Java序列化与反序列化(实践)
Java序列化与反序列化(实践)
基本概念:
序列化是将对象状态转换为可保持或传输的格式的过程。与序列化相对的是反序列化,它将流转换为对象。这两个过程结合起来,可以轻松地存储和传输数据。
昨天在一本书上看到了,好好实践了一下,序列化为一般文件,也序列化为XML文件(使用XStream)。
用于序列化的实体类Person.java 代码如下(记得需要实现Serializable接口):
import java.io.Serializable;
@SuppressWarnings("serial")
public class Person implements Serializable{
private String name;
private int age;
public Person(){
}
public Person(String str, int n){
System.out.println("Inside Person's Constructor");
name = str;
age = n;
}
String getName(){
return name;
}
int getAge(){
return age;
}
}
序列化、反序列化为一般的文件,SerializeToFlatFile.java类的代码如下:
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
public class SerializeToFlatFile {
public static void main(String[] args) {
SerializeToFlatFile ser = new SerializeToFlatFile();
ser.savePerson();
ser.restorePerson();
}
public void savePerson(){
Person myPerson = new Person("Jay",24);
try {
FileOutputStream fos = new FileOutputStream("E:\\workspace\\2010_03\\src\\myPerson.txt");
ObjectOutputStream oos = new ObjectOutputStream(fos);
System.out.println("Person--Jay,24---Written");
System.out.println("Name is: "+myPerson.getName());
System.out.println("Age is: "+myPerson.getAge());
oos.writeObject(myPerson);
oos.flush();
oos.close();
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
}
public void restorePerson() {
try {
FileInputStream fis = new FileInputStream("E:\\workspace\\2010_03\\src\\myPerson.txt");
ObjectInputStream ois = new ObjectInputStream(fis);
Person myPerson = (Person)ois.readObject();
System.out.println("\n--------------------\n");
System.out.println("Person--Jay,24---Restored");
System.out.println("Name is: "+myPerson.getName());
System.out.println("Age is: "+myPerson.getAge());
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
}
}
运行结果为(console输出),当然可以查看到myPerson.txt文件已经生成:
Inside Person's Constructor
Person--Jay,24---Written
Name is: Jay
Age is: 24
--------------------
Person--Jay,24---Restored
Name is: Jay
Age is: 24
序列化、反序列化为XML文件,我使用了XStream来序列化,需要引入xstream-1.3.1.jar包的支持,
http://xstream.codehaus.org/download.html 处可以下载jar,然后引入到Eclipse中的build path中。
Serialize.java的代码如下:
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import com.thoughtworks.xstream.*;
public class Serialize {
public static void main(String[] args) {
Serialize ser = new Serialize();
ser.serializeToXml();
ser.deSerializeFromXml();
}
public void serializeToXml(){
Person[] myPerson = new Person[2];
myPerson[0] = new Person("Jay",24);
myPerson[1] = new Person("Tom",23);
XStream xstream = new XStream();
try {
FileOutputStream fos = new FileOutputStream("E:\\workspace\\2010_03\\src\\myPerson.xml");
xstream.toXML(myPerson,fos);
} catch (FileNotFoundException ex) {
ex.printStackTrace();
}
System.out.println(xstream.toXML(myPerson));
}
public void deSerializeFromXml(){
XStream xs = new XStream();
Person[] myPerson = null;
try {
FileInputStream fis = new FileInputStream("E:\\workspace\\2010_03\\src\\myPerson.xml");
myPerson=(Person[])xs.fromXML(fis);
if (myPerson != null)
{
int len = myPerson.length;
for (int i=0;i<len;i++)
{
System.out.println(myPerson[i].getName());
System.out.println(myPerson[i].getAge());
}
}
} catch (FileNotFoundException ex) {
ex.printStackTrace();
}
}
}
运行结果为(console输出),当然可以查看到myPerson.xml文件已经生成:
Inside Person's Constructor
Inside Person's Constructor
<Person-array>
<Person>
<name>Jay</name>
<age>24</age>
</Person>
<Person>
<name>Tom</name>
<age>23</age>
</Person>
</Person-array>
Jay
24
Tom
23
每一天都要行动,在前进中寻求卓越。