I am running the following aggregation lookup query in spring but it doesn't seems to output the same result as one i run in mongo shell. I am guessing mongo shell knows that from:"testModel" collection exists but how do spring know "testModel" exists as we are only pass strings in Aggregation.lookup("testModel"). I can run all other stages fine for example match or project..
// code running in Mongo Shell
db.demoModel.aggregate([{
$lookup:
{
from: "testModel",
localField: "_id",
foreignField: "makeId",
as: "cool"
}
}]
)
// code from spring
public List<DemoModel> getSomeAutos() throws Exception {
LookupOperation lookupStage = Aggregation.lookup(
"testModel",
"_id",
"makeId",
"cool"
);
Aggregation aggregation = Aggregation.newAggregation(lookupStage);
List<DemoModel> demomode = mongoTemplate.aggregate(aggregation, "demoModel", DemoModel.class).getMappedResults();
return demomode;
}
// DemoModel.class
public class DemoModel {
#Id
private String id;
private String value;
private String label;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getValue() {
return value;
}
public void setValue(String value) {
this.value = value;
}
public String getLabel() {
return label;
}
public void setLabel(String label) {
this.label = label;
}
}
//Mongo demoModel Collection
{
"_id" : ObjectId("5a8ee0d815dc17aa32f90f4b"),
"value" : "Mitsubishi",
"label" : "Mitsubishi"
}
{
"_id" : ObjectId("5a8ee0d815dc17aa32f90f4c"),
"value" : "BMW",
"label" : "BMW"
}
// Mongo testModel Collection
{
"_id" : ObjectId("5a8ee393b80c346266f25aba"),
"make" : "Mitsubishi",
"label" : "3000GT",
"value" : "3000GT",
"makeId" : ObjectId("5a8ee0d815dc17aa32f90f4b")
}
{
"_id" : ObjectId("5a8ee393b80c346266f25af8"),
"make" : "BMW",
"label" : "Alpina A2",
"value" : "Alpina A2",
"makeId" : ObjectId("5a8ee0d815dc17aa32f90f4c")
}
// Response i am getting
[
{
"id": "5a8ee0d815dc17aa32f90f4b",
"value": "Mitsubishi",
"label": "Mitsubishi"
},
{
"id": "5a8ee0d815dc17aa32f90f4c",
"value": "BMW",
"label": "BMW"
}
]
// expected response in this format
{
"_id" : ObjectId("5a8ee0d815dc17aa32f90f4b"),
"value" : "Mitsubishi",
"label" : "Mitsubishi",
"cool" : [
{
"_id" : ObjectId("5a8ee393b80c346266f25aba"),
"make" : "Mitsubishi",
"label" : "3000GT",
"value" : "3000GT",
"makeId" : ObjectId("5a8ee0d815dc17aa32f90f4b")
}]
}
Related
I'm trying to deserialize a json string to Java object. Here is my json string.
{
"header": {
"transactionId": "12345",
"application": "testApp"
},
"items": {
"item": [
{
"attributes": {
"attribute": [
{
"key": "accountType",
"value": "TYPE1"
},
{
"key": "accountId",
"value": "123"
}
]
}
},
{
"attributes": {
"attribute": [
{
"key": "userType",
"value": "TYPE2"
},
{
"key": "userId",
"value": "321"
}
]
}
}
]
}
}
And I want to deserialize this json to Java classes that shown as below.
public class Response {
private Header header;
private List<Object> items;
//getters and setters
}
public class Header {
private String transactionId;
private String application;
//getters and setters
}
public class Account {
private String accountType;
private String accountId;
//getters and setters
}
public class User {
private String userType;
private String userId;
//getters and setters
}
How can I deserialize by using jackson or objectmapper etc.? The main problem is the field names are in the attribute object and the value of 'key' field. Is it possible to find the right field on Java object by using value of the 'key' field and to set the right value with the value of the 'value' field?
One possible solution is to transform the JSON structure before converting to POJO.
https://github.com/octomix/josson
Josson josson = Josson.fromJsonString(yourJsonString);
JsonNode node = josson.getNode(
"map(header," +
" items: items.item#" +
" .attributes.attribute" +
" .map(key::value)" +
" .mergeObjects()" +
" )");
System.out.println(node.toPrettyString());
Output
{
"header" : {
"transactionId" : "12345",
"application" : "testApp"
},
"items" : [ {
"accountType" : "TYPE1",
"accountId" : "123"
}, {
"userType" : "TYPE2",
"userId" : "321"
} ]
}
Here i'm using MongoRepository and i need to query a list of objects that includes certain id in an array of objects inside.
