Servlet.service() for servlet [...] in context with path [/...] threw exception [Servlet execution threw an exception] with root cause

Question

I am trying to set a DataSource connection; the error I actually get is java.lang.AbstractMethodError: com.mysql.jdbc.Connection.isValid(I)Z

but the title's error pops up right above.

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I have a caffeJdbc.java servlet with this DataSource setting

Context ctx = new InitialContext();
DataSource dataSource = (DataSource) ctx.lookup("java:comp/env/jdbc/caffeDB");
Connection con = dataSource.getConnection();

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This is the project web.xml setting, with servlet mapping and resource references

<welcome-file-list>
    <welcome-file>index.html</welcome-file>
</welcome-file-list>
<servlet>
    <servlet-name>tjdbc</servlet-name>
    <servlet-class>caffeJdbc</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>tjdbc</servlet-name>
    <url-pattern>/caffeJdbc</url-pattern>
</servlet-mapping>

<resource-ref>
    <res-ref-name>jdbc/caffeDB</res-ref-name>
    <res-type>javax.sql.DataSource</res-type>
    <res-auth>Container</res-auth>
</resource-ref>

--

server.xml

<GlobalNamingResources>
 <Resource name="jdbc/caffeDB" 
 global="jdbc/caffeDB"
 url="jdbc:mysql://localhost:3306/caffe"/>
</GlobalNamingResources>

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And this is the context.xml

<Context path="/JDBCDataSource">
    <WatchedResource>WEB-INF/web.xml</WatchedResource>
    <ResourceLink global="jdbc/caffeDB"
        name="jdbc/caffeDB"
        type="javax.sql.DataSource">
    </ResourceLink>
</Context>

I loaded both JDBC driver and the commons-dbcp2-2.1.1 one in the lib directory and in the path

Answer 1

May be the JDBC Driver you are using is outdated, Please check that, You can see here for more info.