Recently, I was developing a project with timed tasks. Because I was lazy, I copied it directly from a project to a new project. Everything was normal at the beginning. Later, when I tested the timed task, I found that there were two identical log records at the same time, and the timed task Executed twice, and finally found a solution on the Internet. The original link is as follows http://blog.csdn.net/java85140031/article/details/19168481, since I am a Mac system, my operation is
Right-click on the copied project->properties->web project Settings;
Change context-root to the name of the new project
In addition: modify the org.eclipse.wst.common.component file in the .setting folder under the project;
Modify the list key value of server.xml under org.eclipse.wst.server.core under .plugin under .metadata under the workspace.