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[Java教程]JavaWeb基础工具类——BaseDao


 1 package dao; 2  3 import java.sql.Connection; 4 import java.sql.DriverManager; 5 import java.sql.PreparedStatement; 6 import java.sql.ResultSet; 7 import java.sql.SQLException; 8 import java.sql.Statement; 9 10 public class BaseDao {11   private static String URL = "jdbc:sqlserver://localhost:1433;DatabaseName=StudentManageSys";12   private static String USER = "sa";13   private static String PWD = "sa";14   protected Connection conn = null;15   protected PreparedStatement pstmt = null;16 17   static {18     try {19       Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");20     } catch (ClassNotFoundException e) {21       e.printStackTrace();22     }23   }24 25   protected Connection getConnection() {26     try {27       return conn == null ? DriverManager.getConnection(URL, USER, PWD) : conn;28     } catch (SQLException e) {29       e.printStackTrace();30       return null;31     }32   }33 34   protected void closeAll(Connection conn, Statement stmt, ResultSet rs) {35     try {36       if (conn != null)37         conn.close();38       if (stmt != null)39         stmt.close();40       if (rs != null)41         rs.close();42     } catch (SQLException e) {43       e.printStackTrace();44     }45   }46 47   protected Object execute(String sql, Object... objs) {48     handle(sql, objs);49     try {50       boolean flag = pstmt.execute();51       return flag ? pstmt.getResultSet() : pstmt.getUpdateCount();52     } catch (SQLException e) {53       e.printStackTrace();54       return null;55     }56   }57 58   private void handle(String sql, Object[] objs) {59     conn = getConnection();60     try {61       pstmt = conn.prepareStatement(sql);62       if (objs != null) {63         for (int i = 0; i < objs.length; i++) {64           pstmt.setObject(i + 1, objs[i]);65         }66       }67     } catch (SQLException e) {68       e.printStackTrace();69     }70   }71 }

上第二学期学Servlet的时候写的简单的工具类,毕业了之后又改进了一下,技术还处于菜鸟级别,也只能改成这样了,祝我天天进步!