XMLbeans使用教程

Hibernate已经成为目前流行的面向Java环境的对象/关系数据库映射工具.在Hibernate等对象/关系数据库映射工具出现之前,对数 据库的操作是通过JDBC来实现的,对数据库的任何操作,开发人员都要自己写SQL语句来实现. 对象/关系数据库映射工具出现后,对数据库的操作转成对 JavaBean的操作,极大方便了数据库开发. 所以如果有一个类似的工具能够实现将对XML的读写转成对JavaBean的操作,将会简化XML的读写,即使对XML不熟悉的开发人员也能方便地读写 XML. 这个工具就是XMLBean. 

准备一个XML文档(customers.xml),

　　在本文的例子里,我们将对这个文档进行读写操作. 文档源码如下:

 <?xml version="1.0" encoding="UTF-8"?> 

 <Customers> 

     <customer> 

             <id>1</id> 

             <gender>female</gender> 

             <firstname>Jessica</firstname> 

             <lastname>Lim</lastname> 

             <phoneNumber>1234567</phoneNumber> 

             <address> 

                 <primaryAddress> 

                         <postalCode>350106</postalCode> 

                         <addressLine1>25-1</addressLine1> 

                         <addressLine2>SHINSAYAMA 2-CHOME</addressLine2> 

                 </primaryAddress> 

                 <billingAddress> 

                         <receiver>Ms Danielle</receiver> 

                         <postalCode>350107</postalCode> 

                         <addressLine1>167</addressLine1> 

                         <addressLine2>NORTH TOWER HARBOUR CITY</addressLine2> 

                 </billingAddress> 

             </address> 

     </customer> 

     <customer> 

             <id>2</id> 

             <gender>male</gender> 

             <firstname>David</firstname> 

             <lastname>Bill</lastname> 

             <phoneNumber>808182</phoneNumber> 

             <address> 

                 <primaryAddress> 

                         <postalCode>319087</postalCode> 

                         <addressLine1>1033 WS St.</addressLine1> 

                         <addressLine2>Tima Road</addressLine2> 

                 </primaryAddress> 

                 <billingAddress> 

                         <receiver>Mr William</receiver> 

                         <postalCode>672993</postalCode> 

                         <addressLine1>1033 WS St.</addressLine1> 

                         <addressLine2>Tima Road</addressLine2> 

                 </billingAddress> 

             </address> 

     </customer> 

 </Customers> 

　　这是一个客户的数据模型,每个客户都有客户编号(ID),姓名,性别(gender),电话号码(phoneNumber)和地址,其中地址有两个: 首要地址(PrimaryAddress)和帐单地址(BillingAddress),每个地址有邮编,地址1,和地址2组成.其中帐单地址还有收件人 (receiver).

此外,还要准备一个配置文件(文件名customer.xsdconfig),这个文件的作用我后面会讲,它的内容如下:

 <xb:config xmlns:xb="http://xml.apache.org/xmlbeans/2004/02/xbean/config"> 

   <xb:namespace> 

     <xb:package>sample.xmlbean</xb:package> 

   </xb:namespace> 

 </xb:config>  

和其他面向Java环境的对象/关系数据库映射工具的使用步骤一样,在正式使用XMLBean前,我们要作两个准备.

　　1. 生成XML Schema文件

　　什么是XML Schema文件? 正常情况下,每个XML文件都有一个Schema文件,XML Schema文件是一个XML的约束文件,它定义了 XML文件的结构和元素.以及对元素和结构的约束. 通俗地讲,如果说XML文件是数据库里的记录,那么Schema就是表结构定义.

 

　　为什么需要这个文件? XMLBean需要通过这个文件知道一个XML文件的结构以及约束,比如数据类型等. 利用这个Schema文件,XMLBean将会产生一系列相关的Java Classes来实现对XML的操作. 而作为开发人员,则是利用XMLBean产生的 Java Classes来完成对XML的操作而不需要SAX或DOM.怎样产生这个Schema文件呢? 如果对于熟悉XML的开发人员,可以自己来写这个Schema文件,对于不熟悉XML的开发人员,可以通过一些工具来完成.比较有名的如XMLSPY和 Stylus Studio都可以通过XML文件来生成Schema文件. 加入我们已经生成这个Schema文件(customer.xsd): 

<?xml version="1.0" encoding="UTF-8"?> 

        <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" 

                   elementFormDefault="qualified"> 

          <xs:element name="Customers"> 

            <xs:complexType> 

              <xs:sequence> 

                <xs:element maxOccurs="unbounded" name="customer" 

