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Problems with Spring Boot returning Map with own object as key

I have a problem with Spring Boot.
I am making a REST application, and I have a service that returns a Map(Share, Integer)
Share is a class written by me:
public class Share {
private String ticker;
private String name;
private Double value;
public Share() {
super();
}
public Share(String ticker, String name, Double value) {
super();
this.ticker = ticker;
this.name = name;
this.value = value;
}
public String getTicker() {
return ticker;
}
public void setTicker(String ticker) {
this.ticker = ticker;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Double getValue() {
return value;
}
public void setValue(Double value) {
this.value = value;
}
#Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((ticker == null) ? 0 : ticker.hashCode());
return result;
}
#Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
Share other = (Share) obj;
if (ticker == null) {
if (other.ticker != null)
return false;
} else if (!ticker.equals(other.ticker))
return false;
return true;
}
#Override
public String toString() {
return "Share [ticker=" + ticker + ", name=" + name + ", value=" + value + "]";
}
}
And the #RestController is:
public class ShareController {
#Autowired
private ShareBussines shareBussines;
#RequestMapping("/getShare/{ticker}")
public Share getShare(#PathVariable("ticker") String ticker) throws BrokerNotFoundException, BrokerArgumentException, BrokerGeneralException {
return shareBussines.getShare(ticker);
}
#RequestMapping(value="/buyShares", method=RequestMethod.POST)
public Map<Share, Integer> buyShares(#RequestBody Map<String,Double> sharesToBuy) throws BrokerGeneralException, BrokerArgumentException, BrokerInsufficientStockException {
return shareBussines.buyShares(sharesToBuy);
}
}
The problem is when I call the service from Postman.
The result is:
{
"Share [ticker=AMZN, name=Amazon, value=259.32126508258295]": 1,
"Share [ticker=GOOGL, name=Google, value=249.35339337497606]": 1,
"Share [ticker=FB, name=Facebook, value=181.15005639608364]": 55
}
The Map key is share.toString()... I want the key to be the share JSON.
I try to remove the toString method from Share class, but the result was:
{
"Share#1eb87f": 1,
"Share#40d9fab": 1,
"Share#8db": 54
}
It is using the Object's toString().
Thank you for your advice.

First, it works as you coded it to work:
#RequestMapping(value="/buyShares", method=RequestMethod.POST)
public Map<Share, Integer> buyShares(#RequestBody Map<String,Double> sharesToBuy) throws BrokerGeneralException, BrokerArgumentException, BrokerInsufficientStockException {
return shareBussines.buyShares(sharesToBuy);
}
Share is a key here. And that is kinda weird. Why not create some object like:
public class ShareResponse {
private Share share;
private Integer someVal; // that's the one you have in your Map as a value
// getters and setters
}
And afterward change your service a bit:
#RequestMapping(value="/buyShares", method=RequestMethod.POST)
public List<ShareResponse> buyShares(#RequestBody Map<String,Double> sharesToBuy) throws BrokerGeneralException, BrokerArgumentException, BrokerInsufficientStockException {
// do your business here, create a list of ShareResponse and return it
return shareBussines.buyShares(sharesToBuy); // instead of this
}
And you should get a valid, nicely 'formatted' JSON. If you need each item to be identifiable by some unique value just add some ID field to ShareResponse.
Does it make any sense?)

How to group values in list based on id in java?

