringReader / StringWriter
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- DataInputStream / DataOutputStream
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- ObjectInputStream/ ObjectOutputStream
4. FileInputStream
- class FileInputStream extends InputStream
- public FileInputStream(String name) throws FileNotFoundException
- public FileInputStream(File file) throws FileNotFoundException
- public FileInputStream(FileDescriptor fdObj)
- public native int read() throws IOException
- private native int readBytes(byte b[], int off, int len) throws IOException
- public int read(byte b[]) throws IOException
- public int read(byte b[], int off, int len) throws IOException
- public native long skip(long n) throws IOException
- public native int available() throws IOException
- public void close() throws IOException
- public FileChannel getChannel()
- public boolean markSupported()
- public synchronized void reset() throws IOException
- public synchronized void mark(int readlimit)
5. FileOutputStream
- class FileOutputStream extends OutputStream
- public FileOutputStream(String name) throwsFileNotFoundException
- public FileOutputStream(String name, boolean append)throws FileNotFoundException
- public FileOutputStream(File file) throws FileNotFoundException
- public FileOutputStream(File file, boolean append) throws FileNotFoundException
- public FileOutputStream(FileDescriptor fdObj)
- public native void write(int b) throws IOException
- public void write(byte b[]) throws IOException
- public void write(byte b[], int off, int len) throws IOException
- public void close() throws IOException
- public void flush() throws IOException
6. ( read() write(int))
- try{ // try try{ // fo=new FileOutputStream("out.txt"); int l=s.length(); int i=0; while(i
7. ()
- try{ // fi=new FileInputStream("out.txt"); int i=0; StringBuilder sb=new StringBuilder(); while((i=fi.read())!=-1) { sb.append(Character.toChars(i)); } System.out.println("Received from file: "+sb.toString()); }finally{ if(fi!=null) fi.close(); } }catch(FileNotFoundException e) // try { System.out.println(e); }catch(IOException e) // try { System.out.println(e); }
8. ( read(byte[]) write(byte[]))
- try{// try try{ // fo=new FileOutputStream("out.txt"); int l=s.length(); int i=0; byte[] b=s.getBytes(); fo.write(b); }finally{ if(fo!=null) fo.close(); }
9. ()
- try{ // fi=new FileInputStream("out.txt"); int i=fi.available(); byte[] b=new byte[i]; fi.read(b); String s1=new String(b); System.out.println("Received from file: "+s1); }finally{ if(fi!=null) fi.close(); } }catch(FileNotFoundException e) // try { System.out.println(e); }catch(IOException e) // try { System.out.println(e); }
10. ( read(byte[], int, int) write(byte[], int , int))
- try{ // try try{ // fo=new FileOutputStream("out.txt"); int l=s.length(); int i=0; byte[] b=s.getBytes(); fo.write(b,0,b.length); }finally{ if(fo!=null) fo.close(); }
11. ()
- try{// fi=new FileInputStream("out.txt"); int i=fi.available(); byte[] b=new byte[i]; fi.read(b,0,i); String s1=new String(b); System.out.println("Received from file: "+s1); }finally{ if(fi!=null) fi.close(); } }catch(FileNotFoundException e) // try { System.out.println(e); }catch(IOException e) // try { System.out.println(e); }
12. BufferedInputStream
- class BufferedInputStream extends FilterInputStream
- public BufferedInputStream(InputStream in)
- public BufferedInputStream(InputStream in, int size)
- public synchronized int read() throws IOException
- public synchronized int read(byte b[], int off, int len) throws IOException
- public synchronized long skip(long n) throws IOException
- public synchronized int available() throws IOException
- public synchronized void mark(int readlimit)
- public synchronized void reset() throws IOException
- public boolean markSupported()
- public void close() throws IOException
13. BufferedOutputStream
- class BufferedOutputStream extends FilterOutputStream
- public BufferedOutputStream(OutputStream out)
- public BufferedOutputStream(OutputStream out, int size)
- public synchronized void write(int b) throws IOException