                            type="customerType"/> 

              </xs:sequence> 

            </xs:complexType> 

          </xs:element> 

        <xs:complexType name="customerType"> 

              <xs:sequence> 

                <xs:element name="id" type="xs:int"/> 

                <xs:element name="gender" type="xs:string"/> 

                <xs:element name="firstname" type="xs:string"/> 

                <xs:element name="lastname" type="xs:string"/> 

                <xs:element name="phoneNumber" type="xs:string"/> 

                <xs:element name="address" type="addressType"/> 

              </xs:sequence> 

        </xs:complexType> 

          <xs:complexType name="addressType"> 

              <xs:sequence> 

                <xs:element name="primaryAddress" type="primaryAddressType"/> 

                <xs:element name="billingAddress" type="billingAddressType"/> 

              </xs:sequence> 

          </xs:complexType> 

  

    <xs:complexType name="primaryAddressType"> 

              <xs:sequence> 

                <xs:element name="postalCode" type="xs:string"/> 

                <xs:element name="addressLine1" type="xs:string"/> 

                <xs:element name="addressLine2" type="xs:string"/> 

              </xs:sequence> 

          </xs:complexType> 

          <xs:complexType name="billingAddressType"> 

              <xs:sequence> 

                    <xs:element name="receiver" type="xs:string"/> 

                <xs:element name="postalCode" type="xs:string"/> 

                <xs:element name="addressLine1" type="xs:string"/> 

                <xs:element name="addressLine2" type="xs:string"/> 

              </xs:sequence> 

          </xs:complexType> 

        </xs:schema>  

2. 利用scomp来生成Java Classes

 

　　scomp是XMLBean提供的一个编译工具,它在bin的目录下. 通过这个工具,我们可以将以上的Schema文件生成Java Classes.scomp的语法如下:-

 

　　scomp [options] [dirs]* [schemaFile.xsd]* [service.wsdl]* [config.xsdconfig]*

 

　　主要参数说明:

 

　　-src [dir] -- 生成的Java Classes存放目录

 

　　-srconly -- 不编译Java Classes,不产生Jar文件

 

　　-out [jarFileName] -- 生成的Jar文件,缺省是xmltypes.jar

 

　　-compiler -- Java编译器的路径,即Javac的位置

 

　　schemaFile.xsd -- XML Schema文件位置

 

　　config.xsdconfig -- xsdconfig文件的位置, 这个文件主要用来制定生成的Java Class的一些文件名规则和Package的名称,在本文,package是sample.xmlbean

 

　　在本文,我是这样运行的:

 

       scomp -src build\src  -out build\customerXmlBean.jar schema\customer.xsd

              -compiler C:\jdk142_04\bin\javac customer.xsdconfig

 

　　这个命令行的意思是告诉scomp生成customerXmlBean.jar,放在build目录下,同时生成源代码放在build\src 下, Schema文件是customer.xsd,xsdconfig文件是customer.xsdconfig.其实, 生成的Java源代码没有多大作用,我们要的是jar文件.我们先看一下build\src\sample\xmlbean下生成的Classes.

　　CustomersDocument.java -- 整个XML文档的Java Class映射

　　CustomerType.java -- 节点sustomer的映射

　　AddressType.java -- 节点address的映射

　　BillingAddressType.java -- 节点billingAddress的映射

　　PrimaryAddressType.java -- 节点primaryAddress的映射

　　好了,到此我们所有的准备工作已经完成了. 下面就开始进入重点:利用刚才生成的jar文件读写XML. 

五、利用XMLBean读XML文件

　　新建一个Java Project,将XMLBean2.0.0\lib\下的Jar文件和刚才我们生成的customerXmlBean.jar加入到Project的ClassPath.

　　新建一个Java Class: CustomerXMLBean. 源码如下: 

package com.sample.reader; 

     import java.io.File; 

     import sample.xmlbean.*; 

     import org.apache.commons.beanutils.BeanUtils; 

     import org.apache.xmlbeans.XmlOptions; 

     public class CustomerXMLBean { 

     private String filename = null; 

      

     public CustomerXMLBean(String filename) { 

             super(); 

             this.filename = filename; 

     } 

  

     public void customerReader() { 

             try { 

               File xmlFile = new File(filename); 

               CustomersDocument doc = CustomersDocument.Factory.parse(xmlFile); 

               CustomerType[] customers = doc.getCustomers().getCustomerArray(); 

