课件课后练习代码-经典案例

JavaSE02断点续传工具——DownloadInfo类编写以及TestHttpDownloadtestHttpDownload1方断点续传工具——DownloadInfo序列断点续 工具——DownloadInfo的fetchFileSize方法DownloadThread断点续 工具——完成DownloadFrame的UI及DownloadItem内部 多个文件，的过程中可以临时终止，可以随时继续 图-图-图-图-图-图-

图-图-可以多个要的文件，同时，如图-9所示图-privateStringprivatelongpos;privatelongfileSize;privateStringDownloadInfoinfo=newURLurl=newHttpURLConnectioncon=(HttpURLConnection)url.openConnection();InputStreamis=con.getInputStream();RandomAccessFileraf=newbyte[]buffer=newbyte[BUFFER_SIZE];intb=-1;while((b=is.read(buffer))!=-{raf.write(buffer,0,b);info.setPos(info.getPos()+b);}publicclassDownloadInfoprivateStringprivatelongprivatelongprivateStringfileName;publicDownloadInfo(Stringurl,StringfileName)this.url=this.fileName= publicStringgetUrl()return publicvoidsetUrl(Stringurl)this.url= publiclonggetPos()return publicvoidsetPos(longpos)this.pos= publicStringgetFileName()return publicvoidsetFileName(StringfileName)this.fileName= publiclonggetFileSize()return publicvoidsetFileSize(longfileSize)this.fileSize= }}publicvoidtestHttpDownload1()intBUFFER_SIZE=1024*tryDownloadInfoinfo= URLurl=newHttpURLConnectioncon=(HttpURLConnection)Stringprop="bytes="+info.getPos()+"-con.setRequestProperty("RANGE",InputStreamis=RandomAccessFilerafnewbyte[]buffer=newintb=-while((b=is.read(buffer))!=-1)raf.write(buffer,0,info.setPos(info.getPos()+ }catch(Exceptione) }publicvoidtestHttpDownload2()intBUFFER_SIZE=1024*tryDownloadInfoinfo= URLURLurl=newHttpURLConnectioncon=Stringprop="bytes="+con.setRequestProperty("RANGE",InputStreamis=RandomAccessFileraf/2+"-byte[]buffer=newintb=-while((b=is.read(buffer))!=-1)raf.write(buffer,0,info.setPos(info.getPos()+ }catch(Exceptione) }publicclassTestHttpDownloadpublicvoid{intBUFFER_SIZE=1024*tryDownloadInfoinfo=new URLurl=newHttpURLConnectioncon=(HttpURLConnection)Stringprop="bytes="+info.getPos()+"-con.setRequestProperty("RANGE",InputStreamis=RandomAccessFilerafnewbyte[]buffer=newintb=-while((b=is.read(buffer))!=-1)raf.write(buffer,0,info.setPos(info.getPos()+ }catch(Exceptione) }publicvoidtestHttpDownload2()intBUFFER_SIZE=1024*tryDownloadInfoinfo=newURLurl=newHttpURLConnectioncon=(HttpURLConnection)Stringprop="bytes="+info.getFileSize()/2+"-con.setRequestProperty("RANGE",InputStreamis=RandomAccessFilerafnewbyte[]buffer=newbyte[BUFFER_SIZE];intb=-1;while((b=is.read(buffer))!=-1){raf.write(buffer,0,b);info.setPos(info.getPos()+b);}}catch(Exceptione){}}}使DwnlaInf类的对象可序列化，并测试是否能将DonloaInf类的对象序列化到本地文件，并从本地文件反序列化出DonloaInf类的对象。publicclassDownloadInfoimplementsSerializable类的ObjectOutputStreamoos=ObjectOutputStream(newFileOutputStream(tmpFile));ObjectInputStreamois=newObjectInputStream(newDownloadInfoinfo=(DownloadInfo)publicclassDownloadInfoimplementsSerializableprivatestaticfinallongserialVersionUID=privateStringprivatelongprivatelongprivateStringpublicDownloadInfo(Stringurl,StringfileName)this.url=this.fileName= publicStringgetUrl()return publicvoidsetUrl(Stringurl)this.url= publiclonggetPos()return publicvoidsetPos(longpos)this.pos= publicStringgetFileName()return publicvoidsetFileName(StringfileName)this.fileName= publiclonggetFileSize()return}publicvoidsetFileSize(long{this.fileSize=}publicStringtoString()return"DownloadInfo[url="+url+",pos="+pos+",+fileSize+",fileName="+fileName+}}publicclassTestDownloadInfopublicvoid{tryDownloadInfoinfo=newDownloadInfo("FiletmpFile=newFile("obj.tmp");ObjectOutputStreamoos=newObjectOutputStream(new.