parsing multi nested json with GSON

parsing multi nested json with GSON - java

I have to parse the json file into text file, Sample json file as below,
{
"link":"https://xxx.nt",
"liveChannels":[
{
"name":"Sony TV",
"id":1004,
"link":"https://xxx.nt",
"decryptionTicket":"https://xxxy.nt",
"viewLevel":"Too High",
"programs":
{
"totalItems":1,
"programs":[
{
"name":"Live or die",
"id":1000000000,
"catchUp":["FUN"],
"startOver":["Again"]
}
]
}
}
]
}
I have used GSON to parse the file by creating the below java classes.
Channel
LiveChannel
programs
subprograms
Channel.java
public class channel
{
String link = null;
ArrayList<liveChannels> liveChannels;
public String getLink() {
return link;
}
public void setLink(String link) {
this.link = link;
}
public ArrayList<liveChannels> getliveChannels() {
return liveChannels;
}
public void setliveChannels(ArrayList<liveChannels> liveChannels) {
this.liveChannels = liveChannels;
}
}
livechannel.java
public class liveChannels {
String name = null;
int id;
String link = null;
String decryptionTicket = null;
String viewLevel = null;
public void setName(String name) {
this.name = name;
}
public String getName() {
return name;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getLink() {
return link;
}
public void setLink(String link) {
this.link = link;
}
public String getDecryptionTicket() {
return decryptionTicket;
}
public void setDecryptionTicket(String decryptionTicket) {
this.decryptionTicket = decryptionTicket;
}
public String getViewLevel() {
return viewLevel;
}
public void setViewLevel(String viewLevel) {
this.viewLevel = viewLevel;
}
}
After this how to parse the logic from program onwards.
"programs":
{
"totalItems":1,
program.java
public class programs {
ArrayList<sub_programs> sub_programs;
int totalItems;
public int getTotalItems() {
return totalItems;
}
public void setTotalItems(int totalItems) {
this.totalItems = totalItems;
}
public ArrayList<sub_programs> getProgramsDetails() {
return sub_programs;
}
public void setProgramsDetails(ArrayList<sub_programs> sub_programs) {
this.sub_programs = sub_programs;
}
}
sub_program.java
public class sub_programs {
String name = null;
int id;
String catchUp = null;
String startOver = null;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getCatchUp() {
return catchUp;
}
public void setCatchUp(String catchUp) {
this.catchUp = catchUp;
}
public String getStartOver() {
return startOver;
}
public void setStartOver(String startOver) {
this.startOver = startOver;
}
}
and main look like below,
public static void main(String[] args) throws IOException
{
Gson gson = new Gson();
String contents = FileUtils.readFileToString(
new File("C:/sample.json"), "UTF-8");
channel channelHeader = gson.fromJson(contents, channel.class);
System.out.println("Channel Information --->");
System.out.println("Channel Link: " + channelHeader.getLink());
ArrayList<liveChannels> liveChannels = channelHeader.getliveChannels();
for (int i = 0; i < liveChannels.size(); i++) {
System.out.println("liveChannels Detail --->");
liveChannels liveChannelsDetail = liveChannels.get(i);
System.out.println("Channel Name : " + liveChannelsDetail.getName());
System.out.println("Channel ID : " + liveChannelsDetail.getId());
System.out.println("Channel Description Ticket: " + liveChannelsDetail.getDecryptionTicket());
System.out.println("Channel View Level : " + liveChannelsDetail.getViewLevel());
}
}
}
Could anyone please help to get the logic to parse the program from livechannel class onwards.
As programs is not an array list , What else would be an other way around to get the values.

You are missing the programs object in your liveChannels class.
public class liveChannels {
String name = null;
int id;
String link = null;
String decryptionTicket = null;
String viewLevel = null;
programs programs;
public void setPrograms (programs programs) {
this.programs = programs;
}
public programs getPrograms() {
return programs;
}
...
}
And then in your programs class, you will need to rename the sub_programs field to programs
public class programs {
ArrayList<sub_programs> programs;
...
}
As an aside, your class naming does not follow Java standards and is considered bad practice. Your classes should be named as such:
Channel
LiveChannel
Program
SubProgram
Note that this will not affect GSON's ability to parse your documents as GSON cares more about the property name than it does the actual class name of the field.

Related

How do I leverage a json mapping file to convert from one pojo to another pojo?

