log4j 动态调整日志级别

需求：线上日志级别高，而定位问题时需要低级别日志便于分析问题
功能：不重启服务器，提供设置页，手动触发log4j项目日志级别变化

Demo1：简单日志级别动态调整

实现：本项目中手动调整本项目日志级别，不重启项目

import java.io.Writer;
import java.util.Enumeration;
 
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
import org.apache.log4j.Level;
import org.apache.log4j.LogManager;
import org.apache.log4j.Logger;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
 
/**
 * 动态修改log4j日志级别
 */
@Controller
@RequestMapping(value = "/logger")
public class LoggerController {  
    /**
     * 
     * @param p 需要修改的包名
     * @param l 日志级别
     * @return
     */
    @ResponseBody
    @RequestMapping(value = "/change", method = RequestMethod.GET, produces = "application/json")
    public String change(String p, String l) {
        try {
            Level level = Level.toLevel(l);
            Logger logger = LogManager.getLogger(p);
            logger.setLevel(level);
        } catch (Exception e) {
            return "failed";
        }
        return "success";
    }
     
     
    /**
     * 修改全局日志级别，但是我测试的时候只修改了第三方jar的日志级别，我的项目包的日志级别没有修改成功
     * 可获取到Logger们后循环遍历设置
     * @param l
     * @return
     */
    @ResponseBody
    @RequestMapping(value = "/changeRoot", method = RequestMethod.GET, produces = "application/json")
    public String change(String l) {
        try {
            Level level = Level.toLevel(l);  
            LogManager.getRootLogger().setLevel(level);  
        } catch (Exception e) {
            return "failed";
        }
        return "success";
    }
     
    /**
     * 查看现在包的日志级别
     * @return
     */
    @RequestMapping(value = "/loggers", method = RequestMethod.GET)
    public void index(HttpServletRequest request, HttpServletResponse response) {
         
        StringBuilder sb = new StringBuilder();
        try {
            sb.append("<html>");
            Writer writer = response.getWriter();
            response.setCharacterEncoding("UTF-8");
            response.setContentType("text/html; charset=utf-8");
            Enumeration logs = LogManager.getCurrentLoggers();
            while (logs.hasMoreElements()) {
                Logger logger = (Logger) logs.nextElement();
                sb.append("<span style='display:block;'>");
                sb.append(logger.getName()).append(",").append(logger.getEffectiveLevel());    //可根据名称  显示指定包名的
                sb.append("</span>");
            }
            sb.append("</html>");
            writer.write(sb.toString());
            writer.flush();
            if(writer != null){
                writer.close();
            }
            System.out.println(sb.toString());
        } catch (Exception e) {
        }
         
    }
 
}