java - 使用线程文件写入和读取对象

Question

我有一个主线程，我们从中启动两个后续线程，分别执行文件写入和文件读取操作。我有另一个名为 orderDetails 的类，其中包含属性及其 getter 和 setter。当前程序的运行方式是一次性将对象列表写入文件并读回。

问题:我需要将对象(cust1)的内容写入文件并同时从文件中读回。必须对指定的所有对象(cust1，cust2)执行此操作。建议解决此问题的可能方法。

主类

public class MainThread  {
         public static void main(String[] args) throws InterruptedException {
              Thread1 td1=new Thread1();
              Thread2 td2=new Thread2();
              Thread t1=new Thread(td1);
              Thread t2=new Thread(td2);
              t1.start();
              t1.sleep(100);
              t2.start();
        }
    }

orderDetails 类 - 一个普通的 pojo 类

 public class orderDetails {
        private String custName;
        private double advancePaid;
        private int mobileModel;
        private boolean replacement;
        private String problemFaced;
        private boolean softwareRequirement;
       public orderDetails(String custName, double advancePaid, int mobileModel,
                boolean replacement, String problemFaced,
                boolean softwareRequirement) {
            super();
            this.custName = custName;
            this.advancePaid = advancePaid;
            this.mobileModel = mobileModel;
            this.replacement = replacement;
            this.problemFaced = problemFaced;
            this.softwareRequirement = softwareRequirement;
        } 
        public boolean isSoftwareRequirement() {
            return softwareRequirement;
        }
        public void setSoftwareRequirement(boolean softwareRequirement) {
            this.softwareRequirement = softwareRequirement;
        }
        public int getMobileModel() {
            return mobileModel;
        }
        public void setMobileModel(int mobileModel) {
            this.mobileModel = mobileModel;
        }
        public String getProblemFaced() {
            return problemFaced;
        }
        public void setProblemFaced(String problemFaced) {
            this.problemFaced = problemFaced;
        }
        public boolean isReplacement() {
            return replacement;
        }
        public void setReplacement(boolean replacement) {
            this.replacement = replacement;
        }
        public double getAdvancePaid() {
            return advancePaid;
        }
        public void setAdvancePaid(double advancePaid) {
            this.advancePaid = advancePaid;
        }
        public String getCustName() {
            return custName;
        }
        public void setCustName(String custName) {
            this.custName = custName;
        }

    }

文件写入-将属性写入文件

 public class FileWriting implements Runnable {
        orderDetails cust1=new orderDetails("vid",2000.00,2543,true,"display",false);
        orderDetails cust2=new orderDetails("kesav",8000.00,7845,false,"battery",true);
        ArrayList<orderDetails> orderArr=new ArrayList<orderDetails>();
         orderDetails obj;
                public void run() {
            orderArr.add(cust1);
            orderArr.add(cust2);
             try {
                for(orderDetails obj:orderArr)
                {
                fileOperations(obj);
                }
            }
                catch (IOException e) {
                    e.printStackTrace();
            }
        }

        public void fileOperations(orderDetails obj) throws IOException{
            File f= new File("C:\\Users\\311518\\Desktop\\threadtest2.txt");
            Calendar calNow = Calendar.getInstance();
            Calendar orderDate;
            SimpleDateFormat formatter = new SimpleDateFormat("dd/MM/yyyy");
            FileWriter fstream;
              if(f.exists()){
                  //append mode
             fstream = new FileWriter(f,true);
              }
              else
              {
                  // to open a new file
              f.createNewFile();
                    // write mode
             fstream = new FileWriter(f,false);
              }
              BufferedWriter out = new BufferedWriter(fstream);
                     out.write(obj.getCustName()+" "+obj.getMobileModel()+" "+obj.getProblemFaced()+" "+obj.getAdvancePaid()+" "+obj.isReplacement()+" "+obj.isSoftwareRequirement());  
                     double balanceAmt=obj.getAdvancePaid()-200;
                     out.write(" "+balanceAmt); 
                     orderDate = (Calendar) calNow.clone();
                     out.write(" "+formatter.format(orderDate.getTime()));
                     orderDate.add(Calendar.DAY_OF_YEAR, + 10);
                     out.write(" "+formatter.format(orderDate.getTime()));
                     out.newLine();
                 out.close();
        }
     }

文件读取类-从文件中读取属性

 public class FileReading implements Runnable{
        File f= new File("C:\\Users\\311518\\Desktop\\threadtest2.txt");
        public void run() {
            try {
                readingText();
                System.out.println("Thanks for ur order");
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        public void readingText() throws IOException{
            String [] temp = null;
            FileReader fr = new FileReader(f); 
            BufferedReader br = new BufferedReader(fr); 
            String s; 
            System.out.println("--------ORDER DETAILS------");
             System.out.println("Name Model Adv Prob Replacement S/w Bal OrderDate Deliverdate ");
                while((s = br.readLine()) != null) { 
                                      //display ordered details
                      temp = s.toString().split("\n");
                      for(int i=0;i<temp.length;i++){
                    System.out.println(temp[i]);
                      }
        }

    }
    }

Answer 1

您可以尝试使用公共(public)锁对象，在写入时对其加锁，并等待写入完成后再进行读取。示例:

写:

for(orderDetails obj:orderArr)
{
    synchronized(FileWriting.class)
    {
        fileOperations(obj);
    }
    Thread.yield();
}   

阅读:

synchronized(FileWriting.class) {
    readingText();
    Thread.yield();
}

也许您还应该在循环中添加阅读，并让编写器在完成写入时发出信号，以便读者可以停止。