jaxb有用过的吗遇到困难了

我用jaxb根据xsd或dtd生成相应的java类然后根据java类生成xml文件可是怎么在一个xml里指定同一个对象多次，因为我的xml里是有多个相同的的元素的比如<student></student>是多个但是jaxb提供的类只能指定一个对象，可能是我没有找到，网上的教程也比较少有知道的贴出来看下，谢谢！

解决方案 »

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Supposed you have
<students>
  <student><name>Jane</name></student>
  <student><name>John</name></student>
</students>In the generated Students.java class, you will find a method:
  public List<Student> getStudents ();You will use:
   students.getStudents().add(aNewStudent) to add a new student to the list.
最后生成xml文件的时候只能指定一个对象!
大家用过xmlspy生成java文件吗？有案例的贴上来我看下谢谢！
构建一个students包装类public class Students{  protected List student;
  public Students(){}  public List getStudent(){
    if (student == null){
       student = new ArrayList();
    }
    return student;
  }
}
XML生成的对象强制类型转换为students类型
Students students = (students)Object;
Iterator it = students.getStudent.iterator();
while(it.hasNext()){
  Student student = (Student)it.next();//即可得到多个student对象。这里之前也要构建一个Student的包装类。
}
你这个应该不是用jaxb做的吧，下面是我的类结构:
objectFacotry:
//
// This file was generated by the JavaTM Architecture for XML Binding(JAXB) Reference Implementation, vhudson-jaxb-ri-2.1-661
// See <a href="http://java.sun.com/xml/jaxb">http://java.sun.com/xml/jaxb</a>
// Any modifications to this file will be lost upon recompilation of the source schema.
// Generated on: 2011.08.15 at 07:19:41 �� CST
//
package com.gangyi.util;
import javax.xml.bind.JAXBElement;
import javax.xml.bind.annotation.XmlElementDecl;
import javax.xml.bind.annotation.XmlRegistry;
import javax.xml.namespace.QName;
/**
* This object contains factory methods for each
* Java content interface and Java element interface
* generated in the com package.
* <p>An ObjectFactory allows you to programatically
* construct new instances of the Java representation
* for XML content. The Java representation of XML
* content can consist of schema derived interfaces
* and classes representing the binding of schema
* type definitions, element declarations and model
* groups.  Factory methods for each of these are
* provided in this class.
*
*/
@XmlRegistry
public class ObjectFactory { private final static QName _Root_QNAME = new QName("", "student");    /**
     * Create a new ObjectFactory that can be used to create new instances of schema derived classes for package: generated
     *
     */
    public ObjectFactory() {
    }    /**
     * Create an instance of {@link Foo }
     *
     */
    public Student createFoo() {
        return new Student();
    }    /**
     * Create an instance of {@link JAXBElement }{@code <}{@link Foo }{@code >}}
     */
    @XmlElementDecl(namespace = "", name = "student")
    public JAXBElement<Student> createRoot(Student value) {
        return new JAXBElement<Student>(_Root_QNAME, Student.class, null, value);
    }
}
package-info:
//
// This file was generated by the JavaTM Architecture for XML Binding(JAXB) Reference Implementation, vhudson-jaxb-ri-2.1-661
// See <a href="http://java.sun.com/xml/jaxb">http://java.sun.com/xml/jaxb</a>
// Any modifications to this file will be lost upon recompilation of the source schema.
// Generated on: 2011.08.15 at 07:19:41 �� CST
//@javax.xml.bind.annotation.XmlSchema(namespace = "http://student.com", elementFormDefault = javax.xml.bind.annotation.XmlNsForm.QUALIFIED)
package com.gangyi.util;student:
//
// This file was generated by the JavaTM Architecture for XML Binding(JAXB) Reference Implementation, vhudson-jaxb-ri-2.1-661
// See <a href="http://java.sun.com/xml/jaxb">http://java.sun.com/xml/jaxb</a>
// Any modifications to this file will be lost upon recompilation of the source schema.
// Generated on: 2011.08.15 at 07:19:41 �� CST
//
package com.gangyi.util;import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlType;
/**
* <p>Java class for anonymous complex type.
*
* <p>The following schema fragment specifies the expected content contained within this class.
*
* <pre>
* <complexType>