I have two POJOs (Person.java and User.java) that contain similar information. See below:
public class Person {
private String first_name;
private String last_name;
private Integer age;
private Integer weight;
private Integer height;
public String getFirst_name() {
return first_name;
}
public void setFirst_name(String first_name) {
this.first_name = first_name;
}
public String getLast_name() {
return last_name;
}
public void setLast_name(String last_name) {
this.last_name = last_name;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
public Integer getWeight() {
return weight;
}
public void setWeight(Integer weight) {
this.weight = weight;
}
public Integer getHeight() {
return height;
}
public void setHeight(Integer height) {
this.height = height;
}
}
public class User {
private String name_first;
private String name_last;
private Integer my_age;
private Integer my_weight;
private String social_security;
public String getName_first() {
return name_first;
}
public void setName_first(String name_first) {
this.name_first = name_first;
}
public String getName_last() {
return name_last;
}
public void setName_last(String name_last) {
this.name_last = name_last;
}
public Integer getMy_age() {
return my_age;
}
public void setMy_age(Integer my_age) {
this.my_age = my_age;
}
public Integer getMy_weight() {
return my_weight;
}
public void setMy_weight(Integer my_weight) {
this.my_weight = my_weight;
}
public String getSocial_security() {
return social_security;
}
public void setSocial_security(String social_security) {
this.social_security = social_security;
}
}
I have defined a mapping.json file as shown below using GSON.
{
"columnMap": [
{
"userColumn": "name_first",
"personColumn": "first_name"
},
{
"userColumn": "last_first",
"personColumn": "first_last"
},
{
"userColumn": "my_age",
"personColumn": "age"
},
{
"userColumn": "my_weight",
"personColumn": "weight"
}
]
}
public class Mapping {
private ArrayList<Pair> columnMap;
public Mapping(){
columnMap = new ArrayList<>();
}
public ArrayList<Pair> getColumnMap() {
return columnMap;
}
public void setColumnMap(ArrayList<Pair> columnMap) {
this.columnMap = columnMap;
}
}
I am writing a utility class helper function that converts between a Person and User object the mapped pairs.
public class Pair {
private String userColumn;
private String personColumn;
public String getUserColumn() {
return userColumn;
}
public void setUserColumn(String userColumn) {
this.userColumn = userColumn;
}
public String getPersonColumn() {
return personColumn;
}
public void setPersonColumn(String personColumn) {
this.personColumn = personColumn;
}
public static void main(String args[]){
}
}
My question is below:
As you can see the returnVal object is being set by me (the programmer) to convert from a User POJO to a Person POJO. How do I leverage the pre-defined mapping.json to do this? The reason I am asking is in the future, the mapping.json file may change (maybe the weight mapping no longer exists). So I am trying to avoid re-programming this Utility.userToPerson() function. How can I achieve this? I am thinking Java reflection is the way to go, but I would like to hear back from the Java community.
public class Utility {
public static Person userToPerson(User u){
Person returnVal = new Person();
returnVal.setAge(u.getMy_age()); // <-- Question How do I leverage mapping.json here?
returnVal.setFirst_name(u.getName_first());
returnVal.setLast_name(u.getName_last());
returnVal.setWeight(u.getMy_weight());
return returnVal;
}
}

You can introspect the beans (i.e. User and Person) for the field names and call corresponding getter from User to fetch the value. Later call corresponding setter in Person.
Here I have taken userToPersonFieldsMap for mapping the field, you can load mapping from JSON file and construct the map accordingly.
Important code section is the for loop, where it dynamically calls getter and setter and does the job.
import java.beans.IntrospectionException;
import java.beans.PropertyDescriptor;
import java.lang.reflect.InvocationTargetException;
import java.util.HashMap;
import java.util.Map;
public class UserToPersonMapper {
public static void main(String[] args) throws IntrospectionException, InvocationTargetException, IllegalAccessException {
Map<String, String> userToPersonFieldsMap = new HashMap<>();
userToPersonFieldsMap.put("name_first", "first_name");
userToPersonFieldsMap.put("last_first", "first_last");
userToPersonFieldsMap.put("age", "personAge");
//existing user
User user = new User("Tony", "Stark", 20);
//new person - to be initialised with values from user
Person person = new Person();
for (Map.Entry<String, String> entry : userToPersonFieldsMap.entrySet()) {
Object userVal = new PropertyDescriptor(entry.getKey(), User.class).getReadMethod().invoke(user);
new PropertyDescriptor(entry.getValue(), Person.class).getWriteMethod().invoke(person, userVal);
}
System.out.println(user);
System.out.println(person);
}
}
class User {
private String name_first;
private String last_first;
private int age;
public User(String name_first, String last_first, int age) {
this.name_first = name_first;
this.last_first = last_first;
this.age = age;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getName_first() {
return name_first;
}
public String getLast_first() {
return last_first;
}
public void setName_first(String name_first) {
this.name_first = name_first;
}
public void setLast_first(String last_first) {
this.last_first = last_first;
}
#Override
public String toString() {
return "User{" +
"name_first='" + name_first + '\'' +
", last_first='" + last_first + '\'' +
", age=" + age +
'}';
}
}
class Person {
private String first_name;
private String first_last;
private int personAge;
public void setFirst_name(String first_name) {
this.first_name = first_name;
}
public void setFirst_last(String first_last) {
this.first_last = first_last;
}
public String getFirst_name() {
return first_name;
}
public String getFirst_last() {
return first_last;
}
public int getPersonAge() {
return personAge;
}
public void setPersonAge(int personAge) {
this.personAge = personAge;
}
#Override
public String toString() {
return "Person{" +
"first_name='" + first_name + '\'' +
", first_last='" + first_last + '\'' +
", personAge=" + personAge +
'}';
}
}
You can tweak and try it out this example to make it more align with your requirement.
Note:
This solution uses reflection.

