这篇文章主要介绍了Java对象的XML序列化与反序列化实例解析,小编觉得还是挺不错的,这里分享给大家。
上一篇文章我们介绍了java实现的各种排序算法代码示例,本文我们看看Java对象的xml序列化与反序列化的相关内容,具体如下。
XML是一种标准的数据交换规范,可以方便地用于在应用之间交换各类数据。如果能在Java对象和XML文档之间建立某种映射,例如Java对象的XML序列化和反序列化,那么就可以使Java的对象方便地与其他应用进行交换。
java.beans包里面有两个类XMLEncoder和Decoder,分别用于将符合JabaBeans规范的Java对象以XML方式序列化和反序列化。以下代码显示了如何使用这两个类实现Java对象的XML编码和解码。
待序列化的Java类:
import java.io.Serializable; public class SerialableObject implements Serializable { private static final long serialVersionUID = 8745578444312339136L; public SerialableObject() { } public SerialableObject(int id, String name, double value) { this.id = id; this.name = name; this.value = value; } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public double getValue() { return value; } public void setValue(double value) { this.value = value; } private int id; private String name; private double value; }
XML序列化和反序列化用法演示类:
import java.beans.XMLDecoder; import java.beans.XMLEncoder; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.util.List; import java.util.Vector; public class XmlSerialize { public XmlSerialize() { } public void serializeSingleObject(OutputStream os, Object obj) // 序列化单个java对象 { // XMLEncoder xe = new XMLEncoder(os); XMLEncoder xe = new XMLEncoder(os, "GBK", true, 0); // 仅用于Java SE 7 xe.writeObject(obj); // 序列化成XML字符串 xe.close(); } public Object deserializeSingleObject(InputStream is) // 反序列化单个Java对象 { XMLDecoder xd = new XMLDecoder(is); Object obj = xd.readObject(); // 从XML序列中解码为Java对象 xd.close(); return obj; } public void serializeMultipleObject(OutputStream os, List<Object> objs) // 序列化多个Java对象 { XMLEncoder xe = new XMLEncoder(os); xe.writeObject(objs); // 序列化成XML字符串 xe.close(); } public List<Object> deserializeMultipleObject(InputStream is) // 反序列化多个Java对象 { XMLDecoder xd = new XMLDecoder(is); @SuppressWarnings("unchecked") List<Object> objs = (List<Object>)xd.readObject(); // 从XML序列中解码为Java对象列表 xd.close(); return objs; } public void runSingleObject() { File xmlFile = new File("object.xml"); SerialableObject jo4Out = new SerialableObject(1, "Java序列化为XML", 3.14159265359); // 创建待序列化的对象 try { FileOutputStream ofs = new FileOutputStream(xmlFile); // 创建文件输出流对象 serializeSingleObject(ofs, jo4Out); ofs.close(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } try { FileInputStream ifs = new FileInputStream(xmlFile); SerialableObject jo4In = (SerialableObject)deserializeSingleObject(ifs); System.out.println("id: " + jo4In.getId()); System.out.println("name: " + jo4In.getName()); System.out.println("value: " + jo4In.getValue()); } catch (FileNotFoundException e) { e.printStackTrace(); } } public void runMultipleObject() { File xmlFile = new File("objects.xml"); List<SerialableObject> sos4Out = new Vector<SerialableObject>(); sos4Out.add(new SerialableObject(1, "Java序列化为XML - 1", 3.14)); // 创建待序列化的对象 sos4Out.add(new SerialableObject(2, "Java序列化为XML - 2", 3.14159)); // 创建待序列化的对象 sos4Out.add(new SerialableObject(3, "Java序列化为XML - 3", 3.1415926)); // 创建待序列化的对象 sos4Out.add(new SerialableObject(4, "Java序列化为XML - 4", 3.141592653)); // 创建待序列化的对象 sos4Out.add(new SerialableObject(5, "Java序列化为XML - 5", 3.14159265359)); // 创建待序列化的对象 try { FileOutputStream ofs = new FileOutputStream(xmlFile); // 创建文件输出流对象 serializeSingleObject(ofs, sos4Out); ofs.close(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } try { FileInputStream ifs = new FileInputStream(xmlFile); @SuppressWarnings("unchecked") List<SerialableObject> sos4In = (List<SerialableObject>)deserializeSingleObject(ifs); for (SerialableObject jo4In : sos4In) { System.out.println("id: " + jo4In.getId()); System.out.println("name: " + jo4In.getName()); System.out.println("value: " + jo4In.getValue()); } } catch (FileNotFoundException e) { e.printStackTrace(); } } public static void main(String[] args) { XmlSerialize xs = new XmlSerialize(); xs.runSingleObject(); xs.runMultipleObject(); } }
需要注意的是,待序列化的类必须要符合JavaBeans的格式规范,即:具有一个无参的public构造函数,所有数据成员的访问均采用getter/setter模式,此外,这个类必须是public的,并且实现了java.io.Serializable接口。
程序运行之后,会产生两个文件:
object.xml是runSingleObject方法生成的,存放了单个的SerialableObject的值:
<?xml version="1.0" encoding="GBK"?> <java version="1.7.0" class="java.beans.XMLDecoder"> <object class="SerialableObject"> <void property="id"> <int>1</int> </void> <void property="name"> <string>Java序列化为XML</string> </void> <void property="value"> <double>3.14159265359</double> </void> </object> </java>
objects.xml是runMultipleObject方法产生的,存放了5个SerializableObject的值:
<?xml version="1.0" encoding="GBK"?> <java version="1.7.0" class="java.beans.XMLDecoder"> <object class="java.util.Vector"> <void method="add"> <object class="SerialableObject"> <void property="id"> <int>1</int> </void> <void property="name"> <string>Java序列化为XML - 1</string> </void> <void property="value"> <double>3.14</double> </void> </object> </void> <void method="add"> <object class="SerialableObject"> <void property="id"> <int>2</int> </void> <void property="name"> <string>Java序列化为XML - 2</string> </void> <void property="value"> <double>3.14159</double> </void> </object> </void> <void method="add"> <object class="SerialableObject"> <void property="id"> <int>3</int> </void> <void property="name"> <string>Java序列化为XML - 3</string> </void> <void property="value"> <double>3.1415926</double> </void> </object> </void> <void method="add"> <object class="SerialableObject"> <void property="id"> <int>4</int> </void> <void property="name"> <string>Java序列化为XML - 4</string> </void> <void property="value"> <double>3.141592653</double> </void> </object> </void> <void method="add"> <object class="SerialableObject"> <void property="id"> <int>5</int> </void> <void property="name"> <string>Java序列化为XML - 5</string> </void> <void property="value"> <double>3.14159265359</double> </void> </object> </void> </object> </java>
总结
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