JAXB2.0 Project实例

笔者安装的是Java Web Services Developer Pack是jwsdp-2_0-windows-i586.exe，
You can reach it at:
安装完之后，笔者写了一个Java Application和一个web project，借助Java Web Services Developer Pack工具包中的JAXB，操纵通过xjc工具生成的与xsd文件相对应的Java类，生成该java类的对象，来产生一个xml文件。
下面是笔者编写Java Application的过程。
环境：Window xp,MyEclipse6.0,JDK1.5,JWSDP2.0。
步骤如下：
1、在MyEclipse6.0里面New一个Java Project，命名为：testJABX。

2、导入JAXB的工具包。右键点击testJABX，然后选择Build Path-->Configure Build Path，然后选择libraries选项卡，然后Add External JARS,加入jwsdp-2.0\jaxb\lib这个包下面的jaxb1-impl.jar，jaxb-api.jar，jaxb-impl.jar，jaxb-xjc.jar这四个包。

3、在命令行进入..\jwsdp-2.0\jaxb\bin，然后用xjc +xsd文件名，生成Java类。

4、将生成的类导进你的Java Project，将这些类组织好。
    <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"><xsd:element type="PurchaseOrderType" name="purchaseOrder"><xsd:element type="xsd:string" name="comment"><xsd:complextype name="PurchaseOrderType"><xsd:sequence><xsd:element type="USAddress" name="shipTo"><xsd:element type="USAddress" name="billTo"><xsd:element minoccurs="0" ref="comment"><xsd:complextype name="USAddress"><xsd:sequence><xsd:element type="xsd:string" name="name"><xsd:element type="xsd:string" name="street"><xsd:element type="xsd:string" name="city"><xsd:element type="xsd:string" name="state"><xsd:complextype name="Items"><xsd:sequence><xsd:element maxoccurs="unbounded" minoccurs="1" name="item"><xsd:complextype><xsd:sequence><xsd:element type="xsd:string" name="productName"><xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"><xsd:element name="purchaseOrder" type="PurchaseOrderType"><xsd:element name="comment" type="xsd:string"><xsd:complextype name="PurchaseOrderType"><xsd:sequence><xsd:element name="shipTo" type="USAddress"><xsd:element name="billTo" type="USAddress"><xsd:element ref="comment" minoccurs="0"><xsd:complextype name="USAddress"><xsd:sequence><xsd:element name="name" type="xsd:string"><xsd:element name="street" type="xsd:string"><xsd:element name="city" type="xsd:string"><xsd:element name="state" type="xsd:string"><xsd:complextype name="Items"><xsd:sequence><xsd:element name="item" minoccurs="1" maxoccurs="unbounded"><xsd:complextype><xsd:sequence><xsd:element name="productName" type="xsd:string"><xsd:simpletype name="SKU"><xsd:restriction base="xsd:string"><xsd:pattern value="\d{3}-[A-Z]{2}"></xsd:pattern></xsd:restriction></xsd:simpletype>
    生成的java文件有：Items.java,PurchaseOrderType,USAddress.java,ObjectFactory.java。笔者把它组织在primer.po这个包    下面。
    关于xsd文件生成java文件的资料，读者可以自行上网找，网上大把这样的资料。
    不知怎么回事，贴不上xsd文件。不过，也无关紧要的了

5、写主程序，测试一下。结果是在控制台输出一个xml文件。xml文件中的数据值，是与程序员设置Java对象值一一对应的。
    主程序主要是给xsd生成的Java对象赋值。  
主程序如下：
import java.io.FileOutputStream;
import java.io.IOException;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.GregorianCalendar;
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 javax.xml.bind.*;
import javax.xml.datatype.DatatypeFactory;
import javax.xml.datatype.XMLGregorianCalendar;
import javax.xml.datatype.DatatypeConfigurationException;

import primer.po.*;
 
public class Main {
   
    // This sample application demonstrates how to construct value classes
    // and create a java content tree from scratch and marshal it
    // to XML data
   
    public static void main( String[] args ) {
        try {
            // create a JAXBContext
            JAXBContext jc = JAXBContext.newInstance( "primer.po" );
           
            // create an empty PurchaseOrder
            PurchaseOrderType po = new PurchaseOrderType();
           
            // set the required orderDate attribute
            po.setOrderDate( getDate() );
           
            // create shipTo USAddress object
            USAddress shipTo = createUSAddress( "Alice Smith",
                                                "123 Maple Street",
                                                "Cambridge",
                                                "MA",
                                                "12345" );
                                               