Write arrayList< model class> into txt file using BufferedWriter

I'm trying to get the data from the arrayBundlePack after getting data from enqueue call, I'm trying to use BufferedWriter to the saved data in the arrayBundlePack & write in the txt file, but it just won't get the output I wanted.
I'm not sure if that's the way to output an arrayList model class.
Here's the code
private ArrayList<BundlePack> arrayBundlePack;
Call<BundlePackRepo> call = .............. // api content
call.enqueue(new Callback<BundlePackRepo>() {
#Override
public void onResponse(Call<BundlePackRepo> call, retrofit2.Response<BundlePackRepo> response) {
if (response.isSuccessful()) {
BundlePackRepo repos = response.body();
BundlePackRepo.bundlepacks[] bundlePacksarray;
bundlePacksarray = repos.getBundlePacks();
BundlePack bundlePack;
for (int a = 0; a < bundlePacksarray.length; a++) {
bundlePack = new BundlePack();
bundlePack.setPromotion_kit(bundlePacksarray[a].getPromotion_kit());
bundlePack.setStock_code(bundlePacksarray[a].getStock_code());
bundlePack.setIssue_ref(bundlePacksarray[a].getIssue_ref());
bundlePack.setQuantity(bundlePacksarray[a].getQuantity());
String sysMod = bundlePacksarray[a].getSys_mod();
String modifyDate = bundlePacksarray[a].getModify_dt();
try {
bundlePack.setSys_mod(df.parse(sysMod));
bundlePack.setModify_dt(df.parse(modifyDate));
} catch (java.text.ParseException e) {
e.printStackTrace();
}
bundlePack.setStatus(bundlePacksarray[a].getStatus());
arrayBundlePack.add(bundlePack);
//Trying to put out the data to text file
String filename = "bundlepack.txt";
File txtData = new File(getApplicationContext().getFilesDir(), filename);
FileWriter txtWriter = null;
try {
txtWriter = new FileWriter(txtData);
BufferedWriter fileWriter = new BufferedWriter(txtWriter);
for (BundlePack bdpack : arrayBundlePack) {
fileWriter.write(bdpack.toString());
fileWriter.newLine();
fileWriter.flush();
}
} catch (IOException e) {
e.printStackTrace();
}
}
BundlePack
#Entity
public class BundlePack{
#PrimaryKey(autoGenerate = true)
private int id;
#ColumnInfo(name = "promotion_kit")
private String promotion_kit;
#ColumnInfo(name = "stock_code")
private String stock_code;
#ColumnInfo(name = "issue_ref")
private String issue_ref;
#ColumnInfo(name = "quantity")
private Integer quantity;
#TypeConverters(DateConverter.class)
#ColumnInfo(name = "sys_mod")
private Date sys_mod;
#TypeConverters(DateConverter.class)
#ColumnInfo(name = "modify_dt")
private Date modify_dt;
#ColumnInfo(name = "status")
private String status;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getPromotion_kit() {
return promotion_kit;
}
public void setPromotion_kit(String promotion_kit) {
this.promotion_kit = promotion_kit;
}
public String getStock_code() {
return stock_code;
}
public void setStock_code(String stock_code) {
this.stock_code = stock_code;
}
public String getIssue_ref() {
return issue_ref;
}
public void setIssue_ref(String issue_ref) {
this.issue_ref = issue_ref;
}
public Integer getQuantity() {
return quantity;
}
public void setQuantity(Integer quantity) {
this.quantity = quantity;
}
public Date getSys_mod() {
return sys_mod;
}
public void setSys_mod(Date sys_mod) {
this.sys_mod = sys_mod;
}
public Date getModify_dt() {
return modify_dt;
}
public void setModify_dt(Date modify_dt) {
this.modify_dt = modify_dt;
}
public String getStatus() {
return status;
}
public void setStatus(String status) {
this.status = status;
}
#Override
public String toString() {
return "BundlePack{" +
"id=" + id +
", promotion_kit='" + promotion_kit + '\'' +
", stock_code='" + stock_code + '\'' +
", issue_ref='" + issue_ref + '\'' +
", quantity=" + quantity +
", sys_mod=" + sys_mod +
", modify_dt=" + modify_dt +
", status='" + status + '\'' +
'}';
}
}
BundlePackRepo
public class BundlePackRepo {
private String count;
private bundlepacks[] bundlepacks;
public String getCount() {
return count;
}
public void setCount(String count) {
this.count = count;
}
public bundlepacks[] getBundlePacks() {
return bundlepacks;
}
public void setBundlePacks(bundlepacks[] bundlePacks) {
this.bundlepacks = bundlePacks;
}
public static class bundlepacks {
#SerializedName("promotionkit")
private String promotion_kit;
#SerializedName("stock_code")
private String stock_code;
#SerializedName("iss_ref")
private String issue_ref;
#SerializedName("qty")
private int quantity;
#SerializedName("sys_mod")
private String sys_mod;
#SerializedName("modify_dt")
private String modify_dt;
#SerializedName("status")
private String status;
#SerializedName("id")
private String id;
public String getPromotion_kit() {
return promotion_kit;
}
public void setPromotion_kit(String promotion_kit) {
this.promotion_kit = promotion_kit;
}
public String getStock_code() {
return stock_code;
}
public void setStock_code(String stock_code) {
this.stock_code = stock_code;
}
public String getIssue_ref() {
return issue_ref;
}
public void setIssue_ref(String issue_ref) {
this.issue_ref = issue_ref;
}
public int getQuantity() {
return quantity;
}
public void setQuantity(int quantity) {
this.quantity = quantity;
}
public String getSys_mod() {
return sys_mod;
}
public void setSys_mod(String sys_mod) {
this.sys_mod = sys_mod;
}
public String getModify_dt() {
return modify_dt;
}
public void setModify_dt(String modify_dt) {
this.modify_dt = modify_dt;
}
public String getStatus() {
return status;
}
public void setStatus(String status) {
this.status = status;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
}
}

