隐式集合混叠时使用的集合是表示在XML无需显示根。例如,在我们的例子中,我们需要一个接一个,但不是在根节点来显示每一个节点。让我们再次修改例子,下面的代码添加到它。
xstream.addImplicitCollection(Student.class, "notes");
让我们使用XStream测试上述对象序列化。
创建一个Java类名为XStreamTester在文件 C:\>XStream_WORKSPACE\com\yiibai\xstream.
File: XStreamTester.java
package cn.sxt.xstream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.util.ArrayList;
import java.util.List;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.sax.SAXSource;
import javax.xml.transform.sax.SAXTransformerFactory;
import javax.xml.transform.stream.StreamResult;
import org.xml.sax.InputSource;
import com.thoughtworks.xstream.XStream;
import com.thoughtworks.xstream.io.xml.StaxDriver;
public class XStreamTester {
public static void main(String args[]){
XStreamTester tester = new XStreamTester();
XStream xstream = new XStream(new StaxDriver());
xstream.alias("student", Student.class);
xstream.alias("note", Note.class);
xstream.aliasField("name", Student.class, "studentName");
xstream.addImplicitCollection(Student.class, "notes");
Student student = tester.getStudentDetails();
//Object to XML Conversion
String xml = xstream.toXML(student);
System.out.println(formatXml(xml));
}
private Student getStudentDetails(){
Student student = new Student("Mahesh");
student.addNote(new Note("first","My first assignment."));
student.addNote(new Note("second","My Second assignment."));
return student;
}
public static String formatXml(String xml){
try{
Transformer serializer= SAXTransformerFactory.newInstance().newTransformer();
serializer.setOutputProperty(OutputKeys.INDENT, "yes");
serializer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "2");
Source xmlSource=new SAXSource(new InputSource(new ByteArrayInputStream(xml.getBytes())));
StreamResult res = new StreamResult(new ByteArrayOutputStream());
serializer.transform(xmlSource, res);
return new String(((ByteArrayOutputStream)res.getOutputStream()).toByteArray());
}catch(Exception e){
return xml;
}
}
}
class Student {
private String studentName;
private List<Note> notes = new ArrayList<Note>();
public Student(String name) {
this.studentName = name;
}
public void addNote(Note note) {
notes.add(note);
}
public String getName(){
return studentName;
}
public List<Note> getNotes(){
return notes;
}
}
class Note {
private String title;
private String description;
public Note(String title, String description) {
this.title = title;
this.description = description;
}
public String getTitle(){
return title;
}
public String getDescription(){
return description;
}
}
验证结果
使用javac编译器编译如下类:
C:\XStream_WORKSPACE\cn\sxt\xstream>javac XStreamTester.java
现在运行XStreamTester看到的结果:
C:\XStream_WORKSPACE\cn\sxt\xstream>java XStreamTester
验证输出
<?xml version="1.0" encoding="UTF-8"?><student>
<name>Mahesh</name>
<note>
<title>first</title>
<description>My first assignment.</description>
</note>
<note>
<title>second</title>
<description>My Second assignment.</description>
</note></student>