Tomcat configures the data source to access the MySQL database through JNDI

Last Update:2018-12-06 Source: Internet

Author: User

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<P> 4. Tomcat configures the data source to access the MySQL database through JNDI </P> <p> cannot create JDBC driver of class ''for connect URL 'null' error </P>

1.Add the MySQL JDBC driver to build path and copy it to the Tomcat directory/lib.

2.Add

<Resource Name = "JDBC/BBS" auth = "Container" type = "javax. SQL. datasource"

Maxactive = "100" maxidle = "30" maxwait = "10000"

Username = "root" Password = "0." driverclassname = "com. MySQL. JDBC. Driver"

Url = "JDBC: mysql: // localhost: 3306/BBS? Autoreconnect = true "/>

</Context>

3.Add <web-app> </Web-app> between the web-INF/Web. xml file of the project.

<Resource-ref>

<Description> dB connection </description>

<Res-ref-Name> JDBC/BBS </RES-ref-Name>

<Res-type> javax. SQL. datasource </RES-type>

<Res-auth> container </RES-auth>

</Resource-ref>

4.Create test JSP

<% @ Page contenttype = "text/html; charset = UTF-8" %>

<% @ Page Language = "Java" %>

<% @ Page import = "Java. util. *" %>

<% @ Page import = "Java. SQL. *" %>

<% @ Page import = "javax. SQL. *" %>

<% @ Page import = "javax. Naming. *" %>

<HTML>

<Head>

</Head>

<H1> MySQL JNDI test

<HR>

Datasource DS = NULL;

Try {

Context initctx = new initialcontext ();

If (initctx = NULL)

Throw new exception ("Initial failed! ");

Context CTX = (context) initctx. Lookup ("Java: COMP/ENV ");

If (CTX! = NULL)

DS = (datasource) CTX. Lookup ("JDBC/BBS ");

If (DS = NULL)

Throw new exception ("Look up datasource failed! ");

} Catch (exception e ){

System. Out. println (E. getmessage ());

}

Connection conn = Ds. getconnection ();

Statement stmt = conn. createstatement ();

Resultset rs = stmt.exe cutequery ("select * from user ");

While (Rs. Next ()){

<% = Rs. getint (1) %>

<% = Rs. getstring (2) %>

}

Rs. Close ();

Stmt. Close ();

Conn. Close ();

</Body>

</Html>

5. related error: <1> cannot create JDBC driver of class ''for connect URL 'null' Tomcat first finds the web. <resource-ref> in XML, and then find the server. <resource> in XML. If <Resource Name = "JDBC/testdb"> is not found or the name is incorrect, the error "cannot create JDBC driver of class ''' for connect URL 'null'" is returned. Note that the JDBC/BBS name in step 2 and 3 must be the same, and the URL Information in step 3 must be correct <2> cannot load JDBC Driver Class 'com. mySQL. JDBC. driver 'step 1

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