The internal connection pool has reached its maximum size and no connection is currently available!

You should comment this line in hibernate.cfg.xml

 <!--  <property name="connection.pool_size">1</property> -->

Can not find the tag library descriptor for "http://java.sun.com/jsp/jstl/core"

You would have used this way
    <%@ taglib uri="http://java.sun.com/jsp/jstl/core"  prefix="c" %>

You should use this, prefix should come first
    <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>

Main thing is you will be using tomcat 7 or higher version. You need to use JSTL - 1.2.jar

you  might be simply using JSTL.jar.

just put the JSTL-1.2.jar in lib folder..

how to close the port in computer?

To check the ports open in your computer,

go to cmd, type netstat.

you will get all the ports used in the computer..

If you want to close the port used, netstat -a -n -o in cmd...

you will get the PID. Note this PID go to task manager and kill it..

how to check how many tables are there in database in oracle?

select * from user_tables;

How to check schema in mysql?

Use schema_name;
desc table_name;

How to show current Workspace in Eclipse?

Go to eclipse folder,

1.Edit the eclipse.ini.
2.add -showlocation
3.This should be before -startup



-showlocation
-startup
plugins/org.eclipse.equinox.launcher_1.3.0.v20130327-1440.jar
--launcher.library
plugins/org.eclipse.equinox.launcher.win32.win32.x86_64_1.1.200.v20140116-2212
-product

Files\Java\jdk1.8.0_112 was unexpected at this time.

Its problem with your JAVA_HOME. you would have set your JAVA_HOME with double quotes.