I am having problems loading the MySQL JDBC driver. I have tried everything mentioned here, but am still running into problems.
The error I get is this:
Exception in thread "main" java.lang.ClassNotFoundException: com.mysql.jdbc.driver
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)
at Main.main(Main.java:12)
My code is as follows:
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
public class Main {
public static void main(String args[]) throws Exception {
//accessing the driver
Class.forName("com.mysql.jdbc.driver");
// creating variable to pass the connection information into
Connection dbcon = DriverManager.getConnection(
"jdbc:mysql//localhost:3306/test", "root", "root");
PreparedStatement statement = dbcon
.prepareStatement("select * from names");
ResultSet result = statement.executeQuery();
while (result.next()) {
System.out.println(result.getString(2));
}
}
}
As you can see above I have placed the driver in the lib folder and I have also put it into the Apache tomcat lib folder, because that was suggested as well.
Thank you for any help you can give me.
Andrew
The class name inside the MySql connectorJ JAR file is Driver. so you need to change
Class.forName("com.mysql.jdbc.driver");
to
Class.forName("com.mysql.jdbc.Driver");
It tells you the problem on the first line of your stacktrace:
Exception in thread "main" java.lang.ClassNotFoundException: com.mysql.jdbc.driver
The driver name is com.mysql.jdbc.Driver (capital D).
problem in loading the mysql connection library.please check the proper mysql library is load successfully.because when library load successfully then the library package display all the external loaded library.
Related
I am making a multiple choice quiz that makes use of the sqlite-jdbc-3.21.0.jar driver. You can find it here:
https://bitbucket.org/xerial/sqlite-jdbc/downloads/
I've made a class called Database to handle everything relating to SQLite:
package quizpack;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
public class Database {
Console cnsl = new Console();
ResultSet rs = null;
Connection connection = null;
Statement stmt = null;
public Connection connect() {
try {
connection = DriverManager.getConnection("jdbc:sqlite:./data/data.db");
Class.forName("org.sqlite.JDBC");
} catch (Exception e) {
cnsl.println("connect() error: " + e.getMessage());
}
return connection;
}
}
When i run my quiz in Eclipse it doesn't give any errors. When i compile it it doesn't give any errors (packaged required libraries). As soon as i launch the jar file in commandprompt i get the message: Prohibited package name: java.sql.
That would be: java.lang.SecurityException: Prohibited package name: java.sql
This is the stacktrace of the connect() error:
connect() error: Prohibited package name: java.sql
java.lang.SecurityException: Prohibited package name: java.sql
at java.base/java.lang.ClassLoader.preDefineClass(Unknown Source)
at java.base/java.lang.ClassLoader.defineClass(Unknown Source)
at java.base/java.security.SecureClassLoader.defineClass(Unknown Source)
at java.base/java.net.URLClassLoader.defineClass(Unknown Source)
at java.base/java.net.URLClassLoader.access$100(Unknown Source)
at java.base/java.net.URLClassLoader$1.run(Unknown Source)
at java.base/java.net.URLClassLoader$1.run(Unknown Source)
at java.base/java.security.AccessController.doPrivileged(Native Method)
at java.base/java.net.URLClassLoader.findClass(Unknown Source)
at java.base/java.lang.ClassLoader.loadClass(Unknown Source)
at java.base/java.lang.ClassLoader.loadClass(Unknown Source)
at quiz.Database.connect(Database.java:21)
at quiz.Database.buildQuery(Database.java:51)
at quiz.Quiz.<init>(Quiz.java:22)
at quiz.Main.main(Main.java:13)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Nativ
e Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknow
n Source)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Un
known Source)
at java.base/java.lang.reflect.Method.invoke(Unknown Source)
at org.eclipse.jdt.internal.jarinjarloader.JarRsrcLoader.main(JarRsrcLoa
der.java:58)
What i tried:
Changing the package name.
Changing the sequence of my buildpath.
Tried several placings of where i put the driver jar in my source folder.
Signing my exported jar.
Added the jar to my classpathvariables:
database connection not working in jar, but does work in eclipse
Now i'm a beginning Java programmer, i might have done something wrong from the above list. But i'm hoping someone can shed light on what is actually causing this error to happen.
This seems like a repeat of Prohibited package name: java, but you said you changed your package name.
If you didn't change the package name from java to something else, try changing that. Else, delete your jar file and rebuild.
