I have the following Json file which I am trying to read:
{
"billingInformation": {
"taxes": {
"gst": 2.5,
"hst": 7.8
},
"billTo": {
"name" : "Mike",
"address" : "123, Lake Shore Drive, California",
"phoneNumber" : "601 855 1249"
},
"salesAgent": {
"name" : "Charlotte Thompson",
"agentCode" : 44551
},
"items": {
"item": [
{
"hsnCode": "5112",
"description": "TV Set",
"originCountry": "US",
"quantity": 1,
"unitPrice": 150.00
}
],
"currency": "USD"
}
}
}
I used direct Object Mapping provided by Gson:
result = new String(Files.readAllBytes(Paths.get(path)));
BillingInformation billingInformation = gson.fromJson(result, BillingInformation.class);
But it always resulted in:
class BillingInformation {
taxes: null
billTo: null
salesAgent: null
items: null
}
How can I get the data inside the other objects?
Edit:
Here is the BillingInformation Class:
public class BillingInformation {
#SerializedName("taxes")
private Taxes taxes;
#SerializedName("billTo")
private BillTo billTo;
#SerializedName("salesAgent")
private SalesAgent salesAgent;
#SerializedName("items")
private Items items;
}
and I have the usual getters and setters for the above fields.
You should create a class that looks like this:
class Data {
private BillingInformation billingInformation;
}
And then do the deserialization:
Data fromFile = gson.fromJson(result, Data.class);
I am new with Spring Data MongoDB and I am trying to implement an aggregation query in Java with Spring Data MongoDB. I have tried searching from this problem and approached it using MongoTemplate, but still to no result.
The format of my data:
[{
"_id" : ObjectId("5e1aea6c275360baf96bac29"),
"title" : "postim",
"upvotesBy" : [
"5e18b4c12753608718dfa007",
"5e19ac0f5161a4994ded1f35"
],
"file" : "test",
"description" : "description",
"postedBy" : "5e18b4c12753608718dfa007",
"createdAt" : ISODate("2020-01-12T09:44:12.119+0000"),
"_class" : "com.socialnetwork.post.Post"
},
{
"_id" : ObjectId("5e1aeaf8275360bb4bb47325"),
"title" : "postim2",
"upvotesBy" : [
"5e18b4c12753608718dfa007",
"5e19ac0f5161a4994ded1f35"
],
"file" : "test2",
"description" : "description2",
"postedBy" : "5e18b4c12753608718dfa007",
"createdAt" : ISODate("2020-01-12T09:46:32.909+0000"),
"_class" : "com.socialnetwork.post.Post"
}]
My query:
db.post.aggregate([
{
$match: {}
},
{
$lookup: {
from: "users",
localField: "postedBy",
foreignField: "_id",
as: "user"
}
},
{
$group: {
_id: {
username: "$user.name",
title: "$title",
description: "$description",
upvotes: { $size: "$upvotesBy" },
upvotesBy: "$upvotesBy",
isUpvoted: { $in: [req.query.userId, "$upvotesBy"] },
isPinned: {
$cond: {
if: { $gte: [{ $size: "$upvotesBy" }, 3] },
then: true,
else: false
}
},
file: "$file",
createdAt: {
$dateToString: {
format: "%H:%M %d-%m-%Y",
timezone: "+01",
date: "$createdAt"
}
},
id: "$_id"
}
}
},
{ $sort: { "_id.isPinned": -1, "_id.createdAt": -1 } }
])
This is the query I use in my Javascript backend and I can do this fairly easy with Mongoose. However I am having some difficulty with the Java implementation of it.
private LookupOperation getLookupOperation() {
return LookupOperation.newLookup().from("user")
.localField("postedBy")
.foreignField("_id")
.as("user");
}
#Override
public List<PostSummary> aggregate() {
LookupOperation lookupOperation = getLookupOperation();
return mongoTemplate.aggregate(Aggregation.newAggregation(lookupOperation, Aggregation.group("id")
.addToSet("user.name").as("username")
.addToSet("title").as("title")
.addToSet("description").as("description")
.addToSet("id").as("id")
.push("upvotesBy").as("upvotesBy")
.addToSet("file").as("file")
.addToSet("createdAt").as("createdAt")
), Post.class, PostSummary.class).getMappedResults();
}
When I try to run this I get the following error:
"Cannot convert [] of type class java.util.ArrayList into an instance of class java.lang.Object! Implement a custom Converter<class java.util.ArrayList, class java.lang.Object> and register it with the CustomConversions. Parent object was: com.socialnetwork.post.PostSummary#7159d908"
When I delete the .addToSet("user.name").as("username") from the group aggregation I also get an error from .push("upvotesBy").as("upvotesBy") as it can not convert [] of type class java.util.ArrayList into an instance of class java.lang.String
Also the implementation of the Post Class and the PostSummary Class is simple:
Post.java:
#Document
public class Post {
#Id
private String id;
private String title;
private List<String> upvotesBy;
private String file;
private String description;
private String postedBy;
private Date createdAt = new Date();
// ... Getters and Setters for each field
}
PostSummary.java:
public class PostSummary {
private String username;
private String title;
private String description;
private List<String> upvotesBy;
private String file;
private String createdAt;
private String id;
//... Getters and Setters for the class
}
I also need to implement the isUpvoted and isPinned part of the query, but getting the idea on how to approach the first problem would be a great start.
