String jsonStr = '[{"Id":"0015800001PTKzHAAX","Name":"test1" },{"Id":"0015800001PTKxpAAH","Name":"test2"}]';
        JSONParser parser = JSON.createParser(jsonStr);
        while (parser.nextToken() != null) {
            if (parser.getCurrentToken() == JSONToken.START_ARRAY) {
                while (parser.nextToken() != null) {
                    if (parser.getCurrentToken() == JSONToken.START_OBJECT) {
                        Contact acc = (Contact)parser.readValueAs(Contact.class);
                        system.debug('acc: ' + acc);
                    }
                }
            }
        }