*   <complexContent>
*     <restriction base="{http://www.w3.org/2001/XMLSchema}anyType">
*       <sequence>
*         <element name="name" type="{http://student.com}nameType"/>
*         <element ref="{http://student.com}age"/>
*         <element ref="{http://student.com}sex"/>
*         <element ref="{http://student.com}phone"/>
*       </sequence>
*     </restriction>
*   </complexContent>
* </complexType>
* </pre>
*
*
*/
@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "", propOrder = {
    "name",
    "age",
    "sex",
    "phone"
})
@XmlRootElement(name = "student")
public class Student {    @XmlElement(required = true)
    protected String name;
    protected int age;
    @XmlElement(required = true)
    protected String sex;
    @XmlElement(required = true)
    protected String phone;    /**
     * Gets the value of the name property.
     *
     * @return
     *     possible object is
     *     {@link String }
     *
     */
    public String getName() {
        return name;
    }    /**
     * Sets the value of the name property.
     *
     * @param value
     *     allowed object is
     *     {@link String }
     *
     */
    public void setName(String value) {
        this.name = value;
    }    /**
     * Gets the value of the age property.
     *
     */
    public int getAge() {
        return age;
    }    /**
     * Sets the value of the age property.
     *
     */
    public void setAge(int value) {
        this.age = value;
    }    /**
     * Gets the value of the sex property.
     *
     * @return
     *     possible object is
     *     {@link String }
     *
     */
    public String getSex() {
        return sex;
    }    /**
     * Sets the value of the sex property.
     *
     * @param value
     *     allowed object is
     *     {@link String }
     *
     */
    public void setSex(String value) {
        this.sex = value;
    }    /**
     * Gets the value of the phone property.
     *
     * @return
     *     possible object is
     *     {@link String }
     *
     */
    public String getPhone() {
        return phone;
    }    /**
     * Sets the value of the phone property.
     *
     * @param value
     *     allowed object is
     *     {@link String }
     *
     */
    public void setPhone(String value) {
        this.phone = value;
    }}
这个类是我写的上面的是用jaxb生成的
createXml:
package com.gangyi.main;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.util.List;import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBElement;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;import com.gangyi.util.ObjectFactory;
import com.gangyi.util.Student;
/***
* 通过java对象生成xml文件
* @author ChenChao
* @createTime 2011-8-16
*
*/public class createXml {
/**
* 测试方法
* @author ChenChao
* @return
* @param args
*/
public static void main(String[] args) {
try {
//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 context=JAXBContext.newInstance(ObjectFactory.class);
//创建对象工厂用来返回特定格式的信息
ObjectFactory factory=new ObjectFactory();
//创建学生对象
Student student=new Student();
student.setAge(20);
student.setName("张三");
student.setPhone("110");
student.setSex("男");
Student student2=new Student();
student2.setAge(20);
student2.setName("fdsfdsafs");
student2.setPhone("110");
student2.setSex("男");
//获得xml元素信息对象
JAXBElement<Student> s=factory.createRoot(student);
//管理将 Java 内容树序列化回 XML 数据的过程
Marshaller marshaller=context.createMarshaller();
//设置 Marshaller 底层实现中的特定属性。
marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT,true);
FileOutputStream fso=new FileOutputStream("f:\\"+student.getName()+".xml");
//将以s为根的内容树编组到输出流中。
marshaller.marshal(s,fso);
marshaller.marshal(s, fso);
} catch (JAXBException e) {
e.printStackTrace();
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
}
这个应该和你的schema有关吧，如果你的schema定义的students节点中可以出现的student的个数是0到无穷大，生成类的时候student就会被定义成List类型的，就能SET多个了。PS：我也不太懂，应该是这样的。
不知道这个有用不：http://blog.csdn.net/darxin/article/details/4845820

jaxb有用过的吗 遇到困难了

解决方案 »

jaxb有用过的吗遇到困难了