converting string to gson object - java

I have a string output from server and I am trying to extract some values form the string.
Here is the output from server:
jsonString =
{
"MEANING":"reduce",
"DISPLAY":"",
"TYPE_CD":1,
"SELECTED_IND":1,
"CNT":1,
"SOURCES":[
{ "a":1 }
]
}
Code:
JsonReader reader = new JsonReader(new StringReader(jsonString));
DataObject obj1 = new Gson().fromJson(reader, DataObject.class);
DataObject Class:
DataObject
{
private int MEANING;
private int CNT;
private String TYPE_CD;
private String DISPLAY;
private String MEANING;
private List<Long> SOURCES;
public String getSourceTypeMeaning()
{
return this.MEANING;
}
public String getSourceTypeDisplay()
{
return this.DISPLAY;
}
public String getSourceTypeCd()
{
return this.TYPE_CD;
}
public int getSourceCount()
{
return this.CNT;
}
public List<Long> getSourceList()
{
return this.SOURCES;
}
}
but getting this error
Expected a string but was BEGIN_OBJECT at line 1 column 132
I am not able to find the issue with my code.

Other answers are pointing out that the problem is in the SOURCES field, and that's true, but the solutions they're giving are not correct...
You can't use just a Map to parse the SOURCES field, because this field is indeed an array! You have:
"SOURCES": [ ... ]
Since you have square brackets [ ], you have an array! And it's true there's a Map, but it is contained in the array...
So, what you need to parse that field correctly is:
private List<Map<String, int>> SOURCES;
Note that we use a Map to allow the content of SOURCES to have multiple and unknown values, so that this code could parse not only your JSON, but also something like:
"SOURCES":[
{ "a":1, "b":2 },
{ "c":3 },
{ "x":99, "y":98, "z":97 }
]

SOURCES variable should be Map<String,Long>,because in JSON string SOURCES is key-value collection ("a":1) where "a" is string and 1 is number.
Hope this helps.

Check this
"SOURCES":[
{ "a":1 }
]
This will represent a List of map not List of long.
So change your List<long> to List<Map<String, Long>> or List<Map<Object, Long>>.

Related

Retrofit - Deserilize Json response map into a property

I'm having a problem deserializing the response that I'm getting from retrofit.
My problem is that I get the following response:
"associations": {
"1": {
"uri": "https://api.ap.org/media/v/content/690b9f679b1d4d8abc8042ca53140625?qt=FckGhfkHkvF&et=0a1aza3c0&ai=881778bb579d79e17f54b046a86a81cf",
"altids": {
"itemid": "690b9f679b1d4d8abc8042ca53140625",
"etag": "690b9f679b1d4d8abc8042ca53140625_0a1aza3c0"
},
"version": 0,
"type": "picture",
"headline": "Facebook Ads-Targeting Info"
}
}
My entity looks like the following:
public class Associations{
private Map<String, JsonMember> association;
public Map<String, JsonMember> getAssociation() {
return association;
}
public void setAssociation(Map<String, JsonMember> association) {
this.association = association;
}
}
I want that association takes the value from the map, but I don't know how to specify that it takes the object inside that association. Those association keys can be returned as any number, so I can't hard code the "1".
Any ideas?
Thanks for your help!
You can read your json to a JsonNode and iterate over its properties names with a Iterator<String> iterator obtained calling the JsonNode#fieldNames method, selecting only the properties with a numeric name (this depends from what you mean for numeric, up to you the definition of a isNumber method):
Map<String, JsonMember> map = new HashMap<>();
//reading the jsonnode labelled with "associations"
JsonNode node = mapper.readTree(json).at("/associations");
Iterator<String> iterator = node.fieldNames();
while (iterator.hasNext()) {
String next = iterator.next();
if (isNumber(next)) { //<-- ok next is numeric
map.put(next, mapper.treeToValue(node.get(next), JsonMember.class));
}
}

How to create a JSON Array of JSON objects with a Java for loop?

