MySQL JDBC driver not working with GWT Eclipse Project - mysql

My GWT application does not seem to find mysql-connector-java-5.1.22-bin.jar.
Im using the Google App Engine.
I have set the jar in Project->RIghtClick->Properties->Java Build Path->Libraries->mysql-connector-java-5.1.22-bin.jar. I also added the "MySQL JDBC Driver". The $CLASSPATH is set correctly too (i dont think it matters because Im running the application in Eclipse).
I have tested the same code on command line and it works like a charm.
$ java -cp ~/mysql-connector-java-5.1.22/mysql-connector-java-5.1.22-bin.jar:. JDBCExample
-------- MySQL JDBC Connection Testing ------------
MySQL JDBC Driver Registered!
You made it, take control your database now!
When I run the Web Application in Eclipse, I get this
Exception:
-------- MySQL JDBC Connection Testing ------------
java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
ClassNotFound - Where is your MySQL JDBC Driver?com.mysql.jdbc.Driver
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
at com.google.appengine.tools.development.IsolatedAppClassLoader.loadClass(IsolatedAppClassLoader.java:207)
at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:186)
at com.startupweekend.server.GreetingServiceImpl.readDB(GreetingServiceImpl.java:65)
at com.startupweekend.server.GreetingServiceImpl.greetServer(GreetingServiceImpl.java:21)
Code:
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException e) {
System.out.println("ClassNotFound - Where is your MySQL JDBC Driver?" + e.getMessage());
e.printStackTrace();
return;
}

I'm not completely sure, but you should just put the mysql driver in your WEB-INF/lib folder and then right click -> add to build path. That should make it work.
Bear in mind that in GAE you cannot use common relational databases, you can only use Google CloudSQL.

You don't need the App Engine, just use GWT compile when you're ready for your war file. In any case, right click project folder -> properties -> Google -> App Engine -> uncheck 'Use Google App Engine'. Make sure the mysql-connector is in your lib folder. Enjoy your favorite relational database, and more.
Cheers

Related

Got "java.sql.SQLException: java.lang.ClassCastException: java.math.BigInteger cannot be cast to java.lang.Long" error [duplicate]

When connecting to MySQL, I get an error (see below).
Click here for code
I get this output:
run:
Now connecting to databse...
java.sql.SQLException: java.lang.ClassCastException: java.math.BigInteger cannot be cast to java.lang.Long
java.sql.SQLException: java.lang.ClassCastException: java.math.BigInteger cannot be cast to java.lang.Long
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1074)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:988)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:974)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:919)
at com.mysql.jdbc.ConnectionImpl.buildCollationMapping(ConnectionImpl.java:1062)
at com.mysql.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:3556)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2513)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2283)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:822)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
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:423)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:404)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:317)
at java.sql.DriverManager.getConnection(DriverManager.java:664)
at java.sql.DriverManager.getConnection(DriverManager.java:247)
at dbms_basic.Dbms_Basic.main(Dbms_Basic.java:28)
Caused by: java.lang.ClassCastException: java.math.BigInteger cannot be cast to java.lang.Long
at com.mysql.jdbc.ConnectionImpl.buildCollationMapping(ConnectionImpl.java:1007)
... 15 more
BUILD SUCCESSFUL (total time: 0 seconds)
How can I solve this?
Your error clearly says casting is not possible, because a java.math.BigInteger class instance is not an instance of java.lang.Long class.
Now the question arises who is doing casting at what level, when we ask the JDBC driver to make a connection, it is doing lot of work behind the scene before it actually give us back the proper working object of connection.
The problem seems with your version of MySQL in combination with your version of mysql-connector.jar. Try a newer version of MySQL Connector/J (see https://dev.mysql.com/downloads/connector/j/ for the latest version), for example upgrade to 5.1.47 or 8.0.12 if you are using an older version.
This issue is not there with 5.1.45 as mentioned in the above comments. Available to download at,
https://repo1.maven.org/maven2/mysql/mysql-connector-java/5.1.45/
Another way, because changing the version from mysql does not worked for me, for help another people:
Long.parseLong(String.valueOf(item[0]);
There is a miss-match between your MySQL version, which might be the latest 8.0.19, but the MySQL driver file is older version may be 5.1.23, which is generally available with the NetBeans IDE. To overcome this, download the mysql-connector-java-5.1.48.jar from this link in your PC download connector/j 5.1.48 zip file
(4.6MB)
Now right-click on project name in the netbeans IDE, go to services, in that choose 'Libraries', in it choose 'Add library', then don't opt for available libraries( the drop-down menu will list a JDBCDriver file which has 'mysql-connector-java-5.1.23.jar' file inside it, which is an older version, this is causing the miss-match). Therefore, instead click on 'Create Library', now give it any name of your choice, then click the create button, a browse window will pop-up, go to the directory where you have downloaded the 'mysql-connector-java-5.1.48.zip' folder, open it and select the java jar file 'mysql-connector-java-5.1.48.jar' and click 'ok'. The library folder of your project tree will now show 'JDBCDriver-mysql-connector-java-5.1.48.jar' added in the list of libraries(JDK and Tomcat) . Now try connecting to your database again by clicking on the 'run' button, go to the JSP link, and you see that this time you are connected.
For me updating the connector wasn't enough, I also had to complete my DriverManager.getConnection() url parameter with all the arguments, even if the error message was not mentionning this issue.
In my case this parameters were needed :
"jdbc:mysql://127.0.0.1:3306/database?zeroDateTimeBehavior=convertToNull&serverTimezone=UTC"
Connector : mysql-connector-java-8.0.17.jar
mysql version : 8.0.17
Using java on netbeans.
This is a common issue when you use outdated/unsupported mysql connector driver. If youre using x86 version of Netbeans, your driver will usually be found in the Program(x86) folder an not the Program folder. something like this "C:\Program Files (x86)\MySQL\Connector J 8.0\mysql-connector-java-8.0.23.jar"

