I have a basic SpringBoot 2.1.5.RELEASE app. Using Spring Initializer, JPA, embedded Tomcat, Thymeleaf template engine, and package as an executable JAR file with some RestControllers.
In 1 of the controller this is the body I send:
{
"depositHotel": "xxx",
"destinationHotel": "aaa",
"depositHotelAmount": "0.2",
"destinationHotelAmount": "4",
"destinationAddress": [{
"address": "asdf",
"tag": ""
}],
"refundAddress": [{
"address": "pio",
"tag": ""
}]
}
so I create this class to use it as a RequestBody:
public class HotelswitchHotelOrderRequestBody {
public static class Builder {
private String depositHotel;
private String destinationHotel;
private Float depositHotelAmount;
private Float destinationHotelAmount;
private JSONObject destinationAddress;
private JSONObject refundAddress;
public Builder(String depositHotel, String destinationHotel) {
this.depositHotel = depositHotel;
this.destinationHotel = destinationHotel;
}
public Builder withDepositHotelAmount (Float depositHotelAmount) {
this.depositHotelAmount = depositHotelAmount;
return this;
}
public Builder withDestinationHotelAmount (Float destinationHotelAmount) {
this.destinationHotelAmount = destinationHotelAmount;
return this;
}
public Builder toDestinationAddress (JSONObject destinationAddress) {
this.destinationAddress = destinationAddress;
return this;
}
public Builder toRefundAddress (JSONObject refundAddress) {
this.refundAddress = refundAddress;
return this;
}
public HotelswitchHotelOrderRequestBody build(){
HotelswitchHotelOrderRequestBody order = new HotelswitchHotelOrderRequestBody();
order.depositHotel = this.depositHotel;
order.depositHotelAmount = this.depositHotelAmount;
order.destinationAddress = this.destinationAddress;
order.destinationHotel = this.destinationHotel;
order.destinationHotelAmount = this.destinationHotelAmount;
order.refundAddress = this.refundAddress;
return order;
}
}
private String depositHotel;
private String destinationHotel;
private Float depositHotelAmount;
private Float destinationHotelAmount;
private JSONObject destinationAddress;
private JSONObject refundAddress;
private HotelswitchHotelOrderRequestBody () {
//Constructor is now private.
}
public String getDepositHotel() {
return depositHotel;
}
public void setDepositHotel(String depositHotel) {
this.depositHotel = depositHotel;
}
public String getDestinationHotel() {
return destinationHotel;
}
public void setDestinationHotel(String destinationHotel) {
this.destinationHotel = destinationHotel;
}
public Float getDepositHotelAmount() {
return depositHotelAmount;
}
public void setDepositHotelAmount(Float depositHotelAmount) {
this.depositHotelAmount = depositHotelAmount;
}
public Float getDestinationHotelAmount() {
return destinationHotelAmount;
}
public void setDestinationHotelAmount(Float destinationHotelAmount) {
this.destinationHotelAmount = destinationHotelAmount;
}
public JSONObject getDestinationAddress() {
return destinationAddress;
}
public void setDestinationAddress(JSONObject destinationAddress) {
this.destinationAddress = destinationAddress;
}
public JSONObject getRefundAddress() {
return refundAddress;
}
public void setRefundAddress(JSONObject refundAddress) {
this.refundAddress = refundAddress;
}
}
But I have this error when receiving the object:
JSON parse error: out of START_ARRAY token; nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot deserialize instance of `org.json.JSONObject` out of START_ARRAY token
JSONObject's representation in actual JSON is a hash i.e. {...}. In your json data you're providing an array of hashes [{...}] which is not the same. Judging from your domain I don't think it has to be multiple values, so you can just omit [] in your payload and if it does then the fields in your Java class can be defined as JSONArray.
However, I think you should go with defining an Address class and either using
private Address destinationAddress;
private Address refundAddress;
or if it indeed does have to be an object array
private List<Address> destinationAddresses;
private List<Address> refundAddresses;
I had a similar usecase , where I could not define the json to a POJO. Using com.fasterxml.jackson.databind.JsonNode instead of the JSONObject worked.
