Java程序设计教学课件-第九章 IO读和写.ppt

第9章I/O：读和写,华中科技大学IBM技术中心,华中科技大学IBM技术中心,HUSTclassCopyprivatevoidcopy(InputStreamin,OutputStreamout)throwsIOExceptionbytebuf=newbyte4096;intlen=in.read(buf);while(len!=-1)out.write(buf,0,len);len=in.read(buf);publicvoidcat(Stringfsrc,Stringfdest)tryInputStreamin=newFileInputStream(fsrc);OutputStreamout=newFileOutputStream(fdest,true);copy(in,out);out.close();in.close();catch(IOExceptionex)System.err.println(ex);,华中科技大学IBM技术中心,HUSTc.cat(“in.dat”,”out.dat”);,华中科技大学IBM技术中心,HUSTpublicclassByteArrayOutputStreamTestpublicstaticvoidmain(Stringargs)tryByteArrayOutputStreambaos=newByteArrayOutputStream();PrintStreamps=newPrintStream(baos);for(inti=0;i1000;i+)ps.println(i+ABCDEFGHIJKLMNOPQRSTUVWXYZ);longstart=System.currentTimeMillis();FileOutputStreamfos=newFileOutputStream(ByteArrayOutputStreamTest);baos.writeTo(fos);fos.close();longstop=System.currentTimeMillis();System.out.println(timeelapsed(milliseconds)=+(stop-start);catch(FileNotFoundExceptionfnfe)System.out.println(fnfe.getMessage();catch(IOExceptionioe)System.out.println(ioe.getMessage();,华中科技大学IBM技术中心,HUSTPipedOutputStream(PipedInputStreampis);通过各自的connect()方法连接：在类PipedInputStream中，connect(PipedOutputStreampos);在类PipedOutputStream中，connect(PipedInputStreampis);,华中科技大学IBM技术中心,HUSTPipedInputStreampis=newPipedInputStream();PipedOutputStreampos=newPipedOutputStream(pis);System.out.println(PipedInputStream);trypos.write(dataA);pos.write(dataB);System.out.println(byte)pis.read();System.out.println(byte)pis.read();finallypis.close();pos.close();,华中科技大学IBM技术中心,HUSTpublicclassReadLineTestpublicstaticvoidmain(Stringargs)tryBufferedReaderbr=newBufferedReader(newFileReader(args0);Stringline=null;inti=0;while(line=br.readLine()!=null)i+;System.out.println(i+:+line);br.close();catch(Exceptione)e.printStackTrace();,华中科技大学IBM技术中心,HUSTpublicclassFileTestpublicstaticvoidmain(Stringargs)throwsIOExceptionRandomAccessFileraf=newRandomAccessFile(foo.txt,rw);tryWriterout=newOutputStreamWriter(newFileOutputStream(raf.getFD(