com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException is runtime exception thrown while connecting with database. This exception can occurred with so many reasons.

Sample Code

 try
{
Class.forName("com.mysql.jdbc.Driver");
Connection	connection=DriverManager.getConnection("jdbc:mysql://localhost:3306/", "root", "facingissuesonit");
} catch (ClassNotFoundException ex) {
ex.printStackTrace();
}
catch (SQLException ex) {
ex.printStackTrace();
}
 

Output Message

com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server.
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:404)
    at com.mysql.jdbc.Util.getInstance(Util.java:387)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:917)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:896)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:885)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:860)
    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2332)
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2085)
    at com.mysql.jdbc.ConnectionImpl.(ConnectionImpl.java:795)
    at com.mysql.jdbc.JDBC4Connection.(JDBC4Connection.java:44)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:404)
    at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:400)
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:327)
    at java.sql.DriverManager.getConnection(DriverManager.java:664)
    at java.sql.DriverManager.getConnection(DriverManager.java:247)
    at com.fioit.examples.jdbc.connection.MyConnection.getConnection(MyConnection.java:21)
    at com.fioit.jdbc.examples.schemasetup.DatabaseOperationTest.main(DatabaseOperationTest.java:15)
Caused by: java.lang.NullPointerException
    at com.mysql.jdbc.ConnectionImpl.getServerCharset(ConnectionImpl.java:3005)
    at com.mysql.jdbc.MysqlIO.sendConnectionAttributes(MysqlIO.java:1916)
    at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1845)
    at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1215)
    at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2255)
    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2286)
    ... 14 more

Issue

com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException occurs  in above code for line DriverManager.getConnection().

Solutions

com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException can occurred by many reasons for above example it was happening because of mismatch version of MYSQLServer 6.0.2 while I was using MYSQL jar for 5+ version that were  creating above exception. To solve I added below dependency on pom.xml and issue got resolved.

    mysql
    mysql-connector-java
    8.0.11

More Issues Solution

For more other JAVA/JDBC issues solution follow link JDBC Issues and Solutions.