A common (bad) practice is to return the null reference to indicate the absence of a sound card. Unfortunately, this means the call togetUSB()will try to return the USB port of a null reference, which will result in aNullPointerExceptionat runtime and stop your program from running furth...
// This program shows the importance of overriding equals() and hashCode() methods import java.util.*; class Circle { private int xPos, yPos, radius; public Circle(int x, int y, int r) { xPos = x; yPos = y; radius = r; } public boolean equals(Object arg) { if(arg == nul...
Just like the If statement, the first line starts with If and is followed by the condition you want your program to test for. Within the curly brackets you would include the actions you want the program to take if that condition is met. If the condition is not met, the program executes...
If an EmptyFileException occurs in the checkFileNotEmpty method, it is caught in the main method. The error message indicating an empty file is printed. Flowchart: For more Practice: Solve these Related Problems: Write a Java program to read a file and throw a custom EmptyFileException if ...
A program may simply request a particular type of object (such as a Signature object) implementing a particular service (such as the DSA signature algorithm) and get an implementation from one of the installed providers. If desired, a program may instead request an implementation from a specific...
Last update on April 10 2025 05:38:24 (UTC/GMT +8 hours) This resource offers a total of 160 Java Conditional Statement problems for practice. It includes 32 main exercises, each accompanied by solutions, detailed explanations, and four related problems. ...
Validating the Source Data: Notice that the program includes the following statement: unmarshaller.setValidating(true); This statement highlights an important feature of JAXB: you can have it validate the source data against the associated schema as part of the unmarshalling operation. In this case,...
Notice that at the time of list creation, we have specified that the type of elements in the list will be String. So if we try to add any other type of object in the list, the program will throw compile-time error. Also notice that in for loop, we don’t need typecasting of the...
The following example shows the break statement in action, in the context of a main menu. If the user types in a certain value, a specific part of the code is processed. In each case, we want to break out when done. There's no need to process any code after we've processed each ...
The following section explains the program statements inExample 2–3. To Look Up a Destination With JNDI Create the environment for constructing the initial JNDI naming context. How you create the initial context depends on whether you are using afile-system object store or aLightweight Directory...