Castor (二) -- 自定义映射

    1.概述
 
castor的自定义映射关系通过xml设置。
主要作用有
1）改变映射位置(node)： attribute， element， text
2）改变映射名字(name...)： attributename， elementtagname
3）改变层级关系(location)
4）改变输出格式(handler)： dateformat...
5）改变属性获取和设置方式(get/setmethod, direct="true")
6）隐藏属性(auto-complete="true", transient="true")
 
2.源码
 
 address.java student.java 详见 <span style="color: #000000;"><a class="quote_div" title="castor(一) -- 默认绑定" href="/blog/1060531" target="_blank">castor (一) -- 默认绑定</a></span> 
 
localdatehandler.java
 

package com.siyuan.castor.handler;import java.text.dateformat;import java.text.parseexception;import java.text.simpledateformat;import java.util.date;import org.exolab.castor.mapping.fieldhandler;import org.exolab.castor.mapping.validityexception;import com.siyuan.castor.student;public class localdatehandler implements fieldhandler {		private static final string local_date_format = "yyyy-mm-dd";		public void checkvalidity(object object) throws validityexception,			illegalstateexception {	}		/**	 * @param object the owner of the field	 */	public object getvalue(object object) throws illegalstateexception {		if (object instanceof student) {			date date = ((student) object).getbirthday();			if (date != null) {				dateformat datefmt = new simpledateformat(local_date_format);				return datefmt.format(date);			} else {				return null;			}		}		return null;	}	public object newinstance(object arg0) throws illegalstateexception {		return null;	}	public void resetvalue(object arg0) throws illegalstateexception,			illegalargumentexception {	}		/**	 * @param object the owner of the field	 * @param datestring the field value in the xml source file	 */	public void setvalue(object object, object datestring)			throws illegalstateexception, illegalargumentexception {		if (object instanceof student) {			dateformat datefmt = new simpledateformat(local_date_format);			try {				date date = datefmt.parse((string) datestring);				((student) object).setbirthday(date);			} catch (parseexception e) {				throw new illegalargumentexception(e);			}					}	}}

 
 divdatehandler.java
 

package com.siyuan.castor.handler;import java.text.dateformat;import java.text.parseexception;import java.text.simpledateformat;import java.util.date;import org.exolab.castor.mapping.generalizedfieldhandler;public class divdatehandler extends generalizedfieldhandler {	private static final string local_date_format = "yyyy-mm-dd";		/**	 * automatically supports iterating over the items of a collection 	 * and passing them one-by-one to the convertuponget	 * 	 * setcollectioniteration : could modify it	 */	public divdatehandler() {		setcollectioniteration(false);	}		/**	 * @override	 * @param value the object value to convert after                 *  performing a get operation	 * @return the converted value.	 */	public object convertuponget(object value) {		if (value == null) 			return null;		dateformat datefmt = new simpledateformat(local_date_format);		return datefmt.format((date) value);	}	/**	 * @override	 * @param value the object value to convert before                 *  performing a set operation                 * @return the converted value.	 */	public object convertuponset(object value) {		if (value == null) 			return null;		dateformat datefmt = new simpledateformat(local_date_format);		date date = null;		try {			date = datefmt.parse((string) value);		} catch (parseexception e) {			throw new illegalargumentexception(e);		}			return date;	}	/**	 * @override	 * returns the class type for the field that this     	 * generalizedfieldhandler converts to and from. this     	 * should be the type that is used in the     	 * object model.     	 *                 * @return the class type of of the field	 */	public class getfieldtype() {		return date.class;	}}

