There are actually many good reasons to consider using accessors rather than directly exposing fields of a class – beyond just the argument of encapsulation and making future changes easier. Here are the some of the reasons I am aware of: Encapsulation of behavior associated with getting or setting the property – this allows additional … Read more
Here’s a generic-friendly version: public class MapUtil { public static <K, V extends Comparable<? super V>> Map<K, V> sortByValue(Map<K, V> map) { List<Entry<K, V>> list = new ArrayList<>(map.entrySet()); list.sort(Entry.comparingByValue()); Map<K, V> result = new LinkedHashMap<>(); for (Entry<K, V> entry : list) { result.put(entry.getKey(), entry.getValue()); } return result; } }
Use the appropriately named method String#split(). String string = “004-034556”; String[] parts = string.split(“-“); String part1 = parts[0]; // 004 String part2 = parts[1]; // 034556 Note that split‘s argument is assumed to be a regular expression, so remember to escape special characters if necessary. there are 12 characters with special meanings: the backslash \, … Read more
The other answers explain why, but here is how. Given an instance of Random: Random r = new Random(-229985452) The first 6 numbers that r.nextInt(27) generates are: 8 5 12 12 15 0 and the first 6 numbers that r.nextInt(27) generates given Random r = new Random(-147909649) are: 23 15 18 12 4 0 Then … Read more
Algorithm To generate a random string, concatenate characters drawn randomly from the set of acceptable symbols until the string reaches the desired length. Implementation Here’s some fairly simple and very flexible code for generating random identifiers. Read the information that follows for important application notes. public class RandomString { /** * Generate a random string. … Read more
No, the structure you found is how Java handles it (that is, with overloading instead of default parameters). For constructors, See Effective Java: Programming Language Guide’s Item 1 tip (Consider static factory methods instead of constructors) if the overloading is getting complicated. For other methods, renaming some cases or using a parameter object can help. … Read more
From the Java Tutorial: Nested classes are divided into two categories: static and non-static. Nested classes that are declared static are simply called static nested classes. Non-static nested classes are called inner classes. Static nested classes are accessed using the enclosing class name: OuterClass.StaticNestedClass For example, to create an object for the static nested class, … Read more
Like other answerers, I’d definitely prefer to put the loops in a different method, at which point you can just return to stop iterating completely. This answer just shows how the requirements in the question can be met. You can use break with a label for the outer loop. For example: public class Test { … Read more
Both are technically correct. If you look at the source code for .equals(), it simply defers to ==. I use ==, however, as that will be null safe.
First a disclaimer beforehand: the posted code snippets are all basic examples. You’ll need to handle trivial IOExceptions and RuntimeExceptions like NullPointerException, ArrayIndexOutOfBoundsException and consorts yourself. In case you’re developing for Android instead of Java, note also that since introduction of API level 28, cleartext HTTP requests are disabled by default. You are encouraged to … Read more