I have read the questions on using Sqoop from within a Java program here, here and here.
I came up with the following, but I am stumped by a ClassNotFoundException:
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.*;
import com.cloudera.sqoop.SqoopOptions;
import com.cloudera.sqoop.SqoopOptions.FileLayout;
import com.mysql.jdbc.*;
public class SqoopExample {
public static void main(String[] args) throws Exception {
String driver = "com.mysql.jdbc.driver";
Class.forName(driver);
Configuration config = new Configuration();
// note that this is HDFS path, rather than core path
config.addResource(new Path("./config/core-site.xml"));
config.addResource(new Path("./config/hdfs-site.xml"));
FileSystem dfs = FileSystem.get(config);
SqoopOptions options = new SqoopOptions();
options.setDriverClassName(driver);
options.setConnectString("jdbc:mysql://localhost:3306/dbname");
options.setTableName("v_webstats");
options.setUsername("root");
options.setNumMappers(1);
options.setTargetDir(dfs.getWorkingDirectory()+"/TestDirectory");
options.setFileLayout(FileLayout.TextFile);
new com.cloudera.sqoop.tool.ImportTool().run(options);
}
}
I am sure that all the jars are correctly included and I have tested the connection to my database server and that works as well.
The exact error is:
Exception in thread "main" 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)
at SqoopExample.main(SqoopExample.java:14)
not sure what I am doing wrong.
I believe that proper name of the MySQL JDBC driver class is:
com.mysql.jdbc.Driver
(notice the capital "D" in the "Driver)
Ok I am trying to connect to a mysql db with the following code. I tried looking at documentation but I am just having no luck what so ever.
Here is the code:
public class TESTSQL {
static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
static final String DB_URL = "jdbc:mysql://SLibraryDev.db.996****.hostedresource.com";
static final String USER = "SLD";
static final String PASS = "F11!";
public static void main(String[] args) {
Connection conn = null;
Statement stmt = null;
try {
// STEP 2: Register JDBC driver
Class.forName(JDBC_DRIVER);
// STEP 3: Open a connection
System.out.println("Connecting to database...");
conn = DriverManager.getConnection(DB_URL, USER, PASS);
...
}
This is the error I am getting :
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)
When I comment out "Class.forName(JDBC_DRIVER)" and run it I get this error:
java.sql.SQLException: No suitable driver found for jdbc:mysql://SLibraryDev.db.996****.hostedresource.com
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
What I thought I needed to do was to download and run this : http://dev.mysql.com/downloads/connector/j/ which I did but it seemed like something was wrong with this installer...It seemed like it never finished, like it cut out in the middle of the process. Anyone have any ideas on what I need to do.
Download mysql-connector from following url
http://nearbuy.googlecode.com/files/mysql-connector-java-5.1.13-bin.jar
and add it to your class path.
If you are using netbeans, to add this file to your project do followoing
Right click on your project>click libraries>click add JAR/Folder> then select downloaded jar file
You need to download the mysql jdbc driver jar and include it in your classpath
java.sql.SQLException: No suitable driver found for jdbc:mysql://SLibraryDev.db.996****.hostedresource.com
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
clearly suggests that there is no driver in your class path
simply add the mysql driver jar file in to class path
Hi friends i am facing the following error while trying to connect to a database through java code:
Exception in thread "Main Thread" java.lang.ClassNotFoundException: oracle.jdbc.OracleDriver
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
at com.example.model.Driver.main(Driver.java:13)
My java code is:
package com.example.model;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class Driver {
public static void main(String args[]) throws ClassNotFoundException,
SQLException {
Class.forName("oracle.jdbc.OracleDriver");
// or you can use:
// DriverManager.registerDriver(
// new oracle.jdbc.driver.OracleDriver());
Connection conn = DriverManager.getConnection(
"jdbc:oracle:thin:#127.0.0.1:1521:ORCL", "scott", "tiger");
Statement stmt = conn.createStatement();
ResultSet rset = stmt.executeQuery("select * from customer");
while (rset.next())
System.out.println(rset.getString(1));
rset.close();
stmt.close();
conn.close();
}
}
As per i came to know it could be due to class path issue but don't know how to resolve it.
I set my class path to
C:\bea\user_project\workspace\wlserver_10.3\server\ext\jdbc\oracle\11g\ojdbc5.jar;
I am using weblogic 10.3 workspace and weblogic 10.3 server.
