Troubleshoot JSP database access problems

I. JSP database access method:
1. Create your own virtual directory and create web-inflib, web-infclass, and web-infjar under the virtual directory. The directories are described as follows:
The web-infweb.xml configures access Servlet in this file and configures some initial parameters, for example:
<Servlet>
<Servlet-name> TestServlet </servlet-name> <! -- Servlet name -->
<Servlet-class> com. myweb. TestServlet </servlet-class> <! -- Servlet class name includes package name -->
</Servlet>
<Servlet-mapping>
<Servlet-name> TestServlet </servlet-name> <! -- Servlet name -->
<Url-pattern>/Servlet/TestServlet </url-pattern> <! -- Access the servlet url relative to the root directory -->
</Servlet-mapping>
</Servlet>
Web-inflib is stored in jsp, and the jar accessed by javabean includes some database drivers we use (not supported by java itself, such as mysql ).
Web-infclasses is stored in jsp. The class used in javabean is a class file. If it is a package, you need to store the class according to the package directory.
II. JSP database access problems and solutions:
1. Class cannot be found: The main problem is that the class used is not stored in a proper location, jar is stored in lib, and class files are stored in class.
III. Access database instance: access Mysql through JSP
1. Create the directory test and create the relevant directory below. Web-inf, web-inflib.
2. Configure the virtual directory to point to test.
3. Run mysql-conn. Copy jar to lib.
4. The testdbtext. jsp code is as follows:
<% @ Page language = "java" %>
<% @ Page contentType = "text/html; charset = gb2312" %>
<% @ Page import = "java. SQL. *" %>
<%
Connection sqlConn;
ResultSet sqlRst;
Statement sqlStmt;
String database = "test ";
String user = "root ";
String pass = "123456 ";
Class. forName ("org. gjt. mm. mysql. Driver"). newInstance ();
// Connect to the database
SqlConn = java. SQL. DriverManager. getConnection ("jdbc: mysql: // localhost: 3306/" + database, user, pass );
// Create a statement object
SqlStmt = sqlConn. createStatement ();
// Execute the SQL statement
String sqlQuery = "select * from test ";
SqlRst=sqlStmt.exe cuteQuery (sqlQuery );
While (sqlRst. next ())
{
Out. println (sqlRst. getString (1 ));
Out. println (sqlRst. getString (2 ));
}
%>
Note: To access a database, you must first confirm the corresponding permissions.