 
configuredatehandler.java
 

package com.siyuan.castor.handler;import java.text.dateformat;import java.text.parseexception;import java.text.simpledateformat;import java.util.date;import java.util.properties;import org.exolab.castor.mapping.configurablefieldhandler;import org.exolab.castor.mapping.fieldhandler;import org.exolab.castor.mapping.validityexception;import com.siyuan.castor.student;public class configuredatehandler implements fieldhandler,		configurablefieldhandler {		private static final string date_format_param_name = "date-format";		private dateformat dateformat;		public void checkvalidity(object arg0) throws validityexception,			illegalstateexception {	}	public object getvalue(object object) throws illegalstateexception {		if (object instanceof student) {			date date = ((student) object).getbirthday();			if (date != null) {				return dateformat.format(date);			} else {				return null;			}		}		return null;	}	public object newinstance(object arg0) throws illegalstateexception {		return null;	}	public void resetvalue(object arg0) throws illegalstateexception,			illegalargumentexception {	}	public void setvalue(object object, object datestring)			throws illegalstateexception, illegalargumentexception {		if (object instanceof student) {			try {				date date = dateformat.parse((string) datestring);				((student) object).setbirthday(date);			} catch (parseexception e) {				throw new illegalargumentexception(e);			}					}	}		/**	 * @param params configure information in the xml	 */	public void setconfiguration(properties params) throws validityexception {		string pattern = params.getproperty(date_format_param_name);		if (pattern == null)			throw new validityexception("required parameter \"" + date_format_param_name + "\" is missing");		try {			dateformat = new simpledateformat(pattern);		} catch (illegalargumentexception e) {			throw new validityexception("pattern \"" + pattern + "\" is not a valid date format.");		}	}}

 
student.cst.xml
 

<!doctype mapping public "-//exolab/castor object mapping dtd version 1.0//en""http://castor.exolab.org/mapping.dtd"><mapping>	<description>used for com.siyuan.castor.student</description>		<!-- 	<include href=""></include>	 -->	 	<!-- 	<field-handler />	 -->	<field-handler name="localdatehandler" class="com.siyuan.castor.handler.configuredatehandler">		<param name="date-format" value="yyyy-mm-dd"/>	</field-handler>		<!-- 	verify-constructable="false" 	used with the set-method="%1-9%"	make it able to omit the no-parameter constructor	 -->	<class name="com.siyuan.castor.student" auto-complete="true">				<description>com.siyuan.castor.student</description>				<map-to xml="person"/>					<!-- 			type="java.lang.string" handler="" required="true" direct="true" transient="true"			 set-method="%1-9%" get-method="getname" type="string" //can not omit the no-parameter constructor		-->		<field name="name">			<description>property name</description>      		<bind-xml name="stuname" node="attribute"/>   		</field>				<!-- 		type="string" handler="com.siyuan.castor.handler.divdatehandler" 		type="string" handler="com.siyuan.castor.handler.localdatehandler" 		//type could not be omitted and must be string		location="birthday/birthday1"		-->		<field name="birthday" type="string" handler="localdatehandler">      		<bind-xml name="birth" node="attribute"/>   		</field>   				<field name="friends" collection="set" type="com.siyuan.castor.student" get-method="getfriends" set-method="addfriend">      		<bind-xml name="friend" node="element"/>   		</field>   		   		<field name="subjects" collection="arraylist" type="string" get-method="getsubjects" set-method="addsubject">      		<bind-xml name="subjects" node="element"/>   		</field>   		   		<field name="teachers" collection="map">      		<bind-xml name="teachers" node="element">	      		<class name="org.exolab.castor.mapping.mapitem">	      			<field name="key" type="java.lang.string">	      				<bind-xml name="name" node="attribute"/>	      			</field>	      			<field name="value" type="java.lang.string">	      				<bind-xml name="subject" node="attribute"/>	      			</field>	      		</class>      		</bind-xml>   		</field>   			</class>		<!-- not used for xml mapping	<key-generator />	 -->	</mapping> 

