增刪改

• dao 層方法

	//新增方法
    int insertUser(User user);

    //修改方法
    int updateUser(User user);

    //刪除方法
    int deleteUser(int id);

    //根據id 獲取一條資料
    User findUser(int id);

• dao 層實現

@Override
    public int insertUser(User user) {
        String sql = "insert into user(uname,upwd,usex) value(?,?,?)"
 
;
        int num = BaseDao.executeUpdate(sql, new Object[]{user.getUname(), user.getUpwd(),user.getUsex()});
        return num;
    }

    @Override
    public int updateUser(User user) {
        String sql = "update user set uname=?,upwd=?,usex=? where uid=?";
        int num = BaseDao.executeUpdate
 
(sql, new Object[]{user.getUname(), user.getUpwd(), user.getUsex(), user.getUid()});
        return num;
    }

    @Override
    public int deleteUser(int id) {
        String sql = "delete from user where uid=?";
        int num = BaseDao.executeUpdate(sql, new Object[]{id});
        return num;
    }
 


    @Override
    public User findUser(int id) {
        String sql = "select * from user where uid=?";
        return (User) BaseDao.executeQuery(sql,new Object[]{id},new BeanResultHandler(User.class));
    }

• service / service 實現

 	//新增方法
    int insertUser(User user);

    //修改方法
    int updateUser(User user);

    //刪除方法
    int deleteUser(int id);

    //根據id 獲取一條資料
    User findUser(int id);

	@Override
    public int insertUser(User user) {
        return userDao.insertUser(user);
    }

    @Override
    public int updateUser(User user) {
        return userDao.updateUser(user);
    }

    @Override
    public int deleteUser(int id) {
        return userDao.deleteUser(id);
    }

    @Override
    public User findUser(int id) {
        return userDao.findUser(id);
    }

• UserController

	/*去新增*/
    @RequestMapping("toAdd")
    public String toAdd(){

        return "addUser";
    }

    /*新增*/
    @RequestMapping("add")
    public String add(@RequestParam(value = "uname",required = false) String uname,
                      @RequestParam(value = "upwd",required = false) String upwd,
                      @RequestParam(value = "usex",required = false) String usex){
        //接下來
        User user = new User();
        user.setUname(uname);
        user.setUpwd(upwd);
        user.setUsex(Integer.parseInt(usex));
    /*    if (usex.equals("男")){
            user.setUsex(1);
        }else if (usex.equals("女")){
            user.setUsex(0);
        }*/
        int num = userService.insertUser(user);
        if (num > 0){
            //重定向打破首頁
            return "redirect:toPage";
        }
        return "toAdd";
    }

    /*去修改*/
    @RequestMapping("toUpdate")
    public String toUpdate(@RequestParam(value = "uid",required = false) String uid,Model model){
        User user = userService.findUser(Integer.parseInt(uid));
        model.addAttribute("user",user);
        return "updateUser";
    }

    /*修改*/
    @RequestMapping("update")
    public String update(@RequestParam(value = "uname",required = false) String uname,
                         @RequestParam(value = "upwd",required = false) String upwd,
                         @RequestParam(value = "usex",required = false) String usex,
                         @RequestParam(value = "uid",required = false) String uid){
        User user = new User();
        user.setUname(uname);
        user.setUpwd(upwd);
        user.setUsex(Integer.parseInt(usex));
        user.setUid(Integer.parseInt(uid));

        int num = userService.updateUser(user);
        if (num > 0){
            //
            return "redirect:toPage";
        }
        return "toUpdate";
    }

    //刪除
    /*ajax 請求是不需要 返回值的(因為 ajax 非同步 不需要跳轉)，一定要加上這個註解@ResponseBody*/
    @RequestMapping("delete")
    @ResponseBody
    public void delete(@RequestParam(value = "uid",required = false) String uid,
            HttpServletResponse response){
        int num = userService.deleteUser(Integer.parseInt(uid));


    }

• 分頁 於 模糊查詢

	//獲取資料，第一個引數代表的是當前頁，第二個引數代表頁量
    List<User> selectAllUser(PageUtils pageUtils);

    //查詢總記錄數
    Integer selectUserCount(PageUtils pageUtils);

