Is it easy to host a jsp website like PHP? Is the server open source like Apache? and What is the best server for jsp?
PHP is generally more of an accessible language to beginners or casual web programmers than JSP. Therefore hosting tends to be much more common and also, therefore cheaper.
JSPs are a special type of Java servlet. These run in a servlet container. In a paid for hosting environment this will typically be Apache Tomcat. This is open source. I'd expect any decent Tomcat hosting company to have a setup where deployment is no more difficult than PHP. If you want to look into basic JSP hosting look for shared (rather than private) Tomcat instance options.