Xstream 简明教程
XStream - First Application
在深入了解 XStream 库之前,让我们看一个应用程序的实际使用情况。在此示例中,我们创建了 Student 和 Address 类。我们将创建一个学生对象,然后将其序列化为 XML 字符串。然后对相同的 XML 字符串进行反序列化,以获取回学生对象。
在 C:>XStream_WORKSPACE 中创建一个名为 XStreamTester 的 Java 类文件。
File: XStreamTester.java
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
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());
Student student = tester.getStudentDetails();
//Object to XML Conversion
String xml = xstream.toXML(student);
System.out.println(formatXml(xml));
//XML to Object Conversion
Student student1 = (Student)xstream.fromXML(xml);
System.out.println(student1);
}
private Student getStudentDetails() {
Student student = new Student();
student.setFirstName("Mahesh");
student.setLastName("Parashar");
student.setRollNo(1);
student.setClassName("1st");
Address address = new Address();
address.setArea("H.No. 16/3, Preet Vihar.");
address.setCity("Delhi");
address.setState("Delhi");
address.setCountry("India");
address.setPincode(110012);
student.setAddress(address);
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 int rollNo;
private String firstName;
private String lastName;
private String className;
private Address address;
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public int getRollNo() {
return rollNo;
}
public void setRollNo(int rollNo) {
this.rollNo = rollNo;
}
public String getClassName() {
return className;
}
public void setClassName(String className) {
this.className = className;
}
public Address getAddress() {
return address;
}
public void setAddress(Address address) {
this.address = address;
}
public String toString() {
StringBuilder stringBuilder = new StringBuilder();
stringBuilder.append("Student [ ");
stringBuilder.append("\nfirstName: ");
stringBuilder.append(firstName);
stringBuilder.append("\nlastName: ");
stringBuilder.append(lastName);
stringBuilder.append("\nrollNo: ");
stringBuilder.append(rollNo);
stringBuilder.append("\nclassName: ");
stringBuilder.append(className);
stringBuilder.append("\naddress: ");
stringBuilder.append(address);
stringBuilder.append(" ]");
return stringBuilder.toString();
}
}
class Address {
private String area;
private String city;
private String state;
private String country;
private int pincode;
public String getArea() {
return area;
}
public void setArea(String area) {
this.area = area;
}
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
public String getState() {
return state;
}
public void setState(String state) {
this.state = state;
}
public String getCountry() {
return country;
}
public void setCountry(String country) {
this.country = country;
}
public int getPincode() {
return pincode;
}
public void setPincode(int pincode) {
this.pincode = pincode;
}
public String toString() {
StringBuilder stringBuilder = new StringBuilder();
stringBuilder.append("\nAddress [ ");
stringBuilder.append("\narea: ");
stringBuilder.append(area);
stringBuilder.append("\ncity: ");
stringBuilder.append(city);
stringBuilder.append("\nstate: ");
stringBuilder.append(state);
stringBuilder.append("\ncountry: ");
stringBuilder.append(country);
stringBuilder.append("\npincode: ");
stringBuilder.append(pincode);
stringBuilder.append(" ]");
return stringBuilder.toString();
}
}
Verify the Result
使用以下 javac 编译器编译类:
C:\XStream_WORKSPACE>javac XStreamTester.java
现在,运行 XStreamTester 以查看结果 −
C:\XStream_WORKSPACE>java XStreamTester
Verify the output as follows
<?xml version = "1.0" encoding = "UTF-8"?>
<Student>
<firstName>Mahesh</firstName>
<lastName>Parashar</lastName>
<rollNo>1</rollNo>
<className>1st</className>
<address>
<area>H.No. 16/3, Preet Vihar.</area>
<city>Delhi</city>
<state>Delhi</state>
<country>India</country>
<pincode>110012</pincode>
</address>
</Student>
Student [
firstName: Mahesh
lastName: Parashar
rollNo: 1
className: 1st
address:
Address [
area: H.No. 16/3, Preet Vihar.
city: Delhi
state: Delhi
country: India
pincode: 110012
]
]
Steps to Remember
以下是需要考虑的重要步骤。
Step 1: Create an XStream Object
通过传递 StaxDriver 创建一个 XStream 对象。StaxDriver 使用 Stax pull 解析器(在 Java 6 中可用),是一种快速的 xml 解析器。
XStream xstream = new XStream(new StaxDriver());