The document structure :
{
"_id" : ObjectId("5ccc1c54a3d5eed9a6b8015a"),
"email" : "sineth3#gmail.com",
"name" : "edward3",
"businessName" : "aroma3",
"phone" : "07177222233",
"address" : "no 100 NY",
"bookletSignups" : [
{
"bookletId" : "sample-booklet",
"contactName" : "john doe"
},
{
"bookletId" : "sample-booklet1",
"contactName" : "john doe1"
}
],
"eventSignups" : [
{
"eventId" : "sample-event",
"contactName" : "john doe2"
},
{
"eventId" : "sample-event 1",
"contactName" : "john doe3"
}
],
"infoSignups" : [
{
"infoRequestId" : "sample-info ",
"contactName" : "john doe4"
},
{
"infoRequestId" : "sample-event 1",
"contactName" : "john doe5"
}
],
"webinarSignups" : [
{
"webinarId" : "sample-webinar ",
"contactName" : "john doe6"
},
{
"webinarId" : "sample-webinar 1",
"contactName" : "john doe7"
}
],
"updatedTime" : ISODate("2016-03-03T08:00:00Z")
}
The Repository :
#Repository
public interface UserRepository extends MongoRepository<User,String> {
#org.springframework.data.mongodb.repository.Query(value = "{ 'bookletSignups': { $elemMatch: { 'bookletSignups.bookletId' : ?0 } }}")
List<User> findByBookletId(String id);
}
User model class:
#Id
private String id;
private String email;
private String name;
private String businessName;
private String phone;
private String address;
#DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME)
private Date createdTime;
#DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME)
private Date updatedTime;
#Field("bookletSignups")
#DBRef
private List<BookletSignUp> bookletSignups;
#Field("eventSignups")
#DBRef
private List<EventSignUp> eventSignups;
#Field("infoSignups")
#DBRef
private List<InfoSignUp> infoSignups;
#Field("webinarSignups")
#DBRef
private List<WebinarSignUp> webinarSignups;
So im trying to retrieve User objects that includes a bookletSignups object with the passing bookletId value. But the result is empty. What has gone wrong here?
I would say you need to modify your query to looks like this:
#Repository
public interface UserRepository extends MongoRepository<User,String> {
#org.springframework.data.mongodb.repository.Query(value = "{ 'bookletSignups': { $elemMatch: { 'bookletId' : ?0 } }}")
List<User> findByBookletId(String id);
}
If you check MongoDB documentation for $elemMatch, link to documentation, you can see that basically in $elemMatch operator you are using field in embedded object, so you don't need to specify again name of array in which you are searching for objects.
Everytime I map an array of JSON object into POJOs, I always get the last object.
The JSON is an array of objects, and I have a POJO associate with each object of JSON. But when I mapped into an array of POJO, I always get 1 object.
Here is the JSON :
[ {
"event" : {
"Id" : "123456789",
"Name" : "An event1 name"
},
"branch" : {
"Id" : "112233445566",
"Name" : "A branch1 name",
},
"user" : {
"Id" : "9988776655",
"FirstName" : "John",
"LastName" : "Doe",
},
"event" : {
"Id" : "abcdef",
"Name" : "An event2 name"
},
"branch" : {
"Id" : "885522",
"Name" : "A branch2 name",
},
"user" : {
"Id" : "996633",
"FirstName" : "Jane",
"LastName" : "Doe",
}
} ]
The POJOs:
public class RdV {
private Event event;
private Branch branch;
private User user;
public Event getEvent() {
return event;
}
public void setEvent(Event event) {
this.event = event;
}
public Branch getBranch() {
return branch;
}
public void setBranch(Branch branch) {
this.branch= branch;
}
public User getUser() {
return user;
}
public void setUser(User user) {
this.user = user;
}
#Override
public String toString() {
return "RdV [\n"
+ event + "\n"
+ branch + "\n"
+ user + "\n"
+ "]";
}
}
public class Event {
private String id;
private String name;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name= name;
}
}
The other POJOS, Branch and User are similar to Event.
And when I use the following :
List<RdV> rdv = Arrays.asList(objectMapper.readValue(jsonString, RdV[].class));
all I got is just the last object ( the size of list is 1, instead of 2 ):
==> RdV [
Event {
id="abcdef",
name="An event2 name"
}
Branch {
id="885522",
name="A branch2 name"
}
User {
id="996633",
lastName="Doe",
firstName="Jane"
}
]
Any idea what went wrong the code ?
