To implement this, we need to use Java's
object serialization feature. Here are the steps to modify the `Model` class:
1. Make the `Po
int` class implement the `Serializable`
interface.
```
public class Po
int implements Serializable {
// exist
ing
code
}
```
2. Modify the `Model` class
constructor to read the `po
ints.b
in` file and deserialize the `ArrayList` of po
ints from it:
```
public Model() {
try {
File
InputStream file
In = new File
InputStream("po
ints.b
in");
ObjectInputStream
in = new
ObjectInputStream(file
In);
po
ints = (ArrayList<Po
int>)
in.read
Object();
in.close();
file
In.close();
} catch (IOException | ClassNotFoundException e) {
po
ints = new ArrayList<>();
}
}
```
3. Modify the `saveData` method to serialize the `ArrayList` of po
ints and write it to the `po
ints.b
in` file:
```
public void saveData() {
try {
FileOutputStream fileOut = new FileOutputStream("po
ints.b
in");
ObjectOutputStream out = new
ObjectOutputStream(fileOut);
out.write
Object(po
ints);
out.close();
fileOut.close();
} catch (IOException e) {
System.out.pr
intln("Error sav
ing data to file.");
}
}
```
With these changes, the `Model` class will now read/write the entire `ArrayList` of po
ints
in one operation us
ing
object serialization.
To test that everyth
ing works, we can modify the `Test` class to use the new `Model`
constructor and the `Start` class to use the new `saveData` method.
Here's an example implementation of the `Test` class:
```
public class Test {
public static void ma
in(Str
ing[] args) {
Model model = new Model(); // use new
constructor
// exist
ing tests
// ...
model.saveData(); // save data after tests
}
}
```
And here's an example implementation of the `Start` class:
```
public class Start {
public static void ma
in(Str
ing[] args) {
Model model = new Model(); // use new
constructor
// exist
ing
code to display po
ints
// ...
model.saveData(); // save data on exit
}
}
```
With these changes, the software will now use
object serialization to read/write the entire `ArrayList` of po
ints from/to the `po
ints.b
in` file. Runn
ing the `Test` class should still pass all the tests, and runn
ing the `Start` class should
correctly display all the po
ints from the previous run.
本文介绍了对象序列化的概念及其过程，序列化是指将对象的状态持久化为一系列数据，并可能进行传输的过程。这些数据包含了所有用于重建对象状态所需的信息。
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