            

               for (int i = 0; i < customers.length; i++) { 

                 CustomerType customer = customers[i]; 

                 println("Customer" + i); 

                 println("Customer ID:" + customer.getId()); 

                 println("First name:" + customer.getFirstname()); 

                 println("Last name:" + customer.getLastname()); 

                 println("Gender:" + customer.getGender()); 

                 println("PhoneNumber:" + customer.getPhoneNumber()); 

                 // Primary address 

                 PrimaryAddressType primaryAddress = customer.getAddress().getPrimaryAddress(); 

                 println("PrimaryAddress:"); 

                 println("PostalCode:" + primaryAddress.getPostalCode()); 

                 println("AddressLine1:" + primaryAddress.getAddressLine1()); 

                 println("AddressLine2:" + primaryAddress.getAddressLine2()); 

                 // Billing address 

                 BillingAddressType billingAddress = customer.getAddress().getBillingAddress(); 

                 println("BillingAddress:"); 

                 println("Receiver:" + billingAddress.getReceiver()); 

                 println("PostalCode:" + billingAddress.getPostalCode()); 

                 println("AddressLine1:" + billingAddress.getAddressLine1()); 

                 println("AddressLine2:" + billingAddress.getAddressLine2()); 

              

               } 

             } catch (Exception ex) { 

                     ex.printStackTrace(); 

             } 

     } 

     private void println(String str) { 

           System.out.println(str); 

     } 

    public static void main(String[] args) { 

       String filename = "F://JavaTest//Eclipse//XMLBean//xml//customers.xml"; 

                     

      CustomerXMLBean customerXMLBean = new CustomerXMLBean(filename); 

                    customerXMLBean.customerReader(); 

     } 
 }  

运行它,参看输出结果:

 

        Customer0

        Customer ID:1

        First name:Jessica

        Last name:Lim

        Gender:female

        PhoneNumber:1234567

        PrimaryAddress:

        PostalCode:350106

        AddressLine1:25-1

        AddressLine2:SHINSAYAMA 2-CHOME

        BillingAddress:

        Receiver:Ms Danielle

        PostalCode:350107

        AddressLine1:167

        AddressLine2:NORTH TOWER HARBOUR CITY

 

        Customer1

        Customer ID:2

        First name:David

        Last name:Bill

        Gender:male

        PhoneNumber:808182

        PrimaryAddress:

        PostalCode:319087

        AddressLine1:1033 WS St.

        AddressLine2:Tima Road

        BillingAddress:

        Receiver:Mr William

        PostalCode:672993

        AddressLine1:1033 WS St.

        AddressLine2:Tima Road

 

　　怎么样,是不是很轻松? XMLBean的威力. 

六、利用XMLBean写XML文件

 

　　利用XMLBean创建一个XML文档也是一件轻而易举的事.我们再增加一个Method,

 

　　请看一下的Java Class:

 

     public void createCustomer() { 

     try { 

         // Create Document 

         CustomersDocument doc = CustomersDocument.Factory.newInstance(); 

         // Add new customer 

         CustomerType customer = doc.addNewCustomers().addNewCustomer(); 

         // set customer info 

         customer.setId(3); 

         customer.setFirstname("Jessica"); 

         customer.setLastname("Lim"); 

         customer.setGender("female"); 

         customer.setPhoneNumber("1234567"); 

         // Add new address 

         AddressType address = customer.addNewAddress(); 

         // Add new PrimaryAddress 

         PrimaryAddressType primaryAddress = address.addNewPrimaryAddress(); 

         primaryAddress.setPostalCode("350106"); 

         primaryAddress.setAddressLine1("25-1"); 

         primaryAddress.setAddressLine2("SHINSAYAMA 2-CHOME"); 

  

 // Add new BillingAddress 

         BillingAddressType billingAddress = address.addNewBillingAddress(); 

         billingAddress.setReceiver("Ms Danielle"); 

         billingAddress.setPostalCode("350107"); 

         billingAddress.setAddressLine1("167"); 

         billingAddress.setAddressLine2("NORTH TOWER HARBOUR CITY"); 

  

         File xmlFile = new File(filename); 

         doc.save(xmlFile); 

         } catch (Exception ex) { 

                 ex.printStackTrace(); 

         } 

   }  

修改main method.