EDIT: My desired output:
[
{
"username" : "user1",
"title" : "postim2",
"upvotesBy" : [
"5e18b4c12753608718dfa007",
"5e19ac0f5161a4994ded1f35"
],
"file": "file1",
id: "5e18b4c12753608718dber01"
... Other fields of the original post
},
{
"username" : "user2",
"title" : "postim2",
"upvotesBy" : [
"5e18b4c12753608718dfa007",
"5e19ac0f5161a4994ded1f35"
],
id: "5e18b4c12753608718dber02",
"file": "file2",
... Other fields of the original post
}
]
So from the lookup operation I need only to get the name of the user.
Let's do it
We need to update your aggregation to make it work.
Errors:
users's _id is ObjectId type, but in your post you have stored as String, so $lookup should be changed to Uncorrelated sub-queries
We replace $group by '$addFields' which fits better
We add as last stage $project operator to exclude all unsed fields.
db.post.aggregate([
{
$match: {}
},
{
$lookup: {
from: "users",
let: {
postedBy: "$postedBy"
},
pipeline: [
{
$match: {
$expr: {
$eq: [
{
"$toString": "$_id"
},
"$$postedBy"
]
}
}
}
],
as: "user"
}
},
{
$unwind: "$user"
},
{
$addFields: {
id: {
$toString: "$_id"
},
username: "$user.name",
upvotes: {
$size: "$upvotesBy"
},
isUpvoted: {
$in: [
"5e18b4c12753608718dfa007",
"$upvotesBy"
]
},
isPinned: {
$cond: [
{
$gte: [
{
$size: "$upvotesBy"
},
3
]
},
true,
false
]
},
createdAt: {
$dateToString: {
format: "%H:%M %d-%m-%Y",
timezone: "+01",
date: "$createdAt"
}
}
}
},
{
$sort: {
"isPinned": -1,
"createdAt": -1
}
},
{
$project: {
_id: 0,
user: 0,
upvotesBy: 0,
_class: 0
}
}
])
Now, we transform this query to Spring-Data syntax.
Java Implementation
package postman;
import static org.springframework.data.mongodb.core.aggregation.Aggregation.match;
import static org.springframework.data.mongodb.core.aggregation.Aggregation.project;
import static org.springframework.data.mongodb.core.aggregation.Aggregation.sort;
import static org.springframework.data.mongodb.core.aggregation.Aggregation.unwind;
import java.util.Arrays;
import java.util.List;
import org.bson.Document;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Sort.Direction;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.core.aggregation.Aggregation;
import org.springframework.data.mongodb.core.aggregation.AggregationOperation;
import org.springframework.data.mongodb.core.aggregation.AggregationOperationContext;
import org.springframework.data.mongodb.core.query.Criteria;
import org.springframework.stereotype.Service;
#Service
public class PostmanService {
#Autowired
private MongoTemplate mongoTemplate;
public List<PostSummary> find(String userId){
Aggregation aggregation = Aggregation.newAggregation(
match(new Criteria()),
//lookup("users", "postedBy", "_id", "user")
new AggregationOperation() {
#Override
public Document toDocument(AggregationOperationContext context) {
return new Document("$lookup",
new Document("from", "users")
.append("let", new Document("postedBy", "$postedBy"))
.append("pipeline", Arrays.asList(
new Document("$match",
new Document("$expr",
new Document("$eq", Arrays.asList(
new Document("$toString", "$_id"),
"$$postedBy"
))))))
.append("as", "user"));
}
},
unwind("$user"),
new AggregationOperation() {
#Override
public Document toDocument(AggregationOperationContext context) {
return new Document("$addFields",
new Document("id", new Document("$toString", "$_id"))
.append("username", "$user.name")
.append("upvotes", new Document("$size", "$upvotesBy"))
.append("isUpvoted", new Document("$in", Arrays.asList(userId, "$upvotesBy")))
.append("isPinned", new Document("$cond",
Arrays.asList(new Document("$gte",
Arrays.asList(new Document("$size", "$upvotesBy"), 3)), Boolean.TRUE, Boolean.FALSE)))
.append("createdAt", new Document("$dateToString",
new Document("format", "%H:%M %d-%m-%Y")