I have a for loop which iterates and generates key value pairs for different employees.
I need to create a JSON array like below and write it to a JSON file at the end.
I am having trouble figuring out the ideal way to code it (JSON Objects -> JSON Array -> JSON file?).
I am open to use json-simple/GSON.
Desired JSON file format:
[
{
"employeeFirstName": "Mark",
"employeeLastName": "Williams",
"employeeDepartment": "Sales",
},
{
"employeeFirstName": "John",
"employeeLastName": "Carpenter",
"employeeDepartment": "Accounts",
},
{
"employeeFirstName": "David",
"employeeLastName": "Hunter",
"employeeDepartment": "Marketing",
},
]
I tried using a JSONObject and add it to a JSONArray. But, couldn't figure how to code it for iterations.
My current Java class:
public class Test {
public void createEmployeesJSONArrayFile(ITestContext iTestContext) {
for (ITestResult testResult : iTestContext.getFailedTests().getAllResults()) {
System.out.println("employeeFirstName: " + testResult.getEmployeeFirstName()));
System.out.println("employeeLastName: " + testResult.getEmployeeLastName());
System.out.println("employeeDepartment: " + testResult.getEmployeeDepartment());
}
}
}
What is the simplest or ideal way to achieve this?
A simple way to achieve this would be to use Gson, an API provided by Google. You could write the Collection of ITestResult objects to a file. The toJson function will take the Collection of ITestResult objects and write them to the the given Appenable object, which in this case is a BufferedWriter which points to a file.
(untested, one sec, not at workstation)
Collection<ITestResult> results = iTestContext.getFailedTests().getAllResults();
new GsonBuilder()
.create()
.toJson(results, Files.newBufferedWriter(Paths.get("path", "to", "file")));
If your goal is to write to file eventually, you can also use jackson apis.
ObjectMapper mapper = new ObjectMapper();
//To add indentation to output json
mapper.enable(SerializationFeature.INDENT_OUTPUT);
Collection<ITestResult> results = iTestContext.getFailedTests().getAllResults();
try{
mapper.writeValue(new File("/somepath/output.json"), results);
catch (IOException){
e.printStackTrace();
}
Note: Recommended to use single instance of object mapper
For following snippet:
public static final class Node {
class Employee {
private final String employeeFirstName;
private final String employeeLastName;
private final String employeeDepartment;
public Employee(String employeeFirstName, String employeeLastName, String employeeDepartment) {
this.employeeFirstName = employeeFirstName;
this.employeeLastName = employeeLastName;
this.employeeDepartment = employeeDepartment;
}
}
List<Employee> employees = Arrays.asList(
new Employee("Mark", "Williams", "Sales"),
new Employee("John", "Carpenter", "Accounts"),
new Employee("David", "Hunter", "Marketing"));
// String json = ...
}
Using gson-utils
String json = GsonUtils.writeValue(data);
Using jackson-utils
String json = JacksonUtils.writeValue(data);

How can I convert each integer/double value to String from JSON data containing nested objects and arrays?