Related
I have a rest client that will be getting JSON back from an endpoint. I would like to just get what is in the data[].
{
"responseStatus": "SUCCESS",
"responseDetails": {
"limit": 1000,
"offset": 0,
"size": 2,
"total": 2
},
"data": [
{
"id": "00P000000001M01",
"name__v": "Foo",
"status__v": [
"active__v"
],
"abbreviation__c": "F170053",
"internal_name__c": "Foo",
"therapeutic_area__c": [
"neurology__c"
],
"external_id__v": "84",
"generic_name__c": "Foo",
"scientific_name__c": null
},
{
"id": "00P000000001N01",
"name__v": "Bar",
"status__v": [
"active__v"
],
"abbreviation__c": "B333334",
"internal_name__c": "Bar",
"therapeutic_area__c": [
"bone_muscle_joint__c"
],
"external_id__v": "101",
"generic_name__c": "Bar",
"scientific_name__c": null
}
]
}
Because I will make other calls which will return different fields in the data[], I wanted to map each type to a POJO so I used #JSONProperty
#JsonIgnoreProperties(ignoreUnknown = true)
public class Product extends VBase{
private String fNumber;
private String genericName;
private String scientificName;
private String therapeuticArea;
public String getFNumber() {
return fNumber;
}
#JsonProperty("abbreviation__c")
private void unpackFNumber(Map<String,Object> abbreviation__c){
fNumber = ((Map<String,Object>)abbreviation__c.get("data")).get("abbreviation__c").toString();
}
public void setLyNumber(String fNumber) {
this.fNumber = fNumber;
}
public String getGenericName() {
return genericName;
}
#JsonProperty("generic_name__c")
private void unpackGenericName(Map<String,Object> generic_name__c){
genericName = ((Map<String,Object>)generic_name__c.get("data")).get("generic_name__c").toString();
}
public String getScientificName() {
return scientificName;
}
#JsonProperty("scientific_name__c")
private void unpackScientificName(Map<String,Object>sName){
scientificName = ((Map<String,Object>)sName.get("data")).get("scientific_name__c").toString();
}
public String getTherapeuticArea() {
return therapeuticArea;
}
#JsonProperty("therapeutic_area__c")
private void unpackTheraputicArea(Map<String,Object>tArea){
therapeuticArea=((Map<String,Object>)tArea.get("data")).get("therapeutic_area__c").toString();
}
}
I have tried various ways of just getting the data[].
HttpEntity<MultiValueMap<String, String>> request = new HttpEntity<>(map, headers);
RestTemplate restTemplate = new RestTemplate(clientHttpReq);
ResponseEntity<Product[]> response = restTemplate.exchange(url, HttpMethod.GET, request,Product[].class);
//ResponseEntity<Product[]> response = restTemplate.postForEntity(url,request,Product[].class ,parmMap);
What I have been trying to avoid is making a ResponseDetail POJO with a Data[] as a field. I know it will work but because the fields in the data[] will change based on the endpoint.
Can I use a wrapper class with a List to represent the data[] as all of the POJO will extend VBase?
Here is the exception:
Exception in thread "main" org.springframework.web.client.RestClientException: Error while extracting response for type [class [Lcom.lilly.models.Product;] and content type [application/json;charset=UTF-8]; nested exception is org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: Cannot deserialize instance of `com.lilly.models.Product[]` out of START_OBJECT token; nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot deserialize instance of `com.lilly.models.Product[]` out of START_OBJECT token
at [Source: (PushbackInputStream); line: 1, column: 1]
Declaring a POJO class as below code, and then you can get data property from the POJO.