Thanks.
your JSON doesn't have two separate objects - just one with double properties of Branch, Event and User, you should change it to
[
{
"event": {
"Id": "123456789",
"Name": "An event1 name"
},
"branch": {
"Id": "112233445566",
"Name": "A branch1 name"
},
"user": {
"Id": "9988776655",
"FirstName": "John",
"LastName": "Doe"
}
},
{
"event": {
"Id": "abcdef",
"Name": "An event2 name"
},
"branch": {
"Id": "885522",
"Name": "A branch2 name"
},
"user": {
"Id": "996633",
"FirstName": "Jane",
"LastName": "Doe"
}
}
]
Akin to my earlier question, I'm trying to access data in MongoDB using Spring REST.
I have collections of simple Key-Value Pairs and can access those fine.
{
"_id" : ObjectId("5874ab4a19b38fb91fbb234f"),
"roID" : "7ed3f9a6-bb9b-4d16-8d1a-001b7ec40b51",
"Name" : "[REDACTED]"
}
The problem is, these objects are used in another collection that displays a relationship with properties between them, like this:
{
"_id" : ObjectId("5874ab4f19b38fb91fbb6180"),
"[OBJECT CATEGORY A]" : {
"_id" : ObjectId("5874ab4a19b38fb91fbb257b"),
"roID" : "72f8a8b5-71a7-40ac-b1ac-1ffc98a507ba",
"Name" : "[REDACTED]"
},
"[OBJECT CATEGORY B]" : {
"_id" : ObjectId("5874ab4b19b38fb91fbb32a3"),
"roID" : "919446ab-1898-419f-a704-e8c34985f945",
"Name" : "[REDACTED]"
},
"[RELATIONSHIP INFORMATION]" : [
{
"[PROPERTY A]" : [
{
"[VALUE A]" : 5.0
},
{
"[VALUE B]" : 0.0
}
]
},
Properties are somewhere between 8 and 20.
The definition of the first (plain) object in Java looks like this:
#Document(collection="OBJ")
public class Obj {
public Obj(){};
#Id
public String id;
#Field("roID")
public String roID;
#Field("Name")
public String name;
}
The repository class:
#RepositoryRestResource(collectionResourceRel = "OBJ", path = "OBJ")
public interface ObjRepo extends MongoRepository<Obj, String> {
List<Obj> findByName(#Param("name") String name);
}
The question is: how do I access the nested objects? I've tried using LinkedHashMap in place of the Strings for the complex collection, curl only returns "null" when I try to access them. I tried defining a class
public class BITS {
#Id
private String _id;
#Field("roID")
private String roID;
#Field("Name")
private String name;
public BITS(){}
public BITS(String _id,String roID, String name){
this._id = _id;
this.roID = roID;
this.name = name;
}
}
to access these objects, unsuccessfully.
Turns out the class approach was correct, just not well executed.
I've created a plain JSON Collection for testing purposes:
#Document(collection="JSON")
public class JSON {
#Id
public String id;
#Field("squares")
public Square square;
#Field("dots")
public Dot dot;
public JSON(){};
public JSON(String id, Square square,Dot dot){
this.id = id;
this.square = square;
this.dot = dot;
};
}
Square.java
public class Square {
private String id;
private int x;
private int y;
public Square(){};
public Square(String id,int x, int y){
this.id = id;
this.x = x;
this.y = y;
};
public Map<String, Integer> getSquare()
{
Map<String, Integer> res = new HashMap<>();
res.put("x", x);
res.put("y", y);
return res;
}
}
(Dot is the same, just for the test)
So it's just about remodeling the desired response exactly, despite it being in that format in the database already.
If anyone could point me to where I can remove the clutter from the response tho, that would be nice. Currently looks like this:
"_embedded" : {
"JSON" : [ {
"square" : null,
"dot" : {
"dot" : {
"x" : 4,
"y" : 3
}
},
"_links" : {
"self" : {
"href" : "http://localhost:8080/JSON/58ac466160fb39e5e8dc8b70"
},
"jSON" : {
"href" : "http://localhost:8080/JSON/58ac466160fb39e5e8dc8b70"
}
}
}, {
"square" : {
"square" : {
"x" : 12,
"y" : 2
}
},
"dot" : null,
"_links" : {
"self" : {
"href" : "http://localhost:8080/JSON/58ac468060fb39e5e8dc8b7e"
},
"jSON" : {
"href" : "http://localhost:8080/JSON/58ac468060fb39e5e8dc8b7e"
}
}
} ]
},
"_links" : {
"self" : {
"href" : "http://localhost:8080/JSON"
},
"profile" : {
"href" : "http://localhost:8080/profile/JSON"
}
},
"page" : {
"size" : 20,
"totalElements" : 2,
"totalPages" : 1,
"number" : 0
}
}
I have devised a JSON structure to represent a table with header columns plus table rows that looks like the following.
