Jackson cannot access com.fasterxml.jackson.core.ObjectCodec

Question

This question is a follow up to this one. I can't seem to be able to access the jackson library in the following code:

import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.ObjectReader;
import com.fasterxml.jackson.databind.ObjectWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class ServerConfiguration {
    public String info = null;
    public String idlURL = null;
    public String idlContents = null;
    public List<ServerInfo> servers = new ArrayList<>();

    public final void clear() {
        info = null;
        idlURL = null;
        idlContents = null;
        if (servers != null)
            servers.clear();
    }

    private final static ObjectReader jsonReader;
    private final static ObjectWriter jsonWriter;

    static {
        ObjectMapper mapper = new ObjectMapper();
        mapper.configure(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY, true); // <== Error:(52, 15) java: cannot access com.fasterxml.jackson.core.JsonGenerator class file for com.fasterxml.jackson.core.JsonGenerator not found
        //mapper.configure(SerializationFeature.WRITE_SINGLE_ELEM_ARRAYS_UNWRAPPED, true);
        jsonWriter = mapper.writer();
        jsonReader = mapper.reader(ServerConfiguration.class);
    }

    public static ServerConfiguration fromJson(String json) throws IOException {
        return jsonReader.<ServerConfiguration>readValue(json); // <== Error:(59, 26) java: cannot access com.fasterxml.jackson.core.JsonProcessingException class file for com.fasterxml.jackson.core.JsonProcessingException not found
    }

    public String toJson() throws IOException {
        return jsonWriter.writeValueAsString(this);
    }

}

eventhough the jar files are in the classpath(autocomplete shows the method declaration in Intellij).

What am I missing?

In my case the reason was that I had two different versions of Jackson libraries in the classpath. — Leukipp, Jan 07 '16 at 22:26

score 40 · Answer 1 · answered Mar 09 '16 at 09:36

40

When I had this problem I had the jackson-annotations and jackson-databind jars in my classpath, but not jackson-core.

Adding jackson-core to the classpath solved it for me.

answered Mar 09 '16 at 09:36

gregn3

1,728
2
19
27

2

If you're using Maven, also make sure that you use the correct `` value. This tells maven when and in some cases how it should resolve dependencies. Available values are `compile`, `provided`, `runtime`, `test`, `system` and `import`, you can read more about what they do here: http://stackoverflow.com/a/29230903/2804473 – Simon Cedergren Malmqvist May 24 '16 at 07:29
Adding this to the pom.xml fixed for me. Thanks for sharing your finding, this is based on that.: com.fasterxml.jackson.core jackson-core – SydMK Jul 04 '23 at 05:17

score 16 · Answer 2 · edited Nov 08 '19 at 15:05

16

I was having a similar issue, it turned out to be an IntelliJ issue.

This helped me to resolve the issue:

Try File > Invalidate Caches > Invalidate and Restart.

If it doesn't help, delete .idea directory and reimport from pom/gradle build file.

edited Nov 08 '19 at 15:05

Corentin Pane

4,794
1
12
29

answered Nov 07 '19 at 22:47

Ayush Jaiswal

161
1
3

score 5 · Answer 3 · answered Nov 30 '20 at 18:29

Also double check that all your Jackson dependencies use the same version like below :

implementation 'com.fasterxml.jackson.core:jackson-core:2.10.1'
implementation 'com.fasterxml.jackson.core:jackson-annotations:2.10.1'
implementation 'com.fasterxml.jackson.dataformat:jackson-dataformat-xml:2.10.1'
implementation 'com.fasterxml.jackson.module:jackson-module-kotlin:2.10.1'

I previously had jackson-core:2.11.0 and this was the issue.

score 2 · Answer 4 · answered Mar 23 '21 at 10:57

I also encountered this kind of error: Cannot access com.fasterxml.jackson.core.TreeNode

My first version of the maven POM contained:

jackson-annotations
jackson-databind

It was working fine until I wanted to add jackson-core for unit tests. I added it with the test scope and the error appeared. After some investigation, I found out that to make it working, I had to remove the test scope, otherwise this error appears. If someone has an explanation I would be interested :)

score 0 · Answer 5 · answered Nov 13 '17 at 18:08

0

I had also encountered the same problem, turns out, I had "jackson-core-asl.jar" instead of "jackson-core.jar"

So, check whether you have this jar-file in your classpath. -> https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-core

answered Nov 13 '17 at 18:08

Yash P Shah

779
11
15

score 0 · Answer 6 · edited Mar 06 '23 at 17:56

0

1 go to the .m2/repository and delete the conflicting files

2 mvn -U clean install

edited Mar 06 '23 at 17:56

Roshin Raphel

2,612
4
22
40

answered Mar 02 '23 at 08:56

Simran Chawla

1
1

Jackson cannot access com.fasterxml.jackson.core.ObjectCodec

6 Answers6

Linked