I want to convert each integer/double value to String present in json request before storing in MongoDB database.
There can be multiple fields like amountValue in the json. I am looking for a generic way which can parse json with any number of such attributes value to string. My request will have around 200 fields.
ex: "amountValue": 200.00, to "amountValue": "200.00",
{
"templateName": "My DC Template 14",
"templateDetails": {
"beneficiaryName": "Snow2",
"dcOpenAmount": {
"amountValue": 200.00,
}
}
}
My mongoDB Document is of the form
#Document
public class TemplateDetails {
#Id
private long templateId;
private String templateName;
private Object templateDetail;
}
Because we are storing document in mongodb as an object(Which can accept any type of json request) we dont have field level control on it.
In my controller, converting the request object to json.
This is how I tried. But its not meeting my expectation. It is still keeping the amount value to its original double form.:
ObjectMapper mapper = new ObjectMapper();
try {
String json = mapper.writeValueAsString(templateRequestVO);
System.out.println("ResultingJSONstring = " + json);
} catch (JsonProcessingException e) {
e.printStackTrace();
}
Output :
ResultingJSONstring = {"id":null,"userId":"FU.ZONKO","txnType":"LCI","accessIndicator":"Public","templateId":null,"templateName":"My DC Template 14","tags":null,"templateDetails":{"applicantDetail":{"applicantName":"Tom","applicantAddress":{"addressLine1":"Infosys, Phase 2","city":"PUNE","state":"MAHARASHTRA","country":"INDIA","zip":"40039"},"accountId":"Account1234","customerId":"JPMORGAN"},"beneficiaryName":"Snow2","dcOpenAmount":{"amountValue":200.0,"currency":"USD"}}}
Is there any way to accomplish the result ? Or anything which can help to store documents in mongodb with attribute type as String ?
You can use Json manipulation avaliable in "org.json.JSONObject" to convert Double value to Stirng .
If your Json structure won't change and will remain as said above , you can do the following.
import org.json.JSONObject;
public static void main(String args[]) {
String j = "{ \"templateName\": \"My DC Template 14\", \"templateDetails\": { \"beneficiaryName\": \"Snow2\", \"dcOpenAmount\": { \"amountValue\": 200.00 } } }";
JSONObject jo = new JSONObject(j);
jo.getJSONObject("templateDetails")
.getJSONObject("dcOpenAmount")
.put("amountValue", String.valueOf(jo.getJSONObject("templateDetails").getJSONObject("dcOpenAmount").getDouble("amountValue")));
System.out.println(jo.toString());
}
Following will be the output
{"templateDetails":{"dcOpenAmount":{"amountValue":"200.0"},"beneficiaryName":"Snow2"},"templateName":"My DC Template 14"}
I don't know for mongodb but for a json string you can replace them with a regex and the function replace like this :
public class Test {
public static void main(String[] args) {
String json = "{\"id\":null,\"userId\":\"FU.ZONKO\",\"txnType\":\"LCI\",\"accessIndicator\":\"Public\",\"templateId\":null,\"templateName\":\"My DC Template 14\",\"tags\":null,\"templateDetails\":{\"applicantDetail\":{\"applicantName\":\"Tom\",\"applicantAddress\":{\"addressLine1\":\"Infosys, Phase 2\",\"city\":\"PUNE\",\"state\":\"MAHARASHTRA\",\"country\":\"INDIA\",\"zip\":\"40039\"},\"accountId\":\"Account1234\",\"customerId\":\"JPMORGAN\"},\"beneficiaryName\":\"Snow2\",\"dcOpenAmount\":{\"amountValue\":200.0,\"currency\":\"USD\"}}}";
System.out.println(replaceNumberByStrings(json));
}
public static String replaceNumberByStrings(String str){
return str.replaceAll("(?<=:)\\d+(\\.\\d+)?(?=(,|}))","\"$0\"");
}
}
It will look for all fields with a numeric value in the json string and add quotes to the value. This way they will be interpreted as strings when the json willl be parsed.
It will not work if the value is in an array though, but in this case it should not be a problem.