 
castordiytest.java
 

package com.siyuan.castor.test;import java.io.ioexception;import java.io.inputstream;import java.io.stringreader;import java.io.stringwriter;import java.text.dateformat;import java.text.parseexception;import java.text.simpledateformat;import java.util.arraylist;import java.util.arrays;import java.util.date;import java.util.hashmap;import java.util.hashset;import java.util.list;import java.util.map;import java.util.set;import org.exolab.castor.mapping.mapping;import org.exolab.castor.mapping.mappingexception;import org.exolab.castor.xml.marshalexception;import org.exolab.castor.xml.marshaller;import org.exolab.castor.xml.unmarshaller;import org.exolab.castor.xml.validationexception;import org.xml.sax.inputsource;import com.siyuan.castor.address;import com.siyuan.castor.student;public class castordiytest {	/**	 * @param args	 * @throws validationexception 	 * @throws marshalexception 	 * @throws validationexception 	 * @throws marshalexception 	 */	public static void main(string[] args) throws marshalexception, validationexception{		student stusrc = new student();		stusrc.setage(22);		stusrc.setname("singleman");		stusrc.setmale(true);		address address = new address();		address.setstreet("renmin road");		stusrc.setaddress(address);		dateformat datefmt = new simpledateformat("yyyy-mm-dd");		try {			date birthday = datefmt.parse("1988-11-21");			stusrc.setbirthday(birthday);		} catch (parseexception e) {			e.printstacktrace();		}				student girl = new student();		girl.setage(20);		stusrc.setgirlfriend(girl);				set<student> students = new hashset<student>();		student stu1 = new student();		stu1.setage(21);		students.add(stu1);		student stu2 = new student();		stu2.setage(23);		students.add(stu2);				stusrc.addfriend(stu1);		stusrc.addfriend(stu2);				stusrc.addsubject("english");		stusrc.addsubject("math");		stusrc.addsubject("chinese");				map<string, string> teachers = new hashmap<string, string>();		teachers.put("english", "teacher a");		teachers.put("math", "teacher b");		teachers.put("chinese", "teacher c");		stusrc.setteachers(teachers);				mapping mapping = new mapping();		try {			inputstream mappingfilein = student.class				.getresourceasstream("/com/siyuan/castor/student.cst.xml");			mapping.loadmapping(new inputsource(mappingfilein));						stringwriter result = new stringwriter();			marshaller marshaller = new marshaller();			marshaller.setmapping(mapping);			marshaller.setwriter(result);			marshaller.marshal(stusrc);			system.out.println(result);						system.out.println("=================================================================");						unmarshaller unmarshaller = new unmarshaller(mapping);			student studist = (student) unmarshaller.unmarshal(new stringreader(result.tostring()));			system.out.println(studist);					} catch (mappingexception e) {			e.printstacktrace();		} catch (ioexception e) {			e.printstacktrace();		}	}}

 
3. 输出结果
 

<?xml version="1.0" encoding="utf-8"?><person stuname="singleman" birth="1988-11-21" male="true" age="22"><friend male="false" age="23"/><friend male="false" age="21"/><subjects>english</subjects><subjects>math</subjects><subjects>chinese</subjects><teachers name="english" subject="teacher a"/><teachers name="math" subject="teacher b"/><teachers name="chinese" subject="teacher c"/><girl-friend male="false" age="20"/><address><street>renmin road</street></address></person>=================================================================student[name=singleman,age=22,male=true,birthday=mon nov 21 00:00:00 cst 1988,address=address[street=renmin road],girlfriend=student[name=null,age=20,male=false,birthday=null,address=null,girlfriend=null,friends=[],subjects=[],teachers={}],friends=[student[name=null,age=23,male=false,birthday=null,address=null,girlfriend=null,friends=[],subjects=[],teachers={}], student[name=null,age=21,male=false,birthday=null,address=null,girlfriend=null,friends=[],subjects=[],teachers={}]],subjects=[english, math, chinese],teachers={english=teacher a, math=teacher b, chinese=teacher c}]

 
 
4.参考资料
 
http://www.castor.org/xml-mapping.html
 
http://www.castor.org/xml-fieldhandlers.html#use-configurablefieldhandler-for-more-flexibility
 
附件为mapping文件对应的dtd和xsd文件