struts中读取外部配置文件信息

Posted 2020-08-21

1、在tomcat中webapps目录下放置一个config.properties配置文件；

2、在监听的时候读取写入src目录下；

3、通过Properties类再次读取，可以在service层获取到，具体代码如下：

1、监听类，实现ServletContextListener接口

public class InitJDBCListener implements ServletContextListener {

private static final Logger log = Logger.getLogger(InitJDBCListener.class);

public void contextInitialized(ServletContextEvent event) {

ServletContext context = event.getServletContext();

// autoSetupJDBC(context);

loadJDBCProperties(context);

// 加载项目配置文件

loadConfigProperties(context);

// 此时， web.xml 中的context-param 元素已经被加载到ServletContext 对象中。

setWPSFlag(context);

setJDBCKeys(context);

}

    

private void loadConfigProperties(ServletContext sc){

log.info("加载项目配置文件");

File newMsgProperties = getNewMsgPropertiesFile(sc);

File oldMsgProperties = getOldMsgPropertiesFile(sc);

try {

setMsgProperties(oldMsgProperties, newMsgProperties);

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

private void setMsgProperties(File oldMsgProperties,File newMsgProperties) throws IOException{

if(newMsgProperties != null && oldMsgProperties != null){

FileInputStream fis = new FileInputStream(newMsgProperties);

FileOutputStream fos = new FileOutputStream(oldMsgProperties);

byte[] bs = new byte[fis.available()];

fis.read(bs);

fos.write(bs);

fos.flush();

fis.close();

fos.close();

}

}

private File getOldMsgPropertiesFile(ServletContext sc) {

String appDir = sc.getRealPath(File.separatorChar + "");

String msgPropertiesPath = appDir + "WEB-INF" + File.separatorChar

+ "classes" + File.separatorChar + "config.properties";

File msgFile = new File(msgPropertiesPath);

if (msgFile.exists())

return msgFile;

return null;

}

private File getNewMsgPropertiesFile(ServletContext sc) {

String appDir = sc.getRealPath(File.separatorChar + "");

File appDirFile = new File(appDir);

String appContainerPath = appDirFile.getParent();

String msgPropertiesPath = appContainerPath + File.separatorChar + "config_gagb" + File.separatorChar

+ "config.properties";

File msgFile = new File(msgPropertiesPath);

if (msgFile.exists())

return msgFile;

return null;

}

}

2、在web.xml中配置监听，代码如下：

    <!-- 必须放在ContextLoaderListener之前-->

    <listener>

<listener-class>

org.gagb.webapp.listener.InitJDBCListener

</listener-class>

</listener>

<listener>

<listener-class>

org.springframework.web.context.ContextLoaderListener

</listener-class>

</listener>

3、通过Properties 读取配置文件：

/**

* 读取配置文件

     * config.properties放在src目录下

* @return

*/

public static Properties getConfigProperties() {

Properties prop = new Properties();

try {

java.net.URL url = CommonUtil.class.getResource("/config.properties");

String savePath = url.getPath();

// 以下方法读取属性文件会缓存问题

// InputStream in = PropertiesUtils.class

// .getResourceAsStream("/config.properties");

InputStream in = new BufferedInputStream(new FileInputStream(savePath));

prop.load(in);

} catch (Exception e) {

e.printStackTrace();

return null;

}

return prop;

}

4、在serve中添加Properties静态变量：

  private static Properties pro = CommonUtil.getConfigProperties();

5、在方法中根据key获取value:

  String adcode = pro.getProperty(Constants.AD_CODE);

6、如果在struts.xml中配置了<constant name="struts.custom.i18n.resources" value="ApplicationResources,errors,jdbc,gis,axis,msg,config" /> 则可以直接通过getText("key")获取；

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