请教java多线程死机问题

Question

请各位高手指教，问题详情如下： 我是用eclipse写的java程序，可以同时连接多个读卡器，对多张卡同时执行写卡操作。我对每个读卡器创建了一个线程，程序开始后，多个线程同时启动，轮流排队对每个读卡器进行写卡操作，写卡命令会在屏幕上显示，所以多张卡会在差不多的时间点写完。 
问题是我的程序同时写5张卡基本上没什么问题，但是同时写6张以上的卡时在写到40分钟左右的时候，CPU的使用率就逐渐累加，从10%到20%，然后到40%-50%，之后就会死掉了，没有任何错误提示，都是在发了一条命令后不显示返回数据，然后程序的UI就不动了，但是电脑上的其他程序都是正常的。程序死掉时偶尔会有卡片已经写卡成功，但多数情况下是所有的卡片都没有完成写卡。 eclipse中的VM参数为-Xmx1024m，运行程序的电脑内存为2G。我把程序打包成可执行的jar文件，copy到别的机器上运行。 
我自己的机器是2G内存，其他配置比较高，有时候能同时写成功6张和6张以上的卡，但是在另外一台老机器上就不行，那台机器的内存也是2G，但是其他的配置就比较低了。 读卡器都是连在一个带电源的USB hub上，所以排除了USB口供电不足的问题。 
还有写卡的数据量挺大的，每张卡要写4块程序区，1块数据区，每块区域都是从0000到FFFF，每条命令写0x80个字节，所以每张卡要发2500多次命令。 
我的程序中没有对线程做终止处理，也没有调用isAlive()之类的函数判断线程是否还处于活动状态.

Answer 1

关键的函数如下： main（）如下：         public static void main(String[] args) { 
                try{ 
                        UIManager.setLookAndFeel( 
                                        UIManager.getSystemLookAndFeelClassName()); 
                }catch(Exception e){ 
                        throw new RuntimeException(e); 
                } 
                // TODO Auto-generated method stub 
                SwingUtilities.invokeLater(new Runnable() { 
                        public void run() { 
                                WriteCardByPCSCMain application = new WriteCardByPCSCMain(); 
                                application.getJFrame().setVisible(true); 
                        } 
                }); 
        } 
调用线程的函数： 
        private List <ExecuteThread>  executeThreads = new ArrayList <ExecuteThread>();          public JButton getExeBtn() { 
                if (exeBtn == null) { 
                        exeBtn = new JButton("Execute"); 
                        exeBtn.setBounds(new Rectangle(190, 332, 90, 30)); 
                        exeBtn.setBackground(Color.green); 
                        exeBtn.addActionListener(new ActionListener() { 
                                public void actionPerformed(ActionEvent e) { 
                                        exeBtn.setEnabled(false); 
                                        exeBtn.setBackground(Color.red); 
                                        refreshBtn.setEnabled(false); 
                                        //connBtn.setEnabled(false); 
                                        countNum = 0; 
                                        errorNum=0; 
                                        AddorClearTabPane addorclearTabPane =new AddorClearTabPane();                                                                        if(listModel.size() == 0){ 
                                                JOptionPane.showMessageDialog(null,"没有连接读卡器，请确认。"); 
                                                exeBtn.setEnabled(true); 
                                                refreshBtn.setEnabled(true); 
                                                return; 
                                        } 
                                        
                                        if(executeThreads.size() > 0)                                                                
                                        TabPane.clearRunLog(executeThreads.size()); 
                                        else{ 
                                        String readerName; 
                                        int num = 0; 
                                        addorclearTabPane.clearTab(logTabbedPane); 
                                        for(int i = 0;i < 10;i++){                                        
                                                if(recReaderName ==null 
                                                                || recReaderName.length() ==0) 
                                                        continue;                                                        
                                                readerName = recReaderName; 
                                                String temp =listModel.get(i).toString(); 
                                            addorclearTabPane.addTab(logTabbedPane,num,temp.substring(temp.indexOf("--")+2)); 
                                                    recordReaderName.put(readerName,num); 
                                                    num++; 
                                        } 
                                } 
                                
