Develop Reference

Arraylist Index adding with hashmap?

Inside the arraylist i need to add hashmap values and i declared
arralist as
public static ArrayList<Map<String, Object>> UploadingArray = new ArrayList<>();
and map
Map<String,Object> image_details=new HashMap<>();
and
int imageid;
for(int i=0;i<4;i++){
imageid=i;
new method()
}
image id will change when this function calling from another activity
imageid=(another activity).imageid;
new method(){
image_details.put("imageid",i);
image_details.put("status","New");
UploadingArray.add(imageid,image_details);
}
but the result of UploadingArray like
[0]
id=3;
status=New
[1]
id=3;
status=New
[2]
id=3;
status=New
[3]
id=3;
status=New
why the id is same for all position? any one know the issue please help me?
This is just a model the "i" value will be changed by calling method

They have the same values because you're adding the same object multiple times to your ArrayList.
You should create a new Map object inside your loop:
ArrayList<Map<String, Object>> list = new ArrayList<>();
for(int i = 0; i < 4; i++){
// creating new object on every iteration
Map<String, Object> imageDetails = new HashMap<>();
imageDetails.put("imageId", i);
imageDetails.put("status", "new");
list.add(imageId, imageDetails);
}

HashMap values are changing without telling them to

I have a problem that I am unable to understand..
I am building a HashMap called wholeSetHistory.
I am building a HashMap with the same keys and values that wholeSetHistory has, called wholeSetHistoryT.
In a similar way I create two HashMaps called wholeSetRates, wholeSetRatesT
All HashMaps have this format HashMap<String, HashMap<String, Double>> .
I have this function that creates a train set
public void createTrainSet(HashMap<String, HashMap<String, Double>> wholeSetRates, HashMap<String, HashMap<String, Double>> wholeSetHistory){
for(String fbid : wholeSetHistory.keySet()){
ArrayList<String> locsBe = new ArrayList<>();
HashMap<String, Double> locss = wholeSetHistory.get(fbid);
HashMap<String, Double> locss2 = wholeSetRates.get(fbid);
for(String loc : locss.keySet()){
if(locss.get(loc)==1.0){
locsBe.add(loc);
}
}
ArrayList<Integer> randomNums = new ArrayList<>();
for(int i=0; i<2; i++){
Random rn = new Random();
int randomNum;
do{
int range = locsBe.size() - 1 + 1;
randomNum = rn.nextInt(range);
}while(randomNums.contains(randomNum));
randomNums.add(randomNum);
locss.put(locsBe.get(randomNum), 0.0);
locss2.put(locsBe.get(randomNum), 0.0);
wholeSetHistory.put(fbid, locss);
wholeSetRates.put(fbid, locss2);
}
randomNums.clear();
}
}
So, later on I am using it like this
(... creation of wholeSetHistory, wholeSetHistoryT, wholeSetRates, wholeSetRatesT)
System.out.println(wholeSetHistory.get("1"));//1
createTrainSet(wholeSetRatings, wholeSetHistory, nearUserIDWithVisitedTrueValues);
That means that I am passing to the function as paramater only wholeSetHistory
Although, later I
System.out.println(wholeSetHistory.get("1"));//2
System.out.println(wholeSetHistoryT.get("1"));//3
This is what happens:
The values that changes in wholeSetHistory changes in wholeSetHistoryT too!
For example, prints 2 and 3 are the same(!) and different from 1.
Any help is mych appreciated.

A reference points to a location in memory. If you add the same reference to two different data structures, altering the reference in one will also alter the other. They point to the same object in memory.

How do I convert an object array into a map array?

I have the following code snippet:
//create map array and fill it with 3 dummy maps
Map[] mapArr= new Map[3];
for(int i = 0; i < mapArr.length; i++)
{
Map map = new HashMap();
mapArr[i] = map;
}
//now remove the second element (index == 1) from the map array
mapArr = ArrayUtils.removeElement(mapArr, 1);
My problem is witht he final line of code, because no matter what I try I get the error
Type mismatch: cannot convert from Object[] to Map[]
How do I convert the Object[] returned by removeElement() into a Map[]?

