Java - Create JSON Object from Multiple Multidimensional Arrays - java

I'm trying to convert a very complex array structure to a JSON object, but I'm not sure how to work with the conversion. The structure is as follows:
String[] foo = new String[10];
String[][] bar = new String[10][8];
String[][] blargh = new String[8][2];
// Populate foo
foo[0] = "foo1";
// ... and so on
bar[0][0] = "bar1";
// ... and so on
blargh[0][0] = "blargh1;"
// ... and so on
Then:
public JSONObject createJSONObject() {
/* Now, I would like to create an object with the structue:
[{
foo[0] : {
bar[0][0] : {
// more key-pair values, including blargh[0][0] and blargh[0][1]
},
bar[0][1] : {
// values of blargh[1][0] and blargh[1][1]
},
// etc...
},
foo[1] : {
bar[1][0] : {
/* primary index of bar will always match index of foo, as will the primary index of blargh */
},
// etc..
},
// etc..
}]
// return the JSON encoded object
}
This seems reasonably complex to me, so please tell me if my question/code/structure is confusing or not clear.

Break it down into manageable chunks. Create methods that understand how to construct each nested object individually, and then call them at the appropriate times. For instance, something like:
public JSONObject createJSONObject() {
JSONObject result = new JSONObject();
for (int fooIndex = 0; fooIndex < foo.length; fooIndex++) {
result.put(foo[fooIndex], createBarJsonObject(fooIndex));
}
return result;
}
private JSONObject createBarJsonObject(int index) {
JSONObject result = new JSONObject();
String[] keys = bar[index];
for (int barIndex = 0; barIndex < keys.length; barIndex++) {
result.put(keys[barIndex], createBlarghJsonObject(fooIndex));
}
return result;
}
private JSONObject createBlarghJsonObject(int index) {
JSONObject result = new JSONObject();
String[] keyValue = blargh[index];
result.put(keyValue[0], keyValue[1]);
return result;
}

You're not creating arrays, you're creating objects. There's no point in the enclosing array in your pseudo code.
Object: { key0:val0, key1:val1 }
Array: [ val0, val1, val2 ]
{ // start object
key_foo0 : // foo[0] string as a key
{ // new object as a value
key_bar0_0 :
{
key_blargh0_0: val_blargh0_1, // blargh[0][1] as value
key_bleuuw0_0: val_bleuuw0_1
}
}
} // end object

Related

Easiest way to parse a triple nested JSON?

I am given a JSON that will come in this format:
"template":{
"mod1":[
{
"param1":"55",
"param2":"5",
"param3":"somedata"
}
],
"mod2":[
{
"param1":"somedata",
"param2":"somedata"
}
],
"mod3":[
{
"param1":"somedata",
"param2":"somedata",
"param3":"somedata"
}
],
"mod4":[
{
"param1":"somedata",
"param2":"somedata"
}
],
"mod5":[
{
"param1":"somedata"
}
]
}
}
What is the easiest way to parse it? What I'd like is to get the params inside the mod and their associated values together, to store into a database. The way I am doing it is as so:
JSONObject obj = new JSONObject(json);
System.out.println(obj);
Iterator<String> keys = obj.keys();
while(keys.hasNext()) {
String key = keys.next();
JSONObject currTemplate = (JSONObject) obj.get(key);
if(currTemplate instanceof JSONObject) {
System.out.println("LIST OF ALL MODULES : " + currTemplate);
Iterator<String> currObjKeys = ((JSONObject) currTemplate).keys();
while(currObjKeys.hasNext()) {
String currObjKey = currObjKeys.next();
System.out.println("MODULE: " + currObjKey);
JSONArray array = currTemplate.getJSONArray(currObjKey);
System.out.println("ARRAY: " + array);
for(int i = 0; i < array.length(); i++){
JSONObject object = array.getJSONObject(i);
String[] names = JSONObject.getNames(object);
for(String name: names) {
System.out.println("PARAMS");
System.out.println(name);
System.out.println(object.get(name));
}
}
}
}
And it currently prints what I need correctly. What I am asking is if there is a more efficient way to do it - the way I currently have it is O(N^4), and I was wondering if anyone had any idea to parse the JSON in a more efficient way. Note: the params will not always be in form param1, param2, the names will always be different. Just changed it for confidentiality sake.
Thank you in advance.