Hello folks this may be dumb question but as a beginner am struggling with this how to group values based on id in list, Now let me clarify you briefly am having set of objects like this :
ID:1,UserID:330
ID:2,UserID:303
ID:3,UserID:090
ID:1,UserID:302
ID:2,UserID:306
How my list should look like is(Json Format):
[{"ID":1,"UserID":[330,302]},{"ID":2,"UserID":[303,306]},{"ID":3,"UserID":[090]}]
Now let me post what i have tried so far:
final List<Integer>list=new ArrayList<>();
final List<SpareReturnModel>lisobj=new ArrayList<>();
int duplicate=0;
for(int i=0;i<tView.getSelected().size();i++){
Object o= tView.getSelected().get(i).getValue();
SpareReturnModel asset=(SpareReturnModel) o;
int flag=asset.getFlag();
if(flag==2) {
int warehouseid = asset.getWareHouseID();
asset.setWareHouseID(warehouseid);
int partid = asset.getSerialNoID();
list.add(partid);
}
else {
Log.d("s","no value for header");
}
if(duplicate!=asset.getWareHouseID()){
asset.setParlist(list);
asset.setWareHouseID(asset.getWareHouseID());
lisobj.add(asset);
list.clear();
}
duplicate=asset.getWareHouseID();
}
Gson gson=new Gson();
//this will convert list to json
String value=gson.toJson(listobj);
SpareReturn Model Class:
public class SpareReturnModel {
private Integer SerialNoID;
private String SerialNumber;
private List<Integer>parlist;
public List<Integer> getParlist() {
return parlist;
}
public void setParlist(List<Integer> parlist) {
this.parlist = parlist;
}
public Integer getFlag() {
return flag;
}
public void setFlag(Integer flag) {
this.flag = flag;
}
private Integer flag;
public Integer getWareHouseID() {
return WareHouseID;
}
public void setWareHouseID(Integer wareHouseID) {
WareHouseID = wareHouseID;
}
private Integer WareHouseID;
public Integer getSerialNoID() {
return SerialNoID;
}
public void setSerialNoID(Integer serialNoID) {
SerialNoID = serialNoID;
}
public String getSerialNumber() {
return SerialNumber;
}
public void setSerialNumber(String serialNumber) {
SerialNumber = serialNumber;
}
}
Can someone let me know how to achieve this am struggling with this.

I simplify your class to make solution clearer:
public class SpareReturnModel implements Comparable<SpareReturnModel> {
private Integer id;
private String userId;
public SpareReturnModel(Integer id, String userId) {
this.id = id;
this.userId = userId;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getUserId() {
return userId;
}
public void setUserId(String userId) {
this.userId = userId;
}
#Override
public int compareTo(SpareReturnModel other) {
return this.getId().compareTo(other.getId());
}
#Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
SpareReturnModel model = (SpareReturnModel) o;
if (id != null ? !id.equals(model.id) : model.id != null) return false;
return userId != null ? userId.equals(model.userId) : model.userId == null;
}
#Override
public int hashCode() {
int result = id != null ? id.hashCode() : 0;
result = 31 * result + (userId != null ? userId.hashCode() : 0);
return result;
}
}
and add JsonSpareReturnModel
public class JsonSpareRuturnModel implements Comparable<JsonSpareRuturnModel> {
private final List<SpareReturnModel> modelList;
private final Integer id;
public JsonSpareRuturnModel(List<SpareReturnModel> modelList) {
this.modelList = modelList;
this.id = modelList.get(0).getId();
}
private final String toJson() {
return String.format("{\"ID\":%s,\"UserID\":%s}", id, formatUserIdList());
}
private String formatUserIdList() {
StringBuilder builder = new StringBuilder("[");
Iterator<SpareReturnModel> modelIterator = modelList.iterator();
while (modelIterator.hasNext()) {
builder.append(modelIterator.next().getUserId());
if (modelIterator.hasNext()) {
builder.append(",");
}
}
builder.append("]");
return builder.toString();
}
#Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
JsonSpareRuturnModel that = (JsonSpareRuturnModel) o;
return id != null ? id.equals(that.id) : that.id == null;
}
#Override
public int hashCode() {
return id != null ? id.hashCode() : 0;
}
#Override
public int compareTo(JsonSpareRuturnModel other) {
return this.id.compareTo(other.id);
}
#Override
public String toString() {
return toJson();
}
if you need to group by user id you need to sort your models according to id's
and place them to json format model:
public class Main {
public static void main(String[] args) {
List<SpareReturnModel> models = new ArrayList<>(Arrays.asList(
new SpareReturnModel(1, "330"),
new SpareReturnModel(2, "303"),
new SpareReturnModel(3, "090"),
new SpareReturnModel(1, "302"),
new SpareReturnModel(2, "306")
));
Map<Integer, List<SpareReturnModel>> groupById = new HashMap<>();
for (SpareReturnModel model : models) {
List<SpareReturnModel> listById = groupById.get(model.getId());
if (listById == null) {
groupById.put(model.getId(), new ArrayList<>(Arrays.asList(model)));
} else {
listById.add(model);
}
}
List<JsonSpareRuturnModel> jsonList = new ArrayList<>();
for (Map.Entry<Integer, List<SpareReturnModel>> pair : groupById.entrySet()) {
jsonList.add(new JsonSpareRuturnModel(pair.getValue()));
}
System.out.println(jsonList);
final String expected = "[{\"ID\":1,\"UserID\":[330,302]}, {\"ID\":2,\"UserID\":[303,306]}, {\"ID\":3,\"UserID\":[090]}]";
System.out.println(jsonList.toString().equals(expected));
}
}

How to solve StringConverter ClassCast Exception?

