XStream入門應用程序
在進入XStream庫的細節之前,讓我們來看看應用程序操作。在這個例子中,我們創建Student和Address類。還將創建一個Student對象,然後將其序列化到一個XML字符串。然後反序列化的同一個XML字符串,以重新獲得學生對象。
創建一個名為XStreamTester的Java類文件在 C:\>XStream_WORKSPACE.
文件: 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 String firstName; private String lastName; private int rollNo; 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(); } }
驗證結果
使用javac編譯器編譯如下類:
C:\XStream_WORKSPACE>javac XStreamTester.java
現在運行XStreamTester看到結果:
C:\XStream_WORKSPACE>java XStreamTester
驗證輸出
<?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 ] ]
記住以下步驟
以下是這裡要考慮的重要步驟。
第1步:創建XStream對象。
通過它傳遞一個StaxDriver創建XStream對象。StaxDriver使用SAX解析器(可從Java6),一個快速的XML解析器。
XStream xstream = new XStream(new StaxDriver());
第2步:序列化對象到XML。
使用toXML() 方法來獲取對象的XML字符串表示。
//Object to XML Conversion String xml = xstream.toXML(student);
第3步:反序列化XML獲得對象。
使用 fromXML()方法來從XML對象。
//XML to Object Conversion Student student1 = (Student)xstream.fromXML(xml);