- public synchronized void write(byte b[], int off, int len) throws IOException
- public synchronized void flush() throws IOException
14. BufferedInputStream/BufferedOutputStream
- try{ // try try{ // bo=new BufferedOutputStream(new FileOutputStream("out.txt")); byte[] b=new byte[s.length()]; b=s.getBytes(); bo.write(b,0,b.length); }finally{ if(bo!=null) bo.close(); }
15. ()
- try{// bi=new BufferedInputStream(new FileInputStream("out.txt")); int i=bi.available(); byte[] b=new byte[i]; bi.mark(i); bi.read(b, 0, i); bi.reset(); String s1=new String(b); bi.read(b, 0, i); String s2=new String(b); System.out.println(s1+" "+s2); }finally{ if(bi!=null) bi.close(); } }catch(Exception e){ // try System.out.println(e); }
16. InputStreamReader
- public class InputStreamReader extends Reader
- public InputStreamReader(InputStream in)
- public InputStreamReader(InputStream in, String charsetName)
- public InputStreamReader(InputStream in, Charset cs)
- public InputStreamReader(InputStream in, CharsetDecoder dec)
- public String getEncoding()
- public int read() throws IOException
- public int read(char cbuf[]) throws IOException
- public int read(char cbuf[], int offset, int length) throws IOException
- public boolean ready() throws IOException
- public void close() throws IOException
17. OutputStreamWriter
- class OutputStreamWriter extends Writer
- public OutputStreamWriter(OutputStream out, String charsetName) throws UnsupportedEncodingException
- public OutputStreamWriter(OutputStream out)
- public OutputStreamWriter(OutputStream out, Charset cs)
- public OutputStreamWriter(OutputStream out, CharsetEncoder enc)
- public String getEncoding()
- public void write(int c) throws IOException
- public void write(char cbuf[], int off, int len) throws IOException
- public void write(String str) throws IOException
- public void write(String str, int off, int len) throws IOException
- public void flush() throws IOException
- public void close() throws IOException
18. OutputStreamWriter/InputStreamReader
- try{ // try try{ // or=new OutputStreamWriter(new BufferedOutputStream(new FileOutputStream("out.txt")),"KOI8-R"); or.write(s); }finally{ if(or!=null) or.close(); }
19. ()
- try{ // ir=new InputStreamReader(new BufferedInputStream(new FileInputStream("out.txt")),"KOI8-R"); char[] b=new char[1024]; int i=0; StringBuilder sb=new StringBuilder(); while((i=ir.read(b))!=-1) { sb.append(b, 0, i); } System.out.println("Result: "+sb.toString()); }finally{ if(ir!=null) ir.close(); } }catch(Exception e) // try { System.out.println(e); }
20. FileReader
- class FileReader extends InputStreamReader
- public FileReader(String fileName) throws FileNotFoundException
- public FileReader(File file) throws FileNotFoundException
- public FileReader(FileDescriptor fd)
21. FileWriter
- class FileWriter extends OutputStreamWriter
- public FileWriter(String fileName) throws IOException
- public FileWriter(String fileName, boolean append) throws IOException
- public FileWriter(File file) throws IOException
- public FileWriter(File file, boolean append) throws IOException
- public FileWriter(FileDescriptor fd)
22. FileReader FileWriter
- try{// try try{ // fw=new FileWriter("out.txt");fw.write(s);
- }finally{
- if(fw!=null)
- fw.close();
- }
23. ()
- try{
- fr=new FileReader("out.txt");
- char[] b=new char[1024];
- int i=0;
- StringBuilder sb=new StringBuilder();
- while((i=fr.read(b))!=-1)
- {
- sb.append(b, 0, i);
- }
- System.out.println(sb.toString());
- }finally{
- if(fr!=null)
- fr.close();
- }
- }catch(Exception e)
- {
- System.out.println(e);
- }
24. BufferedReader
- class BufferedReader extends Reader
- public BufferedReader(Reader in, int sz)
- public BufferedReader(Reader in)
- public int read() throws IOException
- public int read(char cbuf[], int off, int len) throws IOException
- String readLine(boolean ignoreLF) throws IOException
- public String readLine() throws IOException
- public long skip(long n) throws IOException
- public boolean ready() throws IOException
- public boolean markSupported()