I have a TableView and a form with some TextBox and ComboBox in my javafx application. I am trying to populate the form components with selected rows data from TableView. I can populate all the TextBox without any error or exception. But while setting values to ComboBoxes, it's throwing an ClassCastException, java.lang.ClassCastException: java.lang.String cannot be cast to entity.StockUOM.
This is my StringCoverter
unitCombo.setConverter(new StringConverter<StockUOM>() {
#Override
public String toString(StockUOM object) {
return object.getStockUOM();
}
#Override
public StockUOM fromString(String string) {
return null;
}
});
This is my entity.StockUOM class
#Entity
#Access(AccessType.PROPERTY)
#NamedQueries({
#NamedQuery(name = StockUOM.findStockUOM, query = "SELECT s from StockUOM s")
})
public class StockUOM implements Externalizable{
public final static String PREFIX = "entity.StockUOM.";
public final static String findStockUOM = PREFIX + "findStockUOM";
private IntegerProperty id;
private int _id;
private StringProperty stockUOM;
private String _stockUOM;
public StockUOM() {
if (id == null) {
id = new SimpleIntegerProperty(this, "id", _id);
}
if( stockUOM== null){
stockUOM= new SimpleStringProperty(this,"stockUOM",_stockUOM);
}
}
public StockUOM(String stockUOM) {
this();
this.stockUOM.set(stockUOM);
}
public IntegerProperty idProperty() {
if (id == null) {
id = new SimpleIntegerProperty(this, "id", _id);;
}
return id;
}
#Id
#GeneratedValue(strategy=GenerationType.AUTO)
public final int getId() {
if (id == null) {
return _id;
} else {
return id.get();
}
}
public final void setId(int id) {
if (this.id == null) {
_id = id;
} else {
this.id.set(id);
}
}
public StringProperty stockUOMProperty() {
if( stockUOM== null){
stockUOM= new SimpleStringProperty(this,"stockUOM",_stockUOM);
}
return stockUOM;
}
public final String getStockUOM() {
if(stockUOM == null){
return _stockUOM;
}else{
return stockUOM.get();
}
}
public void setStockUOM(String stockUOM) {
if (this.stockUOM == null) {
_stockUOM=stockUOM ;
} else {
this.stockUOM.set(stockUOM);
}
}
#Override
public void writeExternal(ObjectOutput out) throws IOException {
out.writeInt(getId());
out.writeChars(getStockUOM());
}
#Override
public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
setId(in.readInt());
setStockUOM((String)in.readObject());
}
#Override
public String toString() {
return getStockUOM();
}
}
This is how i am setting values to ComboBox
unitCombo.setValue(newValue.getUnit());
Here newValue is the instance of StockUOM of ChangeListner which is listening on TableView row selection.
So what's wrong i am doing ? And what's the solution.
Thanks.

The problem is that most probably you defined your ComboBox like:
ComboBox unitCombo = new ComboBox();
So you missed to define the generic argument and you ended up with the raw type (your IDE most probably gives you a warning on this line).
At this point it is not specified what kind of objects do you want to display in the ComboBox.
When you do the following:
unitCombo.setValue(newValue.getUnit());
you set the valueProperty as a String value.
And then comes your converter:
unitCombo.setConverter(new StringConverter<StockUOM>() {
#Override
public String toString(StockUOM object) {
return object.getStockUOM();
}
#Override
public StockUOM fromString(String string) {
return null;
}
});
which expects StockUOM object being displayed, which does not happen hence the error.
You have to decide what kind of object do you want to display: if it is StockUOM, then declare the ComboBox as ComboBox<StockUOM> unitCombo = new ComboBox<StockUOM>();. After this you will have a compile time error on the line where you set the value for a String value, to fix that error you have to modify that line as unitCombo.setValue(newValue);. If you want to display String objects, the methodology is the same.