#Data
public class Example {
private String responseStatus;
private ResponseDetails responseDetails;
private List<Data> data;
#lombok.Data
public static class ResponseDetails {
private int limit;
private int offset;
private int size;
private int total;
}
#lombok.Data
public static class Data {
private String id;
private String name__v;
private String abbreviation__c;
private String internal_name__c;
private String external_id__v;
private String generic_name__c;
private Object scientific_name__c;
private List<String> status__v;
private List<String> therapeutic_area__c;
}
#lombok.Data
#JsonIgnoreProperties(ignoreUnknown = true)
public static class Product {
#JsonProperty("name__v")
private String fNumber;
#JsonProperty("generic_name__c")
private String genericName;
#JsonProperty("scientific_name__c")
private String scientificName;
#JsonProperty("therapeutic_area__c")
private List<String> therapeuticArea;
}
public static void main(String[] args) {
String jsonResult = "{\"responseStatus\":\"SUCCESS\",\"responseDetails\":{\"limit\":1000,\"offset\":0,\"size\":2,\"total\":2},\"data\":[{\"id\":\"00P000000001M01\",\"name__v\":\"Foo\",\"status__v\":[\"active__v\"],\"abbreviation__c\":\"F170053\",\"internal_name__c\":\"Foo\",\"therapeutic_area__c\":[\"neurology__c\"],\"external_id__v\":\"84\",\"generic_name__c\":\"Foo\",\"scientific_name__c\":null},{\"id\":\"00P000000001N01\",\"name__v\":\"Bar\",\"status__v\":[\"active__v\"],\"abbreviation__c\":\"B333334\",\"internal_name__c\":\"Bar\",\"therapeutic_area__c\":[\"bone_muscle_joint__c\"],\"external_id__v\":\"101\",\"generic_name__c\":\"Bar\",\"scientific_name__c\":null}]}";
ObjectMapper objectMapper = new ObjectMapper();
try {
Example example = objectMapper.readValue(jsonResult, new TypeReference<Example>() {
});
//you can get data[] via example.getData()
System.out.println(objectMapper.writeValueAsString(example.getData()));
List<Product> products = objectMapper.readValue(objectMapper.writeValueAsString(example.getData()), new TypeReference<List<Product>>() {
});
//you can also parse data[] as List<Product>
System.out.println(JSONObject.toJSONString(products));
} catch (IOException e) {
e.printStackTrace();
}
}
}
Hi i want to convert this json to json object in java so that i can pass it to http request to call an api
{
"aliasNaming": true,
"dataServiceType": "BROWSE",
"deviceName": "MyDevice",
"langPref": " ",
"maxPageSize": "2000",
"outputType": "VERSION1",
"password": "!jshjhsdhshdj",
"query": {
"autoClear": true,
"autoFind": true,
"condition": [
{
"controlId": "F4211.CO",
"operator": "EQUAL",
"value": [
{
"content": "00098",
"specialValueId": "LITERAL"
}
]
},
{
"controlId": "F4211.DCTO",
"operator": "EQUAL",
"value": [
{
"content": "SM",
"specialValueId": "LITERAL"
}
]
},
{
"controlId": "F4211.UPMJ",
"operator": "GREATER_EQUAL",
"value": [
{
"content": "01/01/17",
"specialValueId": "LITERAL"
}
]
}
],
"matchType": "MATCH_ALL"
},
"returnControlIDs": "F4211.DOCO|F4211.TRDJ|F4211.CRCD|F4211.AN8|F4211.DSC2|F4211.DSC1|F4211.LITM|F4211.LOTN|F4211.UORG|F4211.UPRC|F4211.AEXP",
"targetName": "F4211",
"targetType": "table",
"token": "044biPNadxNVGhyAKdrImoniK98OOa2l86ZA63qCr4gE5o=MDIwMDA4LTIyNDU5MjUxMTY2MzY3NTA3MTRNeURldmljZTE1Mzc0MjYwMjAyNTk=",
"username": "Ali"
}
i have created 4 models using http://www.jsonschema2pojo.org.
