java - Java中使用ArrayList进行对象序列化和反序列化

Question

我试图序列化一个对象数组并将其写入名为 address.ser 的文件，然后从该文件读回，反序列化对象数组并显示其属性。我尝试一次序列化整个 arrayList(在读取时在单个 session 中反序列化它)，并且还尝试将对象数组的每个对象一一序列化(在读取时将其一一反序列化)。问题是，在从 address.ser 文件读回时，我仅获取最后写入的对象的数据，而不获取其他对象的数据。

这是代码片段:

Employee[] a=new Employee[5];

    List<Employee> arr=new ArrayList<Employee>();

    for(int i=0;i<=4;i++)
    {
    a[i]=new Employee();
    System.out.println("Enter name,age,height,weight,house_no:");
    a[i].name=sc.next();
    a[i].age=sc.nextInt();
    a[i].height=sc.nextDouble();
    a[i].weight=sc.nextDouble();
    a[i].house_no=sc.nextInt();
    arr.add(a[i]);
    }

这是将对象写入address.ser的代码片段:

for(int i=0;i<=4;i++)
    {
    try
    {
    fout = new FileOutputStream("e:\\address.ser");
    oos = new ObjectOutputStream(fout);   
    oos.writeObject(a[i]);
    //oos.writeChars("\n");
    }
    catch(Exception e)
    {
        e.printStackTrace();
    }
    finally
    {
    oos.close();
    fout.close();
    }
    }

这是从address.ser读取对象的代码片段:

List<Employee> recordList=new ArrayList<Employee>();
    for(int i=0;i<=4;i++)
    {
    try
    {
        file = new FileInputStream("e:\\address.ser");
        input = new ObjectInputStream (file);

        //deserialize the List
        Employee readCase=(Employee) input.readObject();
        recordList.add(readCase);
        System.out.print("Employee "+i+" ");
        System.out.print((recordList.get(i).name)+" ");
        System.out.print((recordList.get(i).age)+" ");
        System.out.print((recordList.get(i).height)+" ");
        System.out.print((recordList.get(i).weight)+" ");
        System.out.print((recordList.get(i).house_no)+" ");
        System.out.println();

    }
    catch(Exception e)
    {
        e.printStackTrace();
    }
    finally
    {
    file.close();
    input.close();
    }
    }

最终输出为:

Answer 1

这就是办法

public class Test {
    public static void main(String[] args) {
Employee employee=new Employee("jhon");
Employee employee2=new Employee("jojo");
Employee employee3=new Employee("albin");
ArrayList<Employee> list=new ArrayList<Employee>();
list.add(employee);
list.add(employee2);
list.add(employee3);

try {
    FileOutputStream outputStream=new FileOutputStream("add.ser");
    ObjectOutputStream objectOutputStream= new ObjectOutputStream(outputStream);
    objectOutputStream.writeObject(list);
} catch (FileNotFoundException e) {
    e.printStackTrace();
} catch (IOException e) {
    e.printStackTrace();
}


try {
    FileInputStream inputStream=new FileInputStream("add.ser");
    ObjectInputStream objectInputStream =new ObjectInputStream(inputStream);
    ArrayList<Employee> list2=(ArrayList<Employee>) objectInputStream.readObject();
    for (Employee employee4 : list2) {
        System.out.println(employee4.getName());
    }
} catch (FileNotFoundException e) {
    e.printStackTrace();
} catch (IOException e) {
    e.printStackTrace();
} catch (ClassNotFoundException e) {
    e.printStackTrace();
}
    }
}