                                
                                        if(recordReaderName.size() == 0){ 
                                                exeBtn.setBackground(Color.green); 
                                                exeBtn.setEnabled(true); 
                                                return; 
                                        } 
                                        
                                if(seqCount == 0){ 
                                        if(!InitialCard()){ 
                                                exeBtn.setBackground(Color.green); 
                                                exeBtn.setEnabled(true); 
                                                return; 
                                        } 
                                        } 
                                
                                end(); 
                                executeThreads.clear(); 
                                
                                        for (int i = 0; i <recordReaderName.size(); i++) 
                                                executeThreads.add(new ExecuteThread(recReaderName));        
                                        for (ExecuteThread workerThread : executeThreads) { 
                                                workerThread.start(); 
                                        
                                        } 
                                                
                                        
                                }                        
                        }); 
                } 
                return exeBtn; 
        } 

Answer 2

线程实现函数： 
        public class ExecuteThread extends Thread { 
                String readerName;                 public ExecuteThread(String name) { 
                        readerName = name; 
                } 
                public void run() { 
                        execute(); 
                } 
                
                private  synchronized void execute(){ 
                        countNum ++; 
                        if(!connPCSCReader(readerName)) 
                                return; 
                        
                        //send "verify" command 
                        verifyCard(readerName); 
                        if(!flag) 
                                return; 
                        
                        //Erase 
                        eraseCard(readerName); 
                        if(!flag) 
                                return;                        
                        
                        //send Pflash Base and Write                
                        for(int i = 2; i < 6; i++){ 
                                writePflash(readerName,i); 
                                if(!flag) 
                                        return; 
                        } 
                                        
                        TabPane.writeRunLog(readerName, recReaderName, "Write data now,please wait...", "green"); 
                        //verify 
                        verifyCard(readerName); 
                        if(!flag) 
                                return; 
                        updataDflash(readerName); 
                        
                        String retStr;        
                        TabPane.writeRunLog(readerName, recReaderName, "\nPflash Base:","blue"); 
                        String cmd = "00 30 00 02 00"; 
                        TabPane.writeRunLog(readerName, recReaderName, "  "+cmd,"black"); 
                        retStr = sendCMD(readerName,cmd); 
                        if(!verify(readerName,retStr)) 
                                return;                
                        
                        TabPane.writeRunLog(readerName, recReaderName,"Pflash Write:" ,"blue"); 
                        TabPane.writeRunLog(readerName, recReaderName,"00 38 00 00 "+length,"black"); 
                        TabPane.writeRunLog(readerName, recReaderName,chipData02.get(0),"black"); 
                        retStr = sendCMD(readerName,"00 38 00 00 "+length + chipData02.get(0)); 
                        if(!verify(readerName,retStr)) 
                                return; 
                        
                        retStr = closePCSCReader(readerName); 
                        if(retStr.indexOf("46 61 69 6C") != -1 || 
                                        retStr.indexOf("Fail") != -1){ 
                //                JOptionPane.showMessageDialog(null, readerName+"\n断开卡失败."); 
                                TabPane.writeRunLog(readerName, recReaderName," 断开卡失败"+readerName,"red"); 
                                return; 
                        }                         if(!connPCSCReader(readerName)) 
                                return; //                        
                        //CheckSum 
                        TabPane.writeRunLog(readerName, recReaderName, "CheckSum:","black"); 
                        cmd = "A0 BA 00 00 04"+checkSum; 
                        TabPane.writeRunLog(readerName, recReaderName,"  "+cmd,"black"); 
                        retStr = sendCMD(readerName,cmd); 
                        if(!verify(readerName,retStr)){ 
                                return; 
                        }                
//                        
                        retStr = closePCSCReader(readerName); 
                        if(retStr.indexOf("46 61 69 6C") != -1 || 
                                        retStr.indexOf("Fail") != -1){ 
                                //JOptionPane.showMessageDialog(null, readerName+"\n断开卡失败."); 
                                TabPane.writeRunLog(readerName, recReaderName," 断开卡失败"+readerName,"red"); 
                                return; 
                        } 
                        
