使用Apache的Digester解析XML文件

物采系统中，读取*query*.xml文件，使用了Apache的Digester来解析，我做的专家信息导入模块，也需要读取定义在XMl中的导入验证规则。原来使用的是ShiChao提供的SAX解析XML文件方法。现在改为用Digester来解析。

使用的是org.apache.commons.digester3.annotations下的包，annotations顾名思义就是注释模式，可参照：

http://commons.apache.org/digester/guide/annotations.html 上的样例。

我的做法具体如下：

1.我的导入规则验证的XML文件的内容:

 

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

<header name="出生日期">
	<validator type="reg">
		<reg>^\d{4}[\/-]\d{1,2}[\/-]\d{1,2}$</reg>
	</validator>
</header>

<header name="身份证*">
	<validator type="reg">
		<reg>^(\d{17})(\d|[xX])$</reg>
	</validator>
	<validator type="uniq">
		<className>com.cnpc.pms.exp.inf.entity.ExpertInfo</className>
		<filedName>idCardNum</filedName>
	</validator>
</header>

<header name="推荐单位*">
	<validator type="refer">
		<className>com.cnpc.pms.bizbase.rbac.orgview.entity.PurStruOrg</className>
		<filedName>code</filedName>
	</validator>
</header>

<header name="评审专业*">
    <validator type="custom">
		<className>expImportExcelManager</className>
		<methodName>verifyCategory</methodName>
	</validator>
</header>

..................
</validators>

 2.由于使用的是Digester的annotations模式，所以需要建立几个与xml文件内容相互映射的java bean：

  (1).ExpImpValContext类：

package com.cnpc.pms.exp.inf.dto;

import java.util.ArrayList;
import java.util.List;

import org.apache.commons.digester.annotations.rules.ObjectCreate;
import org.apache.commons.digester.annotations.rules.SetNext;
import com.cnpc.pms.base.query.model.PMSQuery;

/**
 * @author Song Shitao
 * @since 2011/7/11
 */
@ObjectCreate(pattern = "validators")
public class ExpImpValContext {

	/** The queries. */
	private List<ExpImpValHeader> headers = new ArrayList<ExpImpValHeader>();

	/**
	 * Adds the header.
	 * 
	 * @param header
	 *            the header
	 */
	@SetNext
	public void addHeader(ExpImpValHeader header) {
		this.headers.add(header);
	}

	/**
	 * Gets the headers.
	 * 
	 * @return the headers
	 */
	public List<ExpImpValHeader> getHeaders() {
		return headers;
	}
}

 (2).ExpImpValHeader类：

package com.cnpc.pms.exp.inf.dto;

import java.util.ArrayList;
import java.util.List;

import org.apache.commons.digester.annotations.rules.ObjectCreate;
import org.apache.commons.digester.annotations.rules.SetNext;
import org.apache.commons.digester.annotations.rules.SetProperty;

/**
 * @author Song Shitao
 * @since 2011/7/11
 */

@ObjectCreate(pattern = "validators/header")
public class ExpImpValHeader {
	/** The name. */
	@SetProperty(attributeName = "name", pattern = "validators/header")
	private String name;
	
	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	/** The validators. */
	private List<ExpImpValidator> validators = new ArrayList<ExpImpValidator>();
	/**
	 * Adds the validator.
	 * 
	 * @param validator
	 *            the validator
	 */
	@SetNext
	public void addValidator(ExpImpValidator validator) {
		this.validators.add(validator);
	}

	/**
	 * Gets the validators.
	 * 
	 * @return the validators
	 */
	public List<ExpImpValidator> getValidators() {
		return validators;
	}
}

 (3).ExpImpValidator类:

package com.cnpc.pms.exp.inf.dto;

import org.apache.commons.digester.annotations.rules.BeanPropertySetter;
import org.apache.commons.digester.annotations.rules.ObjectCreate;
import org.apache.commons.digester.annotations.rules.SetProperty;

/**
 * @author Song Shitao
 * @since 2011/7/11
 */
@ObjectCreate(pattern = "validators/header/validator")
public class ExpImpValidator {
	/** The type. */
	@SetProperty(attributeName = "type", pattern = "validators/header/validator")
	private String type;
	
	@BeanPropertySetter( pattern = "validators/header/validator/className" )    
	private String className;
	@BeanPropertySetter( pattern = "validators/header/validator/filedName" )    
	private String filedName;
	@BeanPropertySetter( pattern = "validators/header/validator/methodName" )    
	private String methodName;
	@BeanPropertySetter( pattern = "validators/header/validator/reg" )    
	private String reg;
	public String getType() {
		return type;
	}
	public void setType(String type) {
		this.type = type;
	}
	public String getClassName() {
		return className;
	}
	public void setClassName(String className) {
		this.className = className;
	}
	public String getFiledName() {
		return filedName;
	}
	public void setFiledName(String filedName) {
		this.filedName = filedName;
	}
	public String getMethodName() {
		return methodName;
	}
	public void setMethodName(String methodName) {
		this.methodName = methodName;
	}
	public String getReg() {
		return reg;
	}
	public void setReg(String reg) {
		this.reg = reg;
	}

}

 注：可以看到在java类里出现了@SetProperty标签和@BeanPropertySetter标签，前者对应的是形如：

       <id value="abc" />这样的映射，后者对应的是形如:<id>abc</id>这样的映射。

3.在main函数中启动：

package com.cnpc.pms.exp.inf.dto;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;

import org.apache.commons.digester.Digester;
import org.apache.commons.digester.annotations.DigesterLoader;
import org.apache.commons.digester.annotations.DigesterLoaderBuilder;
import org.springframework.core.io.Resource;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import com.cnpc.pms.base.util.ConfigurationUtil;

public class Index {
	public static final String DEFAULT_CONFIG_LOCATION = "/conf/expinfo-import-validate-rules.xml";
	public static void main(String[] args) {
		Resource[] resources = ConfigurationUtil
				.getAllResources(DEFAULT_CONFIG_LOCATION);
		if (resources != null) {
			for (int i = 0; i < resources.length; i++) {
				Resource resource = resources[i];
				try {
					ExpImpValContext expImpValContext = parseXMLObject(ExpImpValContext.class, resource);
					List<ExpImpValHeader> list = expImpValContext.getHeaders();
					list.iterator();
				} catch (IOException e) {
				} catch (SAXException e) {
				}
			}
		}
	}
	public static <T> T parseXMLObject(Class<T> clazz, Resource resource) throws IOException, SAXException {
		InputStream is = resource.getInputStream();
		InputSource inputSource = new InputSource(is);
		DigesterLoader digesterLoader =
						new DigesterLoaderBuilder().useDefaultAnnotationRuleProviderFactory()
													.useDefaultDigesterLoaderHandlerFactory();
		Digester digester = digesterLoader.createDigester(clazz);
		return (T) digester.parse(inputSource);
	}
}