pooltest.java

一个具体的jdbc编程实现

import java.io.*; 
import java.sql.*; 
import javax.servlet.*; 
import javax.servlet.http.*; 

public class TestServlet extends HttpServlet {
	private DBConnectionManager connMgr; 
	public void init(ServletConfig conf) throws ServletException {
		super.init(conf);
	connMgr = DBConnectionManager.getInstance(); 
	}

	public void service(HttpServletRequest req, HttpServletResponse res) 
	throws IOException {
		res.setContentType("text/html");
		PrintWriter out = res.getWriter();
		Connection con = connMgr.getConnection("idb");
		if (con == null) {
			out.println("不能获取数据库连接.");
			return;
		}
		ResultSet rs = null; 
		ResultSetMetaData md = null; 
		Statement stmt = null;
	try {
	stmt = con.createStatement();
	rs = stmt.executeQuery("SELECT * FROM EMPLOYEE");
	md = rs.getMetaData(); 
	out.println("<H1>职工数据</H1>"); 
	while (rs.next()) {
		out.println("<BR>"); 
		for (int i = 1; i < md.getColumnCount(); i++) {
			out.print(rs.getString(i) + ", "); 
		}
	}
	stmt.close();
	rs.close(); 
	}
	catch (SQLException e) {
		e.printStackTrace(out); 
	}
	connMgr.freeConnection("idb", con); 
	}
	public void destroy() {
		connMgr.release();
		super.destroy();
	}
}