序列化和反序列化
序列化
将对象转换为可存储或可传输的字节流或其他数据格式的过程。 依赖FastJSON的序列化(序列化为JSON)
public static void main(String[] args) throws Exception {
User user = new User();
user.setAge(18);
user.setUserName("张三");
String jsonString = JSONObject.toJSONString(user);
File file = new File("user.json");
Files.write(file.toPath(), jsonString.getBytes(StandardCharsets.UTF_8));
System.out.println(file.length());
}将对象序列化为字节数组
private static byte[] serialize(User user) {
String name = user.getUserName();
byte[] nameBytes = name.getBytes(StandardCharsets.UTF_8);
ByteBuffer buffer = ByteBuffer.allocate(nameBytes.length + Integer.BYTES);
buffer.putInt(user.getAge());
buffer.put(nameBytes);
return buffer.array();
}对象实现serializable的序列化
private static byte[] serialize(User user) throws IOException {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ObjectOutputStream oob = new ObjectOutputStream(baos);
oob.writeObject(user);
return baos.toByteArray();
}反序列化
将字节流或其他格式的数据还原为对象的过程
依赖FastJSON的反序列化
public static void main(String[] args) throws Exception {
File file = new File("user.json");
byte[] bytes = Files.readAllBytes(file.toPath());
User user = JSONObject.parseObject(new String(bytes, StandardCharsets.UTF_8), User.class);
System.out.println(user);
}将字节数组反序列化为对象
private static User deserialize(byte[] bytes){
ByteBuffer buffer = ByteBuffer.wrap(bytes);
int age = buffer.getInt();
byte[] nameBytes = new byte[buffer.remaining()];
buffer.get(nameBytes);
User user = new User();
user.setAge(age);
user.setUserName(new String(nameBytes, StandardCharsets.UTF_8));
return user;
}对象实现serializable的反序列化
private static User deserialize(byte[] bytes) throws Exception {
ByteArrayInputStream bais = new ByteArrayInputStream(bytes);
ObjectInputStream objectInputStream = new ObjectInputStream(bais);
return (User) objectInputStream.readObject();
}