How-to articles, tricks, and solutions about JAVA

There are several ways to convert a string to a string array in Java. Here are a few options:

In Java, the == operator is used to compare the primitive values of two variables, while the equals() method is used to compare the contents of two objects.

In Java, you can use either a StringBuilder or string concatenation to create a string representation of an object.

To remove leading and trailing whitespace from a string in Java, you can use the trim method of the String class.

In Java, the super keyword is used to refer to the superclass of the current class. It is often used to call the constructor of the superclass, or to access methods or fields of the superclass that have been overridden in the current class.

To use a switch statement on an enumeration (enum) in Java, you can use the enum type as the control expression for the switch statement.

To take a character input from the Scanner in Java, you can use the next() method to read a string and then use the charAt(int index) method to get the first character of that string. Here's an example:

There are several ways to terminate a Java program, depending on the context in which the program is running.

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.

If you are getting the error "The import javax.servlet can't be resolved", it means that the javax.servlet package is not available on the classpath.

This error typically occurs when you are trying to use the HttpServlet class in a Java project, but the necessary libraries are not included in the project's classpath. To fix this error, you need to add the servlet-api.jar library to your project's class

If you see the error "Port 8080 already in use" when starting the Tomcat server, it means that another process is already using port 8080 on your machine.

There are several ways to find out the version of Tomcat that is running on your system:

To trust all certificates when using the Apache HttpClient library to make HTTPS requests, you can create a custom X509TrustManager implementation that trusts all certificates and use it to create an SSLContext with a custom TrustStrategy.

In Java, List is an interface that defines a list data structure, while ArrayList is a class that implements the List interface.

If you are getting the "unable to find valid certification path to requested target" error even after importing the certificate, there are a few possible causes and solutions:<br>

The @Autowired annotation in Spring is used to inject dependencies into a Java object.

If you are seeing the error "Unfortunately, MyApp has stopped," it means that your Android app has crashed. This can be caused by a number of factors, including:

UnsatisfiedDependencyException is a runtime exception that is thrown when the Spring framework is unable to resolve a dependency for a bean.

Mockito is a Java mocking framework that allows you to create mock objects for testing.

To use context in a fragment, you will need to provide enough information within the fragment itself for the reader to understand the context.

To use the values of an enum as string literals in Java, you can use the name() method of the Enum class. This method returns the name of the enum value as a string.

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

In Java, you can use the javafx.util.Pair class to represent a pair or 2-tuple.

Scanner.nextLine() is a method of the Scanner class in Java that reads a line of text from the input.