.append("timezone", "+01")
.append("date", "$createdAt")
)));
}
},
sort(Direction.DESC, "isPinned", "createdAt"),
project().andExclude("user", "_class")
);
System.out.println("Aggregation: " + aggregation.toString());
return mongoTemplate.aggregate(aggregation, mongoTemplate.getCollectionName(Post.class), PostSummary.class).getMappedResults();
}
}
Now, we call aggregation pipeline:
List<PostSummary> l = postmanService.find("5e18b4c12753608718dfa007");
for(PostSummary post: l) {
ObjectWriter ow = new ObjectMapper().writer().withDefaultPrettyPrinter();
System.out.println(ow.writeValueAsString(post));
}
2020-01-12 16:15:22.043 INFO 11148 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path ''
2020-01-12 16:15:22.047 INFO 11148 --- [ main] Postman.PostmanApplication : Started PostmanApplication in 4.602 seconds (JVM running for 5.301)
Aggregation: { "aggregate" : "__collection__", "pipeline" : [{ "$match" : {}}, { "$lookup" : { "from" : "users", "let" : { "postedBy" : "$postedBy"}, "pipeline" : [{ "$match" : { "$expr" : { "$eq" : [{ "$toString" : "$_id"}, "$$postedBy"]}}}], "as" : "user"}}, { "$unwind" : "$user"}, { "$addFields" : { "id" : { "$toString" : "$_id"}, "username" : "$user.name", "upvotes" : { "$size" : "$upvotesBy"}, "isUpvoted" : { "$in" : ["5e18b4c12753608718dfa007", "$upvotesBy"]}, "isPinned" : { "$cond" : [{ "$gte" : [{ "$size" : "$upvotesBy"}, 3]}, true, false]}, "createdAt" : { "$dateToString" : { "format" : "%H:%M %d-%m-%Y", "timezone" : "+01", "date" : "$createdAt"}}}}, { "$sort" : { "isPinned" : -1, "createdAt" : -1}}, { "$project" : { "user" : 0, "_class" : 0}}]}
2020-01-12 16:15:22.161 INFO 11148 --- [ main] org.mongodb.driver.connection : Opened connection [connectionId{localValue:2, serverValue:277}] to localhost:27017
{
"username" : "user1",
"title" : "postim2",
"description" : "description2",
"upvotesBy" : [ "5e18b4c12753608718dfa007", "5e19ac0f5161a4994ded1f35" ],
"file" : "test2",
"createdAt" : "10:46 12-01-2020",
"id" : "5e1aeaf8275360bb4bb47325"
}
{
"username" : "user1",
"title" : "postim",
"description" : "description",
"upvotesBy" : [ "5e18b4c12753608718dfa007", "5e19ac0f5161a4994ded1f35" ],
"file" : "test",
"createdAt" : "10:44 12-01-2020",
"id" : "5e1aea6c275360baf96bac29"
}
I'm using jackson 2.9.8 and I'm trying to beutify my json.
The code I'm using is:
protected void setSuccessMessage(HttpServletResponse response, JSONObject jObj) throws IOException {
// Set the status
response.setStatus(200);
// Create the response
response.setContentType("application/json");
PrintWriter out = response.getWriter();
jObj.put("success", 1);
ObjectMapper mapper = new ObjectMapper();
mapper.configure(SerializationFeature.INDENT_OUTPUT, true);
mapper.setVisibility(PropertyAccessor.ALL, Visibility.ANY);
out.print(mapper.writeValueAsString(jObj));
out.close();
}
However, my output has a new map tag which I don't want. The output is:
{
"map" : {
"success" : 1,
"documents_metata" : {
"myArrayList" : [ {
"map" : {
"documentType" : "PS_XML",
"patientId" : "x",
"effectiveTime" : "2019-05-08",
"author" : "xxx",
"repositoryId" : "xxx",
"id" : "xxx",
"title" : "xxx"
}
}, {
"map" : {
"documentType" : "PS_PDF",
"patientId" : "x",
"effectiveTime" : "2019-05-08",
"author" : "xxx",
"repositoryId" : "xxx",
"id" : "xxx",
"title" : "xxx"
}
} ]
}
}
}
The correct one should be:
{
"success": 1,
"documents_metadata": [
[
{
"documentType": "PS_PDF",
"patientId": "x",
"effectiveTime": "2019-05-08",
"author": "xxx",
"repositoryId": "xxx",
"id": "xxx",
"title": "xxx"
},
{
"documentType": "PS_XML",
"patientId": "x",
"effectiveTime": "2019-05-08",
"author": "xxx",
"repositoryId": "xxx",
"id": "xxx",
"title": "xxx"
}
]
]
}
The json without the jackson is fine but's it's not indented. Do you know how to fix this?
