Java Web系统初始化时从数据库中加载系统参数（Mybatis，spring）

Wed, 22 Mar 2017 01:32:19 +0000

有一些特殊情况，需要在系统初始化时加载一些配置属性做为系统参数到本地文本中
web.xml

InitConfig.java

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：初始化配置文件，从数据库中将配置文件中的数据写到本地
 * @author Adam
 *
 */
public class InitConfig implements ServletContextListener{
  private final Log log = LogFactory.getLog(getClass());
  
  public void contextDestroyed(ServletContextEvent sce) {
    log.info("系统停止...");
  }

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...");  
  }

}

spring.xml

ConfigDaoImpl.java

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：从数据库中将配置文件信息写入本地。
 * @author Adam
 *
 */
@Transactional
public class ConfigDaoImpl extends BaseDaoImpl{
  String profilepath = ConfigDaoImpl.class.getClassLoader().
  getResource("").getPath() + "config.txt";
  
  Properties props = new Properties();
  
  /**
   * 功能：初始化配置文件
   */
  public void initConfig(){
    try {
      profilepath = profilepath.replaceAll("%20", " ");
      File outputFile = new File(profilepath);
      
      outputFile.createNewFile();
      //把所有可用值都写入文本
      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");
  }
}

FileUtils.java

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;

/**
 * 文件工具类
 * 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 "";
  }
}

Constant.java

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Thu, 01 Jan 1970 00:00:00 +0000

Heck's Blog

Java Web系统初始化时从数据库中加载系统参数（Mybatis，spring）

[评论] Java Web系统初始化时从数据库中加载系统参数（Mybatis，spring）