{
"header": [
{
"fieldType": "STRING",
"readOnly": true,
"headerValue": "name"
},
{
"fieldType": "STRING",
"readOnly": true,
"headerValue": "description"
}
],
"rows": [
[
{
"fieldValue" : "engine"
},
{
"fieldValue" : "this is an engine"
}
],
[
{
"fieldValue" : "engine"
},
{
"fieldValue" : "this is an engine"
}
],
[
{
"fieldValue" : "engine"
},
{
"fieldValue" : "this is an engine"
}
],
[
{
"fieldValue" : "engine"
},
{
"fieldValue" : "this is an engine"
}
]
]
}
A row is for example
[
{
"fieldValue" : "engine"
},
{
"fieldValue" : "this is an engine"
}
]
The number of entries in a row matches the number of header columns. So "engine" is the "name" column and "this is an engine" is the "description" column
When I use GSON to turn my POJO's into a JSON String the closest I have got to match this structure is:
{
"header": [
{
"fieldType": "STRING",
"readOnly": true,
"headerValue": "name"
},
{
"fieldType": "STRING",
"readOnly": true,
"headerValue": "description"
}
],
"rows": [
{
"fieldValues": [
"engine",
"this is an engine"
]
},
{
"fieldValues": [
"engine",
"this is an engine"
]
},
{
"fieldValues": [
"engine",
"this is an engine"
]
},
{
"fieldValues": [
"engine",
"this is an engine"
]
}
]
}
Here's the code I'm using to test
enum FieldType {
STRING,
BOOLEAN,
NUMBER,
PHOTO,
PHOTOLIST;
}
class SurveyFields {
private List<SurveyColumn> header;
private List<SurveyRow> rows;
public List<SurveyColumn> getHeader() {
return header;
}
public List<SurveyRow> getRows() {
return rows;
}
public void setHeader(List<SurveyColumn> header) {
this.header = header;
}
public void setRows(List<SurveyRow> rows) {
this.rows = rows;
}
}
class SurveyColumn {
private FieldType fieldType;
private boolean readOnly;
private String headerValue;
public static class Builder {
private FieldType fieldType;
private boolean readOnly;
private String headerValue;
public Builder withFieldType(FieldType fieldType) {
this.fieldType = fieldType;
return this;
}
public Builder withReadOnly(boolean readOnly) {
this.readOnly = readOnly;
return this;
}
public Builder withHeaderValue(String headerValue) {
this.headerValue = headerValue;
return this;
}
public SurveyColumn build() {
return new SurveyColumn(fieldType, readOnly, headerValue);
}
}
public SurveyColumn(FieldType fieldType, boolean readOnly, String headerValue) {
this.fieldType = fieldType;
this.readOnly = readOnly;
this.headerValue = headerValue;
}
}
class SurveyRow {
public static class Builder {
private String[] fieldValues;
public Builder withFieldValues(String[] fieldValues) {
this.fieldValues = fieldValues;
return this;
}
public SurveyRow build() {
return new SurveyRow(fieldValues);
}
}
private String[] fieldValues;
public SurveyRow(String[] fieldValues) {
this.fieldValues = fieldValues;
}
}
public class TestGson {
public static void main(String[] args) {
SurveyFields fields = new SurveyFields();
fields.setHeader(Arrays.asList(new SurveyColumn[] {
new SurveyColumn.Builder().withHeaderValue("name").withFieldType(FieldType.STRING).withReadOnly(true)
.build(),
new SurveyColumn.Builder().withHeaderValue("description").withFieldType(FieldType.STRING)
.withReadOnly(true).build() }));
fields.setRows(Arrays.asList(new SurveyRow[] {
new SurveyRow.Builder().withFieldValues(new String[] { "engine", "this is an engine" }).build(),
new SurveyRow.Builder().withFieldValues(new String[] { "engine", "this is an engine" }).build(),
new SurveyRow.Builder().withFieldValues(new String[] { "engine", "this is an engine" }).build(),
new SurveyRow.Builder().withFieldValues(new String[] { "engine", "this is an engine" }).build()
}));
Gson gson = new Gson();
System.out.println(gson.toJson(fields));
}
}
How can I structure my POJO's to match the expected JSON output?
If you get the JSON from a third party, this site might help you generate POJO from JSON.