checkNotNull(instance); Assertion.checkNotNull(method); Assertion.checkNotNull(aspects); //--- this.instance = instance; this.method = method; this.aspects = aspects; } 代码来源:KleeGroup/vertigo Selector$ClassConditions.subTypeOf(...) /** * Build a predicate to check if the classe is...
在Java中,我们可以使用自定义的check方法,也可以使用一些已经存在的库或框架中提供的check方法。下面是一个自定义的check方法的示例: publicclassCheckUtils{publicstaticvoidcheckNotNull(Objectobj,Stringmessage){if(obj==null){thrownewIllegalArgumentException(message);}}publicstaticvoidcheckPositive(intnum,Stringmess...
funmain(){varname:String?=null// 捕获并处理异常try{checkNotNull(name,{"变量为空"})name!!.count();}catch(e:Exception){println(e)}} 执行结果 : 代码语言:javascript 代码运行次数:0 运行 AI代码解释 java.lang.IllegalStateException:变量为空 上述使用的 先决条件函数checkNotNull原型 : 代码语言:ja...
Preconditions.checkNotNull(object, "发生了空指针异常,啦啦啦啦啦~~~啦完以后打印一下对象信息+"JSON.toJSONString(object)); 看源码 package com.google.common.base; public final class Preconditions { private Preconditions() { } if (reference == null) { throw new NullPointerException(String.valueOf(...
if (str3 == null || str3.length() == 0) { System.out.println("str3 is null or empty."); } else { System.out.println("str3 is not null or empty."); } } } The code example demonstrates the if-else method for checking if a string is null or empty in Java. It utilizes ...
checkNotNull 函数 : 参数为 null , 抛出 IllegalStateException 异常 , 参数为非空 , 返回非空值 ; AI检测代码解析 /** * 如果[value]为空,则抛出[IllegalStateException]。否则 * 返回非空值。 * * @sample samples.misc.Preconditions.failCheckWithLazyMessage ...
String str = null; if (str == null) { System.out.println("The string is null."); } else { System.out.println("The string is not null."); } Employing the Objects.isNull() method: In Java 8 and later versions, you can use the Objects.isNull() method from the java.util.Object...
public class JavaIntegerNull1 { public static void main(String[] args) { Integer userId = new Integer(0); if (userId == null) { System.out.println("Integer wrapper class object is NULL"); } else { System.out.println("Integer wrapper class object is NOT NULL"); ...
But before moving further, if you are not familiar with the concept of string, then do check the article on Strings in Java.Input: Enter the string: AppleOutput: The entered string is null or empty? : FalseProgram 1: Check If a String is Empty or NullIn this program, we will learn ...
In Java, the primitive data typeintcannot be assigned a value ofnullbecause it is a value type, not an object. However, situations may arise where the need arises to represent the absence of a value for an integer-like entity. Why Is It Important to Know ifIntegerIs Null?