Optimistic way of checking null references in java

Question

Can any Java proficient / expert suggest me what is the optimistic way of checking null reference or objects before using it to avoids NullPointerException?

In my code I've more than 100 fields and most of them are required in order to pass value in request, but I need to perform null checks every time before passing it in request to avoid NullPointerException

I have shown below a little piece of code where I'm checking for null values every time for each field (lets say of more 70 times in my one file) which looks not good, code become very ugly and unreadable. Is there any way by which we can write method and perform null object checks through it?

Basically I'm looking better, Optimistic and faster way for doing this, Any quick help is much needed.

if(amount != null && amount != "" && !amount.isEmpty())
        AIMRequest.put("x_Amount", amount);

if(currency != null && currency != "" && !currency.isEmpty())
        AIMRequest.put("x_Currency_Code", currency);

if(expDate != null && expDate != "" && !expDate.isEmpty())
        AIMRequest.put("x_Exp_Date", expDate);

...........so on

the real problem of the code is that it's error prune; if you copy and paste, and forget to modify one variable name, instant bug. — ZhongYu, May 12 '15 at 21:27
Related: http://stackoverflow.com/questions/271526/avoiding-null-statements-in-java?rq=1 — Aify, May 12 '15 at 21:28
Wouldn't the *optimistic* way to check for nulls be to not check for them? ; ) — Radiodef, May 12 '15 at 21:31
What's the point of `s != ""` when you also have `!s.isEmpty()`? — Bubletan, May 12 '15 at 21:31
`amount != "" && !amount.isEmpty()` is the same as `!amount.isEmpty()` — tomse, May 12 '15 at 21:33
By the way, did you really mean *"optimistic"*, or did you actually mean *"optimized"*? — Radiodef, May 12 '15 at 21:37

score 4 · Answer 1 · answered May 12 '15 at 21:35

4

add("x_Amount", amount);
add("x_Currency_Code", currency);
add("x_Exp_Date", expDate);

void add(String name, String value)
{
    if(value!=null && !value.isEmpty())
        AIMRequest.put(name, value); 
}

answered May 12 '15 at 21:35

ZhongYu

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Hi bayou.io - Does this will increase performance etc? – May 13 '15 at 19:53
@user4567570 - don't worry about it; JVM very likely will optimize it. – ZhongYu May 13 '15 at 20:26

Jordi Castilla · Answer 2 · 2015-05-12T21:37:21.953

According your if's, conditions you are comparing Strings, so make a method:

public boolean isValid(String s) {
    return s != null && s != "" && !s.isEmpty();
}

If you want to compare objects with this methods change the signature public boolean isValid(Object o),

and your code will be clean as this:

if(isValid(amount))
        AIMRequest.put("x_Amount", amount);

if(isValid(currency)
        AIMRequest.put("x_Currency_Code", currency);

if(isValid(expDate)
        AIMRequest.put("x_Exp_Date", expDate);

But if you can collect all objects in an array:

public boolean isValid(Object[] os) {
    for (String s : os) {
        boolean isValid = s != null && s != "" && !s.isEmpty();
        if (!isValid) return false;
    }
    return true;
}

Hi Jordi - Does that will increase performance? – May 13 '15 at 13:16 — , May 13 '15 at 13:16

Optimistic way of checking null references in java

2 Answers2