@Override
    public List<User> selectAllUser(PageUtils pageUtils) {
        StringBuffer sb = new StringBuffer("select * from user where 1=1");
        //定義一個佔位符的集合
        List<Object> list = new ArrayList<Object>();
        //首先判斷是否需要查詢
        if (EmptyUtils.isNotEmpty(pageUtils.getQueryWord())){
            //拼接sql語句
            sb.append(" and uname like ?");
            list.add( "%"+ pageUtils.getQueryWord() +"%");
        }
        //排序


        //分頁查詢
        if(EmptyUtils.isNotEmpty(pageUtils.getCurrentPageNo())){
            sb.append(" limit ?,?");
            //給佔位符賦值
            list.add((pageUtils.getCurrentPageNo()-1)*pageUtils.getPageSize());
            list.add(pageUtils.getPageSize());
        }
        return (List<User>) BaseDao.executeQuery(sb.toString(), list.toArray(), new BeanListResultHandler(User.class));
    }

    @Override
    public Integer selectUserCount(PageUtils pageUtils) {
        StringBuffer sb = new StringBuffer("select count(1) from user where 1=1");
        //定義一個佔位符的集合
        List<Object> list = new ArrayList<Object>();
        //首先判斷是否需要查詢
        if (EmptyUtils.isNotEmpty(pageUtils.getQueryWord())){
            //拼接sql語句
            sb.append(" and uname like ? ");
            list.add( "%"+ pageUtils.getQueryWord() +"%");
        }
        List<User> list1 = (List<User>) BaseDao.executeQuery(sb.toString(), list.toArray(), new ArrayResultHandler());
        String count = list1.get(0)+"";
        return Integer.parseInt(count);
    }

• 主頁面程式碼顯示 以及 分頁 ，刪除運用了ajax

<body>
    <div class="box">
        <a href="toAdd">增加</a>
        <form action="toPage" method="post" class="box2">
            <input type="text" name="queryWord">
            <input type="submit" value="確認">
        </form>

    </div>
    <table border="1" cellspacing="0" cellpadding="0" width="400" align="center">
        <tr id="box">
            <th>編號</th><th>姓名</th><th>密碼</th><th>性別</th><th colspan="2">功能</th>
        </tr>
        <c:forEach var="user" items="${pageUtils.userList}">
        <tr>
            <td>${user.uid}</td>
            <td>${user.uname}</td>
            <td>${user.upwd}</td>
            <c:choose>
                <c:when test="${user.usex == 1}">
                    <td>男</td>
                </c:when>
                <c:otherwise>
                    <td>女</td>
                </c:otherwise>
            </c:choose>
            <td>
                <a href="toUpdate?uid=${user.uid}">修改</a>
            </td>
            <td>
                <a href="javascript:;" onclick="showInfo(this,${user.uid});" >刪除</a>
            </td>
        </tr>
        </c:forEach>
    </table>

    <div style="width: 300px;margin: 10px 0 0 650px;">

    <c:choose>
        <c:when test="${pageUtils.currentPageNo>1}">
            <a href="toPage?currentPageNo=1&queryWord=${pageUtils.queryWord}">首頁</a>
            <a href="toPage?currentPageNo=${pageUtils.currentPageNo-1}&queryWord=${pageUtils.queryWord}">上一頁</a>
        </c:when>
        <c:otherwise>
            <span style="color:#999">首頁</span>
            <span style="color:#999">上一頁</span>
        </c:otherwise>
    </c:choose>
    [${pageUtils.currentPageNo}/${pageUtils.totalPageSize}]
    <c:choose>
        <c:when test="${pageUtils.currentPageNo < pageUtils.totalPageSize}">
            <a href="toPage?currentPageNo=${pageUtils.currentPageNo+1}&queryWord=${pageUtils.queryWord}">下一頁</a>
            <a href="toPage?currentPageNo=${pageUtils.totalPageSize}&queryWord=${pageUtils.queryWord}">末頁</a>
        </c:when>
        <c:otherwise>
            <span style="color:#999">下一頁</span>
            <span style="color:#999">末頁</span>
        </c:otherwise>
    </c:choose>
    </div>
    <script type="text/javascript">
        function showInfo(a,id) {
            if (confirm("確認刪除此條資訊")) {
                $.post("${pageContext.request.contextPath}/userController/delete",{"uid":id},function () {
                    $(a).parents("tr").remove();
                })
            }
        }

    </script>

</body>

注意：傳值和路徑問題；