How-to articles, tricks, and solutions about JAVA

An unchecked cast warning in Java occurs when the compiler cannot verify that a cast is safe at compile time.

To read a text file in Java, you can use the BufferedReader class from the java.io package.

There are a few different ways to evaluate a math expression given in string form:

To read a text file in Java, you can use the BufferedReader class from the java.io package.

To create an ArrayList of int arrays in Java, you can use the following syntax:

In Java, a finally block is guaranteed to be executed, unless the virtual machine exits abruptly due to an uncaught exception or a call to System.exit.

To make a RESTful call in Java, you can use the HttpURLConnection class.

To add a button click event in Android Studio, follow these steps:

To convert a string representation of a hex dump to a byte array in Java, you can use the DatatypeConverter class's parseHexBinary method.

To split a string in Java using a dot (.) as the delimiter, you can use the split method of the String class.

To get the integer value of the current year in Java, you can use the Calendar class and the get method.

In Java, the main method is declared as static because the JVM (Java Virtual Machine) needs to be able to invoke it without creating an instance of the class that contains it.

To convert a JsonObject to a String in Java, you can use the JsonObject.toString method.

To check if a key exists in a HashMap in Java, you can use the containsKey method.

In a Java RESTful web service, the @QueryParam annotation is used to bind a query parameter to a method parameter, while the @PathParam annotation is used to bind a path parameter to a method parameter.

In Selenium, you can use the WebDriverWait class to wait for a page to load.

To sort a HashMap by values in Java, you can use the Map.Entry interface and the Comparator interface to create a comparator that compares the values in the map.

To check if a value is of type Integer in Java, you can use the instanceof operator.

To get the path of a running JAR file, you can use the java.lang.Class class's getProtectionDomain method and then the getCodeSource method.

In Spring MVC, the @RequestParam annotation is used to bind a request parameter to a method parameter.

To decode a URL in Java, you can use the URLDecoder class from the java.net package.

It is generally considered bad practice to test private methods, as they are an implementation detail that should not be exposed to the outside world.

The 'Field required a bean of type that could not be found' error in a Spring application typically indicates that the application is trying to inject a dependency into a field, but it cannot find a bean of the required type in the application context.

Getters and setters, also known as accessors, are methods that are used to get and set the values of an object's properties.

To check whether a number is even or odd in Java, you can use the modulus operator (%) to determine the remainder of the number when it is divided by 2.