Did you try to cast it to "Map[]" ?
mapArr = (Map[]) ArrayUtils.removeElement(mapArr, 1);

How to use a listAdapter to display Array of Json values

For an Android application that I'm building for my internship, I'm trying to display a list
of tickets from the current logged in user and display them in a ListView. Let me paste some of my code to let you see where I'm at currently:
JSONArray finalResult = finalResultObject.getJSONArray(TAG_TICKETS);
System.out.println("this is finalResult: " + finalResult);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
for (int i = 0; i < finalResult.length(); i++) {
JSONObject c = finalResult.getJSONObject(i);
if (c.has(TAG_CLIENT_NAME) && !c.isNull(TAG_CLIENT_NAME)) {
String clientName = c.getString(TAG_CLIENT_NAME);
map.put("client_name_map", clientName);
// System.out.println(clientName);
}
if (c.has(TAG_PROJECT_NAME) && !c.isNull(TAG_PROJECT_NAME)) {
String projectName = c.getString(TAG_PROJECT_NAME);
map.put("project_name_map", projectName);
}
// adding HashList to ArrayList
ticketList.add(map);
// System.out.println(map);
}
ListAdapter adapter = new SimpleAdapter(SecondActivity.this, ticketList, R.layout.list_item, new String[] { "client_name_map", "project_name_map" }, new int[] { R.id.client_name,
R.id.project_name });
eventualListAdapter = adapter;
I've got a couple of prints in between, left them in there to let you guys see what I'm looking at right now. My problem is that I do get the required number of items, but it repeats the same item (so it does loop through the array, but doesn't update the values). I'm currently completely new to Android, and therefore still figuring out which kind of Adapters to use etc.
In the end I'm passing the adapter to eventualListAdapter, which I created within the main thread, so I can easily call it to update the UI (I'm not sure if this is anywhere near a clean way, just trying to get things working at this point)
Thanks in advance,
Dennis

You are using the same HashMap instance for all Itens. Just move the HashMap creation to inside the loop:
// adding each child node to HashMap key => value
for (int i = 0; i < finalResult.length(); i++) {
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
JSONObject c = finalResult.getJSONObject(i);
if(c.has(TAG_CLIENT_NAME)&&!c.isNull(TAG_CLIENT_NAME)){
String clientName = c.getString(TAG_CLIENT_NAME);
map.put("client_name_map", clientName);
//System.out.println(clientName);
}
if(c.has(TAG_PROJECT_NAME)&&!c.isNull(TAG_PROJECT_NAME)){
String projectName = c.getString(TAG_PROJECT_NAME);
map.put("project_name_map", projectName);
}
// adding HashList to ArrayList
ticketList.add(map);
//System.out.println(map);
}

