Odtnhj

My intent is to throw two Exceptions at once. The code:

 String str = "foo";

 if (str.length() < 5) 
 throw new Exception("At least 5 characters."); // exception 1
 

 if (!str.matches(".*[0-9]+.*")) 
 throw new Exception("At least 1 digit."); // exception 2
 

foo is less than 5 characters long and doesn't contain any digits. But when I run this program, only exception 1 is thrown.

How do I throw multiple exceptions (of the same type)? Or is my approach misled, and should I go about doing this differently?

If you are checking against a list of possible problems, and you need to report all problems, then it may be neater to do it this way:

String str = "foo";

List<String> errors = new ArrayList<>();

if (str.length() < 5) 
 errors.add("At least 5 characters."); // exception 1


if (!str.matches(".*[0-9]+.*")) 
 errors.add("At least 1 digit."); // exception 2


// Check for more stuff

if (!errors.isEmpty()) 
 throw new Exception("There are problem(s) found:n" + String.join("n", errors));

Effectively, this is the same as what was proposed by other answers/comments, but this approach is a little cleaner/neater for a more complex scenario.

That is not possible. Instead test for the conditions you desire. Like,

String str = "foo";
boolean len = str.length() < 5;
boolean digit = !str.matches(".*[0-9]+.*");
if (len && digit) 
 throw new Exception("At least 5 characters and 1 digit."); // both 1 and 2
 else if (len) 
 throw new Exception("At least 5 characters."); // exception 1
 else if (digit) 
 throw new Exception("At least 1 digit."); // exception 2

You can never throw more than one exception at a time, because they interrupt execution. You could test for each possible problem individually, and throw an exception at the end which contains each failed test separated in a way that is easy to parse (commas would probably be best here).