            // set the required shipTo address
            po.setShipTo( shipTo );
           
            // create billTo USAddress object
            USAddress billTo = createUSAddress( "Robert Smith",
                                                "8 Oak Avenue",
                                                "Cambridge",
                                                "MA",
                                                "12345" );
           
            // set the requred billTo address
            po.setBillTo( billTo );
                                               
            // create an empty Items object
            Items items = new Items();
           
            // get a reference to the ItemType list
            List<items.item> itemList = items.getItem();
           
            // start adding ItemType objects into it
            itemList.add( createItem( "Nosferatu - Special Edition (1929)",
                                      new BigInteger( "5" ),
                                      new BigDecimal( "19.99" ),
                                      null,
                                      null,
                                      "242-NO" ) );
            itemList.add( createItem( "The Mummy (1959)",
                                      new BigInteger( "3" ),
                                      new BigDecimal( "19.98" ),
                                      null,
                                      null,
                                      "242-MU" ) );
            itemList.add( createItem( "Godzilla and Mothra: Battle for Earth/Godzilla vs. King Ghidora",
                                      new BigInteger( "3" ),
                                      new BigDecimal( "27.95" ),
                                      null,
                                      null,
                                      "242-GZ" ) );
           
            // set the required Items list
            po.setItems( items );
          
        // create an element for marshalling
        JAXBElement <purchaseordertype> poElement = (new ObjectFactory()).createPurchaseOrder(po);

            // create a Marshaller and marshal to System.out
            Marshaller m = jc.createMarshaller();
            m.setProperty( Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE );
           
            m.marshal(poElement, new FileOutputStream("test.xml"));
           
            m.marshal(poElement, System.out);
           
        } catch( JAXBException je ) {
            je.printStackTrace();
        } catch( IOException ioe ) {
            ioe.printStackTrace();
        }
    }
   
    public static USAddress createUSAddress(  String name, String street,
                                              String city, String state,
                                              String zip ) {
   
        // create an empty USAddress objects                                            
        USAddress address = new USAddress();
      
        // set properties on it
        address.setName( name );
        address.setStreet( street );
        address.setCity( city );
        address.setState( state );
        address.setZip( new BigDecimal( zip ) );
       
        // return it
        return address;
    }
   
    public static Items.Item createItem( String productName,
                                         BigInteger quantity,
                                         BigDecimal price,
                                         String comment,
                                         XMLGregorianCalendar shipDate,
                                         String partNum ) {
  
        // create an empty ItemType object
        Items.Item item = new Items.Item();
       
        // set properties on it
        item.setProductName( productName );
        item.setQuantity( quantity );
        item.setUSPrice( price );
        item.setComment( comment );
        item.setShipDate( shipDate );
        item.setPartNum( partNum );
       
        // return it
        return item;
    }
                                                                       
    private static XMLGregorianCalendar getDate() {
    try {
        return DatatypeFactory.newInstance().newXMLGregorianCalendar(new GregorianCalendar());
    } catch (DatatypeConfigurationException e) {
        throw new Error(e);
        }
    }
}

6、主程序写好之后，发现会报出一个错误：   
      The type javax.xml.stream.XMLStreamWriter cannot be resolved. It is indirectly referenced from required .class files
    这是因为在JDK1.5中，没有 XMLStreamWriter这个类。
    所以，我们需要导进包含 XMLStreamWriter的jar包。这个包是jsr173_1.0_api.jar。读者可以自己去sun的网站上下载。
    本文附件也加了这个jar包。
    因为这个错误，花费了笔者半天的时间，汗。

7、运行主程序，结果出来了。
<purchaseorder orderdate="2007-09-15T12:01:12.375+08:00"><items><item partnum="242-GZ"><usprice></usprice></item></items></purchaseorder>
Well Done！！
</purchaseordertype> </items.item></xsd:element></xsd:sequence></xsd:complextype></xsd:element></xsd:sequence></xsd:complextype></xsd:element></xsd:element></xsd:element></xsd:element></xsd:sequence></xsd:complextype></xsd:element></xsd:element></xsd:element></xsd:sequence></xsd:complextype></xsd:element></xsd:element></xsd:schema></xsd:element></xsd:sequence></xsd:complextype></xsd:element></xsd:sequence></xsd:complextype></xsd:element></xsd:element></xsd:element></xsd:element></xsd:sequence></xsd:complextype></xsd:element></xsd:element></xsd:element></xsd:sequence></xsd:complextype></xsd:element></xsd:element></xsd:schema>