those models just have getter setter in it. look something like this
#JsonProperty("aliasNaming")
private Boolean aliasNaming;
#JsonProperty("dataServiceType")
private String dataServiceType;
#JsonProperty("deviceName")
private String deviceName;
#JsonProperty("langPref")
private String langPref;
#JsonProperty("maxPageSize")
private String maxPageSize;
#JsonProperty("outputType")
private String outputType;
#JsonProperty("password")
private String password;
#JsonProperty("query")
private Query query;
#JsonProperty("returnControlIDs")
private String returnControlIDs;
#JsonProperty("targetName")
private String targetName;
#JsonProperty("targetType")
private String targetType;
#JsonProperty("token")
private String token;
#JsonProperty("username")
private String username;
#JsonIgnore
private Map<String, Object> additionalProperties = new HashMap<String, Object>();
#JsonProperty("aliasNaming")
public Boolean getAliasNaming() {
return aliasNaming;
}
#JsonProperty("aliasNaming")
public void setAliasNaming(Boolean aliasNaming) {
this.aliasNaming = aliasNaming;
}
#JsonProperty("dataServiceType")
public String getDataServiceType() {
return dataServiceType;
}
#JsonProperty("dataServiceType")
public void setDataServiceType(String dataServiceType) {
this.dataServiceType = dataServiceType;
}
#JsonProperty("deviceName")
public String getDeviceName() {
return deviceName;
}
#JsonProperty("deviceName")
public void setDeviceName(String deviceName) {
this.deviceName = deviceName;
}
#JsonProperty("langPref")
public String getLangPref() {
return langPref;
}
#JsonProperty("langPref")
public void setLangPref(String langPref) {
this.langPref = langPref;
}
#JsonProperty("maxPageSize")
public String getMaxPageSize() {
return maxPageSize;
}
#JsonProperty("maxPageSize")
public void setMaxPageSize(String maxPageSize) {
this.maxPageSize = maxPageSize;
}
#JsonProperty("outputType")
public String getOutputType() {
return outputType;
}
#JsonProperty("outputType")
public void setOutputType(String outputType) {
this.outputType = outputType;
}
#JsonProperty("password")
public String getPassword() {
return password;
}
#JsonProperty("password")
public void setPassword(String password) {
this.password = password;
}
#JsonProperty("query")
public Query getQuery() {
return query;
}
#JsonProperty("query")
public void setQuery(Query query) {
this.query = query;
}
#JsonProperty("returnControlIDs")
public String getReturnControlIDs() {
return returnControlIDs;
}
#JsonProperty("returnControlIDs")
public void setReturnControlIDs(String returnControlIDs) {
this.returnControlIDs = returnControlIDs;
}
#JsonProperty("targetName")
public String getTargetName() {
return targetName;
}
#JsonProperty("targetName")
public void setTargetName(String targetName) {
this.targetName = targetName;
}
#JsonProperty("targetType")
public String getTargetType() {
return targetType;
}
#JsonProperty("targetType")
public void setTargetType(String targetType) {
this.targetType = targetType;
}
#JsonProperty("token")
public String getToken() {
return token;
}
#JsonProperty("token")
public void setToken(String token) {
this.token = token;
}
#JsonProperty("username")
public String getUsername() {
return username;
}
#JsonProperty("username")
public void setUsername(String username) {
this.username = username;
}
#JsonAnyGetter
public Map<String, Object> getAdditionalProperties() {
return this.additionalProperties;
}
#JsonAnySetter
public void setAdditionalProperty(String name, Object value) {
this.additionalProperties.put(name, value);
}
Now i want to set the values in these models by creating their respective objects and finally i got one main object with all the data. like this
Value Vobj1 = new Value();
Vobj1.setContent("00098");
