todatabase.java

用java编写的图书馆管理程序

package bookmanager;
   import java.sql.*;

import javax.swing.JOptionPane;

   public class toDatabase {
   /***************************************************************************
    ***      declaration of the private variables used in the program       ***
    ***************************************************************************/
   
   //for setting the connection and statement
	   JLibrary myMain;
      private Connection connection = null;
      private Statement statement   = null;
      private ResultSet resultset   = null;
   
      public boolean isDouble(String query) {
         try {
            Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
         }
            catch(ClassNotFoundException ea) {
               System.out.println(ea.toString());
            }
            catch(Exception e) {
               System.out.println(e.toString());
            }
      /***************************************************************
       * for making the connection,creating the statement and update *
       * the table in the database. After that,closing the statmenet *
       * and connection. There is catch block SQLException for error *
       ***************************************************************/
         try {
            connection = DriverManager.getConnection("jdbc:odbc:JLibrary");
            statement  = connection.createStatement();
            resultset  = statement.executeQuery(query);
            while(resultset.next()) {
               return true;
            }
            resultset.close();
            statement.close();
            connection.close();
         }
            catch(SQLException SQLe) {
               System.out.println(SQLe.toString());
            }
         return false;
      }
      public int numberOfBooks(String query) {
         try {
            Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
         }
            catch(ClassNotFoundException ea) {
               System.out.println(ea.toString());
            }
            catch(Exception e) {
               System.out.println(e.toString());
            }
      /***************************************************************
       * for making the connection,creating the statement and update *
       * the table in the database. After that,closing the statmenet *
       * and connection. There is catch block SQLException for error *
       ***************************************************************/
         try {
            connection = DriverManager.getConnection("jdbc:odbc:JLibrary");
            statement  = connection.createStatement();
            resultset  = statement.executeQuery(query);
            while(resultset.next()) {
               return resultset.getInt("NumberOfBooks");
            }
            resultset.close();
            statement.close();
            connection.close();
         }
            catch(SQLException SQLe) {
               System.out.println(SQLe.toString());
            }
         return -1;
      }
      public int memberID(String query) {
         try {
            Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
         }
            catch(ClassNotFoundException ea) {
               System.out.println(ea.toString());
            }
            catch(Exception e) {
               System.out.println(e.toString());
            }
      /***************************************************************
       * for making the connection,creating the statement and update *
       * the table in the database. After that,closing the statmenet *
       * and connection. There is catch block SQLException for error *
       ***************************************************************/
         try {
            connection = DriverManager.getConnection("jdbc:odbc:JLibrary");
            statement  = connection.createStatement();
            resultset  = statement.executeQuery(query);
            while(resultset.next()) {
               return resultset.getInt("MemberID");
            }
            resultset.close();
            statement.close();
            connection.close();
         }
            catch(SQLException SQLe) {
               System.out.println(SQLe.toString());
            }
         return -1;
      }
      public void update(String query) {
         try {
            Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
         }
            catch(ClassNotFoundException ea) {
               System.out.println(ea.toString());
            }
            catch(Exception e) {
               System.out.println(e.toString());
            }
      /***************************************************************
       * for making the connection,creating the statement and update *
       * the table in the database. After that,closing the statmenet *
       * and connection. There is catch block SQLException for error *
       ***************************************************************/
         try {
            connection = DriverManager.getConnection("jdbc:odbc:JLibrary");
            statement  = connection.createStatement();
            statement.executeUpdate(query);
            statement.close();
            connection.close();
         }
            catch(SQLException SQLe) {
               System.out.println(SQLe.toString());
            }
      }
   
   
   public String isVerityUser(String query){
	   String Leveled="";
	   try {
           Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
        }
           catch(ClassNotFoundException ea) {
              System.out.println(ea.toString());
           }
           catch(Exception e) {
              System.out.println(e.toString());
           }
           /***************************************************************
            * for making the connection,creating the statement and update *
            * the table in the database. After that,closing the statement *
            * and connection. There is catch block SQLException for error *
            ***************************************************************/
           
           try {
               connection = DriverManager.getConnection("jdbc:odbc:JLibrary");
               statement  = connection.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
               
               ResultSet rs;
               rs=statement.executeQuery(query);
               boolean isexist = false;
   		    try {
   		      isexist = rs.first();
   		    }
   		    catch (SQLException ex1) {
   		    }
   		    //若用户名不存在，提示警告信息
   		    if (!isexist) {
   		      JOptionPane.showMessageDialog(null, "Login error！");
   		      myMain.setEnable("else");
   		    }   
                                           
   		    else {JOptionPane.showMessageDialog(null, "login successly！");
   		    try {
   		        rs.first();
   		     Leveled= rs.getString("Level").trim();
   		       
   		      }
   		      catch (SQLException ex) {
   		      }
   		   statement.close();
           connection.close();
               return Leveled;
         
            }
   		    }
               catch(SQLException SQLe) {
                  System.out.println(SQLe.toString());
                  
               }
               return null;
   }
   }