一.Jaxb处理java对象和xml之间转换常用的annotation有：

1. @XmlType
2. @XmlElement
3. @XmlRootElement
4. @XmlAttribute
5. @XmlAccessorType
6. @XmlAccessorOrder
7. @XmlTransient
8. @XmlJavaTypeAdapter

　二.常用annotation使用说明

 

1. @XmlType

　　@XmlType用在class类的注解，常与@XmlRootElement，@XmlAccessorType一起使用。它有三个属性：name、propOrder、namespace，经常使用的只有前两个属性。如：

@XmlType(name = "basicStruct", propOrder = {
      "intValue",     "stringArray",     "stringValue" )

在使用@XmlType的propOrder 属性时，必须列出JavaBean对象中的所有属性，否则会报错。

　　2.@XmlElement

　　@XmlElement将java对象的属性映射为xml的节点，在使用@XmlElement时，可通过name属性改变java对象属性在xml中显示的名称。如：

　　@XmlElement(name="Address")

　　

　　private String yourAddress;

　　3.@XmlRootElement

　　@XmlRootElement用于类级别的注解，对应xml的跟元素，常与 @XmlType 和 @XmlAccessorType一起使用。如：

　　@XmlType

　　@XmlAccessorType(XmlAccessType.FIELD)

　　@XmlRootElement

　　public class Address {}

　　4.@XmlAttribute

　　@XmlAttribute用于把java对象的属性映射为xml的属性,并可通过name属性为生成的xml属性指定别名。如：

　　@XmlAttribute(name="Country")

　　private String state;

　　5.@XmlAccessorType

　　@XmlAccessorType用于指定由java对象生成xml文件时对java对象属性的访问方式。常与@XmlRootElement、@XmlType一起使用。它的属性值是XmlAccessType的4个枚举值，分　　　别为：

　　XmlAccessType.FIELD:java对象中的所有成员变量

　　XmlAccessType.PROPERTY：java对象中所有通过getter/setter方式访问的成员变量

　　XmlAccessType.PUBLIC_MEMBER：java对象中所有的public访问权限的成员变量和通过getter/setter方式访问的成员变量

　　XmlAccessType.NONE:java对象的所有属性都不映射为xml的元素

　　注意：@XmlAccessorType的默认访问级别是XmlAccessType.PUBLIC_MEMBER，因此，如果java对象中的private成员变量设置了public权限的getter/setter方法，就不要在　　　private变量上使用@XmlElement和@XmlAttribute注解，否则在由java对象生成xml时会报同一个属性在java类里存在两次的错误。同理，如果@XmlAccessorType的访问权限　　　为XmlAccessType.NONE，如果在java的成员变量上使用了@XmlElement或@XmlAttribute注解，这些成员变量依然可以映射到xml文件。

　　6.@XmlAccessorOrder

　　@XmlAccessorOrder用于对java对象生成的xml元素进行排序。它有两个属性值：

　　AccessorOrder.ALPHABETICAL：对生成的xml元素按字母书序排序

　　XmlAccessOrder.UNDEFINED:不排序

　　7.@XmlTransient

　　@XmlTransient用于标示在由java对象映射xml时，忽略此属性。即，在生成的xml文件中不出现此元素。

　　8.@XmlJavaTypeAdapter

　　@XmlJavaTypeAdapter常用在转换比较复杂的对象时，如map类型或者格式化日期等。使用此注解时，需要自己写一个adapter类继承XmlAdapter抽象类，并实现里面的方法。

　　@XmlJavaTypeAdapter(value=xxx.class),value为自己定义的adapter类

　　XmlAdapter如下：

public abstract class XmlAdapter
    
      {    // Do-nothing constructor for the derived classes.    protected XmlAdapter() {}    // Convert a value type to a bound type.    public abstract BoundType unmarshal(ValueType v);    // Convert a bound type to a value type.    public abstract ValueType marshal(BoundType v); }
    

