protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("utf-8"); //这里不设置编码会有乱码
response.setContentType("text/html;charset=utf-8");
response.setHeader("Cache-Control", "no-cache");
int rows = Integer.valueOf(request.getParameter("rows")); //每页中显示的记录行数
int page = Integer.valueOf(request.getParameter("page")); //当前的页码
String sord = request.getParameter("sord");//排序方式
String sidx = request.getParameter("sidx");//排序列名
Boolean search =(request.getParameter("_search").equals("true"))?true:false;//是否用于查询请求
List<demo> allList = new LinkedList<demo>();//返回结果集
String keys="";//查询条件字符串
if(search){
keys=" WHERE ";
String filters = request.getParameter("filters");//具体的条件
System.out.println(filters);
//传入数据的格式是类似这样的："{"groupOp":"AND","rules":[{"field":"id","op":"eq","data":"1"},{"field":"type","op":"ew","data":"2"}]}"
JSONObject jsonObject = JSONObject.fromObject(filters);
String groupOp = "AND";//每个规则之间的关系（and/or）
if (jsonObject.getString("groupOp")!=null&&!"".equals(jsonObject.getString("groupOp"))) {
if (jsonObject.getString("groupOp").equals("OR")) {
groupOp = "OR";
}
}
JSONArray rulesjson = jsonObject.getJSONArray("rules");
//遍历每个条件
for (int z=0; z < rulesjson.size(); z++) {
Object t = rulesjson.get(z);
JSONObject rulejson = JSONObject.fromObject(t);
String field = rulejson.getString("field");
String op = rulejson.getString("op");
String data = rulejson.getString("data");
String string = "";//用于存储单个条件sql语句片段
//开始转化为sql语句
switch (op) {
case "eq"://相等
string=" = '"+data+"' ";
break;
case "ne"://不相等
string=" <> '"+data+"' ";
break;
case "li"://小于
string=" < '"+data+"' ";
break;
case"le"://小于等于
string=" <= '"+data+"' ";
break;
case"gt"://大于
string=" > '"+data+"' ";
break;
case "ge"://大于等于
string=" >= '"+data+"' ";
break;
case "bw"://在...之间
{
if (data.split(",").length==2) {
string=" BETWEEN '"+data.split(",")[0]+"' AND '"+data.split(",")[1]+"' ";
}else {
string=" = '"+data+"' ";//数据错误时处理
}
}
break;
case"bn"://不在...之间
{
if (data.split(",").length==2) {
string=" NOT BETWEEN '"+data.split(",")[0]+"' AND '"+data.split(",")[1]+"' ";
}else {
string=" <> '"+data+"' ";//数据错误时处理
}
}
break;
case"ew"://以...结束
string=" LIKE '%"+data+"' ";
break;
case "en"://不以...结束
string=" NOT LIKE '%"+data+"' ";
break;
case "cn"://包含
string=" LIKE '%"+data+"%' ";
break;
case "nc"://不包含
string=" NOT LIKE '%"+data+"%' ";
break;
case "in"://在
{
string=" IN ( ";
String[] datas = data.split(",");
for (int i = 0; i < datas.length; i++) {
string+= " '"+datas[i]+"' ";
if (i!=datas.length-1) {
string += ",";
}else {
string += " ) ";
}
}
}
break;
case "ni"://不在
{
string=" NOT IN ( ";
String[] datas = data.split(",");
for (int i = 0; i < datas.length; i++) {
string+= " '"+datas[i]+"' ";
if (i!=datas.length-1) {
string += ",";
}else {
string += " ) ";
}
}
}
break;
default:
op=null;
System.out.println("OP符号错误");//OP符号错误
}
if (op!=null) {
if (z==rulesjson.size()-1) {
keys+=" "+field+" "+string +" ";
}else {
keys+=" "+field+" "+string +" "+groupOp+" ";
}
}
}
}
//升降序SQL语句转换
if (sidx!=null&&!"".equals(sidx)) {
System.out.println(sidx);
keys += " ORDER BY " + sidx;
System.out.println("sord="+sord);
if (!sord.equals("asc")) {
keys += " DESC ";
}
}
allList = Factory.getDemoDAOInstance().doSearch(keys);
//分页部分
int total=0;
total=(allList.size()%rows==0)?(allList.size()/rows):((allList.size()/rows)+1);
int j = 0;
int m = (page-1)*rows;
int n = (page-1)*rows+rows;
JSONArray jArray = new JSONArray();
for (j=m; j<allList.size()&&j<n; j++) {
jArray.add(JSONObject.fromObject(allList.get(j)));
}
JSONObject jjson = new JSONObject();
//检索结果及分页信息封装 返回
jjson.accumulate("page", page);
jjson.accumulate("total", total);
jjson.accumulate("records", allList.size());
jjson.accumulate("rows", jArray);
System.out.println(jjson.toString());
response.getWriter().write(jjson.toString());
}
转自脚本之家