connecting MySQL using wamp and hibernate in eclipse [duplicate]

I'm trying to add a database-enabled JSP to an existing Tomcat 5.5 application (GeoServer 2.0.0, if that helps).
The app itself talks to Postgres just fine, so I know that the database is up, user can access it, all that good stuff. What I'm trying to do is a database query in a JSP that I've added. I've used the config example in the Tomcat datasource example pretty much out of the box. The requisite taglibs are in the right place -- no errors occur if I just have the taglib refs, so it's finding those JARs. The postgres jdbc driver, postgresql-8.4.701.jdbc3.jar is in $CATALINA_HOME/common/lib.
Here's the top of the JSP:
<%# taglib uri="http://java.sun.com/jsp/jstl/sql" prefix="sql" %>
<%# taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<sql:query var="rs" dataSource="jdbc/mmas">
select current_validstart as ValidTime from runoff_forecast_valid_time
</sql:query>
The relevant section from $CATALINA_HOME/conf/server.xml, inside the <Host> which is in turn within <Engine>:
<Context path="/gs2" allowLinking="true">
<Resource name="jdbc/mmas" type="javax.sql.Datasource"
auth="Container" driverClassName="org.postgresql.Driver"
maxActive="100" maxIdle="30" maxWait="10000"
username="mmas" password="very_secure_yess_precious!"
url="jdbc:postgresql//localhost:5432/mmas" />
</Context>
These lines are the last in the tag in webapps/gs2/WEB-INF/web.xml:
<resource-ref>
<description>
The database resource for the MMAS PostGIS database
</description>
<res-ref-name>
jdbc/mmas
</res-ref-name>
<res-type>
javax.sql.DataSource
</res-type>
<res-auth>
Container
</res-auth>
</resource-ref>
Finally, the exception:
exception
org.apache.jasper.JasperException: Unable to get connection, DataSource invalid: "java.sql.SQLException: No suitable driver"
[...wads of ensuing goo elided]
The infamous java.sql.SQLException: No suitable driver found
This exception can have basically two causes:
1. JDBC driver is not loaded
In case of Tomcat, you need to ensure that the JDBC driver is placed in server's own /lib folder.
Or, when you're actually not using a server-managed connection pool data source, but are manually fiddling around with DriverManager#getConnection() in WAR, then you need to place the JDBC driver in WAR's /WEB-INF/lib and perform ..
Class.forName("com.example.jdbc.Driver");
.. in your code before the first DriverManager#getConnection() call whereby you make sure that you do not swallow/ignore any ClassNotFoundException which can be thrown by it and continue the code flow as if nothing exceptional happened. See also Where do I have to place the JDBC driver for Tomcat's connection pool?
Other servers have a similar way of placing the JAR file:
GlassFish: put the JAR file in /glassfish/lib
WildFly: put the JAR file in /standalone/deployments
2. Or, JDBC URL is in wrong syntax
You need to ensure that the JDBC URL is conform the JDBC driver documentation and keep in mind that it's usually case sensitive. When the JDBC URL does not return true for Driver#acceptsURL() for any of the loaded drivers, then you will also get exactly this exception.
In case of PostgreSQL it is documented here.
With JDBC, a database is represented by a URL (Uniform Resource Locator). With PostgreSQL™, this takes one of the following forms:
jdbc:postgresql:database
jdbc:postgresql://host/database
jdbc:postgresql://host:port/database
In case of MySQL it is documented here.
The general format for a JDBC URL for connecting to a MySQL server is as follows, with items in square brackets ([ ]) being optional:
jdbc:mysql://[host1][:port1][,[host2][:port2]]...[/[database]] » [?propertyName1=propertyValue1[&propertyName2=propertyValue2]...]
In case of Oracle it is documented here.
There are 2 URL syntax, old syntax which will only work with SID and the new one with Oracle service name.
Old syntax jdbc:oracle:thin:#[HOST][:PORT]:SID
New syntax jdbc:oracle:thin:#//[HOST][:PORT]/SERVICE
See also:
Where do I have to place the JDBC driver for Tomcat's connection pool?
How to install JDBC driver in Eclipse web project without facing java.lang.ClassNotFoundexception
How should I connect to JDBC database / datasource in a servlet based application?
What is the difference between "Class.forName()" and "Class.forName().newInstance()"?
Connect Java to a MySQL database
I've forgot to add the PostgreSQL JDBC Driver into my project (Mvnrepository).
Gradle:
// http://mvnrepository.com/artifact/postgresql/postgresql