gson de-serialising object array without identifier

Im getting an error trying to take a json array to a list of objects, the exception is as below.
com.google.gson.JsonSyntaxException: java.lang.IllegalStateException: Expected BEGIN_ARRAY but was BEGIN_OBJECT at line 1 column 170
here is the code i am trying to use
public static void main(String[] args) throws FileNotFoundException {
Gson gson = new Gson();
Test test = new Test();
JsonElement json = gson.fromJson(test.getFile("fieldTypes.json"), JsonElement.class);
String result = gson.toJson(json);
System.out.println(result);
Type listType = new TypeToken<ArrayList<JiraField>>(){}.getType();
JiraField[] jiraFields = gson.fromJson(result, listType);
for (JiraField jiraField : jiraFields) {
System.out.println(jiraField);
}
}
This is the file contents
[
{
"id": "issuetype",
"key": "issuetype",
"name": "Issue Type",
"custom": false,
"orderable": true,
"navigable": true,
"searchable": true,
"clauseNames": [
"issuetype",
"type"
],
"schema": {
"type": "issuetype",
"system": "issuetype"
}
},
{
"id": "timespent",
"key": "timespent",
"name": "Time Spent",
"custom": false,
"orderable": false,
"navigable": true,
"searchable": false,
"clauseNames": [
"timespent"
],
"schema": {
"type": "number",
"system": "timespent"
}
}
]
The file is being read from the resources folder but that is working fine and the sysout is correctly showing the json contents. i assume there is something im doing wrong ?
ok, so. turns out to be caused by un mapped fields, this is how i got it working
in the object you add the #Expose annotation for the fields you want
public class JiraField {
#Expose
private String id ;
#Expose private String key ;
#Expose private String name ;
#Expose private boolean custom ;
#Expose private boolean orderable ;
#Expose private boolean navigable ;
#Expose private String[] clauseNames ;
Then when you initialise gson, you do it like this
Gson gson = new GsonBuilder().excludeFieldsWithoutExposeAnnotation().create();
then it works :)
JiraFields{id='issuetype', key='issuetype', name='Issue Type', custom=false, orderable=true, navigable=true, clauseNames=[issuetype, type]}
JiraFields{id='timespent', key='timespent', name='Time Spent', custom=false, orderable=false, navigable=true, clauseNames=[timespent]}
Try this:
Type listType = new TypeToken<ArrayList<JiraField[]>>(){}.getType();
I think we need to specify the JiraField[] in-order to get Array.
I'm assuming you have a minified JSON according to the exception message ...at line 1 column 170.... It would be nice if you provide both exact your exact JSON document and your mapping as well, since the posted formatted JSON now has the layout destroyed. I'm also assuming your mapping is custom and basically something like:
final class JiraField {
#SerializedName("id")
final String id = null;
#SerializedName("key")
final String key = null;
#SerializedName("name")
final String name = null;
#SerializedName("custom")
final boolean isCustom = Boolean.valueOf(false);
#SerializedName("orderable")
final boolean isOrderable = Boolean.valueOf(false);
#SerializedName("navigable")
final boolean isNavigable = Boolean.valueOf(false);
#SerializedName("searchable")
final boolean isSearchable = Boolean.valueOf(false);
#SerializedName("clauseNames")
final List<String> clauseNames = null;
#SerializedName("schema")
final List<String> schema = null;
}
Note the JiraField.schema field type: it's a list. Trying to deserialize a list of JiraFields with the default Gson configuration would result into:
java.lang.IllegalStateException: Expected BEGIN_ARRAY but was BEGIN_OBJECT at line 1 column 170 path $[0].schema
The symptom and the column are exactly the same (however, again, I'm just assyming your JSON file is minified), but note the path $[0].schema you probably missed to post: it says that an array begin token [ is expected (since the field is a List<String>), but was an object begin token {. Changing the field type to a more appropriate arbitrary Map<String, String> or any other custom appropriate POJO would fix it. Partially.
#SerializedName("schema")
final Map<String, String> schema = null;
Why partially? Your type token is bound to an ArrayList, but you're casting the deserialization result to an array JiraField[], therefore you'd get something like this:
Exception in thread "main" java.lang.ClassCastException: java.util.ArrayList cannot be cast to [LJiraField;
To fix it, you have to declare your jiraFields variable matching the deserialized value type: it's an array list, but not an array -- these are not the same in Java.
List<JiraField> jiraFields = ...
Another note regarding deserialization is that you don't need an intermediate json object to deserialize from. test.getFile most likely returns a java.io.Reader, so you can pass it directly to deserialize. Summarizing all up, the following should work for you:
// Immutable and thread-safe, can be instantiated once and shared
private static final Gson gson = new Gson();
// Immutable and thread-safe value type, the same story, + List instead of ArrayList - interfaces are usually much better
private static final Type listType = new TypeToken<List<JiraField>>() {
}.getType();
public static void main(final String... args)
throws IOException {
try ( final Reader reader = test.getFile("fieldTypes.json") ) {
final List<JiraField> jiraFields = gson.fromJson(reader, listType);
for ( final JiraField jiraField : jiraFields ) {
System.out.println(jiraField.key + " => " + jiraField.name);
}
}
}
Output:
issuetype => Issue Type
timespent => Time Spent
Type listType = new TypeToken<ArrayList<JiraField>>(){}.getType();
ArrayList<JiraField> jiraFields = gson.fromJson(result, listType);
for (JiraField jiraField : jiraFields) {
System.out.println(jiraField);
}
Try This code
Comment this line
Type listType = new TypeToken<ArrayList<JiraField>>(){}.getType();
Try with this
JiraField[] jiraFields = gson.fromJson(result, JiraField[].class);

How to convert tojson an object with one of field is a jsonstring

I have an entity of:
class A {
String errors ;// a json string of some type (type could vary).
Double value;
...
public A(String theErrors, Double theValue) {
errors = theErrors;
value=theValue;
}
}
A a = new A("{tl:[\"err1\"]...}", 10d);
I need to transform a to a json string.
With google gson library I could use:
String str = gson.toJson(a)
But s.a. errors field is a String, it is escaped, and the result is:
// {"errors": "{ tl:["err1"] ...}", "value":10 }
not a
// {"errors": { tl:["err1"]... }, "value":10 }
As for now I try something like:
String str = gson.toJson(a).replace("\"{", "{").replace("}\"}", "}}")
but that is a fragile solution.
Does anyone know, if there is a better way to fix that? Thanks in advance.
PS: the point is that type of underlying errors object is unknown (it depends on the source of errors)
seems I've found a solution:
String getAsJson(A a) {
JsonObject jsonMedia = (JsonObject) g.toJsonTree(a);
jsonMedia.add("errors", g.fromJson(a.getA(), JsonElement.class));
return g.toJson(jsonMedia);
}

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