解析XML文件的几种方式

前言

虽然更喜欢用json,但是xml更灵活，在配置文件的时候更方便

要用SAXRead需要的jar包

dom4j-1.6.1.jar, jaxen-1.1-beta-10.jar

XML文件格式如下

  
  
<tables>  
    <table tablename="people">
        <fieldname fieldname="name" type="string"/>
        <fieldname fieldname="age" type="int"/>
        <splitsign rule="," />
    table>

    <table tablename="book">
        <fieldname fieldname="name" type="string"/>
        <fieldname fieldname="price" type="int"/>
        <splitsign rule="." />
    table>

    <table tablename="cat">
        <fieldname fieldname="color" type="string"/>
        <fieldname fieldname="category" type="string"/>
        <splitsign rule=" " />
    table>

    <table tablename="people1">
        <fieldname fieldname="name" type="string"/>
        <fieldname fieldname="age" type="int"/>
        <fieldname fieldname="sex" type="string"/>
        <splitsign rule="," />
    table>

tables>  

读取所有的表名称

private String configPath="conf/config_table.xml";
        /**
         * 
         * @return an arrayList tableList
         * @throws DocumentException
         */
        public ArrayList getTableName() throws DocumentException{
            ArrayList tableNameArray = new ArrayList();

            SAXReader reader = new SAXReader();  

            Document document = reader.read(new File(configPath));  

            String xpathtable = "//tables//table";
            List list = document.selectNodes(xpathtable);
            Iterator iter = list.iterator();
            while(iter.hasNext()){
                Element element = (Element) iter.next();
                tableNameArray.add(element.attribute(0).getValue());

            }
            return tableNameArray;
        }

根据表名称，获取所有的字段以及属性

 /**
         * @param table name
         * @return  an String[] String[0] is field, String[1] is sttribute
         * @throws DocumentException
         */
        public String[] getFieldAndAttr(String tablename) throws DocumentException{
            // Initialize table field
            String fieldString = "";
            // Initialize table attribute
            String attrString="";
            // Initialize the split sign
            String splitsignString = "";

            String[] tableFieldAndAttr=null;

            SAXReader reader = new SAXReader();  
            Document document = reader.read(new File(configPath));  

            String xpath = "//tables//table[@tablename='"+tablename+"']//fieldname";
            List list = document.selectNodes(xpath);
            Iterator iter = list.iterator();
            while(iter.hasNext()){
                Element element = (Element) iter.next();
                // connect the field
                fieldString = fieldString+element.attribute(0).getValue()+ " ";
                // connect the attribute
                attrString = attrString+element.attribute(1).getValue()+ " ";
            }
            // remove the last character
            fieldString = fieldString.substring(0,fieldString.length()-1);
            attrString = attrString.substring(0,attrString.length()-1);

            String xpathSplit = "//tables//table[@tablename='"+tablename+"']//splitsign";
            List signlist = document.selectNodes(xpathSplit);
            Iterator splititer = signlist.iterator();
            while(splititer.hasNext()){
                Element splitElement = (Element) splititer.next();
                splitsignString = splitsignString+splitElement.attribute(0).getValue();
            }

            tableFieldAndAttr = new String[]{fieldString,attrString,splitsignString};
            return tableFieldAndAttr;

        }  

另外介绍一下XMLConfiguration, 将所有的字段以及属性放入到map中, 使用XMLConfiguration

需要引入的jar包commons-configuration-1.0.jar,

package teststring;

import org.apache.commons.configuration.ConfigurationException;
import org.apache.commons.configuration.XMLConfiguration;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

/**
 * Created by Administrator on 2017/3/21.
 */
public class TestConf {

    public static void main(String[] args) {
        Map dataMap=new HashMap();
        try {
            XMLConfiguration config = new XMLConfiguration("conf/datawatch_config.xml");
            config.setEncoding("UTF-8");
            config.setDelimiterParsingDisabled(true);
            Iterator iter = config.getKeys();
            while (iter.hasNext())
            {
                String key = iter.next().toString();
                dataMap.put(key, config.getProperty(key));
            }

        } catch (ConfigurationException e) {
            e.printStackTrace();
        }
    }
}

XMLconfig的XPATH的使用, 使用XPATH解析， xpath是我比较喜欢的一种解析方式

<comm>
  <data>
    <name>zksname>
   <age>24age>
  data>
  <data>
    <name>skzname>
    <age>23age>
  data>
comm>

需要引入的jar包 commons-jxpath-1.3.jar,
commons-configuration-1.0.jar
其中 commos-jaxpath-1.3下载地址

 XMLConfiguration config = new XMLConfiguration("conf/datawatch_config.xml");
 //注意下面的两句话，必须这样才能使用xpath去解析
XPathExpressionEngine xPathExpressionEngine = new XPathExpressionEngine();
config.setExpressionEngine(xPathExpressionEngine);
System.out.println(config.getString("data[1]/name"));
System.out.println(config.getString("data[2]/name"));
System.out.println(config.getString("data[name='skz']/age"));

将会输出
zks
skz
23

更多XPATH解析方法参考 菜鸟教程

补充

xml如下

<comm>
  <data>
    <name>zksname>
   <age>24age>
   <sex>mansex>
  data>
  <data>
    <name>skzname>
    <age>23age>
  data>
comm>

如果我想得到第一个data下的所有的， 然后按照上面的，存入map中，怎么做呢， 我们可以得到data下的这个config，可以使用SubnodeConfiguration subnodeConfiguration = config.configurationAt(key),代码如下

 SubnodeConfiguration subnodeConfiguration = config.configurationAt("data[1]");
// 下面就可以用了
 Iterator itea1 = subnodeConfiguration.getKeys();
                while (itea1.hasNext()){
                    System.out.println("iter.next().toString(): "+itea1.next().toString());
                     System.out.println("conf.getProperty"+subnodeConfiguration.getProperty(key));
                }

参考自stackoverflow 和 http://commons.apache.org/proper/commons-configuration/userguide/howto_xml.html