Vobj1.setSpecialValueId("LITERAL");
List<Value> valueList1= new ArrayList<Value>();
valueList1.add(Vobj1);
Value Vobj2 = new Value();
Vobj2.setContent("SM");
Vobj2.setSpecialValueId("LITERAL");
List<Value> valueList2= new ArrayList<Value>();
valueList2.add(Vobj2);
Value Vobj3 = new Value();
Vobj3.setContent("01/01/17");
Vobj3.setSpecialValueId("LITERAL");
List<Value> valueList3= new ArrayList<Value>();
valueList3.add(Vobj3);
Condition Cobj1 = new Condition();
Cobj1.setControlId("F4211.CO");
Cobj1.setOperator("EQUAL");
Cobj1.setValue(valueList1);
Condition Cobj2 = new Condition();
Cobj2.setControlId("F4211.DCTO");
Cobj2.setOperator("EQUAL");
Cobj2.setValue(valueList1);
Condition Cobj3 = new Condition();
Cobj3.setControlId("F4211.UPMJ");
Cobj3.setOperator("GREATER_EQUAL");
Cobj3.setValue(valueList1);
List<Condition> conditionList1 = new ArrayList<Condition>();
conditionList1.add(Cobj1);
conditionList1.add(Cobj2);
conditionList1.add(Cobj3);
Query Qobj1= new Query();
Qobj1.setAutoClear(true);
Qobj1.setAutoFind(true);
Qobj1.setCondition(conditionList1);
Qobj1.setMatchType("MATCH_ALL");
JSONStructure obj=new JSONStructure();
obj.setAliasNaming(true);
obj.setDataServiceType("BROWSE");
obj.setDeviceName("MyDevice");
obj.setLangPref(" ");
obj.setMaxPageSize("2000");
obj.setOutputType("VERSION1");
obj.setPassword("!J0g3t6000");
obj.setQuery(Qobj1);
obj.setReturnControlIDs("F4211.DOCO|F4211.TRDJ|F4211.CRCD|F4211.AN8|F4211.DSC2|F4211.DSC1|F4211.LITM|F4211.LOTN|F4211.UORG|F4211.UPRC|F4211.AEXP");
obj.setTargetName("F4211");
obj.setTargetType("table");
obj.setToken(Token);
obj.setUsername("JOGET");
Now obj is my final object that i am going to pass to an http request and call the api and get the data from it. i want to make sure that my json is created correct, how am i suppose to print the all the data inside this object? and am i going correct with this approach?
if you use maven put gson into your pom.xml
<dependency>
<groupId>com.google.code.gson</groupId>
<artifactId>gson</artifactId>
<version>2.8.5</version>
</dependency>
then print your object like this
System.out.println(new Gson().toJson(yourObj));
your object will print in json
I found two full working examples that is familiar with your case.
1) Using Gson refer to the tutorial Parse json string and java object into Gson tree model
2) Using Jackson refer to the tutorial Convert Java Object to/from JSON using JACKSON API
Hope this help.
I've been trying to create a nested RealmObject using a json but it only creates the first Object and not the nested ones. I would appreciate a help on this.
my Realm classes:
Content.java
public class Content extends RealmObject {
private String uuid;
RealmList<ContentDetailModel> ContentDetail;
public Content() {
super();
this.uuid = UUID.randomUUID().toString();
}
public String getUuid() {
return uuid;
}
public RealmList<ContentDetailModel> getContentDetails() {
return ContentDetail;
}
public void setContentDetails(RealmList<ContentDetailModel> contentDetails) {
this.ContentDetail = contentDetails;
}
}
ContentDetailModel.java:
public class ContentDetailModel extends RealmObject {
String FileName;
String ContentTypeID;
RealmList<ContentDetailMetadataModel> ContentDetailMetadata;
RealmResults<Content> content = null;
public String getFileName() {
return FileName;
}
public void setFileName(String fileName) {
FileName = fileName;
}
public String getContentTypeID() {
return ContentTypeID;
}
public void setContentTypeID(String contentTypeID) {
ContentTypeID = contentTypeID;
}
public RealmList<ContentDetailMetadataModel> getContentDetailMetadata() {
return ContentDetailMetadata;
}
public void setContentDetailMetadata(RealmList<ContentDetailMetadataModel> contentDetailMetadataz) {
