Basic Java Web tools-BaseDao and javawebbasedao

Basic Java Web tools-BaseDao and javawebbasedao

 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 }

I wrote a simple tool class when I was studying Servlet in the second semester. After graduation, I improved my skills and technology is still at the cainiao level. I can only change it to this type. I wish you every day better!