JsonReader stops reading at the end of an array

Question

I'm writing a Spigot plugin for spawning crates. This JsonReader scans the treasure pool file for a specific setting that I request. Thing is, I didn't wanna copy the same while loop over and over again, so I just decided to make this.

It reads the first six tokens successfully, but it stops at token six, where the "max-axis" array stops. There isn't a comma there. It even reads it when I add a fourth number to the array, but stops at that number because there's no comma there. JsonReader.setLenient(true) is used, and JsonWriter.setLenient(true) is used for writing the file. I have tried setting the writer false.

The way this is written is weird, but it's all just for testing. No need to actually return values from the file right now.

PoolFile.scanDocument()

private Object scanDocument(JsonReader reader, Shell handleObj) {
    reader.setLenient(true);

    int retval = -2;
    try {
        JsonToken token = null; Object current = -5;

        while (reader.hasNext()) {
            token = reader.peek();
            //if (token == JsonToken.END_DOCUMENT) break;

            // Output while reading: 0 2 1 3 3 3
            switch(token) {
                case BEGIN_OBJECT:  reader.beginObject(); retval = 0; break;
                case BEGIN_ARRAY:   reader.beginArray(); retval = 1; break;
                case NAME:          current = reader.nextName(); retval = 2; break;
                case NUMBER:        current = reader.nextDouble(); retval = 3; break;
                case BOOLEAN:       current = reader.nextBoolean(); retval = 4; break;
                case STRING:        current = reader.nextString(); retval = 5; break;
                case END_ARRAY:     reader.endArray(); retval = 6; break;
                case END_OBJECT:    reader.endObject(); retval = 7; break;
                default:            reader.skipValue(); retval = -1;
            }

            handleObj.doWithJSONObject(token, retval);
        }
    } catch (IOException e) { retval = -1; e.printStackTrace(); }

    return retval;
}

defaultpool.json

{
    "max-axis": [
        50.0,
        -1.0,
        50.0 // It stops here.
    ],
    "pools": [
        {
            "label": "test",
            "items": {}
        }
    ]
}

EDIT If you'd like to see the application, visit the GitHub page. Source is located under skycrates/src/main

score 4 · Accepted Answer · answered Sep 10 '18 at 03:39

The problem is due to reader.hasNext(). This method is quite misleading when comparing to other Reader class. As per the method description

/** * Returns true if the current array or object has another element. */

So when you call reader.hasNext() after consuming all elements in the first array. It will return false and your loop end. To solve this, change the condition to while (reader.peek() != JsonToken.END_DOCUMENT) instead.

You are amazing! Thank you! – FlashDaggerX Sep 10 '18 at 08:31 — FlashDaggerX, Sep 10 '18 at 08:31

JsonReader stops reading at the end of an array

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