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Castor -- 将Java对象和XML自动绑定的程序

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  1. Castor是什么
  
  Castor是一种将Java对象和XML自动绑定的开源软件. 它可以在Java对象,XML文本,SQL数据表以及LDAP目录之间绑定.
  
  ²网址: http://www.castor.org/
  
  2. Castor使用
  
  ²Java对象指的是具有setX和getX方法的JavaBean,将Castor用于JavaBean具体使用方法如下:
  
  Ø缺省用法: 缺省用法指的是没有使用映射格式描述文件时的用法
  
  import java.io.*;
  
  import org.exolab.castor.xml.*;
  
  public class Test
  
  {
  
  public static void main(String[] argv) {
  
  // build a test bean
  
  FlightBean bean = new FlightBean();
  
  bean.setCarrier("AR");
  
  bean.setNumber(426);
  
  bean.setDepartureTime("6:23a");
  
  bean.setArrivalTime("8:42a");
  
  try {
  
  // write it out as XML
  
  File file = new File("test.xml");
  
  Writer writer = new FileWriter(file);
  
  Marshaller.marshal(bean, writer);
  
  // now restore the value and list what we get
  
  Reader reader = new FileReader(file);
  
  FlightBean read = (FlightBean)
  
  Unmarshaller.unmarshal(FlightBean.class, reader);
  
  System.out.println("Flight " + read.getCarrier() +
  
  read.getNumber() + " departing at " +
  
  read.getDepartureTime() +
  
  " and arriving at " + read.getArrivalTime());
  
  } catch (IOException ex) {
  
  ex.printStackTrace(System.err);
  
  } catch (MarshalException ex) {
  
  ex.printStackTrace(System.err);
  
  } catch (ValidationException ex) {
  
  ex.printStackTrace(System.err);
  
  }
  
  }
  
  }
  
  Ø 标准用法:
  
  import java.io.*;
  
  import org.exolab.castor.xml.*;
  
  import org.exolab.castor.mapping.*;
  
  
  public class Test
  
  {
  
  public static void main(String[] argv) {
  
  // build a test bean
  
  FlightBean bean = new FlightBean();
  
  bean.setCarrier("AR");
  
  bean.setNumber(426);
  
  bean.setDepartureTime("6:23a");
  
  bean.setArrivalTime("8:42a");
  
  try {
  
  // write it out as XML
  
  Mapping map=new Mapping();
  
  map.loadMapping("mapping.xml");
  
  File file = new File("test.xml");
  
  Writer writer = new FileWriter(file);
  
  Marshaller marshaller =new Marshaller(writer);
  
  marshaller.setMapping(map);
  
  marshaller.marshal(bean);
  
  // now restore the value and list what we get
  
  Reader reader = new FileReader(file);
  
  Unmarshaller unmarshaller = new Unmarshaller(map);
  
  FlightBean read = (FlightBean)unmarshaller.unmarshal(reader);
  
  System.out.println("Flight " + read.getCarrier() +
  
  read.getNumber() + " departing at " +
  
  read.getDepartureTime() +" and arriving at " + read.getArrivalTime());
  
  } catch (IOException ex) {
  
  ex.printStackTrace(System.err);
  
  } catch (MarshalException ex) {
  
  ex.printStackTrace(System.err);
  
  } catch (ValidationException ex) {
  
  ex.printStackTrace(System.err);
  
  }
  
  catch (MappingException ex) {
  
  ex.printStackTrace(System.err);
  
  }
  
  }
  
  }
  
  Ø :缺省用法生成的XML文件如下:
  
  <?xml version="1.0" encoding="UTF-8"?>  
  <arrival-time>8:42a</arrival-time>
  <departure-time>6:23</departure-time>
  <carrier>AR</carrier>
  
  也就是说
  •对于具有基本类型值的属性创建元素的一个属性(本例中只有 number 属性通过 getNumber() 方法公开为 int 值)。
  
  •对于每个具有对象类型值的属性创建根元素的一个子元素(本例中的所有其他属性,因为它们是字符串)。
  
  标准用法生成的XML文件如下:


  <?xml version="1.0" encoding="UTF-8"?>
  <flight carrier="AR" depart="6:23a" arrive="8:42a" number="426"/>
  这一般是我们期望的,只所以生成我们所期望的格式,是因为我们使用了映射格式描述文件。它也是XML文件:
  
  <!DOCTYPE databases PUBLIC "-//EXOLAB/Castor Mapping DTD Version 1.0//EN" "http://castor.exolab.org/mapping.dtd">

          <mapping> 

               <description>Basic mapping example</description> 

               <class name="castortest.FlightBean" auto-complete="true">  

                     <map-to xml="flight"/>  

                     <field name="carrier">   

                          <bind-xml name="carrier" node="attribute"/>  

                     </field>  

                     <field name="departureTime">   

                           <bind-xml name="depart" node="attribute"/>  

                      </field>  

                     <field name="arrivalTime">   

                            <bind-xml name="arrive" node="attribute"/> 

                   </field>

              </class>

            </mapping>

 

      •注意class标签里name应该是带有包名的JavaBean类全名


  •map-to xml="flight"指XML文件的根节点,区分大小写
  
  •auto-complete=”false”或没有auto-complete属性时number属性会没有

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