dbaccess.java

java编的销售系统

import java.sql.*;

/**
 * @author Administrator
 * 
 */
public class DBAccess {
    private Connection m_conn;

    private Statement m_stmt;

    String driver = "com.microsoft.jdbc.sqlserver.SQLServerDriver";

    String url = "jdbc:microsoft:sqlserver://localhost:1433;databasename=JAVA";

    String uName = "123a";

    String uPwd = "123";

    /**
     * 
     */
    public DBAccess() {
        this.setDriver(driver);
        this.setConnection(url, uName, uPwd);
    }

    public DBAccess(String driver, String url, String userName, String userPWD) {
        try {
            m_conn = DriverManager.getConnection(url, userName, userPWD);
            m_stmt = m_conn.createStatement();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public boolean setDriver(String driver) {
        try {
            Class.forName(driver);
            return true;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return false;
    }

    public boolean setConnection(String url, String userName, String userPWD) {
        try {
            m_conn = DriverManager.getConnection(url, userName, userPWD);
            m_stmt = m_conn.createStatement();
            return true;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return false;
    }

    // 处理查询
    public ResultSet sendQuery(String sql) {
        try {
            ResultSet m_rs = m_stmt.executeQuery(sql);
            return m_rs;
        } catch (SQLException e) {
            e.printStackTrace();
            return null;
        }
    }

    // 处理数据更新
    public int sendUpdate(String sql) {
        try {
            return m_stmt.executeUpdate(sql);
        } catch (SQLException e) {
            e.printStackTrace();
            return -1;
        }
    }

    // 测试程序
    public static void main(String[] arg) {
        DBAccess db = new DBAccess();
        String sql = "select * from Student";
        ResultSet rs = db.sendQuery(sql);
        try {
            if (rs != null) {
                while (rs.next()) {
                    System.out.println(rs.getInt("Sno") + " "
                            + rs.getString("Sname"));
                }
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

}