1. First check whether the time to build the dependent machine is normal, and the abnormal time may cause the failure to download the dependency
2. https://mvnrepository.com/ can find dependencies, but cannot use maven to download dependencies, but in fact, this website only provides index and query of maven warehouse packages and does not provide downloads. Dependency packages added from this website still need Go to the original website to download
Specific steps are as follows:
First find the dependencies you need and select the version:
You can see the red line circled in the figure, click to add the following address to the repository of settings.xml or pom.xml
Or use the command to download dependencies:
mvn dependency:get -DgroupId=no.tornado -DartifactId=tornadofx -Dversion=1.7.19 -DremoteRepositories=https://repo1.maven.org/maven2/ Detailed explanation of the command Maven command line to manually add dependencies mvn dependency:get command usage Optional parameters (change the right side of the equal sign to 
https://www.cnblogs.com/sunsay/p/12829441.html