Jackson doesn't know anything about JSONObject which comes from another library. So it's writing its internal structure like it would any other class. Use https://github.com/FasterXML/jackson-datatype-json-org to tell Jackson how to treat it:
import com.fasterxml.jackson.datatype.jsonorg.JsonOrgModule;
mapper.registerModule(new JsonOrgModule());
Or use Jackson's own JsonNode (see e.g. Working with Tree Model Nodes in Jackson for a tutorial).
I'm using Retrofit+Gson for parsing JSON.
When I try parse response from Google Places API (ok, I don't try parse, I just try to make model for this response) and I get some error.
This is response from Google Place API:
{
"predictions" : [
{
"description" : "Николаевская область, Украина",
"id" : "3bd747cc4efc2288da48942b909ce18a053c2060",
"matched_substrings" : [
{
"length" : 5,
"offset" : 0
}
],
"place_id" : "ChIJydRVsbqaxUARLq1R8Q3RgpM",
"reference" : "ClRPAAAAwseWiG8NUMt7TqSqz9rMP8R2M4rX7-cMRmIp4OCYL-VdRSr5B5T_PMwWzYOydVStVpYDvm0ldXYPEzxFAuvn1LqhtWHdROhsERwvmx0tVlwSEFdMw0sOe3rDaB2AqKKmF-YaFLvhiEOz3Bklv5-iTa7QQORILVCU",
"structured_formatting" : {
"main_text" : "Николаевская область",
"main_text_matched_substrings" : [
{
"length" : 5,
"offset" : 0
}
],
"secondary_text" : "Украина"
},
"terms" : [
{
"offset" : 0,
"value" : "Николаевская область"
},
{
"offset" : 22,
"value" : "Украина"
}
],
"types" : [ "administrative_area_level_1", "political", "geocode" ]
}, ...],
"status" : "OK"
}
This is my model for this response:
public class GetGoogleMapPlacesResponse {
#SerializedName("predictions")
private List<GooglePlace> googlePlaces;
public List<GooglePlace> getGooglePlaces() {
return googlePlaces;
}
public void setGooglePlaces(List<GooglePlace> googlePlaces) {
this.googlePlaces = googlePlaces;
}
}
But when Retrofit try's to parse response to model I get error:
java.lang.ClassCastException: com.google.gson.internal.LinkedTreeMap cannot be cast to com.myapp.net.rest.response.GetGoogleMapPlacesResponse
And this is raw response in Debug mode:
You're missing a constructor of GetGoogleMapPlacesResponse model.
public class GetGoogleMapPlacesResponse {
private List<GooglePlace> googlePlaces;
private String status;
public GetGoogleMapPlacesResponse(List<GooglePlace> googlePlaces, String status) {
this.googlePlaces = googlePlaces;
this.status = status;
}
...getters & setters
}
But i highly suggest you to use AutoValue with Gson extension and then your model will look like this :
#AutoValue
public abstract class GetGoogleMapPlacesResponse {
#SerializedName("predictions") public abstract List<GooglePlace> googlePlaces;
public abstract String status;
}
For more info look here : https://github.com/rharter/auto-value-gson
UPDATE! Fixed, there was a missed public statement on prices attribute that was the reason this error occurred.
I am trying out Jackson for converting between .json files and objects. However, I keep receiving this error "UnrecognizedPropertyException: Unrecognized field "Prices" (class imp.JsonDTO), not marked as ignorable (one known property: "Ticker"]" .
I am trying to convert a json file that looks like this:
{
"Ticker": "AAPL",
"Prices": [
{
"Date": "1986-01-02T00:00:00",
"Value": 22.25,
"Action": "Sell"
},
{
"Date": "1986-01-03T00:00:00",
"Value": 22.38,
"Action": "Buy"
},
{
"Date": "1986-01-06T00:00:00",
"Value": 22.38,
"Action": "Sell"
}
]
}
I am converting like this:
ObjectMapper mapper = new ObjectMapper();
File file = new File("INTC.json");
JsonDTO dto = mapper.readValue(file, JsonDTO.class);
DTO's that I am using:
public class JsonDTO {
public String Ticker;
List<PriceDTO> Prices = new ArrayList<PriceDTO>();
}
and..
public class PriceDTO {
public String Date;
public double Value;
public String Action;
}
Tried a few different ways for "Prices" but seem unable to get it right.Thanks for help :)