}catch(ExceptionpublicvoidtestDeserializeObj(){; }tryFiletmpFile=newFile("obj.tmp");ObjectInputStreamois=newObjectInputStream(newDownloadInfoinfo=(DownloadInfo)}catch(Exceptione)}}}publicvoid{tryList<DownloadInfo>infoList=newArrayList<DownloadInfo>();DownloadInfoinfo1=newDownloadInfo("DownloadInfoinfo2=DownloadInfo(",DownloadInfoinfo3=newDownloadInfo(" }new}catch(Exceptione)publicvoid{tryFiletmpFile=newObjectInputStreamois=newObjectInputStream(newFileInputStrList<DownloadInfo>infoList=}catch(Exception{; }publicclassTestDownloadInfopublicvoid{tryDownloadInfoinfo=newDownloadInfo(".FiletmpFile=newObjectOutputStreamoos=newnew}catch(Exceptione)}}publicvoidtestDeserializeObj()tryFiletmpFile=newObjectInputStreamoisObjectInputStream(newDownloadInfoinfo=(DownloadInfo)}catch(Exceptione)}}publicvoidtestSerializeList()tryList<DownloadInfo>infoList=newDownloadInfoinfo1=new ",DownloadInfoinfo2=new"",DownloadInfoinfo3=new ",FiletmpFile=newObjectOutputStreamoos=newnew}catch(Exceptione) publicvoidtestDeserializeList()tryFiletmpFile=newObjectInputStreamois=newObjectInputStream(newList<DownloadInfo>infoList=}catch(Exceptione)}}HttpURLConntection类的getResponseCode获取HTTP*获取 *@returnprivateint{intfileSize=-1;try{URLurl=newHttpURLConnectionconn=(HttpURLConnection)url.openConnectionintstateCode=conn.getResponseCode();if(stateCode=={fileSize=conn.getContentLength();returnfileSize;}}catch(MalformedURLException{}catch(IOException{}return}创建DonloaTha类，使其继承Thad类，覆盖un方法来实现线程体，程体中实现文件其中用DnlaInf类的p属性记录文件的位置。publicvoidrun()while(!isStop()&&{tryURLurl=newURL(info.getUrl());HttpURLConnectioncon=(HttpURLConnection)url Stringprop="bytes="+info.getPos()+"- con.setRequestProperty("RANGE", InputStreamis= raf=newRandomAccessFile(info.getFileName(), byte[]buffer=new intb=- while((b=is.read(buffer))!=-1&&!isStop()) raf.write(buffer,0, info.setPos(info.getPos()+ intpercent=(int)(100*info.getPos()/ System.out.println(info.getFileName()+"已 +percent+ if(!isStop())isFinish=}}catch{}catch(IOExceptione)}finallytry}catch(IOExceptione)}}}}publicclassDownloadInfoimplementsSerializableprivatestaticfinallongserialVersionUID=privateStringprivatelongprivatelongprivateStringpublicDownloadInfo(Stringurl,StringfileName)this.url=this.fileName=this.fileSize=}publicStringgetUrl()return}publicvoidsetUrl(Stringurl)this.url=}publiclonggetPos()return}publicvoidsetPos(longpos)this.pos=}publicStringgetFileName()return}publicvoidsetFileName(StringfileName)this.fileName=}publiclonggetFileSize()return}publicvoidsetFileSize(longfileSize)this.fileSize=}publicStringtoString()return"DownloadInfo[url="+url+",pos="pos+",+fileSize+",fileName="+fileName *获取 *@returnprivateint{intfileSize=-1;try{URLurl=newHttpURLConnectionconn=(HttpURLConnection)url.openConnectionintstateCode=conn.getResponseCode();if(stateCode=={fileSize=conn.getContentLength();returnfileSize;}}catch(MalformedURLException{}catch(IOException{}return}}publicclassDownloadThreadextendsThreadprivateDownloadInfoprivateRandomAccessFileprivatebooleanisStop=privatebooleanisFinish=privatestaticintBUFFER_SIZE=8*1024;publicDownloadThread(DownloadInfoinfo){=}publicsynchronizedbooleanisFinish()return publicsynchronizedvoidsetStop(booleanisStop)this.isStop= publicsynchronizedbooleanisStop()return publicvoidrun()while(!isStop()&&!isFinish())tryURLurl=newHttpURLConnectioncon=(HttpURLConnection)Stringprop="bytes="+info.getPos()+"-con.setRequestProperty("RANGE",InputStreamis=raf=newRandomAccessFile(info.getFileName(),byte[]buffer=newintb=-while((b=is.read(buffer))!