一个jaxb的例子看java object和xml之间的转换
这段时间在研究o/x mapping，即Java object和xml之间的转换以及xml文件验证的问题，自己也动手开发了一个小的演示例子，如下所示：
--------开发环境-----
1.jdk1.5
2.jwsdp2.0（Java Web Services Developer Pack 2.0， sun的官网上有的下）
3.程序中需要用到的jar包：
%jwsdp2.0安装目录下%/jaxb/lib/jaxb-api.jar
%jwsdp2.0安装目录下%/jaxb/lib/jaxb-impl.jar
%jwsdp2.0安装目录下%/sjsxp/lib/jsr173_api.jar
%jwsdp2.0安装目录下%/jwsdp-shared/lib/activation.jar
4.开发工具：eclipse3.2
---------------------
定义一个XML schema文件--library.xsd
再定义jwsdp的xjc工具的binding文件---binding.xjb
注意！binding文件的编码格式要用UTF-8，如果直接把代码粘到eclipse里编码格式就不是UTF-8了，这时xjc工具就要报错了，解决办法就是把这个文件用UltraEdit工具转一下。
可以通过binding文件和xsd文件用jaxb自带的xjc工具自动生成java object，是不是很棒啊^_^
现在写o/x mapping的测试主类----Main.java
以上代码的核心是xml文件的编组和解组，用到了接口javax.xml.bind.Marshaller(Marshaller 类负责管理将 Java 内容树序列化回 XML 数据的过程,它提供了基本的编组方法marshal), 以及接口javax.xml.bind.Unmarshaller(Unmarshaller 类管理将 XML 数据反序列化为新创建的 Java 内容树的过程，并可在解组时有选择地验证 XML 数据。它针对各种不同的输入种类提供各种重载的 unmarshal 方法。), 至于xml文件的验证是在解组的时候，调用方法unmarshal会触发验证的机制，验证xml文件是否符合schema的规范。
下面定义build.xml，用ant工具来完成整个项目的编译和运行，方便快捷，^_^
我已经将演示项目的完整代码打包上传到附件了，测试通过，方便网友们下载，有不足之处愿与大家切磋
--------开发环境-----
1.jdk1.5
2.jwsdp2.0（Java Web Services Developer Pack 2.0， sun的官网上有的下）
3.程序中需要用到的jar包：
%jwsdp2.0安装目录下%/jaxb/lib/jaxb-api.jar
%jwsdp2.0安装目录下%/jaxb/lib/jaxb-impl.jar
%jwsdp2.0安装目录下%/sjsxp/lib/jsr173_api.jar
%jwsdp2.0安装目录下%/jwsdp-shared/lib/activation.jar
4.开发工具：eclipse3.2
---------------------
定义一个XML schema文件--library.xsd
<?xml version="1.0" encoding="UTF-8"?> <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" attributeFormDefault="unqualified"> <xs:element name="librarys" type="librarys"/> <xs:complexType name="librarys"> <xs:sequence> <xs:element name="library" minOccurs="1" maxOccurs="unbounded"> <xs:complexType> <xs:sequence> <xs:element name="name" type="xs:string"/> <xs:element name="layer" type="xs:int"/> <xs:element name="row" type="xs:int"/> <xs:element name="book" type="book"/> </xs:sequence> </xs:complexType> </xs:element> </xs:sequence> </xs:complexType> <xs:complexType name="book"> <xs:sequence> <xs:element name="bookID" type="xs:string"/> <xs:element name="bookName" type="xs:string"/> <xs:element name="borrowDate" type="xs:date"/> <xs:element name="user" type="user"/> </xs:sequence> <xs:attribute name="description" type="xs:string"/> </xs:complexType> <xs:complexType name="user"> <xs:sequence> <xs:element name="userID" type="xs:string"/> <xs:element name="userName" type="xs:string"/> <xs:element name="userAge" type="xs:int"/> </xs:sequence> </xs:complexType> </xs:schema>
再定义jwsdp的xjc工具的binding文件---binding.xjb
<jxb:bindings version="1.0" xmlns:jxb="http://java.sun.com/xml/ns/jaxb" xmlns:xs="http://www.w3.org/2001/XMLSchema">
<jxb:bindings schemaLocation="library.xsd" node="/xs:schema"><!-- schemaLocation属性是xsd文件的相对路径 -->
<jxb:globalBindings
fixedAttributeAsConstantProperty="true"
collectionType="java.util.ArrayList"
typesafeEnumBase="xs:NCName"
choiceContentProperty="false"
typesafeEnumMemberName="generateError"
enableFailFastCheck="false"
generateIsSetMethod="false"
underscoreBinding="asCharInWord"/>
<jxb:schemaBindings>
<jxb:package name="com.cuishen.o_x_mapping.object"/>
<!-- 这里是生成的JAVA类文件存放包名 -->
<jxb:nameXmlTransform>
<jxb:elementName suffix="Element"/>
