How-to articles, tricks, and solutions about JAVA

To format a floating-point number as a string without unnecessary decimal zeros, you can use the DecimalFormat class from the java.text package. The DecimalFormat class allows you to specify a pattern for formatting numbers as strings.

To open a .jar file on a Windows system, you can do one of the following:

To parse a date in Java, you can use the SimpleDateFormat class.

To parse a JSON string in Java, you can use the org.json library. This library provides a simple and easy-to-use interface for parsing and manipulating JSON data in Java.

To parse JSON in Kotlin, you can use the JSONObject class from the org.json package.

In Java, you can pass a function as a parameter using a functional interface. A functional interface is an interface that has a single abstract method. You can create a functional interface by annotating an interface with the @FunctionalInterface annotati

There are several ways you can pass an object from one activity to another on Android:

To perform a mouseover (hover) action in Selenium WebDriver using Java, you can use the Actions class.

To POST form data with the RestTemplate class in Spring, you can use the postForObject method and pass it a URL, an object containing the form data, and the response type.

To pretty print XML from Java, you can use the javax.xml.transform.Transformer class from the Java XML Transformer API.

To print a float with 2 decimal places in Java, you can use the printf method and specify a format string with the %.2f format specifier. Here's an example:

To print a Hibernate query string with parameter values, you can use the toString() method of the Query interface.

To print colored text to the console using System.out.println, you will need to use special escape sequences in your string to specify the desired color.

To print out all the elements of a List in Java, you can use a for loop or an enhanced for loop.

To print to the console in Android Studio, you can use the Log class from the android.util package.

To programmatically close a JFrame in Java, you can use the dispose method.

To put input from a Scanner into an array in Java, you can use a loop to read the input and store it in the array.

To read all the files in a folder from Java, you can use the File class from the java.io package to list all the files in a directory. Here's an example of how you can do this:

There are several ways to read and write Excel files in Java. Here are a few options:

To read a file from a relative path in a Java project, you can use the File class from the java.io package and specify the relative path to the file.

To read an integer value from the standard input (keyboard) in Java, you can use the Scanner class from the java.util package.

To read a JSON file into Java using the Simple JSON library, you can use the JSONObject class and the JSONArray class.

To read a text file from the classpath in Java, you can use the getResourceAsStream method of the ClassLoader class to get an InputStream for the file, and then use a BufferedReader to read the contents of the file.

To read XML using XPath in Java, you can use the javax.xml.xpath package.

To reference a method in Javadoc, you can use the {@link} tag.