It occurs that I have a problem configuring tomcat7 properly. After I figured that I couldn't log in, because none of the 4 available manager roles are available by default I decided to add these user specifications in the tomcat-users.xml file in the conf directory of tomcat:
< role rolename="manager-gui" />
< user username="tomcat" password="s3cret" roles="manager-gui" />
< role rolename="manager-script" />
< user username="tomcat" password="s3cret" roles="manager-script" />
< role rolename="manager-jmx" />
< user username="tomcat" password="s3cret" roles="manager-script" />
< role rolename="manager-status" />
< user username="tomcat" password="s3cret" roles="manager-status" />
Of course, these username and password combinations are merely examplary. Also, I had shut down the server after I had saved the changes in the tomcat-users file. Then I started up the server and opened the localhost webpage using the corresponding http connector port(8000 in my case). For some reason, I still wasn't able to access any parts of the welcome page. I clicked manage app and had to enter username and password. I tried all username and password combinations I had added in the tomcat-users.xml file, but everything just failed. Is there anyone who might know what could be the cause of this?