使用 GSON JsonReader 读取一个简单的 JSON 文件

Question

I thought this would be simple but it keeps crashing with InvocationTargetException at reader.hasNext() .

    File jsonInputFile = new File(root + "/dicts/phrases.json");
    JsonReader reader = new JsonReader(new FileReader(jsonInputFile));
    while (reader.hasNext()) {
        System.out.println(reader.nextName());
    }

What exactly is wrong with this? The while loop just goes on forever despite the json file only have one line.

Answer 1

Since it seems to be reading the JSON and it is encountering a BEGIN_TOKEN rather than JsonToken.NAME type

Could you try the below:

           while (jsonReader.hasNext()) 
            {
                JsonToken nextToken = jsonReader.peek();
                 
                if (JsonToken.BEGIN_OBJECT.equals(nextToken)) {
 
                    jsonReader.beginObject();
 
                } else if (JsonToken.NAME.equals(nextToken)) {
 
                    String name = jsonReader.nextName();
                    System.out.println("Token KEY >>>> " + name);
 
                } else if (JsonToken.STRING.equals(nextToken)) {
 
                    String value = jsonReader.nextString();
                    System.out.println("Token Value >>>> " + value);
 
                } else if (JsonToken.NUMBER.equals(nextToken)) {
 
                    long value = jsonReader.nextLong();
                    System.out.println("Token Value >>>> " + value);
 
                } else if (JsonToken.NULL.equals(nextToken)) {
 
                    jsonReader.nextNull();
                    System.out.println("Token Value >>>> null");
                     
                } else if (JsonToken.END_OBJECT.equals(nextToken)) {
 
                    jsonReader.endObject();
 
                }
            }