 

     public static void main(String[] args) { 

     String filename = "F://JavaTest//Eclipse//XMLBean//xml//customers_new.xml"; 

         CustomerXMLBean customerXMLBean = new CustomerXMLBean(filename); 

         customerXMLBean.createCustomer(); 

     }  

运行,打开customers_new.xml:

 

     <?xml version="1.0" encoding="UTF-8"?> 

     <Customers> 

     <customer> 

             <id>3</id> 

             <gender>female</gender> 

             <firstname>Jessica</firstname> 

             <lastname>Lim</lastname> 

             <phoneNumber>1234567</phoneNumber> 

             <address> 

                     <primaryAddress> 

                          <postalCode>350106</postalCode> 

                          <addressLine1>25-1</addressLine1> 

                                        <addressLine2>SHINSAYAMA 2-CHOME</addressLine2> 

                     </primaryAddress> 

                     <billingAddress> 

                         <receiver>Ms Danielle</receiver> 

                         <postalCode>350107</postalCode> 

                        <addressLine1>167</addressLine1> 

                        <addressLine2>NORTH TOWER HARBOUR CITY</addressLine2> 

                     </billingAddress> 

                     </address> 

             </customer> 

     </Customers>  

七、利用XMLBean修改XML文件

 

　　我们再增加一个Method:

 

       public void updateCustomer(int id,String lastname) { 

          try { 

         File xmlFile = new File(filename); 

         CustomersDocument doc = CustomersDocument.Factory.parse(xmlFile); 

         CustomerType[] customers = doc.getCustomers().getCustomerArray(); 

        

         for (int i = 0; i < customers.length; i++) { 

            CustomerType customer = customers[i]; 

           if(customer.getId()==id){ 

                 customer.setLastname(lastname); 

                 break; 

             } 

         } 

         doc.save(xmlFile); 

          } catch (Exception ex) { 

           ex.printStackTrace(); 

          } 

 }

 

　　main method:

 

     public static void main(String[] args) { 

      String filename = "F://JavaTest//Eclipse//XMLBean//xml//customers_new.xml"; 

                      

     CustomerXMLBean customerXMLBean = new CustomerXMLBean(filename); 

                      

     customerXMLBean.updateCustomer(3,"last"); 

     }  

运行之后,我们将会看到客户编号为3的客户的lastname已经改为last.

 

　　八、利用XMLBean删除一个customer

 

　　再增加一个Method:

 

     public void deleteCustomer(int id) { 

      try { 

       File xmlFile = new File(filename); 

      CustomersDocument doc = CustomersDocument.Factory.parse(xmlFile); 

     CustomerType[] customers = doc.getCustomers().getCustomerArray(); 

  

    for (int i = 0; i < customers.length; i++) { 

         CustomerType customer = customers[i];  

         if(customer.getId()==id){ 

                         customer.setNil() ; 

                         break; 

                } 

    } 

    doc.save(xmlFile); 

    } catch (Exception ex) { 

         ex.printStackTrace(); 

         } 

    }  

main method:

 

     public static void main(String[] args) { 

      String filename = "F://JavaTest//Eclipse//XMLBean//xml//customers_new.xml"; 

                      

     CustomerXMLBean customerXMLBean = new CustomerXMLBean(filename); 

                      

     customerXMLBean.updateCustomer(3,"last"); 

     }  

运行之后,我们将会看到客户编号为3的客户的lastname已经改为last.

 

　　八、利用XMLBean删除一个customer

 

　　再增加一个Method:

 

     public void deleteCustomer(int id) { 

      try { 

       File xmlFile = new File(filename); 

      CustomersDocument doc = CustomersDocument.Factory.parse(xmlFile); 

     CustomerType[] customers = doc.getCustomers().getCustomerArray(); 

  

    for (int i = 0; i < customers.length; i++) { 

         CustomerType customer = customers[i];  

         if(customer.getId()==id){ 

                         customer.setNil() ; 

                         break; 

                } 

    } 

    doc.save(xmlFile); 

    } catch (Exception ex) { 

         ex.printStackTrace(); 

         } 

    }  

main method:

 

    

public static void main(String[] args) { 

     String filename = "F://JavaTest//Eclipse//XMLBean//xml//customers_new.xml"; 

                      

     CustomerXMLBean customerXMLBean = new CustomerXMLBean(filename); 

                      

     customerXMLBean.deleteCustomer(3); 

     }  

运行,我们将会看到客户编号为3的客户的资料已经被删除.

　　九、查询XML

　　除了本文在以上讲述的,利用XMLBean能轻轻松松完成XML的读写操作外,结合XPath和XQuery,XMLBean还能完成象SQL查询数据库一样方便地查询XML数据. 关于XML查询以及如何创建XML数据库, 我将在另一篇文章里讨论.

　　十、结束语

　　XMLBean能帮助我们轻易读写XML,这将有助于我们降低XML的学习和使用,有了这个基础,开发人员将为学习更多地XML相关技术和Web Services,JMS等其他J2EE技术打下良好地基础.