compile group: 'postgresql', name: 'postgresql', version: '9.0-801.jdbc4'
Maven:
<dependency>
<groupId>postgresql</groupId>
<artifactId>postgresql</artifactId>
<version>9.0-801.jdbc4</version>
</dependency>
You can also download the JAR and import to your project manually.
url="jdbc:postgresql//localhost:5432/mmas"
That URL looks wrong, do you need the following?
url="jdbc:postgresql://localhost:5432/mmas"
I faced the similar issue.
My Project in context is Dynamic Web Project(Java 8 + Tomcat 8) and error is for PostgreSQL Driver exception: No suitable driver found
It got resolved by adding Class.forName("org.postgresql.Driver") before calling getConnection() method
Here is my Sample Code:
try {
Connection conn = null;
Class.forName("org.postgresql.Driver");
conn = DriverManager.getConnection("jdbc:postgresql://" + host + ":" + port + "/?preferQueryMode="
+ sql_auth,sql_user , sql_password);
} catch (Exception e) {
System.out.println("Failed to create JDBC db connection " + e.toString() + e.getMessage());
}
I found the followig tip helpful, to eliminate this issue in Tomcat -
be sure to load the driver first doing a Class.forName("
org.postgresql.Driver"); in your code.
This is from the post - https://www.postgresql.org/message-id/e13c14ec050510103846db6b0e#mail.gmail.com
The jdbc code worked fine as a standalone program but, in TOMCAT it gave the error -'No suitable driver found'
No matter how old this thread becomes, people would continue to face this issue.
My Case: I have the latest (at the time of posting) OpenJDK and maven setup. I had tried all methods given above, with/out maven and even solutions on sister posts on StackOverflow. I am not using any IDE or anything else, running from bare CLI to demonstrate only the core logic.
Here's what finally worked.
Download the driver from the official site. (for me it was MySQL https://www.mysql.com/products/connector/). Use your flavour here.
Unzip the given jar file in the same directory as your java project. You would get a directory structure like this. If you look carefully, this exactly relates to what we try to do using Class.forName(....). The file that we want is the com/mysql/jdbc/Driver.class
Compile the java program containing the code.
javac App.java
Now load the director as a module by running
java --module-path com/mysql/jdbc -cp ./ App
This would load the (extracted) package manually, and your java program would find the required Driver class.
Note that this was done for the mysql driver, other drivers might require minor changes.
If your vendor provides a .deb image, you can get the jar from /usr/share/java/your-vendor-file-here.jar
Summary:
Soln2 (recommend)::
1 . put mysql-connector-java-8.0.28.jar file in the <where you install your Tomcat>/lib.
Soln1::
1 . put mysql-connector-java-8.0.28.jar file in the WEB-INF/lib.
2 . use Class.forName("com.mysql.cj.jdbc.Driver"); in your Servlet Java code.
Soln1 (Ori Ans) //-20220304
In short:
make sure you have the mysql-connector-java-8.0.28.jar file in the WEB-INF/lib
make sure you use the Class.forName("com.mysql.cj.jdbc.Driver");
additional notes (not important), base on my trying (could be wrong)::
1.1 putting the jar directly inside the Java build path doesnt work
1.2. putting the jar in Data management > Driver Def > MySQL JDBC Driver > then add it as library to Java Build path doesnt work.
1.3 => it has to be inside the WEB-INF/lib (I dont know why)
1.4 using version mysql-connector-java-8.0.28.jar works, only version 5.1 available in Eclipse MySQL JDBC Driver setting doesnt matter, ignore it.
<see How to connect to MySql 8.0 database using Eclipse Database Management Perspective >
Class.forName("com.mysql.cj.jdbc.Driver");
Class.forName("com.mysql.jdbc.Driver");
both works,
but the Class.forName("com.mysql.jdbc.Driver"); is deprecated.
Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.
<see https://www.yawintutor.com/no-suitable-driver-found-for-jdbcmysql-localhost3306-testdb/ >
If you want to connect to a MySQL database, you can use the type-4 driver named Connector/} that's available for free from the MySQL website. However, this driver is typically included in Tomcat's lib directory. As a result, you don't usually need to download this driver from the MySQL site.
-- Murach’s Java Servlets and JSP
I cant find the driver in Tomcat that the author is talking about, I need to use the mysql-connector-java-8.0.28.jar.
<(striked-out) see updated answer soln2 below>
