jsp+beans实现读取数据库的例子

2014-11-23 17:39:05 · 作者: · 浏览: 19

  JSP+beans实现读取数据库的例子


  jsp+beans实现读取数据库的例子
  Select.jsp


  
  
  Select everything from a database
  
  


  
  


  <% out.print(select.connect()); %>
  

  <% out.print(select.select()); %>


  


Format results


  

  <%@ page import="Java.util.Vector" %>
  <% Vector aResult = select.getResult(); %>


  



  
  


  DataBaseSelect.java
  import java.sql.*;
  import java.util.Vector;


  /**
  * DataBaseSelect.java
  * Written by Morgan Catlin
  * August 19, 1999
  *
  * Variables:
  * Vector result = where I put the results of a select query
  *
  * Methods:
  * Vector getResult() = returns result
  * void setResult() = sets result
  * String connect() = connects to a database
  * String select() = selects information from a database
  */


  public class DataBaseSelect {


  private Vector result;


  public DataBaseSelect() {
  result = new Vector();
  } // constructor DataBaseSelect


  public String connect() {
  try {
  Class.forName("a JDBC driver").newInstance();
  return "Driver Loaded!";
  } catch (Exception E) {
  return "Unable to load driver.";
  }
  }


  public String select() {
  try {
  Connection C = DriverManager.getConnection("database connection string");


  Statement Stmt = C.createStatement();


  ResultSet myResult = Stmt.executeQuery("SELECT acolumn from atable");


  while (myResult.next()) {
  result.addElement(myResult.getString(1));
  }


  // Clean up
  myResult.close();
  Stmt.close();
  C.close();
  return "Connection Success!";
  } catch (SQLException E) {
  return "SQLException: " + E.getMessage();
  }
  }


  /**
  * Accessor for result
  **/
  public Vector getResult() {
  return result;
  }


  /**
  * Mutator for result
  **/
  public void setResult(Vector avector) {
  result = avector;
  }


  } // class DataBaseSelect