Sending integer values in response from node js server

Question

I have a node js server implementation and I would like to send some values to an Android (Java) client. The method of the node js server is as follows:

app.get('/GetValues*', function (request, response) {
    // Request needs to be a GET
    if (request.method == 'GET') {

        var username = request.query.account;
        var time_now = Date.now();

        var db = database('./database.db'); 
        var row_account = db.prepare('SELECT SCORE score, STARTED_STUDY_SERVER_MILLIS timestamp, DAYS_TOTAL days_total FROM ACCOUNTS WHERE NAME = ?').get(username);

        var score = row_account.score;
        var days_total = row_account.days_total;
        var days_count = time_now - row_account.timestamp;
        var minutes_count = time_now - row_account.timestamp;

        var statement = db.prepare("UPDATE ACCOUNTS SET DAYS_COUNT = ?, MINUTES_COUNT = ? WHERE ID = ?");
        statement.run(days_count,minutes_count,getAccountID(db, request.query.account));

        var row_usage = db.prepare('SELECT DURATION_ENABLED duration_enabled, DURATION_DISABLED duration_disabled FROM USAGE WHERE NAME = ?').get(username);
        var duration_enabled = row_usage.duration_enabled;
        var duration_disabled = row_usage.duration_disabled;
    }
});

I would like to send the values score (integer), days_total (integer), days_count (integer), minutes_count (long), duration_enabled (long), duration_disabled (long) to the client.

How can I send it to the client? I think response.send() only accepts strings. How can I parse the values in Java when received?

score 2 · Accepted Answer · answered Jun 05 '20 at 18:14

Since you need to send all those values at once, it's common to respond with a JSON in such a case. In express, you can send a JSON response using response.send() or response.json() like this:

app.get('/GetValues*', function (request, response) {
  // ... your db operations here, then
  response.json({
    score: score,
    days_total: days_total,
    days_count: days_count,
    minutes_count: minutes_count,
    duration_enabled: duration_enabled,
    duration_disabled: duration_disabled
  });
});

This will send a response with Content-Type: application/json and a JSON string in the body looking like this:

{"score":12,"days_total":12,"days_count":12,"minutes_count":12,"duration_enabled":12,"duration_disabled":12}

Then you just parse it in your Java code.

By the way, this line

if (request.method == 'GET') {

is unnecessary. Registering a handler via app.get(), express will only handle GET requests anyway.

Sending integer values in response from node js server

1 Answers1