publicclassNullPointerExceptionExample{publicstaticvoidmain(String[]args){Stringmessage=null;// 1. 检查对象是否为空if(message!=null){System.out.println(message.length());}else{System.out.println("消息为空");}// 2. 使用Optional类Optional<String>optionalMessage=Optional.ofNullable(message);optionalMe...
Having an unchecked exception thrown inside a static initializer will inevitably trigger theExceptionInInitializerErrorruntime error. Figure 3(a) shows how invoking theString::lengthmethod on a non-initializedStringvariable (whose value defaults tonull) throws theNullPointerException, which in turn trig...
1) To avoid NullPointerException we should remember one thing i.e. we must initialize all object references with specified values before using. publicvoid display(String str){if(str.equals("Java")){System.out.println("Java");}} In the above case,NullPointerExceptioncan occur if the paramete...
Java compiler forces us to catch and handle the checked exceptions when we use a method that throws it. These checked exceptions are anticipated, for example,FileNotFoundExceptioncan be thrown when we try to read a file from the filesystem. In a normal Java program, we can usetry-catch-fi...
>> explore access now 1. overview exceptions in java may help us find and fix bugs. but what happens when the exception message is null , leaving us scratching our heads for clues? in this quick tutorial, let’s look into this issue. 2. introduction to the problem as usual, let’s ...
java.lang.NullPointerException Example – How to handle Java Null Pointer Exception (with video) Try Catch Java Example Java Stack Example (with video) Online Java Compiler – What options are there What is null in Java 6. Download the Eclipse Project ...
Caused by: java.lang.NullPointerException at main.java.Example.<clinit>(Example.java:13) We can use the following methods, in order to retrieve more information about the underlying exception: getException(): Returns the exception that occurred during a static initialization...
It is not a NULL Pointer Using the value of pointer as a condition In C++, if you use a null pointer in logical expression, then they will be evaluated as false. We can pass the given pointer in the if condition to check if it is null or not. Note: Sometimes dereferencing a nul...
CanintBe Null in Java? In Java, theintdata type is a fundamental building block for numeric representations. Unlike its object-oriented counterparts,intis a primitive data type and is not inherently nullable. However, there are scenarios in which developers may need to handle the absence of a ...
However, it’s not without its limitations. TheCollections.sort()method sorts in ascending order by default, and it can’t handle null values. If you try to sort a list with null values, it will throw aNullPointerException. Moreover, it may not work as expected with custom objects, unle...