String[] array length isnt equal to the actual number of elements inside it

Question

I have a big project im working on, there is a piece of code where i get 2 arrays of String from an http post request on my server using spring and hibernate (json format), when i print the arrays size i get 1 in return, but at the same time i have (as i should/want/expect) 2 elements inside it so when i iterate over the array with the expected length i get an "array out of bound exception" and that's really weird imo.

ps - this problem repeats itself in other places as well, maybe its has something to do with hibernate/spring?.

output:

deviceAaddr - size = 1, [0022C01504D3,0022C015050F]
devicePass - size = 1, [HOMI26,HOMI26]

json:

{"deviceAddr":["0022C01504D3,0022C015050F"],"devicePass":["HOMI26,HOMI26"],"deviceCount":2,"version":"MU18"}

code:

public class AddBatchObject {

    private String[] deviceAddr;

    public String[] getDeviceAddr() {
        return deviceAddr;
    }

    @Override
    public String toString() {
        String batch = "";
        if (deviceAddr != null){
           batch += "deviceAaddr - " + "size = " + deviceAddr.length + ", "  
           + Arrays.asList(deviceAddr).toString() + "\n";
        }
        if (devicePass != null){
           batch += "devicePass - " + "size = " + devicePass.length + ", " +
               Arrays.asList(devicePass).toString() + "\n";
        }
        return batch;
    }

}

rest controller:

@RequestMapping(value = "/add/mac",method = RequestMethod.POST, produces =     "application/json")
public @ResponseBody Object addMac(@RequestBody AddBatchObject addBatchObject, HttpServletRequest request) throws AuthenticationException{
    LoggerUtils.getLogger().info("addMac");
    return AdminAddMac.adminAddMac(addBatchObject,request);
}

Edit: as jtahlborn and Joe answered the json data was incorrect: ["0022C01504D3,0022C015050F"] is a single element array. a two element array would be ["0022C01504D3","0022C015050F"].

Answer 1

The output is correct. Your JSON contains one string that has a comma in it, rather than two distinct strings.

The JSON you probably want is:

{"deviceAddr":["0022C01504D3","0022C015050F"],"devicePass":["HOMI26","HOMI26"],"deviceCount":2,"version":"MU18"}

Answer 2

The json string is proper json with 4 key-value pairs. You can put it in a file data.txt

{
    "deviceAddr": ["0022C01504D3,0022C015050F"],
    "devicePass": ["HOMI26,HOMI26"],
    "deviceCount": 2,
    "version": "MU18"
}

and read it with jackson

import com.fasterxml.jackson.core.JsonFactory;
import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import java.util.Map;

public class Main {
    public static void main(String[] args) throws JsonParseException, IOException {
        JsonFactory jsonFactory = new JsonFactory();
        JsonParser jp = jsonFactory.createJsonParser(new File("data.txt"));
        jp.setCodec(new ObjectMapper());
        JsonNode jsonNode = jp.readValueAsTree();
        readJsonData(jsonNode);
    }
    static void readJsonData(JsonNode jsonNode) {
        Iterator<Map.Entry<String, JsonNode>> ite = jsonNode.fields();
        while(ite.hasNext()){
            Map.Entry<String, JsonNode> entry = ite.next();
            if(entry.getValue().isObject()) {
                readJsonData(entry.getValue());
            } else {
                System.out.println("key:"+entry.getKey()+", value:"+entry.getValue());
            }
        }
    }
}

output

key:deviceAddr, value:["0022C01504D3,0022C015050F"]
key:devicePass, value:["HOMI26,HOMI26"]
key:deviceCount, value:2
key:version, value:"MU18"

I hope this will help you.