If you're working with an older version of Java, though, you need to use the forName method of the Class class to explicitly load the driver before you call the getConnection method
Even with JDBC 4.0, you sometimes get a message that says, "No suitable driver found." In that case, you can use the forName method of the Class class to explicitly load the driver. However, if automatic driver loading works, it usually makes sense to remove this method call from your code.
How to load a MySQL database driver prior to JDBC 4.0
Class.forName{"com.mysql.jdbc.Driver");
-- Murach’s Java Servlets and JSP
I have to use Class.forName("com.mysql.cj.jdbc.Driver"); in my system, no automatic class loading. Not sure why.
<(striked-out) see updated answer soln2 below>
When I am using a normal Java Project instead of a Dynamic Web Project in Eclipse,
I only need to add the mysql-connector-java-8.0.28.jar to Java Build Path directly,
then I can connect to the JDBC with no problem.
However, if I am using Dynamic Web Project (which is in this case), those 2 strict rules applies (jar position & class loading).
<see TOMCAT ON ECLIPSE java.sql.SQLException: No suitable driver found for jdbc:mysql >
Soln2 (Updated Ans) //-20220305_12
In short:
1 . put mysql-connector-java-8.0.28.jar file in the <where you install your Tomcat>/lib.
eg: G:\pla\Java\apache-tomcat-10.0.16\lib\mysql-connector-java-8.0.28.jar
(and for an Eclipse Dynamic Web Project, the jar will then be automatically put inside in your project's Java build path > Server Runtime [Apache Tomcat v10.0].)
Additional notes::
for soln1::
put mysql-connector-java-8.0.28.jar file in the WEB-INF/lib.
use Class.forName("com.mysql.cj.jdbc.Driver"); in your Servlet Java code.
this will create an WARNING:
WARNING: The web application [LearnJDBC] appears to have started a thread named [mysql-cj-abandoned-connection-cleanup] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
<see The web application [] appears to have started a thread named [Abandoned connection cleanup thread] com.mysql.jdbc.AbandonedConnectionCleanupThread >
and that answer led me to soln2.
for soln2::
put mysql-connector-java-8.0.28.jar file in the <where you install your Tomcat>/lib.
this will create an INFO:
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
you can just ignore it.
<see How to fix "JARs that were scanned but no TLDs were found in them " in Tomcat 9.0.0M10 >
(you should now understand what Murach’s Java Servlets and JSP was talking about: the jar in Tomcat/lib & the no need for Class.forName("com.mysql.cj.jdbc.Driver");)
to kinda fix it //-20220307_23
Tomcat 8.5. Inside catalina.properties, located in the /conf directory set:
tomcat.util.scan.StandardJarScanFilter.jarsToSkip=\*.jar
How to fix JSP compiler warning: one JAR was scanned for TLDs yet contained no TLDs?
It might be worth noting that this can also occur when Windows blocks downloads that it considers to be unsafe. This can be addressed by right-clicking the jar file (such as ojdbc7.jar), and checking the 'Unblock' box at the bottom.
Windows JAR File Properties Dialog:
As well as adding the MySQL JDBC connector ensure the context.xml (if not unpacked in the Tomcat webapps folder) with your DB connection definitions are included within Tomcats conf directory.
A very silly mistake which could be possible resulting is adding of space at the start of the JDBC URL connection.
What I mean is:-
suppose u have bymistake given the jdbc url like
String jdbcUrl=" jdbc:mysql://localhost:3306/web_customer_tracker?useSSL=false&serverTimeZone=UTC";
(Notice there is a space in the staring of the url, this will make the error)
the correct way should be:
String jdbcUrl="jdbc:mysql://localhost:3306/web_customer_tracker?useSSL=false&serverTimeZone=UTC";
(Notice no space in the staring, you may give space at the end of the url but it is safe not to)
Run java with CLASSPATH environmental variable pointing to driver's JAR file, e.g.
CLASSPATH='.:drivers/mssql-jdbc-6.2.1.jre8.jar' java ConnectURL
Where drivers/mssql-jdbc-6.2.1.jre8.jar is the path to driver file (e.g. JDBC for for SQL Server).
The ConnectURL is the sample app from that driver (samples/connections/ConnectURL.java), compiled via javac ConnectURL.java.
I was using jruby, in my case I created under config/initializers
postgres_driver.rb
$CLASSPATH << '~/.rbenv/versions/jruby-1.7.17/lib/ruby/gems/shared/gems/jdbc-postgres-9.4.1200/lib/postgresql-9.4-1200.jdbc4.jar'
or wherever your driver is, and that's it !
