First, the method of jsp access the database:
1. Establish your own virtual directory, establish web-inf / lib, web-inf / class, web-inf / jar, and each directory in the virtual directory.
WEB-INF / Web.xml Configuring Access Servlets in this file and configures some initial parameters, as follows:
WEB-INF / LIB is stored in JSP, JavaBean, JAR, including some databases we use (not Java itself, such as mysql).
WEB-INF / CLASSES is stored in JSP, JavaBean, is a class file. If it is a package, you have to store the Class in the directory of the package.
Second, some issues of JSP access to the database and their solutions:
1. The problem could not be found: It is mainly used by the category that is not stored in a suitable location. JAR is stored under LIB, and the class file is stored under the class.
Third, access Database instance: JSP Access MySQL
1. Establish a directory TEST to establish a related directory below. Web-inf, web-inf / lib.
2. Configure the virtual directory to point to TEST.
3. Will mysql-conn. JAR copy to the LIB below.
4. Test / dbtext.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 database SQLCONN = java.sql.driverManager.getConnection ("JDBC: mysql: // localhost: 3306 /" Database, User, pass); // Create a statement object SQLSTMT = sqlconn.createstatement (); // Execute SQL statement string sqlQuery = "select * from test"; sqlrst = sqlstmt.executeQuery (sqlquery); while (sqlrst.next ()) {
Out.println (Sqlrst.getstring (1));
Out.println (SQLRST.GETSTRING (2));
}
%>
Note: Accessing a database must first confirm that there is a corresponding permissions.
