网上投票的示例程序java

package wstp; import java.sql.*; public class connectDB { String DBDriver = "oracle.jdbc.driver.OracleDriver"; String DBUrl = "jdbc:oracle:thin:@localhost:1521:ORACLE"; String DBUser = "jerry"; String DBPsw = "123456"; Connection conn = null; PreparedStatement stmt = null; public connectDB() { try { Class.forName(DBDriver); conn = DriverManager.getConnection(DBUrl,DBUser,DBPsw); } catch (Exception e) { e.printStackTrace(); } } public ResultSet executeQuery(String sql) throws Exception { try { this.stmt = null; this.stmt = conn.prepareStatement(sql); return this.stmt.executeQuery(); } catch (Exception e) { e.printStackTrace(); return null; } } public int executeUpdate(String sql) throws Exception { try { this.stmt = null; this.stmt = conn.prepareStatement(sql); return this.stmt.executeUpdate(); } catch (Exception e) { e.printStackTrace(); return 0; } } public void closeDB() { try { conn.close(); stmt.close(); } catch (Exception e) { e.printStackTrace(); } } }