You are calling toString() to convert each bundlepack instance to a string for output. So you need to an override for toString to the bundlepack class. It needs to format the instance in the form that you need for your purposes.
Since you currently haven't overridden that method, your code is currently calling Object.toString() ... which only outputs the object's class name and hashcode.
Your IDE may well have a helper to generate a toString for a class, based on the fields of the class.

Read json list in java

Previously I was reading json data in the following format:
JSON
{
"CreationTime":"2018-01-12T12:32:31",
"Id":"08f81fd7-21f1-48ba-a991-08d559b88cc5",
"Operation":"AddedToGroup",
"RecordType":14,
"UserType":0,
"Version":1,
"Workload":"OneDrive",
"ClientIP":"115.186.129.229",
"UserId":"omaji7#emumbaa10.onmicrosoft.com",
"EventSource":"SharePoint",
"ItemType":"Web"
}
I am reading this json data from a kafka topic and doing some stream processing on it and passing it onto another topic. In processing I have created two json objects, send and received.
Using this code:
final StreamsBuilder builder = new StreamsBuilder();
KStream<String, String> source_o365_user_activity = builder.stream("o365_user_activity");
source_o365_user_activity.flatMapValues(new ValueMapper<String, Iterable<String>>() {
#Override
public Iterable<String> apply(String value) {
System.out.println("========> o365_user_activity_by_date Log: " + value);
ArrayList<String> keywords = new ArrayList<String>();
try {
JSONObject send = new JSONObject();
JSONObject received = new JSONObject(value);
send.put("current_date", getCurrentDate().toString()); // UTC TIME
send.put("activity_time", received.get("CreationTime")); // CONSTANTS FINAL STATIC(Topic Names, Cassandra keys)
send.put("user_id", received.get("UserId"));
send.put("operation_type", received.get("Operation"));
send.put("app_name", received.get("Workload"));
keywords.add(send.toString());
// apply regex to value and for each match add it to keywords
} catch (Exception e) {
// TODO: handle exception
System.err.println("Unable to convert to json");
e.printStackTrace();
}
return keywords;
}
}).to("o365_user_activity_by_date");
This was fairly simple. Now I have a json data with lists in them.
JSON
{
"CreationTime":"2017-12-27T07:47:46",
"Id":"10ee505b-90a4-4ac1-b96f-a6dbca939694",
"Operation":"Add member to role.",
"OrganizationId":"2f88f444-62da-4aae-b8af-8331a6915801",
"RecordType":8,
"ResultStatus":"success",
"UserKey":"10030000A656FE5B#emumbaa10.onmicrosoft.com",
"UserType":0,
"Version":1,
"Workload":"AzureActiveDirectory",
"ObjectId":"mustafa#emumbaa10.onmicrosoft.com",
"UserId":"omaji7#emumbaa10.onmicrosoft.com",
"AzureActiveDirectoryEventType":1,
"ExtendedProperties":[
{
"Name":"Role.ObjectID",
"Value":"b0f54661-2d74-4c50-afa3-1ec803f12efe"
},
{
"Name":"Role.DisplayName",
"Value":"Billing Administrator"
},
{
"Name":"Role.TemplateId",
"Value":"b0f54661-2d74-4c50-afa3-1ec803f12efe"
},
{
"Name":"Role.WellKnownObjectName",
"Value":"BillingAdmins"
}
],
"Actor":[
{
"ID":"omaji7#emumbaa10.onmicrosoft.com",
"Type":5
},
{
"ID":"10030000A656FE5B",
"Type":3
},
{
"ID":"User_d03ca514-adfa-4585-a8bd-7182a9a086c7",
"Type":2
}
],
"ActorContextId":"2f88f444-62da-4aae-b8af-8331a6915801",
"InterSystemsId":"6d402a5b-c5de-4d9f-a805-9371c109e55f",
"IntraSystemId":"a5568d01-f100-497a-b88b-c9731ff31248",
"Target":[
{
"ID":"User_8f77c311-3ea0-4146-9f7d-db21bd052d3d",
"Type":2
},
{
"ID":"mustafa#emumbaa10.onmicrosoft.com",
"Type":5
},
{
"ID":"1003BFFDA67CCA03",
"Type":3
}
],
"TargetContextId":"2f88f444-62da-4aae-b8af-8331a6915801"
}
How can I go about doing the same thing in my Stream processing?
I want to be able to read JSON data against some keys (including the list data keys).