this.ContentDetailMetadata = contentDetailMetadataz;
}
}
and the rest of nested classes are like these. my Json string is as follows:
"
{
"Content":{
"ContentDetail":[
{
"FileName":"test.mp3",
"ContentTypeID":3,
"ContentDetailMetadata":{
"Metadata":[
{
"ID":2,
"Value":"2017-08-02 09:40:30"
},
{
"ID":1,
"Value":"35.73876557934912,51.50785446166992"
}
]
}
},
{
"FileName":"2.jpg",
"ContentTypeID":2,
"ContentDetailMetadata":[
{
"Metadata":{
"ID":2,
"Value":"2017-08-02 09:40:30"
}
},
{
"Metadata":{
"ID":1,
"Value":"35.73876557934912,51.50785446166992"
}
}
]
}
]
}
}
"
and the code I use to do it is :
realm.createObjectFromJson(json)
{
"Content":{
"ContentDetail":[
{
"FileName":"test.mp3",
"ContentTypeID":3,
"ContentDetailMetadata":[{
"Metadata":[
{
"ID":2,
"Value":"2017-08-02 09:40:30"
},
{
"ID":1,
"Value":"35.73876557934912,51.50785446166992"
}
]
}]
},
Translates to:
public class Root extends RealmObject {
private Content Content;
}
public class Content extends RealmObject {
private RealmList<ContentDetail> ContentDetail;
#LinkingObjects("Content")
private final RealmResults<Root> roots = null;
}
public class ContentDetail extends RealmObject {
private String FileName;
private long ContentTypeID;
//private ContentDetailMetadata ContentDetailMetadata;
private RealmList<ContentDetailMetadata> ContentDetailMetadata;
#LinkingObjects("ContentDetail")
private final RealmResults<Content> contents = null;
}
public class ContentDetailMetadata extends RealmObject {
private RealmList<Metadata> Metadata;
#LinkingObjects("ContentDetailMetadata")
private final RealmResults<ContentDetail> contentDetails = null;
}
public class Metadata extends RealmObject {
private long ID;
private String Value;
#LinkingObjects("Metadata")
private final RealmResults<ContentDetailMetadata> contentDetailMetadatas = null;
}
If your schema doesn't look like that, then createOrUpdateFromJson() won't work.
Personally I would advise against using this schema though, it's pretty bad as a Realm schema. It's advisable to parse the JSON and then map it into a schema that makes more sense!
It looks like your JSON has put all fields for the Content object under the Context JSON object instead of directly under the top-level object where it should be.
If you do this, it should work:
realm.createObjectFromJson(Content.class, json.getJSONObject("Content"));
I have the following JSON to represent the server response for a salt request:
{
"USER":
{
"E_MAIL":"email",
"SALT":"salt"
},
"CODE":"010"
}
And i tried to map it with the following POJO:
public class SaltPOJO {
private String code = null;
private User user = null;
#Override
public String toString() {
return this.user.toString();
}
public String getCode() {
return code;
}
public void setCode(String code) {
this.code = code;
}
public User getUser() {
return user;
}
public void setUser(User user) {
this.user = user;
}
public class User {
private String e_mail = null;
private String salt = null;
#Override
public String toString() {
return this.e_mail + ": " + this.salt;
}
public String getE_mail() {
return e_mail;
}
public void setE_mail(String e_mail) {
this.e_mail = e_mail;
}
public String getSalt() {
return salt;
}
public void setSalt(String salt) {
this.salt = salt;
}
}
}
Now everytime i do this:
Gson gson = new Gson();
SaltPOJO saltPojo = gson.fromJson(json.toString(), SaltPOJO.class);
Log.v("Bla", saltPojo.toString());
The saltPojo.toString() is null. How can i map my JSON into POJO using Gson?
Is the order of my variables important for the Gson mapping?
Is the order of my variables important for the Gson mapping?
No, that's not the case.
How can i map my JSON into POJO using Gson?
It's Case Sensitive and the keys in JSON string should be same as variable names used in POJO class.
