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I encountered this problem recently.
public static void main(String args[]) {
String string = null;
System.out.println(String.valueOf(string)); // This will print a String equal to "null"
System.out.println(string.toString()); // This will throw a NullPointerException
}
Is there any other by which if I invoke that method(pre-defined method in Java) I will get null as output for null String instead of "null" (null as String) or NullPointerException?
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I want to return back a Arraylist of string which contains userName in the response with the response code 200. How to implement this.Thanks in advance.
ResponseEntity<List<String>> someMethod() {
List<String> userNames = getvalues();
return new ResponseEntity<>(userNames, OK);
}
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Suppose we have a string BE231231.
I need an output like this : BE0231231
need to append zero at a this fixed location in java inside a method
public String appendAtIndex(String base, String toAppend, int index){
return base.substring(0,index) + toAppend + base.substring(index);
}
You can implement the logic for restrictions on index accordingly so that base.substring does not give errors.
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Suppose i have below Json String:
{
"name":"noor",
"pass":"12345"
}
I want to mask pass value using Regex, like below
{
"name":"noor",
"pass":"*****"
}
How i can do it, using Java regex?
Try this:
"pass":"(.*?)"
As seen on: https://regex101.com/r/cK4bD0/1
try this
String jsonString = "{ \"name\":\"noor\", \"pass\":\"12345\" }";
String result = jsonString.replaceAll("(?<=pass\":\")(.*?)(?=\")", "*****");
System.out.println(result);
{[^}]*"pass"\s*:\s*"(.*?)"[^}]*}
Here is the DEMO: https://regex101.com/r/nL3tP2/2
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I have
String[] country={"USA","ks a","UK","France"};
I have a variable String z.
I want to say
if(z.equals(any element of my array (USA or ks or France)
but randomly:
if(z.equals(country[i]){
Doing action any code
}
Can anybody help me?
you can use
if ( Arrays.asList(country).contains(z)) {
// your code
}
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When I try to debug the app it gives me an error at the of the arguement saying expression expected
public void onClick(View view) {
Contact contact = new Contact(dbHandler.getContactsCount(),
String.valueOf(nameTxt.getText()), String.valueOf(phoneTxt.getText()),
String.valueOf(emailTxt.getText()), String.valueOf(addressTxt.getText()),);
You have a comma at the end of the line:
new Contact(........., String.valueOf(addressTxt.getText()),);
^
You have to remove it