Avalara: What is a “DateTime” valid format for the json date?

Question

What is the correct JSON date format for Avalara? The following code:

 TransactionModel transaction = new TransactionBuilder(client, "COMPANY", DocumentType.SalesOrder, "myCompany.")
    .withDate(Calendar.getInstance().getTime())
    .withAddress(TransactionAddressType.SingleLocation, null, null, null, null, null, zipCode, "US")
    .withLine( new BigDecimal(100.0), new BigDecimal(1), "P0000000")
    .Create();

throws an exception that does not indicate the correct format:

com.google.gson.JsonSyntaxException: 2019-10-01
    at com.google.gson.DefaultDateTypeAdapter.deserializeToDate(DefaultDateTypeAdapter.java:107)
    at com.google.gson.DefaultDateTypeAdapter.deserialize(DefaultDateTypeAdapter.java:82)
    at com.google.gson.DefaultDateTypeAdapter.deserialize(DefaultDateTypeAdapter.java:35)
    at com.google.gson.TreeTypeAdapter.read(TreeTypeAdapter.java:58)
    at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:93)
    at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:172)
    at com.google.gson.Gson.fromJson(Gson.java:803)
    at com.google.gson.Gson.fromJson(Gson.java:768)
    at com.google.gson.Gson.fromJson(Gson.java:717)
    at net.avalara.avatax.rest.client.serializer.JsonSerializer.DeserializeObject(JsonSerializer.java:15)
    at net.avalara.avatax.rest.client.RestCall.call(RestCall.java:99)
    at net.avalara.avatax.rest.client.AvaTaxClient.createTransaction(AvaTaxClient.java:19174)
    at net.avalara.avatax.rest.client.TransactionBuilder.Create(TransactionBuilder.java:425)

Answer 1

When in doubt, read the source. It looks like com.google.gson.DefaultDateTypeAdapter has a couple default date formats that it will try to use in deserializeToDate . So make sure you are using one of those.

Most of the date formats are coming from java.text.DateFormat

Also check the source of AvaTax-REST-V2

If you have the source linked in your editor, then I recommend putting a breakpoint at a few places in the stack trace to see what's happening. One good candidate would be in deserializeToDate of course.

---

DefaultDateTypeAdapter.java

/**
 * List of 1 or more different date formats used for de-serialization attempts. The first of them is
 * used for serialization as well.
 */
private final List<DateFormat> dateFormats = new ArrayList<DateFormat>();

DefaultDateTypeAdapter(Class<? extends Date> dateType) {
    this.dateType = verifyDateType(dateType);
    dateFormats.add(DateFormat.getDateTimeInstance(DateFormat.DEFAULT, DateFormat.DEFAULT, Locale.US));
    if (!Locale.getDefault().equals(Locale.US)) {
        dateFormats.add(DateFormat.getDateTimeInstance(DateFormat.DEFAULT, DateFormat.DEFAULT));
    }
    if (JavaVersion.isJava9OrLater()) {
        dateFormats.add(PreJava9DateFormatProvider.getUSDateTimeFormat(DateFormat.DEFAULT, DateFormat.DEFAULT));
    }
}

DefaultDateTypeAdapter(Class<? extends Date> dateType, String datePattern) {
    this.dateType = verifyDateType(dateType);
    dateFormats.add(new SimpleDateFormat(datePattern, Locale.US));
    if (!Locale.getDefault().equals(Locale.US)) {
        dateFormats.add(new SimpleDateFormat(datePattern));
    }
}

DefaultDateTypeAdapter(Class<? extends Date> dateType, int style) {
    this.dateType = verifyDateType(dateType);
    dateFormats.add(DateFormat.getDateInstance(style, Locale.US));
    if (!Locale.getDefault().equals(Locale.US)) {
        dateFormats.add(DateFormat.getDateInstance(style));
    }
    if (JavaVersion.isJava9OrLater()) {
        dateFormats.add(PreJava9DateFormatProvider.getUSDateFormat(style));
    }
}

public DefaultDateTypeAdapter(int dateStyle, int timeStyle) {
    this(Date.class, dateStyle, timeStyle);
}

public DefaultDateTypeAdapter(Class<? extends Date> dateType, int dateStyle, int timeStyle) {
    this.dateType = verifyDateType(dateType);
    dateFormats.add(DateFormat.getDateTimeInstance(dateStyle, timeStyle, Locale.US));
    if (!Locale.getDefault().equals(Locale.US)) {
        dateFormats.add(DateFormat.getDateTimeInstance(dateStyle, timeStyle));
    }
    if (JavaVersion.isJava9OrLater()) {
        dateFormats.add(PreJava9DateFormatProvider.getUSDateTimeFormat(dateStyle, timeStyle));
    }
}

Answer 2

For anyone else who finds their way here, a more complete discussion is available on the Avalara developer forums: https://community.avalara.com/avalara/topics/error-parsing-date-jre-sdk

Short answer: Upgrade your dependency on gson, there's nothing wrong with your code. I moved to a more recent version and the error was fixed:

<dependency>
    <groupId>com.google.code.gson</groupId>
    <artifactId>gson</artifactId>
    <version>2.8.5</version>
</dependency>