记录java.util.Map.getOrDefault()方法导致JSP编译失败异常:Unable to compile class for JSP

记录java.util.Map.getOrDefault()方法导致JSP编译失败异常:Unable to compile class for JSP;

一、报错信息：

在这里插入图片描述

type Exception report
message Unable to compile class for JSP:
description The server encountered an internal error that prevented it from fulfilling this request.exception
org.apache.jasper.JasperException: Unable to compile class for JSP: 
An error occurred at line: 114 in the jsp file: /AICSSO/DZZYSSO.jsp
The method getOrDefault(String, String) is undefined for the type Map<String,Object>
111:             JSONObject jsStr = JSONObject.parseObject(result);
112:             System.out.println("jsStr =========================== " + jsStr);
113:             Map<String, Object> map = JSONObject.toJavaObject(jsStr,Map.class);
114:             String userId =(String) map.getOrDefault("msg", "xxx");
115:             System.out.println("闂ㄦ埛楠岃瘉鎺ュ彛鍝嶅簲鏁版嵁锛歶serId = " + userId);
116:             if (userId.equals(sid)){
117:                 //璁よ瘉鎴愬姛锛�

Stacktrace:
org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:102)	org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:198)
	org.apache.jasper.compiler.JDTCompiler.generateClass(JDTCompiler.java:450)
	org.apache.jasper.compiler.Compiler.compile(Compiler.java:361)
	org.apache.jasper.compiler.Compiler.compile(Compiler.java:336)
	org.apache.jasper.compiler.Compiler.compile(Compiler.java:323)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:585)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:363)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:396)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:340)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
	com.ufgov.midas.pt.common.CharsetFilter.doFilter(CharsetFilter.java:63)
note The full stack trace of the root cause is available in the Apache Tomcat/8.0.24 logs.

二、报错原因分析

原文代码报错位置：

Map<String, Object> jsStr = JSONObject.parseObject(result);
System.out.println("jsStr =========================== " + jsStr.toString());
// TODO: 2024-03-01  报错jsp编译失败  TODO: map.getOrDefault() 报错
String userId =(String) map.getOrDefault("msg", "xxx");