Using XMLBean to easily read and write XML

XML becomes more and more important in java applications and is widely used in data storage and exchange. for example, common configuration files are stored in XML format. XML is also applied to technologies such as JavaMessageService and WebServices for data exchange. therefore, correct reading and writing of XML documents is the basis of XML applications. 1. xml parsing

XML becomes more and more important in java applications and is widely used in data storage and exchange. for example, common configuration files are stored in XML format. XML is also used in Java Message Service, Web Services and other technologies as data exchange. therefore, correct reading and writing of XML documents is the basis of XML applications.

Java provides two methods for parsing XML: SAX and DOM, but even so, it is not easy to read and write a slightly complex XML.

II. Introduction to XMLBean

Hibernate has become a popular object/relational database ing tool for Java environments. before the emergence of object/relational database ing tools such as Hibernate, database operations were implemented through JDBC. for any database operations, developers should write their own SQL statements. after the object/relational database ing tool appears, database operations are converted to operations on JavaBean, which greatly facilitates database development. therefore, if there is a similar tool that can convert XML read/write into a JavaBean operation, it will simplify XML read/write, developers who are not familiar with XML can easily read and write XML. this tool is XMLBean.

3. prepare XMLBean and XML documents

XMLBean is an open source project of Apache and can be downloaded from the http://www.apache.org. The latest version is 2.0. the directory after decompression is as follows:

xmlbean2.0.0     +---bin     +---docs     +---lib     +---samples     +---schemas

In addition, you must prepare an XML document (customers. xml ),

In this example, we will read and write this document. the source code of this document is as follows:

 
     
              
   
    1
               
   
    female
               
   
    Jessica
               
   
    Lim
               
   
    1234567
                               
                           
    
     350106
                            #25-1                        SHINSAYAMA 2-CHOME                
                   
                           
    
     Ms Danielle
                            
    
     350107
                            #167                        NORTH TOWER HARBOUR CITY                
                   
      
              
   
    2
               
   
    male
               
   
    David
               
   
    Bill
               
   
    808182
                               
                           
    
     319087
                            1033 WS St.                        Tima Road                
                   
                           
    
     Mr William
                            
    
     672993
                            1033 WS St.                        Tima Road                
                   
  
 

This is a data model of a customer. each customer has a customer ID, name, gender, phoneNumber, and address. the addresses include: primaryAddress and Bill address. each address consists of a zip code, address 1, and address 2. the bill address also contains the recipient ). in addition, a configuration file (File name: customer. xsdconfig). I will talk about the role of this file later. its content is as follows:

   
      
   
    sample.xmlbean
     
  
 

IV. procedure for using XMLBean

Similar to other Java-Oriented Object/relational database ing tools, we need to make two preparations before using XMLBean.

1. generate an XML Schema file

What is an XML Schema file? Under normal circumstances, each XML file has a Schema file, which is an XML constraint file that defines the structure and elements of the XML file. and constraints on elements and structures. in general, if an XML file is a record in a database, Schema is the table structure definition.

Why is this file required? XMLBean needs to use this file to understand the structure and constraints of an XML file, such as the data type. using this Schema file, XMLBean will generate a series of related Java Classes for XML operations. as a developer, Java Classes generated by XMLBean are used to perform XML operations without the need for SAX or DOM. how to generate this Schema file? If you are familiar with XML, you can write this Schema file by yourself. for developers who are not familiar with XML, you can use some tools. for example, XMLSPY and Stylus Studio can generate Schema files through XML files. the Schema file (customer. xsd ):

2. use scomp to generate Java Classes

Scomp is a compilation tool provided by XMLBean. it is in the bin directory. through this tool, we can generate the above Schema file Java Classes. scomp syntax as follows :-

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

Description of main parameters:

-Src [dir] -- generated Java Classes storage directory-srconly -- do not compile Java Classes, do not generate Jar file-out [jarFileName] -- generated Jar file, xmltypes by default. jar-compiler -- Java compiler path, that is, the Javac location schemaFile. xsd -- XML Schema file location

Config. xsdconfig -- the location of the xsdconfig file. This file is mainly used to develop some file naming rules for the generated Java Class and the name of the Package. in this article, the package is sample. xmlbean.

In this article, I run:

 scomp -src build\src  -out build\customerXmlBean.jar schema\customer.xsd             -compiler C:\jdk142_04\bin\javac customer.xsdconfig

This command line tells scomp to generate customerXmlBean. jar, which is placed in the build directory, and the generated source code is put under build \ src. the Schema file is customer. the xsdconfig file is customer. xsdconfig. in fact, the generated Java source code does not have much effect. what we need is the jar file. let's take a look at the Classes generated under build \ src \ sample \ xmlbean.

CustomersDocument. java -- mertype is mapped to the Java Class of the entire XML document. java -- AddressType of node sustomer. java -- Biling of node address BillingAddressType. java -- ing of node billingAddress PrimaryAddressType. java -- ing of node primaryAddress

Now all our preparations have been completed. next we will focus on reading and writing XML using the generated jar file.

5. use XMLBean to read XML files

Create a Java Project and add the Jar file in XMLBean2.0.0 \ lib \ and the customerXmlBean. jar file we just generated to the ClassPath of the Project.

Create a Java Class: mermerxmlbean. the source code is as follows:

 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();    }    }

Run it. see the output result:

  Customer#0       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       Customer#1       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

How is it easy? The power of XMLBean.

6. use XMLBean to write XML files

Creating an XML document using XMLBean is also a breeze. let's add another Method,

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();        }  }

Modify 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();    }

Run and open customers_new.xml:

 
     
     
              
   
    3
               
   
    female
               
   
    Jessica
               
   
    Lim
               
   
    1234567
                                   
                            
    
     350106
                             #25-1                                       SHINSAYAMA 2-CHOME                    
                       
                           
    
     Ms Danielle
                            
    
     350107
                           #167                       NORTH TOWER HARBOUR CITY                    
                                   
      
 

7. use XMLBean to modify XML files

Let's add another 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");    }

After running, we will see that the lastname of the customer with the customer number 3 has been changed to last.

8. use XMLBean to delete a customer

Add another 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);    }

Run, we will see that the customer information with the customer number 3 has been deleted.

9. Query XML

In addition to the above description, XMLBean can easily complete XML read/write operations. combined with XPath and XQuery, XMLBean can also conveniently Query XML data like an SQL query database. I will discuss XML queries and how to create an XML database in another article.

10. Conclusion

XMLBean can help us read and write XML easily, which will help us to learn and use XML. With this foundation, developers will learn more XML-related technologies and Web Services, other J2EE technologies such as JMS lay a good foundation.

The above is the use of XMLBean to easily read and write XML content. For more information, please follow the PHP Chinese network (www.php1.cn )!