package dbase;
import java.io.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;
/**
Test servlet for JDBC to perform the following operations on
a table called test in the test database (this database is
always available for testing in MySQL).
DROP TABLE IF EXISTS test;
CREATE TABLE test ( name VARCHAR(20) NOT NULL, age INTEGER NOT NULL );
INSERT INTO test VALUES ('Fred', 34);
SELECT * FROM test;
Display the result
DROP TABLE test;
For a more object-oriented version see BookDisplayServlet
*/
public class DBaseTestServlet extends HttpServlet
{
private Connection connection;
/** Load the database driver and make a connection
*/
public void init() throws ServletException
{
try
{
Class.forName("com.mysql.jdbc.Driver");
connection = DriverManager.getConnection(
"jdbc:mysql://localhost:3306/web_db", "c2206", "c2206");
}
catch (ClassNotFoundException e)
{
System.out.println("Cannot load driver");
}
catch (SQLException e)
{
System.out.println("Cannot make a connection");
}
}
/**
Execute some SQL statements and queries
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws IOException, ServletException
{
String name = "";
int age = 0;
response.setContentType("text/html");
PrintWriter out = response.getWriter();
try
{
Statement st = connection.createStatement();
st.execute("DROP TABLE IF EXISTS test");
st.execute(
"CREATE TABLE test ("
+ "name VARCHAR(20) NOT NULL,"
+ "age INTEGER NOT NULL )" );
st.execute("INSERT INTO test VALUES ('Fred', 34)");
ResultSet result = st.executeQuery("SELECT * FROM test");
result.next(); // only one row
name = result.getString("name");
age = result.getInt("age");
st.execute("DROP TABLE test");
}
catch (SQLException e)
{
System.out.println("Error in statement");
}
out.println("\n"
+ "Testing JDBC\n"
+ "\n"
+ "The name is " + name + "
"
+ "The age is " + age
+ "\n"
+ "\n" );
}
/** Free database resources and close connection
*/
public void destroy()
{
try
{
connection.close();
}
catch (SQLException e)
{
e.printStackTrace();
}
}
}