　三.示例

　　1.Shop.java

package jaxb.shop;import java.util.Set;import javax.xml.bind.annotation.XmlAccessOrder;import javax.xml.bind.annotation.XmlAccessType;import javax.xml.bind.annotation.XmlAccessorType;import javax.xml.bind.annotation.XmlAttribute;import javax.xml.bind.annotation.XmlElement;import javax.xml.bind.annotation.XmlRootElement;import javax.xml.bind.annotation.XmlType;import javax.xml.bind.annotation.XmlElementWrapper;import javax.xml.bind.annotation.XmlAccessorOrder;@XmlAccessorOrder(XmlAccessOrder.ALPHABETICAL)@XmlAccessorType(XmlAccessType.FIELD)@XmlType(name = "shop", propOrder = { "name", "number", "describer", "address","orders" })

@XmlRootElement(name = "CHMart")public class Shop {	@XmlAttribute	private String name;	// @XmlElement	private String number;	@XmlElement	private String describer;	@XmlElementWrapper(name = "orders")	@XmlElement(name = "order")	private Set
     
       orders;	@XmlElement	private Address address;	public Shop() {	}	public Shop(String name, String number, String describer, Address address) {		this.name = name;		this.number = number;		this.describer = describer;		this.address = address;	}	getter/setter略
     

//同时使用了@XmlType（propOrder={}）和@XmlAccessorOrder(XmlAccessOrder.ALPHABETICAL)，但是生成的xml只按照propOrder定义的顺序生成元素

　　2.Order.java

package jaxb.shop;import java.math.BigDecimal;import java.util.Date;import javax.xml.bind.annotation.XmlAccessType;import javax.xml.bind.annotation.XmlAccessorType;import javax.xml.bind.annotation.XmlAttribute;import javax.xml.bind.annotation.XmlRootElement;import javax.xml.bind.annotation.XmlType;import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;@XmlType(name="order",propOrder={"shopName","orderNumber","price","amount","purDate","customer"})@XmlAccessorType(XmlAccessType.FIELD)@XmlRootElementpublic class Order {//	@XmlElement　　	private String shopName;	@XmlAttribute	private String orderNumber;//	@XmlElement	@XmlJavaTypeAdapter(value=DateAdapter.class)	private Date purDate;//	@XmlElement	private BigDecimal price;//	@XmlElement	private int amount;//	@XmlElement	private Customer customer;	public Order() {	}	public Order(String shopName, String orderNumber, Date purDate,			BigDecimal price, int amount) {		this.shopName = shopName;		this.orderNumber = orderNumber;		this.purDate = purDate;		this.price = price;		this.amount = amount;	}

getter/setter略

//@XmlAccessorType(XmlAccessType.FIELD)，所以此处注释掉了@XmlElement，xml中依然会生成这些元素

　　3.Customer.java

package jaxb.shop;import java.util.Set;import javax.xml.bind.annotation.XmlType;import javax.xml.bind.annotation.XmlAttribute;import javax.xml.bind.annotation.XmlElement;import javax.xml.bind.annotation.XmlRootElement;import javax.xml.bind.annotation.XmlAccessType;import javax.xml.bind.annotation.XmlAccessorType;@XmlType@XmlAccessorType(XmlAccessType.FIELD)@XmlRootElementpublic class Customer {	@XmlAttribute	private String name;	private String gender;	private String phoneNo;	private Address address;	private Set
     
       orders;	public Customer() {	}	public Customer(String name, String gender, String phoneNo, Address address) {		this.name = name;		this.gender = gender;		this.phoneNo = phoneNo;		this.address = address;	}
     

getter/setter略

　　4.Address.java

package jaxb.shop;import javax.xml.bind.annotation.XmlAttribute;import javax.xml.bind.annotation.XmlType;import javax.xml.bind.annotation.XmlElement;import javax.xml.bind.annotation.XmlRootElement;import javax.xml.bind.annotation.XmlAccessType;import javax.xml.bind.annotation.XmlAccessorType;import javax.xml.bind.annotation.XmlAccessOrder;import javax.xml.bind.annotation.XmlAccessorOrder;@XmlType(propOrder={"state","province","city","street","zip"})@XmlAccessorOrder(XmlAccessOrder.ALPHABETICAL)@XmlAccessorType(XmlAccessType.NONE)@XmlRootElementpublic class Address {	@XmlAttribute　	private String state;		@XmlElement	private String province;		@XmlElement	private String city;	@XmlElement	private String street;		@XmlElement	private String zip;	public Address() {		super();	}	public Address(String state, String province, String city, String street,			String zip) {		super();		this.state = state;		this.province = province;		this.city = city;		this.street = street;		this.zip = zip;	}

getter/setter略

//注意：虽然@XmlAccessorType为XmlAccessType.NONE,但是在java类的私有属性上加了@XmlAttribute和@XmlElement注解后，这些私有成员会映射生成xml的元素