I had this exact issue when developing a Spring Boot application in STS, but ultimately deploying the packaged war to WebSphere(v.9). Based on previous answers my situation was unique. ojdbc8.jar was in my WEB-INF/lib folder with Parent Last class loading set, but always it says it failed to find the suitable driver.
My ultimate issue was that I was using the incorrect DataSource class because I was just following along with online tutorials/examples. Found the hint thanks to David Dai comment on his own question here: Spring JDBC Could not load JDBC driver class [oracle.jdbc.driver.OracleDriver]
Also later found spring guru example with Oracle specific driver: https://springframework.guru/configuring-spring-boot-for-oracle/
Example that throws error using org.springframework.jdbc.datasource.DriverManagerDataSource based on generic examples.
#Config
#EnableTransactionManagement
public class appDataConfig {
\* Other Bean Defs *\
#Bean
public DataSource dataSource() {
// configure and return the necessary JDBC DataSource
DriverManagerDataSource dataSource = new DriverManagerDataSource("jdbc:oracle:thin:#//HOST:PORT/SID", "user", "password");
dataSource.setSchema("MY_SCHEMA");
return dataSource;
}
}
And the corrected exapmle using a oracle.jdbc.pool.OracleDataSource:
#Config
#EnableTransactionManagement
public class appDataConfig {
/* Other Bean Defs */
#Bean
public DataSource dataSource() {
// configure and return the necessary JDBC DataSource
OracleDataSource datasource = null;
try {
datasource = new OracleDataSource();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
datasource.setURL("jdbc:oracle:thin:#//HOST:PORT/SID");
datasource.setUser("user");
datasource.setPassword("password");
return datasource;
}
}
I was having the same issue with mysql datasource using spring data that would work outside but gave me this error when deployed on tomcat.
The error went away when I added the driver jar mysql-connector-java-8.0.16.jar to the jres lib/ext folder
However I did not want to do this in production for fear of interfering with other applications. Explicity defining the driver class solved this issue for me
spring.datasource.driver-class-name: com.mysql.cj.jdbc.Driver
You will get this same error if there is not a Resource definition provided somewhere for your app -- most likely either in the central context.xml, or individual context file in conf/Catalina/localhost. And if using individual context files, beware that Tomcat freely deletes them anytime you remove/undeploy the corresponding .war file.
For me the same error occurred while connecting to postgres while creating a dataframe from table .It was caused due to,the missing dependency. jdbc dependency was not set .I was using maven for the build ,so added the required dependency to the pom file from maven dependency
jdbc dependency
For me adding below dependency to pom.xml file just solved like magic! I had no mysql connector dependency and even adding mssql jdbc jar file to build path did not work either.
<dependency>
<groupId>com.microsoft.sqlserver</groupId>
<artifactId>mssql-jdbc</artifactId>
<version>9.4.0.jre11</version>
</dependency>
In my case I was working on a Java project with Maven and encountered this error.
In your pom.xml file make sure you have this dependencies
<dependencies>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.11</version>
</dependency>
</dependencies>
and where you create connection have something like this
public Connection createConnection() {
try {
String url = "jdbc:mysql://localhost:3306/yourDatabaseName";
String username = "root"; //your my sql username here
String password = "1234"; //your mysql password here
Class.forName("com.mysql.cj.jdbc.Driver");
return DriverManager.getConnection(url, username, password);
} catch (SQLException | ClassNotFoundException e) {
e.printStackTrace();
}
return null;
}
faced same issue. in my case ':' colon before '//' (jdbc:mysql://localhost:3306/dbname) was missing, and it just fixed the problem.
make sure : and // are placed properly.
I ran into the same error. In my case, the JDBC URL was correct, but the issue was with classpath. However, adding MySQL connector's JAR file to the -classpath or -cp (or, in the case of an IDE, as a library) doesn't resolve the issue. So I will have to move the JAR file to the location of Java bytecode and run java -cp :mysql_connector.jar to make this work. If someone runs into the same issue as mine, I'm leaving this here.
I encountered this issue by putting a XML file into the src/main/resources wrongly, I deleted it and then all back to normal.

