java对配置文件（XML/properties）的操作

1.对properties文件的操作：

public class PropUtil {
    private static Map<String, String> map = new HashMap<String,String>();
    private PropUtil() {
        ResourceBundle prop = ResourceBundle.getBundle("config");
        Enumeration<String> em = prop.getKeys();
        while (em.hasMoreElements()) {
            String topic = (String) em.nextElement();
            map.put(topic, (String)prop.getObject(topic));
        }
    }
    public static String getValueByTagName(String tagName){
        if(map.get(tagName)==null){
              new PropUtil();
        }
        return map.get(tagName);
    }
}

import com.yjdgis.database.*;
import com.yjdgis.jcio.JCPGInput;
import com.yjdgis.log.LogFactory;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Properties;
import java.util.logging.Level;
import org.apache.log4j.Logger;

public class Configuration {

    private Properties props;
    private FileInputStream ips;
   // static Logger LOG = LogFactory.getInstance(Configuration.class);

    public Configuration() {
        props = new Properties();
    }

    public Configuration(String filepath) {//加载属性配置文件
        props = new Properties();
        try {
            ips = new FileInputStream(filepath);
            props.load(ips);
            ips.close();
        } catch (Exception e) {
            e.printStackTrace();
        } 
    }

    /**
     * 通过属性名获取属性值
     * @param key 属性名
     * @return
     */
    public String getValue(String key) {
        if (props.containsKey(key)) {
            String value = props.getProperty(key);
            return value;
        } else {
            return "";
        }

    }

    /**
     * 
     * @param key
     * @param value
     * @param isSave 
     */
    public void setValue(String filename, String key, String value, boolean isSave) {
        if (props.containsKey(key)) {
            props.setProperty(key, value);
        }
        if (isSave) {

            FileOutputStream out;
            try {
                out = new FileOutputStream(filename);
                props.store(out, "This file is a envir");
                out.flush();
                out.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * 在指定的属性文件中获取相关属性名的属性值
     * @param fileName
     * @param key
     * @return
     */
    public String getValue(String fileName, String key) {
        try {
            String value = null;
            ips = new FileInputStream(fileName);
            props.load(ips);
            ips.close();
            if (props.containsKey(key)) {
                value = props.getProperty(key);
                return value;
            } else {
                return value;
            }
        } catch (Exception e) {
            //LOG.info(fileName + ",file doesn't exist!");
            e.printStackTrace();
            return "";
        } 
    }

    public void clear() {
        props.clear();
    }
}

 2、对XML的操作

package com.kmyjd.utils;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import org.dom4j.Document;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;

public class XmlUtils {
    private static String filePath;
    static{
        filePath = XmlUtils.class.getClassLoader().getResource("user.xml").getPath();
    }
    
    public static Document getDocument() throws Exception{
        SAXReader reader = new SAXReader();
        Document  document = reader.read(new File(filePath));
        return document;
    }
    
    public static void write2Xml(Document document) throws Exception,
　　　　　FileNotFoundException{
        OutputFormat format = OutputFormat.createCompactFormat();
        format.setEncoding("UTF-8");
        XMLWriter writer = new XMLWriter(new FileOutputStream(filePath));
        writer.write(document);
        writer.close();
    }
}