Why not convert JSON to Object and then filter against using the field in Object?

Can't you do like this?
send.put("target_0_id", received.get("Target").getJSONObject(0).get("ID"));

You can use gson library and can convert the json to object and using getter and setter you can build your desired output JSON. You can also parse the input JSON to fetch the JSONArray details. Following is the code how you can do it using POJO.
Input class:
public class Input {
private String UserType;
private String TargetContextId;
private String RecordType;
private String Operation;
private String Workload;
private String UserId;
private String OrganizationId;
private String InterSystemsId;
private ExtendedProperties[] ExtendedProperties;
private String ActorContextId;
private String CreationTime;
private String IntraSystemId;
private Target[] Target;
private Actor[] Actor;
private String Id;
private String Version;
private String ResultStatus;
private String ObjectId;
private String AzureActiveDirectoryEventType;
private String UserKey;
public String getUserType ()
{
return UserType;
}
public void setUserType (String UserType)
{
this.UserType = UserType;
}
public String getTargetContextId ()
{
return TargetContextId;
}
public void setTargetContextId (String TargetContextId)
{
this.TargetContextId = TargetContextId;
}
public String getRecordType ()
{
return RecordType;
}
public void setRecordType (String RecordType)
{
this.RecordType = RecordType;
}
public String getOperation ()
{
return Operation;
}
public void setOperation (String Operation)
{
this.Operation = Operation;
}
public String getWorkload ()
{
return Workload;
}
public void setWorkload (String Workload)
{
this.Workload = Workload;
}
public String getUserId ()
{
return UserId;
}
public void setUserId (String UserId)
{
this.UserId = UserId;
}
public String getOrganizationId ()
{
return OrganizationId;
}
public void setOrganizationId (String OrganizationId)
{
this.OrganizationId = OrganizationId;
}
public String getInterSystemsId ()
{
return InterSystemsId;
}
public void setInterSystemsId (String InterSystemsId)
{
this.InterSystemsId = InterSystemsId;
}
public ExtendedProperties[] getExtendedProperties ()
{
return ExtendedProperties;
}
public void setExtendedProperties (ExtendedProperties[] ExtendedProperties)
{
this.ExtendedProperties = ExtendedProperties;
}
public String getActorContextId ()
{
return ActorContextId;
}
public void setActorContextId (String ActorContextId)
{
this.ActorContextId = ActorContextId;
}
public String getCreationTime ()
{
return CreationTime;
}
public void setCreationTime (String CreationTime)
{
this.CreationTime = CreationTime;
}
public String getIntraSystemId ()
{
return IntraSystemId;
}
public void setIntraSystemId (String IntraSystemId)
{
this.IntraSystemId = IntraSystemId;
}
public Target[] getTarget ()
{
return Target;
}
public void setTarget (Target[] Target)
{
this.Target = Target;
}
public Actor[] getActor ()
{
return Actor;
}
public void setActor (Actor[] Actor)
{
this.Actor = Actor;
}
public String getId ()
{
return Id;
}
public void setId (String Id)
{
this.Id = Id;
}
public String getVersion ()
{
return Version;
}
public void setVersion (String Version)
{
this.Version = Version;
}
public String getResultStatus ()
{
return ResultStatus;
}
public void setResultStatus (String ResultStatus)
{
this.ResultStatus = ResultStatus;
}
public String getObjectId ()
{
return ObjectId;
}
public void setObjectId (String ObjectId)
{
this.ObjectId = ObjectId;
}
public String getAzureActiveDirectoryEventType ()
{
return AzureActiveDirectoryEventType;
}
public void setAzureActiveDirectoryEventType (String AzureActiveDirectoryEventType)
{
this.AzureActiveDirectoryEventType = AzureActiveDirectoryEventType;
}
public String getUserKey ()
{
return UserKey;
}
public void setUserKey (String UserKey)
{
this.UserKey = UserKey;
}
#Override
public String toString()
{
return "ClassPojo [UserType = "+UserType+", TargetContextId = "+TargetContextId+", RecordType = "+RecordType+", Operation = "+Operation+", Workload = "+Workload+", UserId = "+UserId+", OrganizationId = "+OrganizationId+", InterSystemsId = "+InterSystemsId+", ExtendedProperties = "+ExtendedProperties+", ActorContextId = "+ActorContextId+", CreationTime = "+CreationTime+", IntraSystemId = "+IntraSystemId+", Target = "+Target+", Actor = "+Actor+", Id = "+Id+", Version = "+Version+", ResultStatus = "+ResultStatus+", ObjectId = "+ObjectId+", AzureActiveDirectoryEventType = "+AzureActiveDirectoryEventType+", UserKey = "+UserKey+"]";
}}
Target class:
public class Target {
private String Type;
private String ID;
public String getType() {
return Type;
}
public void setType(String Type) {
this.Type = Type;
}
public String getID() {
return ID;
}
public void setID(String ID) {
this.ID = ID;
}
#Override
public String toString() {
return "ClassPojo [Type = " + Type + ", ID = " + ID + "]";
}}
Actor class :
public class Actor {
private String Type;
private String ID;
public String getType() {
return Type;
}
public void setType(String Type) {
this.Type = Type;
}
public String getID() {
return ID;
}
public void setID(String ID) {
this.ID = ID;
}
#Override
public String toString() {
return "ClassPojo [Type = " + Type + ", ID = " + ID + "]";
}}
ExtendedProperties class :
public class ExtendedProperties {
private String Name;
private String Value;