=-1&&!isStop())raf.write(buffer,0,info.setPos(info.getPos()+intpercent=(int)(100*info.getPos()/System.out.println(info.getFileName()+"已 +percent+ if(!isStop()) isFinish= }catch(MalformedURLExceptione)}catch(IOExceptione)}finallytry}catch(IOExceptione)}}}}}创建eDonlaTha类，在ain方法中，创建两个DwnlaTha类的对象，调用该类的a方法，启动两个线程测试多线程。publicclassTestDownloadThreadpublicstaticvoidmain(String[]args)DownloadInfoinfo1=newDownloadInfoinfo2=newDownloadInfo(DownloadThreadthread1=newDownloadThread(info1);DownloadThreadthread2=newDownloadThread(info2);}}创建Donloaae类，继承Ja类，用来表示断点续传工具的界面。在该类中创建内部类PoPanel，表示的进度条Panl。在Donloaame类中创建内部类DwnlaI使其实现序列化接口，表示一个项的所有信息和操作。在Dwnlaam类中创建aTabPan方法，ini方法，aonnPan方法以及构造方法初始化界面。publicclassDownloadFrameextendsprivateclassProgressPanelextendsJPanelprivateintonline;publicProgressPanel(){}publicvoidpaint(Graphics{for(inti=0;i<online;{g.fill3DRect(6+i*4,8,3,16,} privateclassDownloadItemimplementsSerializableprivatestaticprivatestaticfinalprivatestaticintSTATUS_INIT1;intSTATUS_START2;//开始状态，按钮上显示intSTATUS_STOP=3;//停止状态，按钮上显示ProgressPanelprogressPanel;JLabellabel;JButtonbutton; DownloadInfo transientDownloadThread intstatus;//当 voidsetActionListener()button.addActionListener(newActionListener()publicvoidactionPerformed(ActionEvente)switch(status)caseStringurl="请输 地址if(url==null||url.length()==StringfileName=if(fileName==null||url.length()==Filefile=newtry//创建 //创建 info=newDownloadInfo(url,//创 线thread=new//设 状}catch(IOExceptione1) case case thread=new voidinit()status= 的文件 voidstart()status= voidstop()status= voidupdate()if(thread!=null)if(thread.isFinish()) }elseif(info.getFileSize()!=-1)intpercent=(int)(info.getPos()*100/progressPanel.online=label.setText("文件："+info.getFileName()+"正 中 +percent+}elselabel.setText("文件："+info.getFileName()+"正 中}publicDownloadItem()}}}}}在DownloadFrame类中定义THREAD_NUM常量，表示同时的文件数量；定义List类型}}}privatestaticfinalintTHREAD_NUM=privateList<DownloadItem>itemList=new在DownloadFrame类中创建createTabPane方法和createContentPaneprivateJPanelcreateTabPane()JPanelp=newJPanel(newGridLayout(10,1,6,6));p.setBackground(newColor(35,31,p.setBorder(newEmptyBorder(8,8,8,for(inti=0;i<THREAD_NUM;i++){DownloadItemitem=newDownloadItem();//JLabellabel=newitem.label=label;//JButtonbtn=newJButton();btn.setForeground(newColor(249,250,251));btn.setBackground(newColor(220,31,36));item.button=btn;//ProgressPanelpp=newgressPanel=JPanelp1=newJPanel(newBorderLayout(6,p1.setBackground(newColor(35,31,32));p1.add(BorderLayout.EAST,btn);p1.add(BorderLayout.CENTER,pp);}return}privateComponentcreateContentPane()JPanelp=newJPanel(newBorderLayout());p.setBackground(newColor(35,31,32));p.add(BorderLayout.CENTER,createTabPane());returnp;}publicDownloadFrame()setSize(500,400);}守护线程，用来更新项的显示信息。privateclassInnerThreadextendsThreadpublicInnerThread(){}publicvoidrun(){while(true){tryfor(inti=0;i<itemList.size();i++){}}catch(InterruptedExceptione)}}}}在DownloadFrame类中定义innerThread属性，该属性使用transient关键字修饰，序列化DownloadFrame类时，不序列化innerThread属性；定义downloadInfoFile常量，设置序列化privatetransientInnerThreadinnerThread=newprivatestaticfinalStringdownloadInfoFile=privatestaticvoidsave(DownloadFrameframe)Filefile=newFile(downloadInfoFile);System.out.println("save:"+file);try{}catch(IOException{ }ObjectOutputStreamoos=newnewObjectOutputStreamoos=newnewFileOutputStream(file));privateprivatestaticDownloadFrameload()Filefile=newifreturnnull;else{System.out.println("load:"+}tryObjectInputStreamois=newObjectInputStream(newDownloadFrameframe=(DownloadFrame)}cuEonreturn} publicvoidinit()this.addWindowListener(new{publicvoidwindowClosing(WindowEvente)(itemList!