Exception in thread "main" java.lang.NoClassDefFoundError: com/fasterxml/jackson/annotation/JsonAutoDetect Error when trying to convert json to POJO

Question

I need to convert a json to a POJO, I have decided to go for the JACKSON library for that, I have added jackson-databind-2.2.3.jar and jackson-core-2.0.6.jar to my path and then have created the following classes:

1- Data-binding class :

package Distributed;  import java.io.IOException; import java.net.MalformedURLException; import java.net.URL; import com.fasterxml.jackson.core.JsonParseException; import com.fasterxml.jackson.databind.DeserializationFeature; import com.fasterxml.jackson.databind.JsonMappingException; import com.fasterxml.jackson.databind.ObjectMapper;  public class DataBinding {   public static void main(String[] args) throws JsonParseException, JsonMappingException, MalformedURLException, IOException {         String url = "http://frstmwarwebsrv.orsyptst.com:9000/duobject?searchString=TSK(ZTA010OU05)(000)&filtercheck=nameSWF&p.index=0&p.size=8";         ObjectMapper mapper = new ObjectMapper();         mapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);         DuObject duobject = mapper.readValue(new URL(url), DuObject.class);         Dataset[] datasets = duobject.getDataset();         for (Dataset dataset : datasets) {             System.out.println(dataset.getName());         }     }   } 

2- Dataset class :

package Distributed;  import java.util.HashMap; import java.util.Map;    public class Dataset {  private String id, name; private Map<String , Object> otherProperties = new HashMap<String , Object>();    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; }  public Object get(String name) {     return otherProperties.get(name); }  } 

3- DuObject class :

package Distributed;  public class DuObject {  private String name; public String getName() {     return name; } public void setName(String name) {     this.name = name; } public Dataset[] getDataset() {     return dataset; } public void setDataset(Dataset[] dataset) {     this.dataset = dataset; } private Dataset[] dataset;  } 

Here is my json object when launching teh URL used :

 { "facets": { "application": [   {     "name": "u_",     "distribution": 2   } ], "node": [   {     "name": "frstlwardu03_05",     "distribution": 2   } ], "area": [   {     "name": "x",     "distribution": 2   } ], "company": [   {     "name": "war001",     "distribution": 2   } ]  }, "duObjects": [ {   "id": "TASK|TSK(ZTA010OU05)(000)|ZECPFICO00",   "name": "TSK(ZTA010OU05)(000)",   "mu": "ZECPFICO00",   "label": "",   "uprocHeader": "ZTA010OU05|000",   "uprocHeaderLabel": "Uproc Tech Planif ne pas supprimer tous les jours f\u00c3\u00a9ri\u00c3\u00a9s",   "uprocHeaderType": "CL_INT",   "domain": "I",   "domainLabel": "Internal Activities",   "application": "U_",   "applicationLabel": "DU",   "highlightResult": {     "name": "name",     "word": "TSK"   } }, {   "id": "TASK|TSK(ZTA010OU05)(000)|ZECPSDA000",   "name": "TSK(ZTA010OU05)(000)",   "mu": "ZECPSDA000",   "label": "",   "uprocHeader": "ZTA010OU05|000",   "uprocHeaderLabel": "Uproc Tech Planif ne pas supprimer tous les jours f\u00c3\u00a9ri\u00c3\u00a9s",   "uprocHeaderType": "CL_INT",   "domain": "I",   "domainLabel": "Internal Activities",   "application": "U_",   "applicationLabel": "DU",   "highlightResult": {     "name": "name",     "word": "TSK"   } } ], "totalCount": 2, "pageSize": 10, "pageCurrent": 1, "pageNb": 1 } 

What I want to do is to get DuObject.name and store it in a DataSet table; however when I run Databinding class I got the following error :

Exception in thread "main" java.lang.NoClassDefFoundError:     com/fasterxml/jackson/annotation/JsonAutoDetect at com.fasterxml.jackson.databind.introspect.VisibilityChecker$Std.<clinit>  (VisibilityChecker.java:172) at com.fasterxml.jackson.databind.ObjectMapper.<clinit>(ObjectMapper.java:193) at Distributed.DataBinding.main(DataBinding.java:16)   Caused by: java.lang.ClassNotFoundException:   com.fasterxml.jackson.annotation.JsonAutoDetect at java.net.URLClassLoader$1.run(Unknown Source) at java.net.URLClassLoader$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) ... 3 more 

I am a newbie to jackson livbrary and I have no clue why I am having this error.

Thanks in advance for your help.

After adding the annotation jar I am facing the following error :

Exception in thread "main" java.lang.NoSuchMethodError:      com.fasterxml.jackson.core.JsonFactory.createParser(Ljava/net/URL;)Lcom/fasterxml/jackson/core/JsonParser; at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:2011) at Distributed.DataBinding.main(DataBinding.java:18) 

I have changed the three JARS to 2.1.2 version and the error I am getting now is :

    Exception in thread "main" java.lang.NullPointerException at Distributed.DataBinding.main(DataBinding.java:21) 

In fact the Dataset table is returning null, any idea why the data set doese not contain the json name field?

Answer 1

You have to add one jar : jackson-annotations-2.1.2.jar

You can download it from here

Edit:

Also , since you have array in your json it needs to be traversed :

    ObjectMapper mapper = new ObjectMapper();     mapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);     JsonNode node = mapper.readTree(new URL(url));     node = node.get("duObjects");      TypeReference<List<Dataset>> typeRef = new TypeReference<List<Dataset>>() {     };     List<Dataset> list = mapper.readValue(node.traverse(), typeRef);     for (int i = 0; i < list.size(); i++) {         Dataset dataSet = list.get(i);         System.out.println(dataSet.getName());     }