Java HashMap content seems to change without changing it

I have a problem concerning a HashMap in Java. To explain the problem in a detailed way, i will first post some code you can refer to.
public void BLASTroute(String args[]) throws IOException, InterruptedException{
...
correctMapping CM = new correctMapping();
CM.correctMapping(RB.BLASTresults, exists);
CalculateNewConsensusSequence CNCS =
new CalculateNewConsensusSequence();
char[] consensus = CNCS.calculateNewConsensusSequence(
CM.newSeq, CM.remindGaps, EMBLreaderReference.sequence, exists);
HashMap<Integer, ArrayList<String>> gapsFused =
new HashMap<Integer, ArrayList<String>>();
for (Integer i : CM.remindGaps.keySet()) {
ArrayList<String> newList = CM.remindGaps.get(i);
gapsFused.put(i, newList);
}
GenerateGeneLists GGL = new GenerateGeneLists(
EMBLreaderReference, CM.newSeq, gapsFused, exists,
GQList, allMappedPositions);
System.out.println(CM.remindGaps.hashCode());
gapsFused=GGL.generateGeneListSNP(gapsFused);
System.out.println(CM.remindGaps.hashCode());
System.out.println(gapsFused.hashCode());
GGL.generateGeneListFrameShift(gapsFused);
}
The following occurs:
in my class correctMapping, i fill a global variable called remindGaps. I use it later in some functions, and nothing happens/everything works as expected.
Then, i make a copy of the HashMap called gapsFused (i don't know if this has something to do with my problem).
Now comes the interesting part: In the class GenerateGeneLists, i don't do a thing with the remindGaps HashMap.
However, after the function generateGeneListSNP is performed, remindGaps changed! I'll post the code for you as well, so that you can help me better:
public GenerateGeneLists(EMBL_reader EMBLreaderReference,
HashMap<String,ArrayList<String>> newSeq,
HashMap<Integer,ArrayList<String>> gapsFused, File exists,
ArrayList<GeneQualifier> GQlist,
HashMap<Integer,Integer> allMappedPositions)
throws InterruptedException{
this.EMBLreaderReference=EMBLreaderReference;
this.newSeq=newSeq;
//this.gapsFused=gapsFused;
this.exists=exists;
this.GQlist=GQlist;
this.allMappedPositions=allMappedPositions;
for (GeneQualifier GQ : this.GQlist){
startlist.add(GQ.start);
stoplist.add(GQ.stop);
startMap.put(GQ.start,GQ);
}
}
public HashMap<Integer,ArrayList<String>> generateGeneListSNP(
HashMap<Integer,ArrayList<String>> gapsFused)
throws IOException{
File GQSNP = new File (exists+"/GQsnp.txt");
BufferedWriter SNP = new BufferedWriter(new FileWriter(GQSNP));
SNP.write("#Gene_start\tGene_stop\tlocus_tag\tproduct" +
"\tputative_SNP_positions(putative_changes)\n");
HashMap<GeneQualifier,ArrayList<Integer>> GQreminder =
new HashMap<GeneQualifier,ArrayList<Integer>>();
for (String s : newSeq.keySet()){
ArrayList<String> blub = newSeq.get(s);
char[] qrySeq = blub.get(0).toCharArray();
char[] refSeq = blub.get(1).toCharArray();
int start = Integer.valueOf(blub.get(2));
int stop = Integer.valueOf(blub.get(3));
for (int i=0;i<refSeq.length;i++){
if (qrySeq[i]!=refSeq[i]&&qrySeq[i]!='-'&&qrySeq[i]!='.'){
if (mismatchList.containsKey(start+i)){
ArrayList<Character> blah = mismatchList.get(start+i);
blah.add(qrySeq[i]);
mismatchList.put(start+i, blah);
}
else {
ArrayList<Character> blah = new ArrayList<Character>();
blah.add(qrySeq[i]);
mismatchList.put(start+i,blah);
}
}
else if (qrySeq[i]!=refSeq[i]&&(qrySeq[i]=='-'||qrySeq[i]=='.')){
if (!gapsFused.containsKey(start+i)){
ArrayList<String> qwer = new ArrayList<String>();
qwer.add(String.valueOf(qrySeq[i]));
gapsFused.put(start+i,qwer);
}
else {
ArrayList<String> qwer = gapsFused.get(start+i);
qwer.add(String.valueOf(qrySeq[i]));
gapsFused.put(start+i,qwer);
}
if (!deletionPositionsAndCount.containsKey((start+i))){
int count = 1;
deletionPositionsAndCount.put(start+i, count);
}
else {
int count = deletionPositionsAndCount.get(start+i);
count = count+1;
deletionPositionsAndCount.put(start+i, count);
}
}
}
}
for (Integer a : mismatchList.keySet()){
for (int i=0;i<startlist.size();i++){
int start = startlist.get(i);
int stop = stoplist.get(i);
if (a>=start && a<=stop){
GeneQualifier GQ = startMap.get(start);
if (!GQreminder.containsKey(GQ)){
ArrayList save = new ArrayList<Integer>();
save.add(a);
GQreminder.put(GQ,save);
}
else {
ArrayList save = GQreminder.get(GQ);
save.add(a);
GQreminder.put(GQ,save);
}
break;
}
}
}
for (GeneQualifier GQ : GQreminder.keySet()) {
ArrayList<Integer> save = GQreminder.get(GQ);
int start = GQ.start;
int stop = GQ.stop;
String locus_tag =
GQ.geneFeatures.get("locus_tag").get(0).replace("\n", "");
String product =
GQ.geneFeatures.get("product").get(0).replace("\n", "");
SNP.write(start + "\t" + stop + "\t" + locus_tag +
"\t" + product + "\t");
boolean end = false;
for (int i = 0; i < save.size(); i++) {
if (i==save.size()-1) end=true;
int posi = save.get(i);
SNP.write(posi + "(");
ArrayList<Character> mismatches = mismatchList.get(posi);
for (int j = 0; j < mismatches.size(); j++) {
char snipp = mismatches.get(j);
if (j == mismatches.size() - 1) {
SNP.write(snipp + ")");
} else {
SNP.write(snipp + ",");
}
}
if (end == false){
SNP.write(",");
}
}
SNP.write("\n");
}
SNP.close();
return gapsFused;
}
As you can see, remindGaps is not used in this class, but still it undergoes changes. Do you have an idea why this is the case?
What I tested is, whether remindGaps changes if i manually change gapsFused (the made copy of the first HashMap). This is not the case, so i don't think that the copying process went wrong (for example only points to the other HashMap or references it).
I would really appreciate your ideas and help in order to solve this problem.