public String getName() {
return Name;
}
public void setName(String Name) {
this.Name = Name;
}
public String getValue() {
return Value;
}
public void setValue(String Value) {
this.Value = Value;
}
#Override
public String toString() {
return "ClassPojo [Name = " + Name + ", Value = " + Value + "]";
}}
Main class :
public class Stack {
public static void main(String[] args) {
doIt();
}
private static void doIt() {
String received = "{\"CreationTime\":\"2017-12-27T07:47:46\",\"Id\":\"10ee505b-90a4-4ac1-b96f-a6dbca939694\",\"Operation\":\"Add member to role.\",\"OrganizationId\":\"2f88f444-62da-4aae-b8af-8331a6915801\",\"RecordType\":8,\"ResultStatus\":\"success\",\"UserKey\":\"10030000A656FE5B#emumbaa10.onmicrosoft.com\",\"UserType\":0,\"Version\":1,\"Workload\":\"AzureActiveDirectory\",\"ObjectId\":\"mustafa#emumbaa10.onmicrosoft.com\",\"UserId\":\"omaji7#emumbaa10.onmicrosoft.com\",\"AzureActiveDirectoryEventType\":1,\"ExtendedProperties\":[{\"Name\":\"Role.ObjectID\",\"Value\":\"b0f54661-2d74-4c50-afa3-1ec803f12efe\"},{\"Name\":\"Role.DisplayName\",\"Value\":\"Billing Administrator\"},{\"Name\":\"Role.TemplateId\",\"Value\":\"b0f54661-2d74-4c50-afa3-1ec803f12efe\"},{\"Name\":\"Role.WellKnownObjectName\",\"Value\":\"BillingAdmins\"}],\"Actor\":[{\"ID\":\"omaji7#emumbaa10.onmicrosoft.com\",\"Type\":5},{\"ID\":\"10030000A656FE5B\",\"Type\":3},{\"ID\":\"User_d03ca514-adfa-4585-a8bd-7182a9a086c7\",\"Type\":2}],\"ActorContextId\":\"2f88f444-62da-4aae-b8af-8331a6915801\",\"InterSystemsId\":\"6d402a5b-c5de-4d9f-a805-9371c109e55f\",\"IntraSystemId\":\"a5568d01-f100-497a-b88b-c9731ff31248\",\"Target\":[{\"ID\":\"User_8f77c311-3ea0-4146-9f7d-db21bd052d3d\",\"Type\":2},{\"ID\":\"mustafa#emumbaa10.onmicrosoft.com\",\"Type\":5},{\"ID\":\"1003BFFDA67CCA03\",\"Type\":3}],\"TargetContextId\":\"2f88f444-62da-4aae-b8af-8331a6915801\"}";
JSONObject send = new JSONObject();
Gson gson = new Gson();
Input inputObject = gson.fromJson(received, Input.class);
// you can add values here and customize the output JSON
send.put("userId", inputObject.getUserId());
send.put("Workload", inputObject.getWorkload());
// read Actor list
Actor[] arr = inputObject.getActor();
for (int i = 0; i < arr.length; i++) {
// write your logic here how you want to handle the Actor list
// values
System.out.println(arr[i].getID() + " : " + arr[i].getType());
}
// read ExtendedProperties list
ExtendedProperties[] extendedProperties = inputObject.getExtendedProperties();
for (int j = 0; j < extendedProperties.length; j++) {
// write your logic here how you want to handle the
// ExtendedProperties list values
System.out.println(extendedProperties[j].getName() + " : " + extendedProperties[j].getValue());
}
System.out.println("*************");
}}
alternate main class without using POJO. Here org.json library have been used to parse the input JSON.
public class Test {
public static void main(String[] args) {
doIt();
}
private static void doIt() {
String received = "{\"CreationTime\":\"2017-12-27T07:47:46\",\"Id\":\"10ee505b-90a4-4ac1-b96f-a6dbca939694\",\"Operation\":\"Add member to role.\",\"OrganizationId\":\"2f88f444-62da-4aae-b8af-8331a6915801\",\"RecordType\":8,\"ResultStatus\":\"success\",\"UserKey\":\"10030000A656FE5B#emumbaa10.onmicrosoft.com\",\"UserType\":0,\"Version\":1,\"Workload\":\"AzureActiveDirectory\",\"ObjectId\":\"mustafa#emumbaa10.onmicrosoft.com\",\"UserId\":\"omaji7#emumbaa10.onmicrosoft.com\",\"AzureActiveDirectoryEventType\":1,\"ExtendedProperties\":[{\"Name\":\"Role.ObjectID\",\"Value\":\"b0f54661-2d74-4c50-afa3-1ec803f12efe\"},{\"Name\":\"Role.DisplayName\",\"Value\":\"Billing Administrator\"},{\"Name\":\"Role.TemplateId\",\"Value\":\"b0f54661-2d74-4c50-afa3-1ec803f12efe\"},{\"Name\":\"Role.WellKnownObjectName\",\"Value\":\"BillingAdmins\"}],\"Actor\":[{\"ID\":\"omaji7#emumbaa10.onmicrosoft.com\",\"Type\":5},{\"ID\":\"10030000A656FE5B\",\"Type\":3},{\"ID\":\"User_d03ca514-adfa-4585-a8bd-7182a9a086c7\",\"Type\":2}],\"ActorContextId\":\"2f88f444-62da-4aae-b8af-8331a6915801\",\"InterSystemsId\":\"6d402a5b-c5de-4d9f-a805-9371c109e55f\",\"IntraSystemId\":\"a5568d01-f100-497a-b88b-c9731ff31248\",\"Target\":[{\"ID\":\"User_8f77c311-3ea0-4146-9f7d-db21bd052d3d\",\"Type\":2},{\"ID\":\"mustafa#emumbaa10.onmicrosoft.com\",\"Type\":5},{\"ID\":\"1003BFFDA67CCA03\",\"Type\":3}],\"TargetContextId\":\"2f88f444-62da-4aae-b8af-8331a6915801\"}";
JSONObject send = new JSONObject();
JSONObject input = new JSONObject(received);
// you can add values here and customize the output JSON
send.put("userId", input.getString("UserId"));
send.put("Workload", input.getString("Workload"));
// read Actor list
JSONArray actorArray = input.getJSONArray("Actor");
for (int i = 0; i < actorArray.length(); i++) {
// write your logic here how you want to handle the Actor list
// values
System.out.println(
actorArray.getJSONObject(i).getString("ID") + ":" + actorArray.getJSONObject(i).getInt("Type"));
}
// read ExtendedProperties list
JSONArray extendedProperties = input.getJSONArray("ExtendedProperties");
for (int j = 0; j < extendedProperties.length(); j++) {
// write your logic here how you want to handle the
// ExtendedProperties list values
System.out.println(extendedProperties.getJSONObject(j).getString("Name") + " : "
+ extendedProperties.getJSONObject(j).getString("Value"));
}
System.out.println("*************");
}}