- public void mark(int readAheadLimit) throws IOException
- public void reset() throws IOException
- public void close() throws IOException
25. BufferedWriter
- class BufferedWriter extends Writer
- public BufferedWriter(Writer out)
- public BufferedWriter(Writer out, int sz)
- public void write(int c) throws IOException
- public void write(char cbuf[], int off, int len) throws IOException
- public void write(String s, int off, int len) throws IOException
- public void newLine() throws IOException
- public void flush() throws IOException
- public void close() throws IOException
26. BufferedReader/BufferedWriter
- try{ // try try{ // bw=new BufferedWriter(new FileWriter("out.txt")); bw.write(s);}finally{ if(bw!=null) bw.close(); } try{ // br=new BufferedReader(new FileReader("out.txt")); String s1=br.readLine(); System.out.println(s1); }finally{ if(br!=null) br.close(); } }catch(Exception e) // try { System.out.println(e); }
27. DataInputStream
- class DataInputStream extends FilterInputStream implements DataInput
- public DataInputStream(InputStream in)
- void readFully(byte b[]) throws IOException
- void readFully(byte b[], int off, int len) throws IOException
- int skipBytes(int n) throws IOException
- boolean readBoolean() throws IOException
- byte readByte() throws IOException
- int readUnsignedByte() throws IOException
- short readShort() throws IOException
- int readUnsignedShort() throws IOException
- char readChar() throws IOException
- int readInt() throws IOException
- long readLong() throws IOException
- float readFloat() throws IOException
- double readDouble() throws IOException
- String readLine() throws IOException
28. DataOutputStream
- class DataOutputStream extends FilterOutputStream implements DataOutput
- public DataOutputStream(OutputStream out)
- void write(int b) throws IOException
- void write(byte b[]) throws IOException
- void write(byte b[], int off, int len) throws IOException
- void writeBoolean(boolean v) throws IOException
- void writeByte(int v) throws IOException
- void writeShort(int v) throws IOException
- void writeChar(int v) throws IOException
- void writeInt(int v) throws IOException
- void writeLong(long v) throws IOException
- void writeFloat(float v) throws IOException
- void writeDouble(double v) throws IOException
- void writeBytes(String s) throws IOException
- void writeChars(String s) throws IOException
29. DataInputStream/DataOutputStream
- int i=10; char c='a'; boolean b=true; float f=10.6f; String s="Hello"; try{ try{ dout=new DataOutputStream(new FileOutputStream("out2.txt")); dout.writeInt(i); dout.writeChar(c); dout.writeBoolean(b); dout.writeFloat(f); dout.writeUTF(s); }finally{ if(dout!=null) dout.close(); }
30. ()
- try{ di=new DataInputStream(new FileInputStream("out2.txt")); int j=di.readInt(); char c1=di.readChar(); boolean b1=di.readBoolean(); float f1=di.readFloat(); String s1=di.readUTF(); System.out.println("Int: "+j+" char: "+c1+" bool: "+b1+" float: "+f1+" Str: "+s1); }finally{ if(di!=null) di.close(); }}catch(Exception e) { System.out.println(e); }
31. ObjectInputStream
- class ObjectInputStream extends InputStream implements ObjectInput, ObjectStreamConstants
- public ObjectInputStream(InputStream in) throws IOException
- public final Object readObject()throws IOException, ClassNotFoundException
32. ObjectOutputStream
- class ObjectOutputStream extends OutputStream implements ObjectOutput, ObjectStreamConstants
- public ObjectOutputStream(OutputStream out) throws IOException
- public final void writeObject(Object obj) throws IOException
33. ObjectInputStream/ObjectOutputStream
- TestClass tc=new TestClass(10,"Hello, world"); System.out.println(tc); try{ try{ oo=new ObjectOutputStream(new BufferedOutputStream(new FileOutputStream("out3.txt"))); oo.writeObject(tc); }finally{ if(oo!=null)oo.close(); } try{ oi=new ObjectInputStream(new BufferedInputStream(new FileInputStream("out3.txt"))); TestClass ttt=(TestClass)oi.readObject(); System.out.println(ttt); }finally{ if(oi!=null)oi.close(); } }catch(Exception e){ System.out.println(e); }
34. e-mail: [email protected]