You have to remember that in Java all objects are passed as reference. So, when you did:
ArrayList<String> newList = CM.remindGaps.get(i);
you basically pointed newList to the same list as contained in the remindGaps map. Now, even though you work with the gapsFused, any changes to its values effect the same underlying list in the memory - to which both remindGaps and gapsFused are pointing.
Change your copy code to the following and see if it makes a difference:
ArrayList<String> newList = new ArrayList<String>(CM.remindGaps.get(i));
By doing this, you are creating a new list that newList will be pointing to and thus the changes will be encapsulated.

Your code is very long and hard to read (mainly because it doesn't respect Java naming conventions), but my guess is that your problem comes from the fact that your copy of the map simply copies the ArrayList references from one map to another:
HashMap<Integer, ArrayList<String>> gapsFused = new HashMap<Integer, ArrayList<String>>();
for (Integer i : CM.remindGaps.keySet()) {
ArrayList<String> newList = CM.remindGaps.get(i);
gapsFused.put(i, newList);
}
In the above code, you don't create any new list. You just store the same lists in another map. If you need a new list, the code should be:
Map<Integer, List<String>> gapsFused = new HashMap<Integer, List<String>>();
for (Integer i : CM.remindGaps.keySet()) {
List<String> newList = new ArrayList<STring>(CM.remindGaps.get(i));
gapsFused.put(i, newList);
}

Without analyzing all your code:
HashMap<Integer, ArrayList<String>> gapsFused = new HashMap<Integer, ArrayList<String>>();
for (Integer i : CM.remindGaps.keySet()) {
ArrayList<String> newList = CM.remindGaps.get(i);
gapsFused.put(i, newList);
}
After this code gapFused will contain entries that are copies of the entries of remindGaps, therefore those entries will reference the same objects (key and values). So if you add or remove entries in one Map it will have no effect on the other, but if you change a value accessing it through one Map you will see the change also accessing it through the other map (for example remingGaps.get(1).add("hello")).
The name "newList" used in your code is confusing because it is not a new list, just a reference on an existing one...

Since the value of the Map is an ArrayList and you are doing just a shallow copy (meaning the new Map has a reference to the same Lists as are in the first Map) and changes to the lists in the second map would be reflected in the first map. To avoid this you would need to make deep copies of the lists when you create the new Map.