class not found com.mysql.jdbc.Driver jdbc when trying to connect to a Mysql Database

I'm developing a web application in java where I'm trying to connect to a MySQL database using JDBC template ( with springs dao) but I always get:
SEVERE: Servlet.service() for servlet [dispatcher] in context with path [/DealingOfInsiders] threw exception [Request processing failed;
nested exception is org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot load JDBC driver class 'com.mysql.jdbc.Driver '] with root cause
java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
[....]
I think the problem is coming from the file mysql-connector-java-5.1.25-bin.jar which contains the targeted class ...
So I tried many things to get this problem solve :
I've configured the build path of my project whith this jar but it didn't worked
I ve also put the file in the folder : WEB-INF/lib , didn't worked
I ve configured a classpath variable to this jar in eclipse ( preference ->java->buildpath->classpath variabe ) it didn't worked
I have put the jar file in the tomcat library but it didn't work as well
'com.mysql.jdbc.Driver '
^^ // remove this space
There appears to be a trailing space on the name?
'com.mysql.jdbc.Driver '
Apart from that, "com.mysql.jdbc.Driver" is correct.
The WEB-INF/lib folder is a good place for project-specific drivers & libraries; keeping the Tomcat shared folders up-to-date is not so easy.
Back in JDBC days you had to load the class with Class.forName( clazzName) to register it before you asked JDBC for a connection, but that's not the issue here.
I had this issue but with the Postgres driver and I'm using Eclipse. If you're using Tomcat 7, try adding the JAR file to the lib folder in your Tomcat directory. That worked for me. I didn't have to use Class.forName() or put the JAR in my classpath. I hope this helps you.