The java.lang.ClassNotFoundException: oracle.jdbc.OracleDriver definitely means that the mentioned class is not on the class path. And because ojdbc5.jar has it, the whole question is: "how did you set your classpath"?
Here is what I get on my machine using your code (using the default package):
$ cat > Driver.java
...
$ javac Driver.java
$ java -cp /home/pascal/opt/Oracle/Middleware/wlserver_10.3/server/ext/jdbc/oracle/11g/ojdbc5.jar:. Driver
Exception in thread "main" java.sql.SQLException: The Network Adapter could not establish the connection
at oracle.jdbc.driver.SQLStateMapping.newSQLException(SQLStateMapping.java:70)
at oracle.jdbc.driver.DatabaseError.newSQLException(DatabaseError.java:131)
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:197)
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:525)
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:413)
at oracle.jdbc.driver.PhysicalConnection.(PhysicalConnection.java:508)
at oracle.jdbc.driver.T4CConnection.(T4CConnection.java:203)
at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:33)
at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:510)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:185)
at Driver.main(Driver.java:15)
Caused by: oracle.net.ns.NetException: The Network Adapter could not establish the connection
at oracle.net.nt.ConnStrategy.execute(ConnStrategy.java:328)
at oracle.net.resolver.AddrResolution.resolveAndExecute(AddrResolution.java:421)
at oracle.net.ns.NSProtocol.establishConnection(NSProtocol.java:634)
at oracle.net.ns.NSProtocol.connect(NSProtocol.java:208)
at oracle.jdbc.driver.T4CConnection.connect(T4CConnection.java:966)
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:292)
... 7 more
Caused by: java.net.ConnectException: Connection refused
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
at java.net.Socket.connect(Socket.java:529)
at java.net.Socket.connect(Socket.java:478)
at java.net.Socket.(Socket.java:375)
at java.net.Socket.(Socket.java:189)
at oracle.net.nt.TcpNTAdapter.connect(TcpNTAdapter.java:127)
at oracle.net.nt.ConnOption.connect(ConnOption.java:126)
at oracle.net.nt.ConnStrategy.execute(ConnStrategy.java:306)
... 12 more
The driver is found (I get an exception because I'm not running any Oracle server but this is another story).
I will try to put it in the weblogic's lib folder... and restart the server, so you will be sure that it is a classpath problem...
You should download the oracle drivers from oracle and put the .jar file in the project's CLASSPATH...
You can download it at Oracle's drivers download page
I just started with the connectivity and tried this example. I have installed the necessary softwares. Also copied the jar file into the /ext folder.Yet the code below has the following error
import java.sql.*;
public class Jdbc00 {
public static void main(String args[]){
try {
Statement stmt;
Class.forName("com.mysql.jdbc.Driver");
String url =
"jdbc:mysql://localhost:3306/mysql"
DriverManager.getConnection(url,"root", "root");
//Display URL and connection information
System.out.println("URL: " + url);
System.out.println("Connection: " + con);
//Get a Statement object
stmt = con.createStatement();
//Create the new database
stmt.executeUpdate(
"CREATE DATABASE JunkDB");
stmt.executeUpdate(
"GRANT SELECT,INSERT,UPDATE,DELETE," +
"CREATE,DROP " +
"ON JunkDB.* TO 'auser'#'localhost' " +
"IDENTIFIED BY 'drowssap';");
con.close();
}catch( Exception e ) {
e.printStackTrace();
}//end catch
}//end main
}//end class Jdbc00
But it gave the following error
D:\Java12\Explore>java Jdbc00
java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
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)
at Jdbc00.main(Jdbc00.java:11)
Could anyone please guide me in correcting this?
The jar file that contains the MySQL driver class (com.mysql.jdbc.Driver) isn't being found on the classpath when you run your application. This is what the ClassNotFoundException is complaining about.
You'll need to add it either to the CLASSPATH environment variable, or using the classpath option when running Java. For example:
java -cp mysql-connector-java-5.0.8-bin.jar Jdbc00
Use the name and location of whatever MySQL connector jar file you're using. (If you haven't already installed MySQL on localhost, so your application has something to connect to, you might have to do that too.)
As #Ash says, the problem is that the Connector/J drivers are not on your classpath. You can download the latest version (5.0.12) from this page.