java - 以二进制格式保存数组

Question

我有以下数组

import java.io.*;
import java.util.*;
import java.util.logging.*;

public class SaveData{
int counter =1;
public void saveTheData(ArrayList<myClass> myClassObj){
    try{
        FileOutputStream fout = new FileOutputStream(counter+"SaveGame.ser", true);
        ObjectOutputStream oos = new ObjectOutputStream(fout);
        oos.writeObject(myClassObj.toString() );
        counter++;
        oos.close();
    } catch (Exception e) {
        e.printStackTrace();
    } 
}
}

抱歉，我是 Java 新手，请原谅我提出任何愚蠢的问题。上面的代码以 ser 格式保存数组。我需要将其保存为二进制格式，然后也能够在以后从二进制格式中读取它。我不知道你是怎么做到的

非常感谢任何帮助

Answer 1

正如其他人所说，如果您想编写二进制文件，请不要在序列化对象时使用 toString() 方法。您还需要在class myClass 中实现Serializable。然后反序列化就像序列化一样简单，使用ObjectInputStream.readObject() .

生成的 SaveData 类应如下所示:

import java.io.*;
import java.util.*;

public class SaveData {
    int counter = 1;

    public void saveTheData(ArrayList<myClass> myClassObj) {
        try {
            FileOutputStream fout = new FileOutputStream(counter
                    + "SaveGame.ser", true);
            ObjectOutputStream oos = new ObjectOutputStream(fout);
            oos.writeObject(myClassObj);
            counter++;
            oos.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public ArrayList<myClass> loadTheData(int saveNum) {
        try {
            FileInputStream fin = new FileInputStream(saveNum + "SaveGame.ser");
            ObjectInputStream ois = new ObjectInputStream(fin);
            ArrayList<myClass> myClassObj = (ArrayList<myClass>) ois.readObject();
            ois.close();
            return myClassObj;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
}

myClass 看起来像这样:

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

public class myClass implements Serializable {
    private static final long serialVersionUID = /* some UID */;
    /* ...
     * class properties
     */

    myClass(/* args */) {
        // Initialize
    }

    /* ...
     * class methods
     */

    private void writeObject(ObjectOutputStream o) throws IOException {
        // Write out to the stream
    }

    private void readObject(ObjectInputStream o) throws IOException,
            ClassNotFoundException {
        // Read in and validate from the stream
    }
}