You can use #SerializedName annotation to use any variable name as your like.
Sample code:
class SaltPOJO {
#SerializedName("CODE")
private String code = null;
#SerializedName("USER")
private User user = null;
...
class User {
#SerializedName("E_MAIL")
private String e_mail = null;
#SerializedName("SALT")
private String salt = null;
You don't have proper mapping between your getter and setter. If you change your json to something like below, it would work:
{
"user":
{
"email":"email",
"salt":"salt"
},
"code":"010"
}
If you are getting json form third party then unfortunately, you would have to change your pojo or you could use adapter.
I'm running into a few issues similar to what others have had in the past with Json parsing in Java. This is the first time I try something like this so any help/tips is extremely useful.
I'm trying to parse in data from this site: https://api.bitcoinaverage.com/exchanges/USD
I have tried numerous ways with both Json and Gson. And have tried looking for help here but to no avail.
Here are the classes that are set up (these were auto generated):
Info.java:
public class Info{
private String display_URL;
private String display_name;
private Rates[] rates;
private String source;
private Number volume_btc;
private Number volume_percent;
public String getDisplay_URL(){
return this.display_URL;
}
public void setDisplay_URL(String display_URL){
this.display_URL = display_URL;
}
public String getDisplay_name(){
return this.display_name;
}
public void setDisplay_name(String display_name){
this.display_name = display_name;
}
public Rates[] getRates(){
return this.rates;
}
public void setRates(Rates[] rates){
this.rates = rates;
}
public String getSource(){
return this.source;
}
public void setSource(String source){
this.source = source;
}
public Number getVolume_btc(){
return this.volume_btc;
}
public void setVolume_btc(Number volume_btc){
this.volume_btc = volume_btc;
}
public Number getVolume_percent(){
return this.volume_percent;
}
public void setVolume_percent(Number volume_percent){
this.volume_percent = volume_percent;
}
}
Rates.java:
public class Rates {
private Number ask;
private Number bid;
private Number last;
public Number getAsk(){
return this.ask;
}
public void setAsk(Number ask){
this.ask = ask;
}
public Number getBid(){
return this.bid;
}
public void setBid(Number bid){
this.bid = bid;
}
public Number getLast(){
return this.last;
}
public void setLast(Number last){
this.last = last;
}
}
MainClass.java:
public class MainClass {
public static void main(String[] args) throws Exception {
Gson gson = new Gson();
String json = readUrl("https://api.bitcoinaverage.com/exchanges/USD");
Info page = gson.fromJson(json, Info.class);
System.out.println(page.getDisplay_name());
}
private static String readUrl(String urlString) throws Exception {
BufferedReader reader = null;
try {
URL url = new URL(urlString);
reader = new BufferedReader(new InputStreamReader(url.openStream()));
StringBuffer buffer = new StringBuffer();
int read;
char[] chars = new char[1024];
while ((read = reader.read(chars)) != -1)
buffer.append(chars, 0, read);
return buffer.toString();
} finally {
if (reader != null)
reader.close();
}
}
}
When I try to call a getter, a null is returned.
How do I go about parsing the data properly, and then being able to call an attribute from which ever object I want? For example, if I want an attribute from "anx_hk" or "bitfinex".
This is the first time me posting something here so I hope I'm following the proper guidelines.
I also plan on passing this over to Android once I get the fell for parsing Json better. Thanks for the help! It'll greatly be appreciated.
I'll be honest with you, that's a pretty lame API response. Here it is
{
"anx_hk": {
"display_URL": "https://anxbtc.com/",
"display_name": "ANXBTC",
"rates": {
"ask": 454.26,
"bid": 444.46,
"last": 443.78
},
"source": "bitcoincharts",
"volume_btc": 11.73,
"volume_percent": 0.02
},
...,
"timestamp": "Fri, 04 Apr 2014 04:30:26 -0000",
...
}
There's no JSON array here, so you can get rid of all your array types. This response is a JSON object, which contains a bunch of JSON objects (which share a format) and a JSON name value pair where the name is timestamp.
