简单的图书管理系统,增删改查,用LISt实现,java新手看

package nanyou.txl.dao; /** * 持久层,将联系人持久化 */ import java.sql.SQLException; import java.util.List; import java.util.Scanner; import org.apache.commons.dbutils.QueryRunner; import nanyou.txl.domain.Person; import nanyou.txl.tools.DataSourceUtils; import javax.sql.DataSource; import org.apache.commons.dbutils.handlers.BeanListHandler; import org.apache.commons.dbutils.QueryRunner; import org.apache.commons.dbutils.handlers.BeanListHandler; //实现对联系人表的增删改查操作 //用DBUTILS工具类完成 public class PersonDao { QueryRunner qr=new QueryRunner(DataSourceUtils.getDataSource()); /* * 查询并打印联系人 * 通过查询语句 打印联系人数据[关键功能] */ public void printPerson(String sqlString){ List <Person>list=null; try { list= qr.query(sqlString, new BeanListHandler<>(Person.class)); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); System.out.println("sql异常"); } if (list.size()==0||list.get(0).getId()==0) { System.out.println("查无此人!"); } else { System.out.println("ID\t姓名\t电话\t\t地址\t\t邮箱"); //遍历集合,输出信息 for(Person bean : list) { System.out.println(bean.getId()+"\t"+bean.getUsername()+"\t"+bean.getPhone()+"\t"+bean.getAddress()+"\t\t"+bean.getPostbox()); } } System.out.println("\n");//换行 } //查询所有联系人 public void selectAllforPhone() { // 调用控制层,查询所有账务数据 String sqlString="SELECT * FROM `addressbook`.`book` ORDER BY `username`;"; printPerson(sqlString); } public void selectAllforPhoneDESC() { // 调用控制层,查询所有账务数据 String sqlString="SELECT * FROM `addressbook`.`book` ORDER BY `username` DESC;"; printPerson(sqlString); } public void selectAllforNameDESC(){ String sqlString="SELECT * FROM `addressbook`.`book` ORDER BY `username` DESC;"; printPerson(sqlString); } public void selectAllforName(){ String sqlString="SELECT * FROM `addressbook`.`book` ORDER BY `username`;"; printPerson(sqlString); } //通过名字查询 public void selectforname() { // TODO Auto-generated method stub Scanner in = new Scanner(System.in); System.out.print("请输入需要查询的姓名:"); String name = in.next(); String sql = "select * from book where username= '"+name+"'"; printPerson(sql); } //通过ID查询 public int selectforID() { // TODO Auto-generated method stub Scanner in = new Scanner(System.in); System.out.println("请输入ID"); int id =in.nextInt(); String sql = "select * from book where id="+id; printPerson(sql); return id; } //通过电话查询联系人 public void selectforPhon() { // TODO Auto-generated method stub Scanner in = new Scanner(System.in); System.out.println("请输入要查询的电话:"); long id =in.nextLong(); String sql = "select * from book where phone="+id; printPerson(sql); } //增加联系人 public void adduser() { // TODO Auto-generated method stub Scanner in = new Scanner(System.in); Person per = new Person(); System.out.print("请输入联系人姓名：\n"); per.setUsername(in.next()); System.out.print("请输入电话：\n"); per.setPhone(in.nextLong()); System.out.print("请输入地址：\n"); per.setAddress(in.next()); System.out.print("请输入邮箱：\n"); per.setPostbox(in.next()); String sql = "insert into book (username,phone,address,postbox) values(?,?,?,?)"; try { Object[] params = {per.getUsername(),per.getPhone(),per.getAddress(),per.getPostbox()}; qr.update(sql,params); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); System.out.println("添加失败\n"); } System.out.println("添加成功！\n"); } /** * 修改联系人 * */ public void edituser() { // TODO Auto-generated method stub selectAllforPhone(); System.out.println("请确认要修改的联系人ID:\n"); Scanner in = new Scanner(System.in); int id =in.nextInt();//选择联系人ID Person per = new Person(); System.out.print("请输入联系人姓名：\n"); per.setUsername(in.next()); System.out.print("请输入电话：\n"); per.setPhone(in.nextLong()); System.out.print("请输入地址：\n"); per.setAddress(in.next()); System.out.print("请输入邮箱：\n"); per.setPostbox(in.next()); String sql = "update book set username=?,phone=?,address=?,postbox=? where id=?"; try { Object[] params = {per.getUsername(),per.getPhone(),per.getAddress(),per.getPostbox(),id}; qr.update(sql,params); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); System.out.println("修改失败"); } System.out.println("修改信息成功！\n"); } //删除联系人 public void deletuser() { // TODO Auto-generated method stub selectAllforPhone(); Scanner in = new Scanner(System.in); int id=selectforID(); System.out.println("确定删除?输入 y/yes 或者返回主菜单\n");//确认删除 String cho =in.next(); cho.toLowerCase(); //输入转换为小写 if (cho.equals("yes")||cho.equals("y")) { String sql = "delete from book where id="+id; try { qr.update(sql); } catch (SQLException e) { System.out.println("删除失败\n"); throw new RuntimeException(e); } System.out.println("删除成功\n"); }else { System.out.println("取消删除,返回主菜单\n"); } } }