exercise26_7.java

java程序设计 机械工业出版社 书籍代码

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

public class Exercise26_7 extends HttpServlet {
  private static final String CONTENT_TYPE = "text/html";
  PreparedStatement pstmtGetResult;

  public void init() throws ServletException {
    initializeJdbc();
  }

  /**Initialize database connection*/
  private void initializeJdbc() {
    try {
      // Declare driver and connection string
      String driver = "sun.jdbc.odbc.JdbcOdbcDriver";
      String connectionString = "jdbc:odbc:exampleMDBDataSource";
      /* For Oracle
      String driver = "oracle.jdbc.driver.OracleDriver";
      String connectionString =
      "jdbc:oracle:thin:scott/[e-mail]:1521:ora9i";
      */
      // Load the Oracle JDBC Thin driver
      Class.forName(driver);

      // Connect to the sample database
      Connection conn = DriverManager.getConnection
        (connectionString);

      pstmtGetResult = conn.prepareStatement
        ("select name, current from csci4990_01 where ssn = ?");
    }
    catch (Exception ex) {
      ex.printStackTrace();
    }
  }

  /**Process the HTTP Get request*/
  public void doGet(HttpServletRequest request, HttpServletResponse
    response) throws ServletException, IOException {
    response.setContentType(CONTENT_TYPE);
    PrintWriter out = response.getWriter();

    String ssn = "";
    try {
      ssn = request.getParameter("ssn");

      pstmtGetResult.setString(1, ssn);
      ResultSet rs = pstmtGetResult.executeQuery();

      if (rs == null)
        out.println("Not found");
      else {
        while (rs.next()) {
          out.println(rs.getString(1));
          out.println(rs.getDouble(2));
        }
      }
    }
    catch(Exception e) {
      e.printStackTrace();
    }

    out.close();
  }

  /**Clean up resources*/
  public void destroy() {
  }
}