Avoiding duplicates while adding jsonobjects into the jsonarray using java

I have a list of objects and am converting into JSONArray. Am iterating over the JSONObjects and making an array of JSONObjects.
Now, i want to avoid duplicates objects to get insert into the JSONArray.
Please find my java code below.
JSONArray responseArray1 = new JSONArray();
if (!itemList.isEmpty())
{
jsonArray = new JSONArray(itemList);
for (int i = 0; i < jsonArray.length(); i++)
{
JSONObject jsonObj = jsonArray.getJSONObject(i);
JSONObject responseObj = new JSONObject();
String attr_label = jsonObj.optString("attr_label");
if(StringUtils.equalsIgnoreCase(attr_label, "long_description")) {
long_description = jsonObj.optString("value");
}
else if(StringUtils.equalsIgnoreCase(attr_label, "description")) {
description = jsonObj.optString("value");
}
responseObj.put("id", jsonObj.opt("id")); // i will get duplicate id
responseObj.put("code", jsonObj.opt("code")); // i will get duplicate code
responseObj.put("long_description", long_description);
responseObj.put("description", description);
responseArray1.put(responseObj);
}
}
Please find my actual jsonArray :
[
{
"code":"xyaz",
"attr_label":"long_description",
"id":"12717",
"value":"Command Module"
},
{
"code":"xyaz",
"attr_label":"description",
"id":"12717",
"value":"Set Point Adjustment"
},
]
Am expecting like the below jsonArray :
[
{
"code":"xyaz",
"id":"12717",
"long_description":"Command Module"
"description" : "Set Point Adjustment"
}
]
Update :
I have tried with the below code to avoid duplicate insertion of id & code field. but is not working properly. Its inserting duplicates also.
List<String> dummyList=new ArrayList<String>();
JSONArray responseArray2 = new JSONArray(itemList);
if (!itemList.isEmpty())
{
jsonArray = new JSONArray(itemList);
for (int i = 0; i < jsonArray.length(); i++)
{
JSONObject jsonObj = jsonArray.getJSONObject(i);
JSONObject responseObj = new JSONObject();
String itemCode = jsonObj.optString("code");
String id = jsonObj.optString("id");
if(!dummyList.contains(itemCode) && !dummyList.contains(id) ) {
dummyList.add(String.valueOf(jsonObj.opt("id")));
dummyList.add(String.valueOf(jsonObj.opt("code")));
responseObj.put("id", jsonObj.opt("id"));
responseObj.put("code", jsonObj.opt("code"));
responseObj.put("long_description", long_description);
responseObj.put("description", description);
responseArray2.put(responseObj);
}
}
}
Make a temporary array list and add unique code in that arrayList and check if it already exists in arrayList then don't put this again
String code = jsonObj.opt("code");
if(!arrayList.contains(code))
{
arrayList.add(code);
responseObj.put("id", jsonObj.opt("id"));
responseObj.put("code", jsonObj.opt("code"));
responseObj.put("long_description", long_description);
responseObj.put("description", description);
}
use TreeSet and add Comparator to their constructor in which it compare the duplicate data of the object.
for example:-
Set<Sample> sampleSet=new TreeSet<>(new Sample());
where Sample Class look like:-
class Sample implements Camparator<Sample>{
private String name;
private String id;
//getter
//setter
#Override
public String compare(Sample o1,Sample o2){
return o1.getName.compareTo(o2.getName);
}
}
This will give a set of unique name entries.

Finding length of nested json array in Java

I have a junk of json that has a nested json array inside of it. What would be the best way to get that nested json out and then get the length of it. I want to get the two fields inside of "/details" then use them
{
"Lane2":[
{
"authHost":"host.com",
"action-items":[
{
"/details":[
{
"path":"/something/details",
"httpMethod":"get"
}
]
},
{
"/summary":[
{
"path":"/something/summary",
"httpMethod":"get"
}
]
},
{
"/summary":[
{
"path":"/action-items/summary",
"httpMethod":"get"
}
]
}
]
}
]
}
I agree use the JSON parser, here's a simple example if you want to try on your own:
public String[] parseJA(JSONArray input, String[] key) throws JSONException{
// Parses a JSONArray with matching KEY value into a Sring[]
output = new String[input.length()];
joOutput = new JSONObject[input.length()];
for(int i = 0; i < input.length();++i) {
output[i] = input.getString(i);
joOutput[i] = input.getJSONObject(i);
output[i] = joOutput[i].getString(key[i]);
}
return output;
}

