对象输入输出流是java io流的一种，通过ObjectOutputStream.writeObject(Object obj)将对象写入ObjectOutputStream，通过ObjectInputStream.readObject()读出对象。

例子

创建Student类并实现Serializable接口

public class Student implements Serializable {
private static final long serialVersionUID = 1L;
private String name;
private int age;
public Student(String name, int age) {
this.name = name;
this.age = age;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
@Override
public String toString() {
return "Student{" +
"name='" + name + '\'' +
", age=" + age +
'}';
}
}

写一个测试类

public class ObjectOutputStreamDemo {
public static void main(String[] args) {
try {
Student s1 = new Student("张三", 18);
Student s2 = new Student("李四", 19);
List list = new ArrayList<>();
list.add(s1);
list.add(s2);
// create a new file with an ObjectOutputStream
FileOutputStream ot = new FileOutputStream("students.txt");
ObjectOutputStream oot = new ObjectOutputStream(ot);
// write something in the file
oot.writeObject(list);
// close the stream
oot.close();
// create an ObjectInputStream for the file we created before
ObjectInputStream ois = new ObjectInputStream(new FileInputStream("students.txt"));
// read and print what we wrote before
List studentList = (List) ois.readObject();
for (Student s : studentList) {
System.out.println(s.toString());
}
} catch (Exception ex) {
ex.printStackTrace();
}
}
}

输出结果

Student{name='张三', age=18}
Student{name='李四', age=19}