Analysis of the Usage Methods of JSONObject and JSONArray

Import required: json-lib-2. 2.2-. jar package

1. json: It is a super simple 1-to-1 relationship with one key corresponding to one value. For json nesting, just remember that the symbol ":" is preceded by the key and the symbol is followed by the value braces.
String arrayStr=[{name1:{name2:{name3:'value1',name4:'value2'}}},{}]

Procedures for extracting name4 values:

1) Convert the above string to an JSONArray object; 2) Taking out the first item of the object, the JSONObject object; 3) Taking out the value JSONObject object of name1; 4) Taking out the value JSONObject object of name2; 5) Taking out the value value2 of name4;

The string in the json array format in the example can be directly converted to the JSONArray format through the method:

JSONArray.fromObject(String)
JSONArray getJsonArray = JSONArray. fromObject (arrayStr); //Convert the result to an JSONArray object
JSONObject getJsonObj = getJsonArray. getJSONObject (0); //Get the first item in the json array
String result=getJsonObj.getJSONObject("name1").getJSONObject("name2").getJSONObject("name4");

2.JSONObject

json object, that is, one key corresponds to one value, using curly braces {}, such as: {key: value}

3.JSONArray

json array, using brackets [], except that the items in the array are also in json key-value pair format

The key-value pair is added to the Json object, and the Json object is added to the JSONArray object

JSONObject Json = new JSONObject();
JSONArray JsonArray = new JSONArray();
Json. put ("key", "value"); //Add a key-value pair to an JSONObject object
JsonArray. add (Json); //Add an JSONObject object to an Json array

4. Map map and json are both key-value pairs, but the difference is that the key-value pairs in map are separated by an equal sign and the key-value pairs in json are separated by a colon. In fact, json is a special form of map.

Function of JSONObject and JSONArray: Do not refresh jsp page to write back the query results:

/* Example: */
    Map<String,String> strmap=new JSONObject();
    Map map = new HashMap();
    map.put("cudenddate", cudenddate);
    map.put("cudbegindate", cudbegindate);
    List auditList = kyDataHeadAuditService.getAuditAllDataList(map,paper, currentPage, pageDirection, 10);
    
    map.put("auditList",auditList); 
    map.put("currentpage", String.valueOf(paper.getCurrentpage()));
    map.put("allSize", String.valueOf(paper.getAllSize()));
    response.getWriter().write(JSONArray.fromObject(map).toString());
    response.getWriter().flush();
    response.getWriter().close();

$.post("kyDataHeadAuditAction.do?action=findKyHeadAuditList",{
            orgLevel : levs,
            sbtype : sbType,
            jytype : jyType}
          function(data) {
            var arr = data[0].auditList;
            if (arr.length > 0) {
              var html = "";
              for ( var i = 0; i < arr.length; i++) {//  Update list 
                var kyReportBean = arr[i];
                html += "<tr><td><input type='checkbox' name='kyreportid' value='"
                    + kyReportBean.kyReportid
                    + "'/>&nbsp;</td>";
                html += "<td align='center'>"
                    + kyReportBean.kyReportid
                    + "&nbsp;</td>";
                html += "<td align='center'><input type='button' value=' View ' onclick=\"bmSearchAudit('kyDataAuditAction.do?action=searchAuditDetail&insurCode="+kyReportBean.kyReportid+"')\">" + "&nbsp;</td></tr>";
              }
              var allsize = data[0].allSize;
              var currentpage = data[0].currentpage;
              cleartable(0);//  Empty a form 
              $("#tablelist").append(html);
              hideLoading();//  Cancel animation 
              $("#allSize").append(data[0].allSize);
              $("#currentpage").append((parseInt(data[0].currentpage) + parseInt(1)));
              changePage(allsize, currentpage);//  Update page turning 
              $("#currentpagevalue").val(currentpage);
            } else
              cleartable(0);
            hideLoading();//  Cancel animation 

          }, "json");