Application Server was not connected before run configuration stop, reason: // Unable to ping server at localhost:1099 (a minute ago)

这个错误的原因是连接到本地主机的Tomcat服务器失败。其中一种可能的原因是端口被占用，可以尝试修改Tomcat的端口号以避免冲突。另外，内存溢出也可能导致此错误。如果以上解决方案无效，还可以检查Tomcat的bin目录下的catalina.bat文件，查看是否存在可能导致冲突的配置。删除可能会解决问题。

对于另一个问题，当Tomcat启动正常但是访问网页时出现404错误，可能有以下原因：首先，检查IDEA的JRE和环境变量是否一致，如果不一致，可以修改IDEA和环境变量的JRE设置。另外一种方法是直接修改Tomcat的setclasspath.bat文件，添加set JAVA_HOME和set JRE_HOME的路径。<span class="em">1</span><span class="em">2</span><span class="em">3</span>
#### 引用[.reference_title]
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