自己写的一个SystemConfig，备份下

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java 代码

package org.wanwei.test.xmlreader;

import java.io.InputStream;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.apache.log4j.Logger;
import org.jdom.Document;
import org.jdom.Element;
import org.jdom.input.SAXBuilder;

/**
 * 读取系统配置文件systemConfig.xml.
 * 只支持读取简单的XML配置:
 * eg:
 *                2007-06-20
 *
 * 不支持带属性的XML读取:
 *
 * @author wanwei
 * @since 2007-7-4
 */
public class SystemConfig
{
    private static final Logger logger = Logger.getLogger(SystemConfig.class);

    private static final String DEFAULT_SPLIT = "/";

    private static final Map cacheMap = new HashMap();

    private static boolean initialize = false;
    /**
     * 从systemConfig.xml文件中读取相应配置
     * note:第一次读取需要初始化,以后都从缓存中读取.
     * @param configPath eg:/config/assocication/bj_comp_eff_date
     * @return String not null or empty
     * @throws Exception "unmatching configPath" will throw if no matching text found
     */
    public static String getConfigTextValue(String configPath) throws Exception
    {
        if( !initialize )
        {
            initialize();
        }
        String value = (String) cacheMap.get(configPath);
        if( value == null || value.length() == 0 )
        {
            getConfigTextValue(configPath, true);
        }
        return value;
    }
    /**
     * 从systemConfig.xml文件中读取相应配置
     * @param configPath eg:/config/assocication/bj_comp_eff_date
     * @param reinitialize if true ,system will read the xml files again.
     * @return String not null or empty
     * @throws Exception Exception "unmatching configPath" will throw if no matching text found
     */
    public static final String getConfigTextValue(String configPath, boolean reinitialize)
            throws Exception
    {
        if( reinitialize )
        {
            initialize();
        }
        String value = (String) cacheMap.get(configPath);
        if( value == null || value.length() == 0 )
            throw new Exception("unmatching configPath:" + configPath);
        return value;
    }

    /**
     * read xml files and cache them.
     * @throws Exception
     */
    private static void initialize() throws Exception
    {
        SAXBuilder sb = new SAXBuilder();
        InputStream is = ClassLoader.getSystemResourceAsStream("org/wanwei/test/xmlreader/systemconfig.xml");
        Document doc = sb.build(is); // 构造文档对象
        Element root = doc.getRootElement(); // 获取根元素
        recursiveReadElement(root, "");// 递归读取xml元素
        initialize = true;
        // logger the cacheMap.
        if( logger.isInfoEnabled() )
            logger.info("initialize system config:\n"+mapToString(cacheMap));
        //System.out.println(mapToString(cacheMap));
    }

    private static void recursiveReadElement(Element root, String parentName)
    {
        List list = root.getChildren();
        String text = root.getTextTrim();
        String url = parentName + DEFAULT_SPLIT + root.getName();
        if( text != null && text.length() > 0 )
        {
            cacheMap.put(url, text);
        }
        if( list != null && list.size() >= 0 )
        {
            for( int i = 0; i < list.size(); i++ )
            {
                if( list.get(i) instanceof Element )
                {
                    recursiveReadElement((Element) list.get(i), url);
                }
            }
        }
    }

    private static String mapToString(Map map)
    {
        StringBuffer mapBuffer = new StringBuffer();
        if( map == null || map.isEmpty() )
            return "";
        Set KeySet = map.keySet();
        Iterator iterator = KeySet.iterator();
        while( iterator.hasNext() )
        {
            String key = (String) iterator.next();
            String value = (String) map.get(key);
            mapBuffer.append(key + "=" + value);
            if( iterator.hasNext() )
                mapBuffer.append(";\n");
        }
        return mapBuffer.toString();
    }

    public static void main(String[] arg0)
    {
        try
        {
            System.out.println(SystemConfig.getConfigTextValue("/config/assocication/bj_comp_eff_date"));
            System.out.println("OK");
        } catch( Exception e )
        {
            e.printStackTrace();
            System.out.println("ERROR");
        }
    }
}