public class DatatablesLazyLoad extends HttpServlet{
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.process(request, response);
}
private void process(HttpServletRequest request, HttpServletResponse response) {
ServletContext servletContext=request.getSession().getServletContext();
WebApplicationContext wac =WebApplicationContextUtils.getRequiredWebApplicationContext(servletContext);
DictionaryServiceImpl ds=(DictionaryServiceImpl)wac.getBean("oracledictionaryService");
String flag = request.getParameter("flag");
String tableCode = request.getParameter("tableCode");
String fieldCode = request.getParameter("fieldCode");
if(flag==null)return;
if(flag.equals("titles")){
}else if(flag.equals("details")){
String draw = request.getParameter("draw");
String start = request.getParameter("start");
String length = request.getParameter("length");
StringBuilder sql = new StringBuilder("select ");
List titles = this.getTitles(tableCode,fieldCode,ds);
for(int i=0;i<titles.size();i++){
Map record = (Map)titles.get(i);
sql.append(" ").append(record.get("FIELDNAME")).append(", ");
}
if(sql.lastIndexOf(",")>0) sql.deleteCharAt(sql.lastIndexOf(","));
sql.append(" from ").append(tableCode);
sql.append(" where 1=1 ");
String filterSql = getFilterSql(titles,request);
Integer totalCount =ds.getSqlRecordCount("select count(*) from (" + sql.toString()+ ") tmp");
Integer filterCount = ds.getSqlRecordCount("select count(*) from (" + sql.toString()+filterSql+ ") tmp");
String[] strings = fieldCode.split(",");
String orderSql = getOrderSql(strings,request);
sql.append(filterSql);
sql.append(orderSql);
List<Map> lt = ds.executeSqlToRecordMap(sql.toString(),Integer.valueOf(start),Integer.valueOf(length));
Map result = new LinkedHashMap();
result.put("draw", draw);
result.put("recordsTotal", totalCount);
result.put("recordsFiltered", filterCount);
int count=Integer.valueOf(length)+1;
for(Map r : lt){
r.put("DT_RowId", r.get("id"));
Map rowDate = new LinkedHashMap();
rowDate.putAll(r);
r.put("DT_RowData", rowDate);
r.put("countInx", count);
count++;
}
result.put("data", lt);
try {
convertListToJson(result, response);
} catch (Exception e1) {
e1.printStackTrace();
}
}
}
private List getTitles(String tableCode,String fieldCode,DictionaryServiceImpl ds){
StringBuilder sql = new StringBuilder("select UPPER(ODS_DF_NAME) fieldName,ODS_DF_CN_NAME fieldLabel,ODS_DF_CODE fieldCode,UPPER(ODS_DF_DATA_TYPE) fieldType from ODS.ODS_DF_INFO_REG ");
sql.append(" where 1=1 ");
sql.append(" and ODS_TB_CODE = '"+tableCode+"'");
sql.append(" and ODS_DF_NAME in (");
String[] tmp = fieldCode.split(",");
StringBuilder ids = new StringBuilder();
for(String t : tmp){
if(StringUtils.isEmpty(t)) continue;
ids.append("'").append(t).append("',");
}
if(ids.lastIndexOf(",")>0) ids.deleteCharAt(ids.lastIndexOf(","));
sql.append(ids);
sql.append(")");
List lt = ds.executeSqlToRecordMap(sql.toString());
return lt;
}
private String getFilterSql(List<Map> fieldLt,HttpServletRequest request) {
StringBuilder filterSql = new StringBuilder(" and ( ");
String searchKey = "search[value]";
String searchValue = request.getParameter(searchKey);
System.out.println(searchValue);
if(StringUtils.isEmpty(searchValue)) return "";
List<String> filterDetail = new ArrayList();
for(int i=0;i<fieldLt.size();i++){
Map field = fieldLt.get(i);
if(field.get("FIELDTYPE").equals("VARCHAR")){
String subKey = "columns["+i+"][searchable]";
if("true".equals(request.getParameter(subKey))){
String fieldName = field.get("FIELDNAME").toString();
String subSql = fieldName + " like '%"+searchValue+"%'";
filterDetail.add(subSql);
}
}
}
if(filterDetail.size()==0) return "";
boolean f = true;
for(String subSql : filterDetail){
if(f){
f= false;
filterSql.append(subSql);
}else{
filterSql.append(" OR ").append(subSql);
}
}
filterSql.append(")");
return filterSql.toString();
}
private String getOrderSql(String[] titles,HttpServletRequest request){
StringBuilder orderSql = new StringBuilder(" order by ");
String indexKey = "order[0][column]";
String dirKey = "order[0][dir]";
Integer columnIndex = Integer.valueOf(request.getParameter(indexKey));
String dir = request.getParameter(dirKey);
if(columnIndex<=titles.length){
orderSql.append(titles[columnIndex]).append(" ").append(dir);
return orderSql.toString();
}
return "";
}
public void convertListToJson(Map map,HttpServletResponse response)throws Exception{
JSONArray json = JSONArray.fromObject(map);
response.setHeader("Cache-Control", "no-cache");
response.setContentType("text/html; charset=GBK");
PrintWriter writer;
writer = response.getWriter();
writer.write(json.get(0).toString());
writer.close();
}
}