JSON mapping to Java returning null value

I'm trying to map JSON to Java using gson.I was succesful in writing the logic but unsuccesful in getting the output.Below posted are my JSON and Java files.Any help would be highly appreciated.
This is the output i'm getting
value:null
Below posted is the code for .json files
{
"catitem": {
"id": "1.196289",
"src": "http://feeds.reuters.com/~r/reuters/MostRead/~3/PV-SzW7Pve0/story06.htm",
"orig_item_date": "Tuesday 16 June 2015 07:01:02 PM UTC",
"cat_id": "1",
"heding": "Putin says Russia beefing up nuclear arsenal",
"summary": "KUvdfbefb bngfb",
"body": {
"bpart": [
"KUBINKA,dvdvdvdvgbtgfdnhfbnrtdfbcv dbnfg"
]
}
}
}
Below posted is my .java file
public class offc {
public static void main(String[] args) {
JsonReader jr = null;
try {
jr = new JsonReader(new InputStreamReader(new FileInputStream(
"C:\\Users\\rishii\\IdeaProjects\\rishi\\src\\file3.json")));
} catch (Exception ex) {
ex.printStackTrace();
}
Doll s = new Doll();
Gson g = new Gson();
Doll sr1 = g.fromJson(jr, Doll.class);
System.out.println(sr1);
}
}
Below posted is the code for Doll.java
class Doll {
private catitem ct;
public void setCt(catitem ct) {
this.ct = ct;
}
public catitem getCt() {
return ct;
}
#Override
public String toString()
{
return "value:" + ct;
}
class catitem {
private String id;
private String src;
private String orig_item_date;
private String cat_id;
private String heding;
private String summary;
private body ber;
catitem(String id, String src, String orig_item_date, String cat_id, String heding,
String summary) {
this.id = id;
this.src = src;
this.orig_item_date = orig_item_date;
this.cat_id = cat_id;
this.heding = heding;
this.summary = summary;
}
public void setId(String id) {
this.id = id;
}
public String getId() {
return id;
}
public void setSrc(String src) {
this.src = src;
}
public String getSrc() {
return src;
}
public void setOrig_item_date(String Orig_item_date) {
this.orig_item_date = Orig_item_date;
}
public String getOrig_item_date() {
return getOrig_item_date();
}
public void setCat_id(String cat_id) {
this.cat_id = cat_id;
}
public String getCat_id() {
return cat_id;
}
public void setHeding(String heding) {
this.heding = heding;
}
public String getHeding() {
return heding;
}
public void setSummary(String summary) {
this.summary = summary;
}
public String getSummary() {
return summary;
}
public void setBer(body ber) {
this.ber = ber;
}
public body getBer() {
return ber;
}
#Override
public String toString() {
return "id:" + id + "cat_id" + cat_id + "summary" + summary + "orig_date"
+ orig_item_date + "heding" + heding;
}
}
class body {
private String bpart;
public void setBpart(String r) {
this.bpart = r;
}
public String getBpart() {
return bpart;
}
#Override
public String toString() {
return "hiii";
}
}
}