com.mysql.jdbc.Driver not found with mysql connector in buildpath

I use Eclipse juno. I have mysql-connector-java-5.1.22-bin.jar in my buildpath and i try to establish a DB connection to my mysql database. Here is my code
public Connection getConnectionToDB() {
try {
Class.forName(driver);
Connection con = DriverManager.getConnection(url + dbName,
userName, password);
return con;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
When i debug it i found out the problem is at:
Class.forName(driver);
i also tried replacing it with:
Class.forName(driver).newInstance();
At this line, it breaks out to the exception and throws this exception:
java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1676)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1521)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
at main.jdbc.BaseJdbc.getConnectionToDB(BaseJdbc.java:18)
at main.jdbc.UserDriverJdbc.queryUserById(UserDriverJdbc.java:15)
at main.drivers.UserDriver.findUserById(UserDriver.java:50)
at main.drivers.UserDriver.isLoginValid(UserDriver.java:56)
at main.controllers.LoginController.doPost(LoginController.java:33)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
at org.apache.catalina.core.StandardContextValve.__invoke(StandardContextValve.java:164)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
at org.apache.catalina.core.StandardHostValve.__invoke(StandardHostValve.java:164)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:562)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:395)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:250)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:188)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:166)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)
The answer was quite tricky for me to find but i figure it out. It was ofcourse classpath problem.
If you ever encounter a problem like this and try to solve it inside eclipse, go to
eclipse -> window -> preferences -> java -> buildpath -> classpath
and add the
"mysql-connector-java-5.1.22-bin.jar"
as new variable. Name it whatever you like. Hope this helps.
You need to make sure you have the proper libraries and jar files loaded in your project. I dealt with this a lot when working with postgresql. I would think you're just missing the jar file.
This was my problem which was answered here:
SO Link
"If this code works in your J2SE it means you need to have a JAR file somewhere containing com.mysql.jdbc.Driver class (so called JDBC driver). This JAR needs to be visible in Tomcat. So, I would suggest to place mysql-jdbc.jar at physical location to /WEB-INF/lib directory of your project." From
I've been looking for a solution everywhere. Maybe this is not your solution, but using Eclipse i was exporting as a JAR file and got same exception, but then exported as "Runnable JAR"and it worked.
If you use netbeans then do the followings:
go to your application>>>libraries>>add jar (by right click)>> "mysql-connector-java-5.1.22-bin.jar"
In Your Eclipse Go to Windows->Preferences->Java->BuildPath->ClassPathVariables->New
Now Add Your Mysql-Connector jar file what you downloaded From Mvn repository or anywhere ...Now ApplyAndClose ...restart the server it will work...
Note: If You are using Servlet then use eclipse from the package not from the installer..If you will use the installer you will get lot of problem

Tomcat JDBC MySQL ClassNotFoundException

I would like to use springMVC and JPA (using hibernate) on my tomcat 7 server (running locally on my Mac).
I was able to set up everything successfully with an embedded H2 database.
Now I switched to mysql and am getting the following error
java.lang.ClassNotFoundException: "com.mysql.jdbc.Driver"
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1711)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1556)
This suggests tomcat is having trouble finding the mysql-connector for java.
There are a multitude of tutorials on how to add the connector to $CATALINA_HOME/lib.
After trying to use a maven dependency for my project, I followed the advice and copied the .jar file into the lib directory:
$ ls $CATALINA_HOME/lib/mysql*.jar
/Users/david/Applications/tomcat/lib/mysql-connector-java-5.1.20-bin.jar
I have read and execute permissions on the directory and file.
At the moment I can't figure out how to make tomcat aware of the jar. The folder is included in
$CATALINA_HOME/conf/catalina.properties
and I have restarted the server multiple times.
Thanks for you help.
Normally, the output of a CNFE is as follows:
java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
whereas your error message shows
java.lang.ClassNotFoundException: "com.mysql.jdbc.Driver"
I think you've still got quotes around the driver class name in your config.