How-to articles, tricks, and solutions about JAVA

There are several ways you can iterate through the characters of a string in Java.

The error "Error creating bean with name 'dataSource' defined in class path resource" in Spring Boot typically indicates that there is a problem with the configuration of the dataSource bean.

To convert a string to an integer in Android, you can use the Integer.parseInt method.

To load a file from the resource folder in a Java application, you can use the ClassLoader and getResourceAsStream method.

To get the IP address of the current machine using Java, you can use the InetAddress.getLocalHost method of the java.net package.

To convert milliseconds to "X mins, X seconds" in Java, you can use the TimeUnit class from the java.util.concurrent package.

To reverse an int array in Java, you can use a loop to swap the elements at the beginning and end of the array, and then move the pointers inward until they meet in the middle of the array.

A PriorityQueue is a queue data structure that pops the element with the highest priority first.

To set a background drawable programmatically in Android, you can use the setBackgroundDrawable method of the View class.

You can use the Gson library to convert a JSON string to a Map in Java.

In Java, HashMap, LinkedHashMap, and TreeMap are all implementations of the Map interface.

Java does not have a destructor like some other programming languages.

There are a few ways you can return multiple values from a Java method:

Here is an example of how you can initialize an array of objects in Java:

You can use environment variables in your application.properties file by using the spring.profiles.active property.

To store multiple values under the same key in a HashMap in Java, you can use a List or an array as the value for the key.

To create a regular expression that includes all special characters, you can use the following pattern:

To split a string in Java by new line, you can use the split method of the String class and pass it the regular expression "\n" or "\r\n", depending on the platform you are running on.

To use two values in a switch case statement in Java, you can use the case label for each value, or you can use the case label with a range of values.

To use a Comparator in Java to sort a list of objects, you can use the Collections.sort method and pass it a List and a Comparator.

To convert a List to a Set in Java, you can use the new HashSet<>(list) constructor to create a new HashSet and initialize it with the elements of the List.

To convert a java.util.Date object to an XMLGregorianCalendar in Java, you can use the toGregorianCalendar method of the DatatypeFactory class.

To clear or empty a StringBuilder in Java, you can use the setLength method and set the length to 0.

In Java, a Set is an interface that extends the Collection interface.

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