有一些特殊情況，需要在系統初始化時載入一些配置屬性到本地文字中

web.xml

	<listener>
		<listener-class>
			org.springframework.web.context.ContextLoaderListener
		</listener-class>
	</listener>
	
	<!-- 系統初始化從資料庫中配置表載入資料到配置檔案中，必須寫在spring的監聽器下方，否則bean物件未初始化 -->
	<listener>
    	        <listener-class>com.actions.common.listener.InitConfig</listener-class>  
  	</listener>
 

package com.actions.common.listener;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

import com.dao.impl.ConfigDaoImpl;
import com.sun.org.apache.commons.logging.Log;
import com.sun.org.apache.commons.logging.LogFactory;

/**
 * 功能：初始化配置檔案，從資料庫中將配置檔案中的資料寫到本地
 * @author Adam
 *
 */
public class InitConfig implements ServletContextListener{
	private final Log log = LogFactory.getLog(getClass());
	
	public void contextDestroyed(ServletContextEvent sce) {
		log.info("系統停止...");
	}

	public void contextInitialized(ServletContextEvent sce) {
		log.info("System initialization Start...");
		WebApplicationContext rwp = WebApplicationContextUtils.getRequiredWebApplicationContext(sce.getServletContext());
		ConfigDaoImpl configDaoImpl= (ConfigDaoImpl)rwp.getBean("configDaoImpl");
		configDaoImpl.initConfig();
		log.info("System initialization End...");  
	}

}
 

	<bean id="configDaoImpl" class="com.dao.impl.ConfigDaoImpl">
		<property name="sqlMapClient" ref="sqlMapClient"/>
	</bean>

package com.dao.impl;

import java.io.File;
import java.util.List;
import java.util.Properties;

import org.springframework.transaction.annotation.Transactional;

import com.pojos.MyConfig;
import com.util.FileUtils;

/**
 * 功能：從資料庫中將配置檔案資訊寫入本地。
 * @author Adam
 *
 */
@Transactional
public class ConfigDaoImpl extends BaseDaoImpl{
	String profilepath = ConfigDaoImpl.class.getClassLoader().
	getResource("").getPath() + "config.txt";
	
	Properties props = new Properties();
	
	/**
	 * 功能：初始化配置檔案
	 */
	public void initConfig(){
		try {
			profilepath = profilepath.replaceAll("%20", " ");
			File outputFile = new File(profilepath);
			
			outputFile.createNewFile();
			//把所有可用值都寫入文字
			List list = this.getAllKeyAndValue();
			if(list != null && list.size()>0){
				String content = "";
				for(int i =0 ; i < list.size(); i++ ){
					MyConfig con = (MyConfig) list.get(i);
					if(content.equals("")){
						content = con.getCon_key()+"="+con.getCon_value();
					}else{
						content = content + "\r" + con.getCon_key()+"="+con.getCon_value();
					}
				}
				FileUtils.writeFileUTF8(content,profilepath);
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	
	public String getValueByKey(String con_key) throws Exception {
		return (String) super.findByObj("MyConfig.getValueByKey", con_key);
	}
	
	public List getAllKeyAndValue() throws Exception{
		return super.findAll("MyConfig.getAllKeyAndValue");
	}
}

 

package com.util;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;

/**
 * 檔案工具類
 * FileUtils
 * @version 1.0
 */
public class FileUtils {
	static String root_path = FileUtils.class.getClassLoader().
	getResource("").getPath() + "config.txt";
	
	public static String getValueByKey(String con_key){
		try {
			root_path = root_path.replaceAll("%20", " ");
			File file = new File(root_path);
			FileInputStream fis = new FileInputStream(file);
			BufferedReader br = new BufferedReader(new InputStreamReader(fis,
					"UTF-8"));
			String line = br.readLine();
			while (line!= null) {
				if(line.indexOf(con_key)>=0){
					String [] arr = line.split("=");
					if(arr[0].equals(con_key)){
						return arr[1];
					}
				}else{
					line = br.readLine();
				}
			}
			br.close();
			fis.close();
		} catch (Exception e) {
			e.printStackTrace();
		}
		return "";
	}
}

public interface Constant {
	public static final String SYSTEM_ROOT = FileUtils.getValueByKey("SYSTEM_ROOT");
}