JNDI is a very important standard in J2EE, usually in the EJB programming, Tomcat4.0 provides methods of using JNDI directly in JSP and Servelt, talk about configuring and using JNDI in Tomcat 4.0. Method (with the JNDI connection database as an example) assume that the database is mysql, the experiment example is in the Tomcat_Home / WebApps / dbtest directory
A. Add mysql JDBC connection library mm.mysql-2.0.9-bin.jar into Tomcat_Home / Common / LIB
B. Configure the Tomcat_Home / conf / sere.xml file to join a context: This is the root path of dbtest, which is ready to prepare in dbtest.
C. Add joining
factory org.apache.commons.dbcp.basicDataSourceFactory
<-!.. 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 0 for no limit -.> maxActive 100
maxidle 30
maxWait 10000
username test password < Value> Test driverclassname org.gjt.mm.mysql.driver < / value>
URL jdbc: mysql: // localhost: 3306 / test Every small segment has an English annotation, which is Tomcat, which will be added according to Sample, mainly modified DriverClassName, URL, and user account; need to emphasize "JDBC / TestDB" is JDNI Find Name.
D. Using JSPH or Servlet The following is the code in JSP files about JSP file (file name UserHandLeDb.jsp) Need to pay attention to JNDI Name To add "Java: Comp / ENV /"
<% @ page language = "java"%> <% @ page import = "java.util. *"%> <% @ page import = "java.sql. *"%> <% @ page import = "javax. SQL. * "%> <% @ Page Import =" javax.naming. * "%>
<% String jndi_name = "java: comp / env / jdbc / testdb"; string select_user_sql = "SELECT Userid, Name, Birthday, Email from EMP"; String ColNames [] [] = {{"User ID", "Name" , "Birth day", "email"}, {"userid", "name", "birthday", "email"}}; vector useerSet = new vector (); Vector columnset = new vector ();
For (int i = 0; i
Context ctx = new initialcontext (); if (ctx == null) throw new exception ("no content"); DataSource DS = (Datasource) ctx.lookup (JNDI_NAME);
Connection conn = ds.getConnection ();
try {PreparedStatement psPreparedStatement = conn.prepareStatement (select_user_sql); ResultSet resultSet = psPreparedStatement.executeQuery (); while (resultSet.next ()) {columnSet = new Vector (); for (int i = 0; i
E. Quote UserHandLeDb.jsp
test database </ title> <body> <% @ include file = "UserHandledb.jsp"%> <table border = "1 "> <% for (int i = 0; i <userSet.size (); i ) {Vector colset = (vector) UserSet.Get (i); out.print (" <tr> "); for (int J = 0; j <colset.size (); j ) {string col = (string) colset.get (j); out.print ("<TD>" COL "</ td>");} Out.Print ("</ TR>");}%> </ table> </ body> </ html></p>
<p>F. Add <Resource-Ref> <Description> DB Connection </ description> <res-ref-name> JDBC / TESTDB <REY> JAVAX.SQL.DataSource </ res-type> <res-auth> container </ res-auth> </ resource-ref> The Name matching of the RESOURCE segment in C in JDBC / TESTDB</p>
<p>G. The observation first determines that the database has been started, then start Tomcat, if Tomcat starts an exception, the possible reason is that the database's JDBC library is not loaded</p></div><div class="text-center mt-3 text-grey">
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