Java-WEB使用MySQL库读写基础示例(Jsp+Servlet+ajax)

开始学习java-WEB了，做了个基础练习，
java调用MySQL库，使用Servlet、ajax实现数据库的读写。
演示在菜单第一类的前2项，其他没有。
使用时注意将Gson.jar、mysql-connector-java-8.0.11.jar
复制到Tomcat的Lib里面，是序列化和连接数据库用的。
因为刚学，前端写不好，只作为数据库操作的基础参考，如有错误自行修正。

数据库连接设置在：DBUtil.java文件；
数据库为sql格式文件，在MySQL编辑器，比如navicat，里运行安装；
未使用框架，页码分页等均自写，Function.java

Java编辑器为IntelliJ IDEA 2018.1.5 x64，自行下载百度激活。

//页码显示，添加删除记录动态原位置顺序更新
public static String[] Paging (int fPage_Ing,String tableName,int fPage_Pading,String terms,String search)
    {
        int fPage_Count; //总页数

        String pageStr = "";
        fPage_Count = GetPageCount(fPage_Pading,tableName,terms,search);


        if (fPage_Ing>fPage_Count) fPage_Ing=fPage_Count;


        int p_begin = 0, p_end = 10;
        boolean view_first, view_last;

        if (fPage_Count <= 10)
        {
            p_begin = 0;
            p_end = fPage_Count;
            view_first = false;
            view_last = false;
        }
        else
        {
            p_begin = (fPage_Ing - 1) - 5;
            if (p_begin <= 0)
            {
                p_begin = 0;
                p_end = 10;
                view_first = false;
                view_last = true;
            }
            else
            {
                p_end = p_begin   10;
                if (p_end >= fPage_Count)
                {
                    p_begin = fPage_Count - 10;
                    p_end = fPage_Count;
                    view_first = true;
                    view_last = false;
                }
                else
                {
                    p_end = p_begin   10;
                    view_first = true;
                    view_last = true;
                }
            }
        }

        for (int i = p_begin; i < p_end; i  )
        {
            if ((i 1)==fPage_Ing) {
                pageStr  = "[<button style=\"outline: none;color:#ffff00;font-size: 1.2rem;border:0px;background:transparent;cursor: pointer\">"  
                        (i   1)   "</button>] ";
            } else {
                pageStr  = "[<button onclick=\"ajaxGetPaging("   (i 1)   ")\" style=\"outline: none;color:#fff;font-size: 0.85rem;border:0px;background:transparent;cursor: pointer\">"  
                        (i   1)   "</button>] ";

            }
        }
        if (view_first)
        {
            pageStr = "[<button onclick=\"ajaxGetPaging(1)\" style=\"outline: none;color:#fff;font-size: 0.85rem;border:0px;background:transparent;cursor: pointer\">" 
                    "1</button>] " " ... "  pageStr;
        }

        if (view_last)
        {
            pageStr  =" ... [<button onclick=\"ajaxGetPaging(" fPage_Count ")\" style=\"outline: none;color:#fff;font-size: 0.85rem;border:0px;background:transparent;cursor: pointer\">" 
                    fPage_Count "</button>] ";
        }

        pageStr  = "&nbsp;&nbsp;&nbsp;&nbsp;";


        String[] strArr = new String[2];

        strArr[0] = pageStr;
        strArr[1] = fPage_Ing "";

        return strArr;
    }

<script type="text/javascript">

    $(document).ready(function(){
        ajaxGetPaging(1);
    });

    function ajaxGetPaging(page_ing) {
        $.ajax({
            type: "POST",
            url: "/User?action=paging&page=" page_ing,
            data:{
                Sort:$("#Hd_Sort").val(),
                Search:$("#tcSearch").val()
            },
            dataType: "text",
            success: function(data){
                //alert(data);
                $("#paging_top").html("页码: " data);
                $("#paging_bottom").html("页码: " data);
                ajaxGetUserInfo(page_ing);
            }, error: function(){
                alert("Request data error!");
            }
        });
    }

    function ajaxGetUserInfo(page_ing) {
        clearHtml();
        $.ajax({
            type: "POST",
            url: "/User?action=getuser&page=" page_ing,
            data:{
                Sort:$("#Hd_Sort").val(),
                Search:$("#tcSearch").val()
            },
            dataType: "json",
            success: function(data){
                packJson = data;
                for(var i = 0; i < packJson.length; i  ){
                    $("#user_" (i 1) "2").html(((page_ing-1)*12 (i 1)) ".");
                    $("#user_" (i 1) "3").html(packJson[i].USER_Group);
                    $("#user_" (i 1) "4").html(packJson[i].USER_Name);
                    $("#user_" (i 1) "5").html(packJson[i].USER_RegTime);
                    $("#user_" (i 1) "6").html(
                        "[ <a onclick=\"editInfo(" packJson[i].uid ");\" " 
                            "style=\"height: 10px; outline: none;color:#ffffcc;border:0px;background:transparent;cursor: pointer\"><i class='fa fa-pencil-square-o' ></i> 编辑</a> ]&nbsp;&nbsp;&nbsp;"  
                        "[ <a onclick=\"deleteInfo(\'" packJson[i].USER_Nic "\',\'" packJson[i].uid "\',\'" page_ing "\');\" " 
                            "style=\"outline: none;color:#ffffcc;border:0px;background:transparent;cursor: pointer\"><i class='fa fa-remove'></i> 删除</a> ]"
                    );
                }
            }, error: function(){
                alert("Request data error!");
            }
        });
    }

     function deleteInfo(uname,uid,page_ing) {
        zeroModal.confirm("<span style=\"color:#ff6666\">删除</span> " uname, function() {
            $.ajax({
                type: "POST",
                url: "/User?action=delete&page=" page_ing "&id=" uid,
                dataType: "text",
                success: function(data){
                    ajaxGetPaging(data);
                }, error: function(){
                    alert("Request data error!");
                }
            });
        })
    }

    function clearHtml() {
        for (var i=0;i<12;i  )
        {
            for (var t=0;t<6;t  )
            {
                $("#user_" (i 1) (t 1)).html("&nbsp;");
            }
        }
    }

    function ajaxSort(sort) {
        $("#Hd_Sort").val(sort);
        ajaxGetPaging(1);
    }

    function ajaxSearch() {
        ajaxGetPaging(1);
    }
</script>