</jxb:nameXmlTransform>
</jxb:schemaBindings>
<!-- 这里是定义xsd中一个复合类型与Java类的映射（如果要修改才定义，不修改则不需要） -->
<jxb:bindings node="//xs:complexType[@name='librarys']">
<jxb:class name="Librarys"/>
</jxb:bindings>
<jxb:bindings node="//xs:complexType[@name='book']">
<jxb:class name="Book"/>
<!-- 这里是定义复合类型的一个元素名称与Java类中属性的映射（如果要修改才定义，不修改则不需要） -->
<jxb:bindings node=".//xs:element[@name='bookID']">
<jxb:property name="id"/>
</jxb:bindings>
</jxb:bindings>
<jxb:bindings node="//xs:complexType[@name='user']">
<jxb:class name="User"/>
<!-- 这里是定义复合类型的一个元素名称与Java类中属性的映射（如果要修改才定义，不修改则不需要） -->
<jxb:bindings node=".//xs:element[@name='userID']">
<jxb:property name="id"/>
</jxb:bindings>
</jxb:bindings>
</jxb:bindings>
</jxb:bindings>
注意！binding文件的编码格式要用UTF-8，如果直接把代码粘到eclipse里编码格式就不是UTF-8了，这时xjc工具就要报错了，解决办法就是把这个文件用UltraEdit工具转一下。
可以通过binding文件和xsd文件用jaxb自带的xjc工具自动生成java object，是不是很棒啊^_^
现在写o/x mapping的测试主类----Main.java
package com.cuishen.o_x_mapping;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.GregorianCalendar;
import java.util.List;
import javax.xml.XMLConstants;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBElement;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;
import javax.xml.bind.ValidationEvent;
import javax.xml.bind.ValidationEventHandler;
import javax.xml.bind.ValidationEventLocator;
import javax.xml.datatype.DatatypeConfigurationException;
import javax.xml.datatype.DatatypeFactory;
import javax.xml.datatype.XMLGregorianCalendar;
import javax.xml.validation.Schema;
import javax.xml.validation.SchemaFactory;
import com.cuishen.o_x_mapping.object.Book;
import com.cuishen.o_x_mapping.object.Librarys;
import com.cuishen.o_x_mapping.object.User;
import com.cuishen.o_x_mapping.object.ObjectFactory;
import com.cuishen.o_x_mapping.utils.FileUtils;;
/**
* o/x mapping测试主类
* @author cuishen
* @date 2008-4-2
* @version 1.0
*/
public class Main {
public static void object2xml() {
try {
JAXBContext context = JAXBContext.newInstance("com.cuishen.o_x_mapping.object");
Librarys libs = new Librarys();
List<Librarys.Library> libList = libs.getLibrary();
User usr = createUser("1011", 28, "cuishen");
Book book = createBook("成长比成功更重要", getDate(), "成功励志书", "88-91-211", usr);
libList.add(createLibrary("上海图书馆", 2, 4, book));
usr = createUser("1017", 22, "sanmao");
book = createBook("七龙珠", getDate(), "漫画", "34-16-310", usr);
libList.add(createLibrary("徐汇图书馆", 3, 11, book));
// create an element for marshalling
JAXBElement<Librarys> element = (new ObjectFactory()).createLibrarys(libs);
Marshaller m = context.createMarshaller();
m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
m.setProperty("jaxb.encoding", "gbk");
m.marshal(element, System.out);
File xmlFile = FileUtils.makeFile(getXmPath());
OutputStream ot = new FileOutputStream(xmlFile);
m.marshal(element, ot);
} catch (JAXBException e) {
e.printStackTrace();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public static void xml2object(Unmarshaller u) {
try {
//JAXBContext jc = JAXBContext.newInstance( "com.cuishen.o_x_mapping.object" );
//Unmarshaller u = jc.createUnmarshaller();
// unmarshal a po instance document into a tree of Java content
// objects composed of classes from the com.cuishen.o_x_mapping.object package.