　　5.DateAdapter.java

package jaxb.shop;import java.util.Date;import java.text.SimpleDateFormat;import javax.xml.bind.annotation.adapters.XmlAdapter;public class DateAdapter extends XmlAdapter
     
       {	private String pattern = "yyyy-MM-dd HH:mm:ss";	SimpleDateFormat fmt = new SimpleDateFormat(pattern);		@Override	public Date unmarshal(String dateStr) throws Exception {				return fmt.parse(dateStr);	}	@Override	public String marshal(Date date) throws Exception {				return fmt.format(date);	}}
     

//用于格式化日期在xml中的显示格式，并且由xml unmarshal为java对象时，将字符串解析为Date对象

　　6.ShopTest.java

package jaxb.shop;import java.io.FileReader;import java.io.FileWriter;import java.io.IOException;import java.math.BigDecimal;import java.util.Date;import java.util.HashSet;import java.util.Set;import javax.xml.bind.JAXBContext;import javax.xml.bind.JAXBException;import javax.xml.bind.Marshaller;import javax.xml.bind.Unmarshaller;public class ShopTest {	public static void main(String[] args) throws JAXBException, IOException{		Set
     
       orders = new HashSet
      
       ();				Address address1 = new Address("China", "ShangHai", "ShangHai", "Huang", "200000");		Customer customer1 = new Customer("Jim", "male", "13699990000", address1);		Order order1 = new Order("Mart", "LH59900", new Date(), new BigDecimal(60), 1);		order1.setCustomer(customer1);				Address address2 = new Address("China", "JiangSu", "NanJing", "ZhongYangLu", "210000");		Customer customer2 = new Customer("David", "male", "13699991000", address2);		Order order2 = new Order("Mart", "LH59800", new Date(), new BigDecimal(80), 1);		order2.setCustomer(customer2);				orders.add(order1);		orders.add(order2);				Address address3 = new Address("China", "ZheJiang", "HangZhou", "XiHuRoad", "310000");		Shop shop = new Shop("CHMart", "100000", "EveryThing",address3);		shop.setOrder(orders);						FileWriter writer = null;		JAXBContext context = JAXBContext.newInstance(Shop.class);		try {			Marshaller marshal = context.createMarshaller();			marshal.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);			marshal.marshal(shop, System.out);						writer = new FileWriter("shop.xml");			marshal.marshal(shop, writer);		} catch (Exception e) {			e.printStackTrace();		}				Unmarshaller unmarshal = context.createUnmarshaller();		FileReader reader = new FileReader("shop.xml") ;		Shop shop1 = (Shop)unmarshal.unmarshal(reader);				Set
       
         orders1 = shop1.getOrder();		for(Order order : orders1){			System.out.println("***************************");			System.out.println(order.getOrderNumber());			System.out.println(order.getCustomer().getName());			System.out.println("***************************");		}	}}
       
      
     

　　7.生成的xml文件

     
         
      
       100000
          
      
       EveryThing
          
      
        
       
        ZheJiang
               
       
        HangZhou
               
       
        XiHuRoad
               
       
        310000
           
    
              
                   
        
         Mart
                    
        
         80
                    
        
         1
                    
        
         2012-03-25 12:57:23
                    
                        
         
          male
                         
         
          13699991000
                         
         
                    
          
           JiangSu
                              
          
           NanJing
                              
          
           ZhongYangLu
                              
          
           210000
                          
            
                
               
                   
        
         Mart
                    
        
         60
                    
        
         1
                    
        
         2012-03-25 12:57:23
                    
                        
         
          male
                         
         
          13699990000
                         
         
                    
          
           ShangHai
                              
          
           ShangHai
                              
          
           Huang
                              
          
           200000
                          
            
                
           
      
     

　　以上是以一个简单的商店订单模型作为示例。