=null&&itemList.size()>{for(DownloadItemitem:itemList)if(item.status==DownloadItem.STATUS_START)}}}}(itemList!=null&&itemList.size()>for(DownloadItemitem:itemList){}{}innerThread=newInnerThread();}publicstaticvoidmain(String[]args)DownloadFrameframe=load();if(frame==null){frame=new}}publicclassDownloadInfoimplementsSerializableprivatestaticfinallongserialVersionUID=privateStringprivatelongprivatelongprivateStringfileName;publicDownloadInfo(Stringurl,StringfileName)this.url=this.fileName=this.fileSize= publicStringgetUrl()return publicvoidsetUrl(Stringurl)this.url= publiclonggetPos()return publicvoidsetPos(longpos)this.pos=}publicStringgetFileName()return}publicvoidsetFileName(String{this.fileName=}publiclonggetFileSize()return publicvoidsetFileSize(longfileSize)this.fileSize=}*获取要文件的大*privateintfecthFileSize()intfileSize=-tryURLurl=newHttpURLConnectionconn=intstateCode=if(stateCode=={fileSize=return}}catch(MalformedURLExceptione)}catch(IOExceptione)}return}}publicclassDownloadThreadextendsThreadprivateprivateprivateprivateprivateDownloadInfoRandomAccessFileraf;booleanisStop=false;booleanisFinish=false;staticintBUFFER_SIZE=8*publicDownloadThread(DownloadInfoinfo)= publicsynchronizedbooleanisFinish()return publicsynchronizedvoidsetStop(booleanisStop)this.isStop= publicsynchronizedbooleanisStop()return publicvoidrun()while(!isStop()&&!isFinish())tryURLurl=newURL(info.getUrl()); HttpURLConnectioncon=(HttpURLConnection) Stringprop="bytes="+info.getPos()+"- con.setRequestProperty("RANGE", InputStreamis=con.getInputStream(); raf=newRandomAccessFile(info.getFileName(), byte[]buffer=new intb=- while((b=is.read(buffer))!=-1&&!isStop()) raf.write(buffer,0, info.setPos(info.getPos()+}if(!isStop())isFinish=}}catch{}catch(IOExceptione)}finallytry}catch(IOExceptione)}}}}}publicclassDownloadFrameextendsJFrameprivateprivateprivatestaticfinalintTHREAD_NUM=List<DownloadItem>itemList=newArrayList<DownloadItem>();transientInnerThreadinnerThread=newInnerThread();privatestaticfinalStringdownloadInfoFile=publicDownloadFrame()setSize(500,400);}public{this.addWindowListener(newpublicvoidwindowClosing(WindowEvente)if(itemList!=null&&itemList.size()>0)for(DownloadItemitem:itemList)if(item.status==DownloadItem.STATUS_START) (itemList!=null&&>{for(DownloadItemitem:itemList)}}innerThread=new}privateComponentcreateContentPane()JPanelp=newJPanel(newp.setBackground(newColor(35,31,p.add(BorderLayout.CENTER,return}privateJPanelcreateTabPane()JPanelp=newJPanel(newGridLayout(10,p.setBackground(newColor(35,31,p.setBorder(newEmptyBorder(8,8,8,for(inti=0;i<THREAD_NUM;i++)DownloadItemitem=new//JLabellabel=newitem.labelitem.label=//JButtonbtn=newbtn.setForeground(newColor(249,250,btn.setBackground(newColor(220,31,item.button=btn;//ProgressPanelpp=newgressPanel=pp;JPanelp1=newJPanel(newBorderLayout(6,p1.setBackground(newColor(35,31,p1.add(BorderLayout.EAST,p1.add(BorderLayout.CENTER, return privateclassProgressPanelextendsJPanelprivateintpublicProgressPanel()}publicvoidpaint(Graphicsg)f