The common JSON objects have two fields of type double (that's what type your field should be, not Number)
"volume_btc": 11.73,
"volume_percent": 0.02
, three fields of type String
"display_URL": "https://anxbtc.com/",
"display_name": "ANXBTC",
"source": "bitcoincharts",
and one that is a JSON object that contains three more doubles
"rates": {
"ask": 454.26,
"bid": 444.46,
"last": 443.78
}
The actual issue here is that, I'm assuming, the JSON objects in the root JSON object have names that may change or new ones may be added. This is not a good fit for a POJO. Instead you'd want to use a Map<String, Info>, but Gson can't map to that by default. It is not well suited for such deserialization. You'd have to provide your own TypeAdapter.
Instead, I'm going to suggest you use Jackson.
If we put that all together, we get something like
class ApiResponse {
private Map<String, Info> page = new HashMap<>();
private Date timestamp;
public Map<String, Info> getPage() {
return page;
}
#JsonAnySetter
public void setPage(String name, Info value) {
page.put(name, value);
}
public Date getTimestamp() {
return timestamp;
}
public void setTimestamp(Date timestamp) {
this.timestamp = timestamp;
}
}
class Info {
private String display_URL;
private String display_name;
private Rates rates;
private String source;
private Double volume_btc;
private Double volume_percent;
public String getDisplay_URL() {
return this.display_URL;
}
public void setDisplay_URL(String display_URL) {
this.display_URL = display_URL;
}
public String getDisplay_name() {
return this.display_name;
}
public void setDisplay_name(String display_name) {
this.display_name = display_name;
}
public Rates getRates() {
return this.rates;
}
public void setRates(Rates rates) {
this.rates = rates;
}
public String getSource() {
return this.source;
}
public void setSource(String source) {
this.source = source;
}
public Double getVolume_btc() {
return this.volume_btc;
}
public void setVolume_btc(Double volume_btc) {
this.volume_btc = volume_btc;
}
public Double getVolume_percent() {
return this.volume_percent;
}
public void setVolume_percent(Double volume_percent) {
this.volume_percent = volume_percent;
}
}
class Rates {
private Double ask;
private Double bid;
private Double last;
public Number getAsk() {
return this.ask;
}
public void setAsk(Double ask) {
this.ask = ask;
}
public Double getBid() {
return this.bid;
}
public void setBid(Double bid) {
this.bid = bid;
}
public Double getLast() {
return this.last;
}
public void setLast(Double last) {
this.last = last;
}
}
With deserialization code such as
String json = readUrl("https://api.bitcoinaverage.com/exchanges/USD");
ObjectMapper mapper = new ObjectMapper();
ApiResponse response = mapper.readValue(json, ApiResponse.class);
System.out.println(response);
With appropriate toString() methods (mine were auto-generated with Eclipse), you would get something like
ApiResponse [pages={bitkonan=Info [display_URL=https://bitkonan.com/, display_name=BitKonan, rates=Rates [ask=475.0, bid=438.01, last=437.0], source=api, volume_btc=7.24, volume_percent=0.01], vaultofsatoshi=Info [display_URL=https://vaultofsatoshi.com, display_name=Vault of Satoshi, rates=Rates [ask=460.0, bid=460.0, last=460.0], source=api, volume_btc=11.46, volume_percent=0.02], bitstamp=Info [display_URL=https://bitstamp.net/, display_name=Bitstamp, rates=Rates [ask=439.16, bid=436.34, last=436.34], source=api, volume_btc=22186.29, volume_percent=35.19], ...}, timestamp=Fri Apr 04 01:02:43 EDT 2014]
as output.
The api response contains many objects, but seems that you are trying to read them as a single Info object.
You may try to read the response as a Map<String, Info>, and iterate the entries.
Map<String, Info> hashMap = gson.fromJson(body, HashMap.class);
for (Map.Entry entry : hashMap.entrySet()) {
// your code
}