Create list of java objects from json

I have following json which i need to convert into list of java objects.
{
"model":[
{
"syscall_1":"execve",
"syscall_2":"brk"
},
{
"syscall_1":"brk",
"syscall_2":"access"
},
{
"syscall_1":"access",
"syscall_2":"mmap"
},
{
"syscall_1":"mmap",
"syscall_2":"access"
}
]
}
I am using gson and its TypeToken>(){}.getType() API ,however I am bit confused about how my objects should look corresponding to input json.
How can I use TypeToken in this scenario?
Another option (not using the type token, but still achieves what you want) would be to parse the entire json object, then access the model array like so:
import com.google.gson.Gson;
import java.util.List;
public class TestMe {
public static void main(String[] args) {
String jsonSt2 = "{\"model\":[{\"syscall_1\":\"execve\",\"syscall_2\":\"brk\"},{\"syscall_1\":\"brk\",\"syscall_2\":\"access\"},{\"syscall_1\":\"access\",\"syscall_2\":\"mmap\"},{\"syscall_1\":\"mmap\",\"syscall_2\":\"access\"}]}";
System.out.println("your json: " + jsonSt2);
ModelObject object = new Gson().fromJson(jsonSt2, ModelObject.class);
System.out.println("Created Model object, array size is " + object.model.size());
for (ModelItem mi : object.model) {
System.out.println(mi.syscall_1 + " " + mi.syscall_2);
}
}
}
class ModelObject {
List<ModelItem> model;
}
class ModelItem {
String syscall_1;
String syscall_2;
}
Output
Created Model object, array size is 4
execve brk
brk access
access mmap
mmap access
mmap access
If you can use org.json to parse and construct list objects, you can try this.
String jsonSt2 = "{\"model\":[{\"syscall_1\":\"execve\",\"syscall_2\":\"brk\"},{\"syscall_1\":\"brk\",\"syscall_2\":\"access\"},{\"syscall_1\":\"access\",\"syscall_2\":\"mmap\"},{\"syscall_1\":\"mmap\",\"syscall_2\":\"access\"}]}";
List<Model> models = new ArrayList<>();
JSONObject jsonModelObject = new org.json.JSONObject(jsonSt2);
Object modelObject = jsonModelObject.get("model");
if (modelObject instanceof JSONArray) {
JSONArray itemsArray =(JSONArray) modelObject;
for (int index = 0; index < itemsArray.length(); index++) {
Model model = new Model();
JSONObject modelItereative = (JSONObject) itemsArray.get(index);
model.setSyscall_1(modelItereative.getString("syscall_1"));
model.setSyscall_2(modelItereative.getString("syscall_1"));
models.add(model);
}
}else if(modelObject instanceof JSONObject){
Model model = new Model();
JSONObject modelItereative = (JSONObject) modelObject;
model.setSyscall_1(modelItereative.getString("syscall_1"));
model.setSyscall_2(modelItereative.getString("syscall_1"));
models.add(model);
}
for(Model d22:models){
System.out.println(d22.getSyscall_1() + " " + d22.getSyscall_2());
}

How to convert JSON formatted string of data rows of a table in to java array in android

I have a JSON string like this of data for a table in an android app. one of {} is a row of data for the table. I want to separate these {}s into an array and then each element inside this array into other sub-arrays separating other elements inside {}. Please suggest an appropriate way of accomplishing this criteria using JSON. Thank you.
[
{
"nodeName":"prime_mtsc22#smpp3",
"nodeId":"MTSC3",
"tidPrefix":"4",
"optStatus":"offline",
"daStart":"1",
"daEnd":"3",
"description":"Description"
},
{
"nodeName":"prime_mtsc22#smpp2",
"nodeId":"MTSC58",
"tidPrefix":"1",
"optStatus":"blocked",
"daStart":"5",
"daEnd":"10",
"description":"new description"
},
{
"nodeName":"prime_mtsc22#smpp1",
"nodeId":"MTSC1",
"tidPrefix":"15",
"optStatus":"online",
"daStart":"12",
"daEnd":"20",
"description":"Description"
},
{
"nodeName":"prime_mtsc22#smpp0",
"nodeId":"MTSC15",
"tidPrefix":"15",
"optStatus":"offline",
"daStart":"25",
"daEnd":"30",
"description":"Description"
}
]
ok so in that case the code to use is this
String jsonString = <your jsonString>;
// THIS IS NOT NEEDED ANYMORE
//JSONObject json = new JSONObject(jsonString);
JSONArray topArray = null;
try {
// Getting your top array
// THIS IS NOT NEEDED ANYMORE
//topArray = json.getJSONArray(jsonString);
//use this instead
topArray = new JSONArray(jsonString);
// looping through All elements
for(int i = 0; i < topArray.length(); i++){
JSONObject c = topArray.getJSONObject(i);
//list holding row data
List<NodePOJO> nodeList = new ArrayList<NodePOJO>();
// Storing each json item in variable
String nodeName = c.getString("nodeName");
String nodeID = c.getString("nodeID");
NodePOJO pojo = new NodePOJO();
pojo.setNodeName(nodeName);
//add rest of the json data to NodePOJO class
//the object to list
nodeList.add(pojo);
}
} catch (JSONException e) {
e.printStackTrace();
}
ok?
Use JSONObject for this http://developer.android.com/reference/org/json/JSONObject.html
Example
String jsonString = <your jsonString>;
JSONObject json = new JSONObject(jsonString);
JSONObject topArray = ;
try {
// Getting your top array
topArray = json.getJSONArray(TAG_ARRAY_TOP);
// looping through All elements
for(int i = 0; i < topArray.length(); i++){
JSONObject c = topArray.getJSONObject(i);
//list holding row data
List<NodePOJO> nodeList = new ArrayList<NodePOJO>();
// Storing each json item in variable
String nodeName = c.getString("nodeName");
String nodeID = c.getString("nodeID");
NodePOJO pojo = new NodePOJO();
pojo.setNodeName(nodeName);
//add rest of the json data to NodePOJO class
//the object to list
nodeList.add(pojo);
}
} catch (JSONException e) {
e.printStackTrace();
}
Use the NodePOJO class to hold each row values.
public class NodePOJO {
private String nodeName;
// do for rest of the json row data
public void setNodeName(String nodeName) {
this.nodeName = nodeName;
}
public String getNodeName() {
return this.nodeName;
}
}

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