can't deserialize guava type with GWTP-Rest + jackson-guava from Spring service using guava-datatype

I use GWTP-Rest and i need to deserialize an dto which contains an ListMultimap. All the elements of the dto are deserialize but not the ListMultimap. below the code of dto. JsonAnnotation are working and come from the correct artifactId which is compatible with gwt-jackson. I imports with maven gwt-guava-jackson and inherits the module.
public class GetdtoMobileResult implements ExpirableResult, DtoData {
#JsonProperty("diffusions")
private ListMultimap<Integer, Diffusion> diffusions;
private TimeInterval visibleRange;
#JsonProperty("ttl")
private long ttl;
private dtoHourRange hourRange;
GetTVGuideMobileResult() {
super();
}
public GetTVGuideMobileResult(
final ArrayListMultimap<Integer, Diffusion> diffusions,
final TimeInterval visibleRange, final long ttl, final MediamatHourRange range) {
super();
this.diffusions = diffusions;
this.visibleRange = visibleRange;
this.ttl = ttl;
this.hourRange = range;
}
#JsonIgnore
#Override
public ListMultimap<ChannelId, Diffusion> getDiffusions() {
return ArrayListMultimap.create();
}
#JsonProperty("diffusions")
public ListMultimap<Integer, Diffusion> getdiffusions()
{
return diffusions;
}
#Override
public TimeInterval getVisibleRange() {
return visibleRange;
}
#JsonProperty("ttl")
#Override
public long ttl() {
return ttl;
}
#Override
public dtoHourRange getHourRange() {
return hourRange;
}
// #### setter add to able deserialization on client side mobile. ######
#JsonProperty("diffusions")
public void setDiffusions(final ListMultimap<Integer, Diffusion> diffusions) {
this.diffusions = diffusions;
}
public void setHourRange(final dtoHourRange hourRange) {
this.hourRange = hourRange;
}
#JsonProperty("ttl")
public void setTtl(final long ttl) {
this.ttl = ttl;
}
public void setVisibleRange(final TimeInterval visibleRange) {
this.visibleRange = visibleRange;
}
}
I receive the correct object from server {"diffusions":{"..."} ,...}. Serialization is doing by the lib jackson-datatype-guava, which if i correctly understood is using by jackson-guava. Interface which are implements define getter of the object, and implements Serializable.
I have another problem's, probably linked to his, my ListMultimap use normaly an dto as key which wrap an integer, but jackson tell me that my dto is not supported as map's key. Code of my dto :
public class DtoId implements Serializable {
/**
* serial version Uid
*/
private static final long serialVersionUID = -5816632906385308130L;
private int id;
DtoId() {
// for serialization
}
public DtoId(final int id) {
super();
this.id = id;
}
public int getId() {
return id;
}
public void setId(final int id) {
this.id = id;
}
#Override
public String toString() {
return Integer.toString(id);
}
#Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + id;
return result;
}
#Override
public boolean equals(final Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
ChannelId other = (ChannelId) obj;
if (id != other.id) {
return false;
}
return true;
}
}

Ok, problem's come from bad dependency between project on guava. I provided same version of guava to the client, shared & server, now serialization works, sorry to the bad question.
Second error continue to occurs, i will post this on an other page.

