Java序列化流的奇妙之旅

// 序列化对象信息：必须实现序列化标记接口Serializable
public class Person implements Serializable {
// 序列化版本UID
private static final long serialVersionUID = 1L;
private String name;
private int age;
private String sex;
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;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}

@Override
public String toString() {
return "Person{" + "name='" + name + ", age=" + age + ", sex='" + sex + '}';
}
public Person() {
}
public Person(String name, Integer age, String sex) {
this.name = name;
this.age = age;
this.sex = sex;
}
}

public class Demo2 {
public static void main(String[] args) throws IOException, ClassNotFoundException {
//数据准备：集合类都实现了序列化接口Serializable
List<Person> list = new ArrayList<>();
list.add(new Person("张三",38,"男"));
list.add(new Person("李四",38,"男"));
list.add(new Person("如花",18,"女"));

// 序列化保存到普通文件
File file = new File("D:/demo2.txt");
ObjectOutputStream objectOutputStream = new ObjectOutputStream(new FileOutputStream(file));
objectOutputStream.writeObject(list);
objectOutputStream.close();

// 读取普通文件反序列化
ObjectInputStream objectInputStream = new ObjectInputStream(new FileInputStream(file));
List<Person> personList = (List<Person>) objectInputStream.readObject();
objectInputStream.close();
for (Person person:personList){
System.out.println(person);
}

}
}

**
* 任意元素类型的List 集合的对象存储到普通文件，读取直接使用
* @param <T>
*/
public class ObjectList<T extends List> {
// 序列化保存到普通文件
private File file = new File("D:/demoList.txt");

public void writerList(T t) throws IOException {
ObjectOutputStream objectOutputStream = new ObjectOutputStream(new FileOutputStream(file));
objectOutputStream.writeObject(t);
objectOutputStream.close();
}

public T readList() throws IOException, ClassNotFoundException {
// 读取普通文件反序列化
ObjectInputStream objectInputStream = new ObjectInputStream(new FileInputStream(file));
T t = (T) objectInputStream.readObject();
objectInputStream.close();
return t;
}

public boolean isExists(){
return file.exists();
}
public boolean delete(){
return file.delete();
}

// 测试
public static void main(String[] args) throws IOException, ClassNotFoundException {
ObjectList<List<Person>> objectList = new ObjectList<>();
//数据准备：集合类都实现了序列化接口Serializable
List<Person> list = new ArrayList<>();
list.add(new Person("张三",38,"男"));
list.add(new Person("李四",38,"男"));
list.add(new Person("如花",18,"女"));
// 持久化对象数据
objectList.writerList(list);
// 查询持久化对象数据
List<Person> personList = objectList.readList();
System.out.println("遍历持久化对象数据>");
for (Person person:personList){
System.out.println(person);
if (person.getAge()==38){// 修改年龄38的都改为18
person.setAge(18);
}
}
// 修改后持久化对象数据
objectList.writerList(personList);
System.out.println("遍历修改持久化对象数据>");
List<Person> personList1 = objectList.readList();
for (Person person:personList1){
System.out.println(person);
}
// 删除对象存储的持久化文件
if (objectList.isExists()){
System.out.println("删除对象存储的持久化文件");
objectList.delete();
}

}

}