Use Jackson To Stream Parse an Array of Json Objects
Yes, you can achieve this sort of part-streaming-part-tree-model processing style using an ObjectMapper
:
ObjectMapper mapper = new ObjectMapper();
JsonParser parser = mapper.getFactory().createParser(new File(...));
if(parser.nextToken() != JsonToken.START_ARRAY) {
throw new IllegalStateException("Expected an array");
}
while(parser.nextToken() == JsonToken.START_OBJECT) {
// read everything from this START_OBJECT to the matching END_OBJECT
// and return it as a tree model ObjectNode
ObjectNode node = mapper.readTree(parser);
// do whatever you need to do with this object
}
parser.close();
What you are looking for is called Jackson Streaming API. Here is a code snippet using Jackson Streaming API that could help you to achieve what you need.
JsonFactory factory = new JsonFactory();
JsonParser parser = factory.createJsonParser(new File(yourPathToFile));
JsonToken token = parser.nextToken();
if (token == null) {
// return or throw exception
}
// the first token is supposed to be the start of array '['
if (!JsonToken.START_ARRAY.equals(token)) {
// return or throw exception
}
// iterate through the content of the array
while (true) {
token = parser.nextToken();
if (!JsonToken.START_OBJECT.equals(token)) {
break;
}
if (token == null) {
break;
}
// parse your objects by means of parser.getXxxValue() and/or other parser's methods
}