                        if(!connPCSCReader(readerName)) 
                                return; 
//                        
                        //INS: Verify ADM4 
                        TabPane.writeRunLog(readerName, recReaderName, "Verify ADM4:","blue"); 
                        cmd = "A020000E08"+adm4; //S9000 
                        TabPane.writeRunLog(readerName, recReaderName, "  "+cmd,"black"); 
                        retStr = sendCMD(readerName,cmd); 
                        if(!verify(readerName,retStr)) 
                                return; 
                
                        //INS: Verify ADM1 
                        TabPane.writeRunLog(readerName, recReaderName, "Verify ADM1:","blue"); 
                        cmd = "A0 20 000B 08 0000000000000000"; //S9000 
                        TabPane.writeRunLog(readerName, recReaderName, "  "+cmd,"black"); 
                        retStr = sendCMD(readerName,cmd); 
                        if(!verify(readerName,retStr)) 
                                return; 
                
                        //INS: Verify CHV2  
                        cmd = "A0 20 0002 08 35363738FFFFFFFF"; //S9000 
                        retStr = sendCMD(readerName,cmd); 
                        if(!verify(readerName,retStr)) 
                                return; 
                        
                        //INS: Select 3F00 
                        cmd = "A0A40000023F00" ;//S9F16/) 
                        retStr = sendCMD(readerName,cmd); 
                        if(!verify(readerName,retStr)) 
                                return; 
                        
                        //ICCID 
                        cmd = "a0a40000023f00"; 
                        retStr = sendCMD(readerName,cmd); 
                        if(!verify(readerName,retStr)) 
                                return; 
        
                        cmd = "a0a40000022FE2" ;  
                        retStr = sendCMD(readerName,cmd); 
                      if(!verify(readerName,retStr)) 
                                return; 
        
                        
                        String strTemp=""; 
                        if(seqCount == 0){ 
                                        cmd = "A0D600000A" + seqence; 
                        }else{ 
                                int countNo = Integer.parseInt(seqence.substring(12),16) + seqCount; 
                                strTemp = Integer.toHexString(countNo).toUpperCase(); 
                                while(strTemp.length() < 8) 
                                        strTemp = "0" + strTemp; 
                                cmd = "A0D600000A" + seqence.substring(0,12)+strTemp;                        
                        } 
                        seqCount ++; 
                        TabPane.writeRunLog(readerName, recReaderName, "  "+cmd, "black"); 
                        retStr = sendCMD(readerName,cmd); 
                        if(!verify(readerName,retStr)){ 
                                seqCount --; 
                                return; 
                        } 
                        strTemp = cmd.substring(10); 
                        TabPane.writeRunLog(readerName, recReaderName, "Read seqence:", "blue"); 
                        cmd = "A0 B0 00 00 0a"; 
                        TabPane.writeRunLog(readerName, recReaderName, "  "+cmd, "black"); 
                        retStr = sendCMD(readerName,cmd); 
                        if(!verify(readerName,retStr)) { 
                                seqCount --; 
                                return; 
                        } 
                        retStr = retStr.replace(" ", ""); 
                        if(retStr.indexOf(strTemp) != -1) 
                        { 
                                String ICCIDret = retStr.toString(); 
                                ICCIDret = ICCIDret.substring(0,20); 
                        //        JOptionPane.showMessageDialog(null, readerName + "\nISIM卡："+strTemp+"制作完成."); 
                                TabPane.writeRunLog(readerName, recReaderName," ICCID："+ICCIDret,"green"); 
                        TabPane.writeRunLog(readerName, recReaderName," SIM卡制作完成"+readerName,"green"); 
                        } 
                        else { 
                                seqCount --; 
                        } 
                        retStr = closePCSCReader(readerName); 
                        if(retStr.indexOf("46 61 69 6C") != -1 || 
                                        retStr.indexOf("Fail") != -1){ 
                        //        JOptionPane.showMessageDialog(null, readerName+"\n断开卡失败."); 
                                TabPane.writeRunLog(readerName, recReaderName,"断开卡失败，这不是个错误，SIM卡已制作完成"+readerName,"green"); 
                                return; 
                        } 
                        
                        if(countNum == recordReaderName.size()) { 
                                exeBtn.setBackground(Color.green); 
                                exeBtn.setEnabled(true); 
                        }                        
                } 
  }