Question

您好我遇到序列化对象的问题。我真正想要做的是从服务器获取记录使用hashmap序列化它并将其保存在sqllite db中。

我可以将序列化的对象保存到我的存储卡中，但是当我反序列化时，nohting就会出现，我以前的所有数据都会被删除。

以下是序列化的示例代码

序列化

Employee e = new Employee();
  e.name = "Reyan Ali";
  e.address = "Phokka Kuan, Ambehta Peer";
  e.SSN = 11122333;
  e.number = 101;
  try
  {
     FileOutputStream fileOut =
     new FileOutputStream("/tmp/employee.ser");
     ObjectOutputStream out = new ObjectOutputStream(fileOut);
     out.writeObject(e);
     out.close();
     fileOut.close();
     System.out.printf("Serialized data is saved in /tmp/employee.ser");
  }catch(IOException i)
  {
      i.printStackTrace();
  }

}

反序列化

  Employee e = null;
  try
  {
     FileInputStream fileIn = new FileInputStream("/tmp/employee.ser");
     ObjectInputStream in = new ObjectInputStream(fileIn);
     e = (Employee) in.readObject();
     in.close();
     fileIn.close();
  }catch(IOException i)
  {
     i.printStackTrace();
     return;
  }catch(ClassNotFoundException c)
  {
     System.out.println("Employee class not found");
     c.printStackTrace();
     return;
  }
  System.out.println("Deserialized Employee...");
  System.out.println("Name: " + e.name);
  System.out.println("Address: " + e.address);
  System.out.println("SSN: " + e.SSN);
  System.out.println("Number: " + e.number);
}

其次，sqlite中可以保存序列化对象的列类型是什么。如果你们有人有一个很好的教程请分享。

Answer 1

对您的代码进行了一些更改，如下所示。

首先在Employee.java类中实现Serializable接口

public void serailize() {
    Employee e = new Employee();
    e.setName("Reyan Ali");
    e.setAddress("Phokka Kuan, Ambehta Peer");
    e.setSSN(11122333);
    e.setNumber(101);
    try {
        ObjectOutputStream out = new ObjectOutputStream(openFileOutput(
                "employee.ser", MODE_PRIVATE));
        out.writeObject(e);
        out.close();
        System.out.printf("Serialized data is saved in /tmp/employee.ser");
    } catch (IOException i) {
        i.printStackTrace();
    }
}

public void deSerailize() {
    Employee e = null;
    try {
        ObjectInputStream in = new ObjectInputStream(
                openFileInput("employee.ser"));
        e = (Employee) in.readObject();
        in.close();
    } catch (IOException i) {
        i.printStackTrace();
        return;
    } catch (ClassNotFoundException c) {
        System.out.println("Serialized class not found");
        c.printStackTrace();
        return;
    }
    System.out.println("Deserialized Employee...");
    System.out.println("Name: " + e.name);
    System.out.println("Address: " + e.address);
    System.out.println("SSN: " + e.SSN);
    System.out.println("Number: " + e.number);
}

OpenFileInput（）和openFileOutPut（）是应用程序专用文件。

我认为将序列化数据存储在文件中是很好的。

序列化对象并保存在Sqlite DB中

1 个答案: