JAXB使用

使用jaxb，可以简单的在java对象和xml之间的转换，具体参考javaAPI文档里面的软件包 javax.xml.bind。

需要了解三个类：JAXBContext，Unmarshaller，Marshaller。

import javax.xml.bind.annotation.XmlRootElement;@XmlRootElementpublic class Student {    private  String name;    private String gender;    private int age;    public Student(String name, String gender, int age) {        super();        this.name = name;        this.gender = gender;        this.age = age;    }    public Student() {        super();        // TODO Auto-generated constructor stub    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public String getGender() {        return gender;    }    public void setGender(String gender) {        this.gender = gender;    }    public int getAge() {        return age;    }    public void setAge(int age) {        this.age = age;    }    @Override    public String toString() {        return "Student [name=" + name + ", gender=" + gender + ", age=" + age                + "]";    }}

import java.util.List;import javax.xml.bind.annotation.XmlAttribute;import javax.xml.bind.annotation.XmlRootElement;@XmlRootElement(name= "studnets")public class Lstudent {    private List<Student> students;    private String name ;    public Lstudent(){    }    @XmlAttribute    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public List<Student> getStudents() {        return students;    }    public void setStudents(List<Student> students) {        this.students = students;    }}

import javax.xml.bind.annotation.XmlAttribute;import javax.xml.bind.annotation.XmlElement;import javax.xml.bind.annotation.XmlRootElement;@XmlRootElement(name ="AA")public class Tw {    private  String aString;    private String bString;    private String cString;    public Tw() {    }    public Tw(String aString, String bString, String cString) {        super();        this.aString = aString;        this.bString = bString;        this.cString = cString;    }    @XmlElement    public String getaString() {        return aString;    }    public void setaString(String aString) {        this.aString = aString;    }    @XmlAttribute    public String getbString() {        return bString;    }    public void setbString(String bString) {        this.bString = bString;    }    @XmlAttribute(name="passwd")    public String getcString() {        return cString;    }    public void setcString(String cString) {        this.cString = cString;    }    }

public class T_student_Test {    @Test    public void test1() throws Exception{        //JAXBContext 类提供到 JAXB API 的客户端入口点。它提供了管理实现 JAXB 绑定框架操作所需的 XML/Java 绑定信息的抽象，这些操作包括：解组、编组和验证。        JAXBContext jaxbContext = JAXBContext.newInstance(Student.class);        Student student = new Student("小明", "男", 20);        //Marshaller 类负责管理将 Java 内容树序列化回 XML 数据的过程        Marshaller createMarshaller = jaxbContext.createMarshaller();        createMarshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);        File file = new File("d:\\student123.xml");        if(!file .exists()){            file.createNewFile();        }        createMarshaller.marshal(student,new FileOutputStream(file));        //Unmarshaller 类使客户端应用程序能够将 XML 数据转换为 Java 内容对象树。        Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();        Student student2 = (Student)unmarshaller.unmarshal(file);        System.out.println(student2.toString());    }    @Test    public void test2() throws Exception{        Tw tw = new Tw();        tw.setaString("第一个元素");        tw.setbString("第二个元素");        tw.setcString("第三个元素");        JAXBContext.newInstance(Tw.class).createMarshaller().marshal(tw , System.out);    }    @Test    public void test3() throws Exception{        List<Student> list = new ArrayList<Student>();        list.add(new Student("大白", "男", 23));        list.add(new Student("小白", "男", 13));        list.add(new Student("小美", "女", 18));        Lstudent tt = new Lstudent();        tt.setName("abc");        tt.setStudents(list);        Marshaller marshaller = JAXBContext.newInstance(Lstudent.class).createMarshaller();        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);        marshaller.marshal(tt , System.out);    }}

里面有三个注解@XmlRootElement，@XmlElement，@XmlElement
见名都知道是什么意思，所以也没有什么好说的。还是多动手才印象深刻。