I'm trying to install tomcat 7 on Ubuntu Server 12.04 with:

sudo apt-get install tomcat7

I tried to do this according this install tutorial, but immediately I receive this answer:

Reading package lists... Done

Building dependency tree       

Reading state information... Done

Package tomcat7 is not available, but is referred to by another package.

This may mean that the package is missing, has been obsoleted, or

is only available from another source



E: Package 'tomcat7' has no installation candidate

Update:

I tried to download & install tomcat7 step by step as this tutorial.
But when I try to run program

`$ ./catalina.sh run` 

I catch few warnings + SEVERE: Cannot start server. Server instance is not configured:

nazar_art@nazar-desctop:/usr/local/tomcat/apache-tomcat-7.0.42/bin$ ./catalina.sh run

Using CATALINA_BASE: /usr/local/tomcat/apache-tomcat-7.0.42

Using CATALINA_HOME: /usr/local/tomcat/apache-tomcat-7.0.42

Using CATALINA_TMPDIR: /usr/local/tomcat/apache-tomcat-7.0.42/temp

Using JRE_HOME: /usr/lib/jvm/java-7-oracle

Using CLASSPATH: /usr/local/tomcat/apache-tomcat-7.0.42/bin/bootstrap.jar:/usr/local/tomcat/apache-tomcat-7.0.42/bin/tomcat-juli.jar

Jul 25, 2013 8:49:54 PM org.apache.catalina.startup.Catalina load

WARNING: Unable to load server configuration from [/usr/local/tomcat/apache-tomcat-7.0.42/conf/server.xml]

Jul 25, 2013 8:49:54 PM org.apache.catalina.startup.Catalina load

WARNING: Permissions incorrect, read permission is not allowed on the file.

Jul 25, 2013 8:49:54 PM org.apache.catalina.startup.Catalina load

WARNING: Unable to load server configuration from [/usr/local/tomcat/apache-tomcat-7.0.42/conf/server.xml]

Jul 25, 2013 8:49:54 PM org.apache.catalina.startup.Catalina load

WARNING: Permissions incorrect, read permission is not allowed on the file.

Jul 25, 2013 8:49:54 PM org.apache.catalina.startup.Catalina start

SEVERE: Cannot start server. Server instance is not configured.

• How to solve this trouble and install tomcat7?