Problem connecting to Mysql from jsp in tomcat

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I am trying to connect to Mysql from Jsp in Tomcat and I am getting Java.lang.NullPointer Exception. Please provide any help as soon as possible.

I have set the web.xml and the server.xml properly.

My web.xml contains:

xml Syntax (Toggle Plain Text)
<description>MySQL Test App</description>
	<resource-ref>
		  <description>DB Connection</description>
		  <res-ref-name>jdbc/TestDB</res-ref-name>
		  <res-type>javax.sql.DataSource</res-type>
		  <res-auth>Container</res-auth>
	</resource-ref>
<description>MySQL Test App</description>
	<resource-ref>
		  <description>DB Connection</description>
		  <res-ref-name>jdbc/TestDB</res-ref-name>
		  <res-type>javax.sql.DataSource</res-type>
		  <res-auth>Container</res-auth>
	</resource-ref>

server.xml I have added this:

xml Syntax (Toggle Plain Text)
<Context path="/become3" docBase="become3"
			debug="5" reloadable="true" crossContext="true">
 
	  <Logger className="org.apache.catalina.logger.FileLogger"
				 prefix="localhost_become3_log." suffix=".txt"
				 timestamp="true"/>
 
	  <Resource name="jdbc/TestDB"
				   auth="Container"
				   type="javax.sql.DataSource"/>
 
	  <ResourceParams name="jdbc/TestDB">
		<parameter>
		  <name>factory</name>
		  <value>org.apache.commons.dbcp.BasicDataSourceFactory</value>
		</parameter>
 
		<!-- Maximum number of dB connections in pool. Make sure you
			 configure your mysqld max_connections large enough to handle
			 all of your db connections. Set to -1 for no limit.
			 -->
		<parameter>
		  <name>maxActive</name>
		  <value>100</value>
		</parameter>
 
		<!-- Maximum number of idle dB connections to retain in pool.
			 Set to 0 for no limit.
			 -->
		<parameter>
		  <name>maxIdle</name>
		  <value>30</value>
		</parameter>
 
		<!-- Maximum time to wait for a dB connection to become available
			 in ms, in this example 10 seconds. An Exception is thrown if
			 this timeout is exceeded.  Set to -1 to wait indefinitely.
			 -->
		<parameter>
		  <name>maxWait</name>
		  <value>10000</value>
		</parameter>
 
		<!-- MySQL dB username and password for dB connections  -->
		<parameter>
		 <name>username</name>
		 <value>root</value>
		</parameter>
		<parameter>
		 <name>password</name>
		 <value>root</value>
		</parameter>
 
		<!-- Class name for mm.mysql JDBC driver -->
		<parameter>
		   <name>driverClassName</name>
		   <value>com.mysql.jdbc.Driver</value>
		</parameter>
 
		<!-- The JDBC connection url for connecting to your MySQL dB.
			 -->
		<parameter>
		  <name>url</name>
		  <value>jdbc:mysql://localhost:3306/first?autoReconnect=true</value>
		</parameter>
	  </ResourceParams>
	</Context>
<Context path="/become3" docBase="become3"
			debug="5" reloadable="true" crossContext="true">

	  <Logger className="org.apache.catalina.logger.FileLogger"
				 prefix="localhost_become3_log." suffix=".txt"
				 timestamp="true"/>

	  <Resource name="jdbc/TestDB"
				   auth="Container"
				   type="javax.sql.DataSource"/>

	  <ResourceParams name="jdbc/TestDB">
		<parameter>
		  <name>factory</name>
		  <value>org.apache.commons.dbcp.BasicDataSourceFactory</value>
		</parameter>

		<!-- Maximum number of dB connections in pool. Make sure you
			 configure your mysqld max_connections large enough to handle
			 all of your db connections. Set to -1 for no limit.
			 -->
		<parameter>
		  <name>maxActive</name>
		  <value>100</value>
		</parameter>

		<!-- Maximum number of idle dB connections to retain in pool.
			 Set to 0 for no limit.
			 -->
		<parameter>
		  <name>maxIdle</name>
		  <value>30</value>
		</parameter>

		<!-- Maximum time to wait for a dB connection to become available
			 in ms, in this example 10 seconds. An Exception is thrown if
			 this timeout is exceeded.  Set to -1 to wait indefinitely.
			 -->
		<parameter>
		  <name>maxWait</name>
		  <value>10000</value>
		</parameter>

		<!-- MySQL dB username and password for dB connections  -->
		<parameter>
		 <name>username</name>
		 <value>root</value>
		</parameter>
		<parameter>
		 <name>password</name>
		 <value>root</value>
		</parameter>

		<!-- Class name for mm.mysql JDBC driver -->
		<parameter>
		   <name>driverClassName</name>
		   <value>com.mysql.jdbc.Driver</value>
		</parameter>

		<!-- The JDBC connection url for connecting to your MySQL dB.
			 -->
		<parameter>
		  <name>url</name>
		  <value>jdbc:mysql://localhost:3306/first?autoReconnect=true</value>
		</parameter>
	  </ResourceParams>
	</Context>

JSP Syntax (Toggle Plain Text)
<%@ page import = "java.util.*" %>
<%@ page import = "java.sql.*" %>
<%@ page import = "javax.sql.*" %>
<%@ page import = "java.io.*" %>
<%@ page import = "javax.naming.*" %>
 
<html>
  <head>
    <title>DB Test</title>
  </head>
  <body>
 
  <h2>Results</h2>
 
  <%
 
	   try {
 
		   Connection con1 = null;
		   String connectionURL = "jdbc:mysql://localhost:3306/first";
		   String id = "";
 
		   Class.forName("com.mysql.jdbc.Driver").newInstance();
		   String sql = "select id from deals";
		   PreparedStatement pstmt2 = con1.prepareStatement(sql);
		   con1 = DriverManager.getConnection(connectionURL, "*******", "******");
		   out.println(con1);
 
			ResultSet rs = pstmt2.executeQuery(sql);
 
			while(rs.next()){
				id = rs.getString(1);
			}
 
			out.println(id);
	   }
	   catch(Exception e){
		e.printStackTrace();	
	   }
  %>			
  </body>
</html>
<%@ page import = "java.util.*" %>
<%@ page import = "java.sql.*" %>
<%@ page import = "javax.sql.*" %>
<%@ page import = "java.io.*" %>
<%@ page import = "javax.naming.*" %>

<html>
  <head>
    <title>DB Test</title>
  </head>
  <body>

  <h2>Results</h2>
	
  <%
  
	   try {
		
		   Connection con1 = null;
		   String connectionURL = "jdbc:mysql://localhost:3306/first";
		   String id = "";

		   Class.forName("com.mysql.jdbc.Driver").newInstance();
		   String sql = "select id from deals";
		   PreparedStatement pstmt2 = con1.prepareStatement(sql);
		   con1 = DriverManager.getConnection(connectionURL, "*******", "******");
		   out.println(con1);

			ResultSet rs = pstmt2.executeQuery(sql);
			
			while(rs.next()){
				id = rs.getString(1);
			}

			out.println(id);
	   }
	   catch(Exception e){
		e.printStackTrace();	
	   }
  %>			
  </body>
</html>

Last edited by peter_budo; Mar 21st, 2010 at 11:10 am. Reason: Please do not use CODE SNIPPED for posting question. Use FORUM THREAD.

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anuraggupta16

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Mar 22nd, 2010

Re: Problem connecting to Mysql from jsp in tomcat

don't EVER try to put Java code in JSP.

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