Error Solving

JDBC - java.lang.ClassNotFoundException: com.mysql.jdbc.Driver Solution

  Error:

    java.lang.ClassNotFoundException: com.mysql.jdbc.Driver

    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Unknown Source)

   Solution:

    Download  mysql-connector jar file from here:http://dev.mysql.com/downloads/connector/j/

       Extract that file get mysql-connector-java-5.1.22-bin.jar 

      i) Paste that file in:/usr/lib/jvm/java-6-openjdk/jre/lib

                         and :/usr/lib/jvm/java-6-openjdk/jre/lib/ext    

                                           (or)         

      ii)Paste that file in:/usr/lib/jvm/java-6-sun-1.6.0.26/jre/lib

                         and :/usr/lib/jvm/java-6-sun-1.6.0.26/jre/lib/ext

Warning

when compile my java coding i got below warning:
            Note: PurchaseDetails.java uses unchecked or unsafe operations.
           Note: Recompile with -Xlint:unchecked for details.

Solution:

   This comes up in Java 5 and later if you're using collections without type specifiers (e.g., Arraylist()instead of ArrayList<String>()). It means that the compiler can't check that you're using the collection in a type-safe way, using generics.To get rid of the warning, just be specific about what type of objects you're storing in the collection. So, instead of

List myList = new ArrayList();

use

List<String> myList = new ArrayList<String>();