JAXBElement poe = (JAXBElement)u.unmarshal(new FileInputStream(getXmPath()));
Librarys librarys = (Librarys)poe.getValue();
List libList = librarys.getLibrary();
for(int i = 0; i < libList.size(); i++) {
Librarys.Library lib = (Librarys.Library)libList.get(i);
System.out.println("librarys ==> ");
System.out.println("===> library :");
System.out.println("=========> layer " + lib.getLayer());
System.out.println("=========> name " + lib.getName());
System.out.println("=========> row " + lib.getRow());
System.out.println("=========> book :");
Book book = lib.getBook();
System.out.println("=============> id " + book.getId());
System.out.println("=============> borrowDate " + book.getBorrowDate());
System.out.println("=============> name " + book.getBookName());
System.out.println("=============> desc " + book.getDescription());
System.out.println("=============> user :");
User usr = book.getUser();
System.out.println("==================> userID " + usr.getId());
System.out.println("==================> userName " + usr.getUserName());
System.out.println("==================> Age " + usr.getUserAge());
}
} catch( JAXBException je ) {
je.printStackTrace();
} catch( IOException ioe ) {
ioe.printStackTrace();
}
}
/**
* 对xml文件解组时的验证
* @return boolean
*/
public static Unmarshaller validate() {
// create a JAXBContext capable of handling classes generated into
// the com.cuishen.o_x_mapping.object package
JAXBContext jc;
Unmarshaller u = null;
try {
jc = JAXBContext.newInstance( "com.cuishen.o_x_mapping.object" );
u = jc.createUnmarshaller();
SchemaFactory sf = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
try {
Schema schema = sf.newSchema(new File(getXSDPath()));
u.setSchema(schema);
u.setEventHandler(
new ValidationEventHandler() {
public boolean handleEvent(ValidationEvent ve) {
if (ve.getSeverity() == ValidationEvent.WARNING || ve.getSeverity() != ValidationEvent.WARNING) {
ValidationEventLocator vel = ve.getLocator();
System.out.println("Line:Col[" + vel.getLineNumber() + ":" + vel.getColumnNumber() + "]:" + ve.getMessage());
return false;
}
return true;
}
}
);
} catch (org.xml.sax.SAXException se) {
System.out.println("Unable to validate due to following error.");
se.printStackTrace();
} catch (MalformedURLException e) {
e.printStackTrace();
}
} catch (JAXBException e) {
e.printStackTrace();
}
return u;
}
private static String getXmPath() throws MalformedURLException {
String xmlPath = FileUtils.extractDirPath(FileUtils.extractDirPath(Main.class.getClassLoader().getResource(".").toString()));
xmlPath = FileUtils.makeFilePath(xmlPath, "src/com/cuishen/o_x_mapping/xml/library.xml");
URL url = new URL(xmlPath);
return url.getPath();
}
private static String getXSDPath() throws MalformedURLException {
String xsdPath = FileUtils.extractDirPath(FileUtils.extractDirPath(Main.class.getClassLoader().getResource(".").toString()));
xsdPath = FileUtils.makeFilePath(xsdPath, "library.xsd");
URL url = new URL(xsdPath);