The issue is in class Doll, You have a field ct but in json catitem. Rename the field ct to catitem or if you are using Gson use #SerializedName("catitem") on filed ct and it will work.

java.lang.NullPointerException while reading value from json to java object

Here I am reading json value from youtube to java.
I am getting values properly except the thumbnail data while getting thumbnail object value i am getting java.lang.NullPointerException
public class JsonVideoDetais {
public static void main(String... args) {
BufferedReader reader = null;
StringBuilder buffer = null;
try {
String link = "https://gdata.youtube.com/feeds/api/videos/" + "aa_wFClyiVE" + "?v=2&alt=jsonc";
URL url = new URL(link);
reader = new BufferedReader(new InputStreamReader(url.openStream(), "UTF-8"));
buffer = new StringBuilder();
int read;
char[] chars = new char[1024];
while ((read = reader.read(chars)) != -1) {
buffer.append(chars, 0, read);
}
} catch (Exception e) {
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException ex) {
Logger.getLogger(JsonVideoDetais.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
videoDetails data;
data = new Gson().fromJson(buffer.toString(), videoDetails.class);
System.out.println(data.getData().getTitle());
System.out.println(data.getData().getTn().getHqDefault());
System.out.println(data.getData().getTn().getSqDefault());
}
}
class videoDetails {
private Data data;
public Data getData() {
return data;
}
public void setData(Data data) {
this.data = data;
}
public String toString() {
return String.format("data:%s", data);
}
}
class Data {
private String id;
private String title;
private String description;
private int duration;
private Thumbnail tn;
public Thumbnail getTn() {
return tn;
}
public void setTn(Thumbnail tn) {
this.tn = tn;
}
public int getDuration() {
return duration;
}
public void setDuration(int duration) {
this.duration = duration;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public String toString() {
return String.format("title:%s,id:%s,description:%s,tn:%s,duration:%d", title, id, description, tn, duration);
}
}
class Thumbnail {
private String sqDefault;
private String hqDefault;
public String getSqDefault() {
return sqDefault;
}
public void setSqDefault(String sqDefault) {
this.sqDefault = sqDefault;
}
public String getHqDefault() {
return hqDefault;
}
public void setHqDefault(String hqDefault) {
this.hqDefault = hqDefault;
}
public String toString() {
return String.format("sqDefault:%s,hqDefault:%s", hqDefault, sqDefault);
}
}
I am getting following exception
Exception in thread "main" java.lang.NullPointerException
at utility.JsonVideoDetais.main(JsonVideoDetais.java:52)
while calling
System.out.println(data.getData().getTn().getHqDefault());
System.out.println(data.getData().getTn().getSqDefault());
If you wll see this link. It is having value for sqDefault and hqDefault
I would like to fetch the value of sqDefault and hqDefault.
How to do this.

In your Data class, i created an object like this. I guess the Thumbnail object is getting set to thumbnail, tn is not working on my side too.
private Thumbnail thumbnail;// instead of tn
and the resultant output is : -
Blood Glucose Hindi - Dr. Anup, MD Teaches Series
https://i1.ytimg.com/vi/aa_wFClyiVE/hqdefault.jpg
https://i1.ytimg.com/vi/aa_wFClyiVE/default.jpg

Using debugger to find out which object is null is fastest way to solve your problem.
OR
Find the null return value with the following code:
System.out.println(data);
System.out.println(data.getData());
System.out.println(data.getData().getTn());
--The following text are newly added-----------------
Well, I have run your program on my laptop, and it seem that the json response of https://gdata.youtube.com/feeds/api/videos/aa_wFClyiVE?v=2&alt=jsonc#data/thumbnail/hqDefault contains no tn field at all. That's why you always got null value.

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