easyui—图书的删除&修改

 

目录

一.图书的删除

1.编写删除的方法

2.编写servlet

二.图书修改

1.编写修改的方法

二.编写servlet

---

一.图书的删除

1.编写删除的方法

@Override
public void delBooks(int bid) {
	Connection conn = null;
	PreparedStatement ps = null;
	String sql = "delete from tb_book where bid = "+ bid;
	try {
		//获取连接
		conn = DBHelper.getConn();
		//传入执行对象
		ps = conn.prepareStatement(sql);
		//返回所影响的行数
		ps.executeUpdate();
	} catch (Exception e) {
		e.printStackTrace();
	}finally {
		DBHelper.myClose(conn, ps, null);
	}
}

2.编写servlet

 

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		//设置编码
		request.setCharacterEncoding("utf-8");
		response.setCharacterEncoding("utf-8");
		response.setContentType("application/json;charset=utf-8");
		//通过request获取前端传递过来的图书编号
		Integer bid = request.getParameter("bid")!=null?Integer.valueOf(request.getParameter("bid")):0;
		//实例化业务逻辑层
		IBooksBiz ibb = new BooksBizImpl();
		//Map集合
		Map maps = new HashMap();
		//调用删除的方法
		try {
			ibb.delBooks(bid);
			maps.put("message", true);
		} catch (Exception e) {
			maps.put("message", false);
		}
		//JSON工具
		ObjectMapper mapper = new ObjectMapper();
		String writeValueAsString = mapper.writeValueAsString(maps);
		//out对象
		PrintWriter out = response.getWriter();
		out.write(writeValueAsString);
		out.flush();
		out.close();
	}
}

二.图书修改

1.编写修改的方法

@Override
public void editBooks(int bid, Books book) {
	Connection conn = null;
	PreparedStatement ps = null;
	String sql = "update tb_book set bname = ? , bprice = ? , btype = ? where bid = "+bid;
	try {
		//获取连接
		conn = DBHelper.getConn();
		//传入执行对象
		ps = conn.prepareStatement(sql);
		//占位符赋值
		ps.setString(1, book.getBname());
		ps.setFloat(2, book.getBprice());
		ps.setString(3, book.getBtype());
		//返回所影响的行数
		ps.executeUpdate();
	} catch (Exception e) {
		e.printStackTrace();
	}finally {
		DBHelper.myClose(conn, ps, null);
	}	
}

二.编写servlet

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		//不考虑模糊查询
		request.setCharacterEncoding("utf-8");
		response.setCharacterEncoding("utf-8");
		response.setContentType("application/json;charset=utf-8");
		//实例化biz
		IBooksBiz ibb = new BooksBizImpl();
		//id
		Integer bid = request.getParameter("bid")!=null?Integer.valueOf(request.getParameter("bid")):0;
		String bname = request.getParameter("bname");
		Float bprice = Float.valueOf(request.getParameter("bprice"));
		String btype = request.getParameter("btype");
		Books book = new Books(bname, bprice, btype);
		ObjectMapper mapper = new ObjectMapper();
		Map maps = new HashMap();
		//判断book是否修改成功
		try {
			ibb.editBooks(bid,book);
			maps.put("success", true);
		} catch (Exception e) {
			maps.put("success", false);
		}
		String writeValueAsString = mapper.writeValueAsString(maps);
		PrintWriter out = response.getWriter();
		out.write(writeValueAsString);
		out.flush();
		out.close();		
	}