Problems of popular approaches Most of the answers you’ll find around the internet will suggest you to either install the dependency to your local repository or specify a “system” scope in the pom and distribute the dependency with the source of your project. But both of these solutions are actually flawed. Why you shouldn’t apply … Read more
You can use getActivity(), which returns the activity associated with a fragment. The activity is a context (since Activity extends Context).
Go to URL in your browser: firefox – click on HTTPS certificate chain (the lock icon right next to URL address). Click “more info” > “security” > “show certificate” > “details” > “export..”. Pickup the name and choose file type example.cer chrome – click on site icon left to address in address bar, select “Certificate” … Read more
Set<Foo> foo = new HashSet<Foo>(myList);
The following is part of the List interface (which ArrayList implements): E e = list.get(list.size() – 1); E is the element type. If the list is empty, get throws an IndexOutOfBoundsException. You can find the whole API documentation here.
Java 8 (2014) solves this problem using streams and lambdas in one line of code: List<Person> beerDrinkers = persons.stream() .filter(p -> p.getAge() > 16).collect(Collectors.toList()); Here’s a tutorial. Use Collection#removeIf to modify the collection in place. (Notice: In this case, the predicate will remove objects who satisfy the predicate): persons.removeIf(p -> p.getAge() <= 16); lambdaj allows … Read more
Here is the shortest version (Java 1.5+ required): repeated = new String(new char[n]).replace(“\0”, s); Where n is the number of times you want to repeat the string and s is the string to repeat. No imports or libraries needed.
Coding from the hip, it would be something like: java.lang.reflect.Method method; try { method = obj.getClass().getMethod(methodName, param1.class, param2.class, ..); } catch (SecurityException e) { … } catch (NoSuchMethodException e) { … } The parameters identify the very specific method you need (if there are several overloaded available, if the method has no arguments, only give … Read more
In general, the answer to your question is “yes”, but… .equals(…) will only compare what it is written to compare, no more, no less. If a class does not override the equals method, then it defaults to the equals(Object o) method of the closest parent class that has overridden this method. If no parent classes … Read more
Are you doing this for logging purposes? If so there are several libraries for this. Two of the most popular are Log4j and Logback. Java 7+ For a one-time task, the Files class makes this easy: try { Files.write(Paths.get(“myfile.txt”), “the text”.getBytes(), StandardOpenOption.APPEND); }catch (IOException e) { //exception handling left as an exercise for the reader … Read more