Convert java bean to json data in struts 2

I have a java bean class 'MenuItem' which consist of list of children .
I want to display iterate and render through this object in jsp and display the menu tree.
I tried the json data creation, but it needs ajax call. And in my case, I need to submit the page instead of ajax.
I am using struts 2. Can anyone please suggest how can I render and iterate through my bean object in jsp ?
Thanks in Advance.
Here is my Menu bean object:
public class MenuItem implements Serializable {
private static final long serialVersionUID = 8690828081102943225L;
private Long id;
private String name;
private Collection<MenuItem> children;
private String url;
private String actionHoverLabel;
private String actionLabel;
private Long displayOrder;
private Boolean isLeaf;
private Boolean isVisible;
private Long menuLevel;
private Long parentId;
public String getActionHoverLabel() {
return actionHoverLabel;
}
public void setActionHoverLabel(String actionHoverLabel) {
this.actionHoverLabel = actionHoverLabel;
}
public String getActionLabel() {
return actionLabel;
}
public void setActionLabel(String actionLabel) {
this.actionLabel = actionLabel;
}
public Long getDisplayOrder() {
return displayOrder;
}
public void setDisplayOrder(Long displayOrder) {
this.displayOrder = displayOrder;
}
public Boolean getIsLeaf() {
return isLeaf;
}
public void setIsLeaf(Boolean isLeaf) {
this.isLeaf = isLeaf;
}
public Boolean getIsVisible() {
return isVisible;
}
public void setIsVisible(Boolean isVisible) {
this.isVisible = isVisible;
}
public Long getMenuLevel() {
return menuLevel;
}
public void setMenuLevel(Long menuLevel) {
this.menuLevel = menuLevel;
}
public Long getParentId() {
return parentId;
}
public void setParentId(Long parentId) {
this.parentId = parentId;
}
public MenuItem() {
children = new ArrayList<MenuItem>();
isVisible = true;
}
public MenuItem(Long id, String name) {
this.id = id;
this.name = name;
children = new ArrayList<MenuItem>();
isVisible = true;
}
public Long getId() {
return this.id;
}
public void setId(Long id) {
this.id = id;
}
public String getName() {
return this.name;
}
public void setName(String name) {
this.name = name;
}
public Collection<MenuItem> getChildren() {
return this.children;
}
public void setChildren(Collection<MenuItem> children) {
this.children = children;
}
public boolean isLeaf() {
if (children != null && children.size() > 0) {
return false;
} else {
return true;
}
}
public void addChild(MenuItem child) {
if (child != null && children != null) {
children.add(child);
child.setParentId(this.getId());
}
}
public void removeChild(MenuItem child) {
if (child != null && children != null) {
children.remove(child);
child.setParentId(null);
}
}
public void setUrl(String url) {
this.url = url;
}
public String getUrl() {
if (url == null) {
return name;
} else {
return url;
}
}
#Override
public boolean equals(Object obj) {
MenuItem m = null;
boolean isEqual = false;
if (id != null && id >= 0) {
m = (MenuItem) obj;
if (m.getId().equals(id)
isEqual = true;
} else {
isEqual = super.equals(obj);
}
return isEqual;
}
#Override
public int hashCode() {
if (id != null && id >= 0) {
return id.hashCode();
} else {
return super.hashCode();
}
}
#Override
public String toString() {
return "name: " + name + " id: " + id;
}

If you want to operate on the bean in JSP, you can very well do that with struts tags. The bean has to be in the scope.
Why do you need JSON in this case?
If you still want JSON, the check for GSON library and Jackson mapper library.
On the JSP, you can store the JSON object in a variable and then operate on that.
On page submit Struts action would form the JSON and then set it in a page bean variable.

Go to www.json.org
Download Java Library for JSON encoding.
Compile it (build a jar for convenience).
Write a method alike this to JSON Serialize your bean:
public static String toJson(SomeBean bean)
{
JSONObject jo = new JSONObject(bean);
return jo.toString();
}
Deserialization is a little tricky but should work like:
JSONObject jo = new JSONObject(jsonString);
SomeBean res = new SomeBean();
res.someProperty = jo.getString("someProperty");
res.someIntProperty= jo.getInt("someIntProperty");
Obviously you have to take care of complex properties, but for simple beans it should work out like a charm.
Straight from sources:
/**
* Construct a JSONObject from an Object using bean getters.
* It reflects on all of the public methods of the object.
* For each of the methods with no parameters and a name starting
* with <code>"get"</code> or <code>"is"</code> followed by an uppercase letter,
* the method is invoked, and a key and the value returned from the getter method
* are put into the new JSONObject.
*
* The key is formed by removing the <code>"get"</code> or <code>"is"</code> prefix.
* If the second remaining character is not upper case, then the first
* character is converted to lower case.
*
* For example, if an object has a method named <code>"getName"</code>, and
* if the result of calling <code>object.getName()</code> is <code>"Larry Fine"</code>,
* then the JSONObject will contain <code>"name": "Larry Fine"</code>.
*
* #param bean An object that has getter methods that should be used
* to make a JSONObject.
*/
public JSONObject(Object bean) {
this();
this.populateMap(bean);
}
Are you sure you've everything set up correctly (Classpath) ?