Java – Convert Json date to java date

datetimegsonjavajson

My json respons contains a CreatedOn Date:

{
"CreatedOn" : "\/Date(1406192939581)\/"
}

I need to convert CreatedOn to a simple date format and count the days of difference from CreatedOn Date to Present Date.

When I debug the below code string CreatedOn showing a null value. How come?

JSONObject store = new JSONObject(response);

if (response.contains("CreatedOn"))
{
    String CreatedOn = store.getString("CreatedOn");
}

Best Solution

JSONObject store = new JSONObject(response);
if(store.has("CreatedOn")) {
  Timestamp stamp = new Timestamp(store.getLong("CreatedOn"));
  Date date = new Date(stamp.getTime());
  System.out.println(date);
}

JSONObject store = new JSONObject(response);
if(store.has("CreatedOn")) {
Integer datetimestamp = Integer.parseInt(store.getString("CreatedOn").replaceAll("\\D", ""));
 Date date = new Date(datetimestamp);
 DateFormat formatter = new SimpleDateFormat("HH:mm:ss:SSS");
 String dateFormatted = formatter.format(date);
}

consider using JSON methods instead of contains. JSON has "has()" which validate if key exists.

You should also make sure that you try {} catch {} the String first, to make sure its valid JSON.

Update:

Your Value is /Date(1406192939581)/

which means it must be formatted first. Get it by parsing the string with

Integer datetimestamp = Integer.parseInt(store.getString("CreatedOn").replaceAll("\\D", ""));

Related Solutions

Java – Is Java “pass-by-reference” or “pass-by-value”

Java is always pass-by-value. Unfortunately, when we deal with objects we are really dealing with object-handles called references which are passed-by-value as well. This terminology and semantics easily confuse many beginners.

It goes like this:

public static void main(String[] args) {
    Dog aDog = new Dog("Max");
    Dog oldDog = aDog;

    // we pass the object to foo
    foo(aDog);
    // aDog variable is still pointing to the "Max" dog when foo(...) returns
    aDog.getName().equals("Max"); // true
    aDog.getName().equals("Fifi"); // false
    aDog == oldDog; // true
}

public static void foo(Dog d) {
    d.getName().equals("Max"); // true
    // change d inside of foo() to point to a new Dog instance "Fifi"
    d = new Dog("Fifi");
    d.getName().equals("Fifi"); // true
}

In the example above aDog.getName() will still return "Max". The value aDog within main is not changed in the function foo with the Dog "Fifi" as the object reference is passed by value. If it were passed by reference, then the aDog.getName() in main would return "Fifi" after the call to foo.

Likewise:

public static void main(String[] args) {
    Dog aDog = new Dog("Max");
    Dog oldDog = aDog;

    foo(aDog);
    // when foo(...) returns, the name of the dog has been changed to "Fifi"
    aDog.getName().equals("Fifi"); // true
    // but it is still the same dog:
    aDog == oldDog; // true
}

public static void foo(Dog d) {
    d.getName().equals("Max"); // true
    // this changes the name of d to be "Fifi"
    d.setName("Fifi");
}

In the above example, Fifi is the dog's name after call to foo(aDog) because the object's name was set inside of foo(...). Any operations that foo performs on d are such that, for all practical purposes, they are performed on aDog, but it is not possible to change the value of the variable aDog itself.

For more information on pass by reference and pass by value, consult the following SO answer: https://stackoverflow.com/a/430958/6005228. This explains more thoroughly the semantics and history behind the two and also explains why Java and many other modern languages appear to do both in certain cases.

Jquery – How to format a Microsoft JSON date

eval() is not necessary. This will work fine:

var date = new Date(parseInt(jsonDate.substr(6)));

The substr() function takes out the /Date( part, and the parseInt() function gets the integer and ignores the )/ at the end. The resulting number is passed into the Date constructor.

I have intentionally left out the radix (the 2nd argument to parseInt); see my comment below.

Also, I completely agree with Rory's comment: ISO-8601 dates are preferred over this old format - so this format generally shouldn't be used for new development.

For ISO-8601 formatted JSON dates, just pass the string into the Date constructor:

var date = new Date(jsonDate); //no ugly parsing needed; full timezone support

Best Solution

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Java – Is Java “pass-by-reference” or “pass-by-value”

Jquery – How to format a Microsoft JSON date

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