System.out.println("xsd path ==========> " + url.getPath());
return url.getPath();
}
public static void main(String args[]) {
System.out.println("======== object to xml ...");
object2xml();
System.out.println("======== xml to object ...");
xml2object(validate());
}
public static Librarys.Library createLibrary(String name, int layer, int row, Book book) {
Librarys.Library library = new Librarys.Library();
library.setName(name);
library.setLayer(layer);
library.setRow(row);
library.setBook(book);
return library;
}
public static Book createBook(String name, XMLGregorianCalendar date, String desc, String id, User usr) {
Book book = new Book();
book.setBookName(name);
book.setBorrowDate(date);
book.setDescription(desc);
book.setId(id);
book.setUser(usr);
return book;
}
public static User createUser(String id, int age, String name) {
User usr = new User();
usr.setId(id);
usr.setUserAge(age);
usr.setUserName(name);
return usr;
}
private static XMLGregorianCalendar getDate() {
try {
return DatatypeFactory.newInstance().newXMLGregorianCalendar(new GregorianCalendar());
} catch (DatatypeConfigurationException e) {
throw new Error(e);
}
}
}
以上代码的核心是xml文件的编组和解组，用到了接口javax.xml.bind.Marshaller(Marshaller 类负责管理将 Java 内容树序列化回 XML 数据的过程,它提供了基本的编组方法marshal), 以及接口javax.xml.bind.Unmarshaller(Unmarshaller 类管理将 XML 数据反序列化为新创建的 Java 内容树的过程，并可在解组时有选择地验证 XML 数据。它针对各种不同的输入种类提供各种重载的 unmarshal 方法。), 至于xml文件的验证是在解组的时候，调用方法unmarshal会触发验证的机制，验证xml文件是否符合schema的规范。
下面定义build.xml，用ant工具来完成整个项目的编译和运行，方便快捷，^_^
<project basedir="." default="run">
<!--这里是jwsdp的安装目录 -->
<property name="jwsdp.home" value="d:\Sun\jwsdp-2.0"/>
<!--这里是log4j的安装目录 -->
<property name="log4j.home" value="D:\conserv\o-x-mapping\implement\lib"/>
<path id="xjc.classpath">
<pathelement path="src"/>
<pathelement path="bin"/>
<pathelement path="lib"/>
<pathelement path="schemas"/>
<!--for use with bundled ant-->
<fileset dir="${jwsdp.home}" includes="jaxb/lib/*.jar"/>
<fileset dir="${jwsdp.home}" includes="sjsxp/lib/*.jar"/>
<fileset dir="${jwsdp.home}" includes="jwsdp-shared/lib/activation.jar"/>
<fileset dir="${jwsdp.home}" includes="jwsdp-shared/lib/resolver.jar"/>
<fileset dir="${log4j.home}" includes="log4j-1.2.5.jar"/>
</path>
<taskdef name="xjc" classname="com.sun.tools.xjc.XJCTask">
<classpath refid="xjc.classpath" />
</taskdef>
<!--compile Java source files-->
<target name="compile" description="Compile all Java source files">
<echo message="Compiling the schema..." />
<!-- mkdir dir="src" /-->
<xjc schema="library.xsd" binding="binding.xjb" destdir="src"/>
<echo message="Compiling the java source files..." />
<mkdir dir="bin" />
<javac destdir="bin" debug="on">
<src path="src" />
<classpath refid="xjc.classpath" />
</javac>
</target>
<target name="run" depends="compile" description="Run the sample app">
<echo message="Running the sample application..." />
<java classname="com.cuishen.o_x_mapping.Main" fork="true">
<classpath refid="xjc.classpath" />
</java>
</target>
</project>
我已经将演示项目的完整代码打包上传到附件了，测试通过，方便网友们下载，有不足之处愿与大家切磋