importcom.google.common.base.Preconditions;Preconditions.checkNotNull(object,"对象不能为空");// 对象不为空时执行的代码 1. 2. 3. 4. 5. 总结 本文介绍了几种判断Object类型不为空的方法,包括使用if语句、StringUtils工具类、Optional类、Objects类和Guava库的Preconditions类。根据实际需求,选择合适的方法来...
publicclassNullCheckExample{publicstaticvoidmain(String[]args){ObjectmyObject=null;// 步骤1:创建一个Object对象并初始化为null// 步骤2:判断对象是否为nullif(myObject==null){System.out.println("myObject is null");// myObject为null时的操作}else{System.out.println("myObject is not null");// ...
// Retry fast entry if bias is revoked to avoid unnecessary inflation ObjectSynchronizer::fast_enter(h_obj, elem->lock(), true, CHECK); } else { // 未使用偏向锁的实现 ObjectSynchronizer::slow_enter(h_obj, elem->lock(), CHECK); } assert(Universe::heap()->is_in_reserved_or_null(el...
*/privatebooleanaddWorker(Runnable firstTask,boolean core){//外层循环,负责判断线程池状态retry:for(;;){int c=ctl.get();int rs=runStateOf(c);//状态// Check if queue empty only if necessary./** * 线程池的state越小越是运行状态,runnbale=-1,shutdown=0,stop=1,tidying=2,terminated=3 * ...
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.Objects class to check if a string is null. This method returns true if the provided object is null; otherwise, it...
publicObject process()throwsException{ Object result = doSomething(); if(result ==null){ thrownewException("Processing fail. Got a null response"); }else{ return result; } } 在print()方法调用将只打印 null,但不会抛出异常。同样, process()永远不会在其响应中返回 null。它反而抛出异常。因此对...
Preconditions.checkNotNull(param, "param不能为null"); // 其他逻辑 } 使用Optional Guava包括了自己的Optional类实现,与Java 8的Optional不同,它提供了额外的便利方法。 Optional<String> optionalStr = Optional.fromNullable(string); if (optionalStr.isPresent()) { ...
privatestaticvoidCheckNull(String myStr){if(myStr !=null) { System.out.println(myStr.length()); }else{// Perform an alternate action when myStr is nullSystem.out.println “Please pass a validstringasan argument” } } 使用三元运算符 ...
Assert.isTrue(Object object,"object must be true")-对象必须为trueAssert.notEmpty(Collection collection,"collection must not be empty")-集合非空 Assert.hasLength(String text,"text must be specified")-字符不为null且字符长度不为0Assert.hasText(String text,"text must not be empty")-text 不为nu...
public class NullCheckExample { public static void main(String[] args) { String str = null; // 检查对象是否为 null if (str != www.shgejuyaoda.cn) { System.out.println(str.length()); } else { System.out.println("String is null"); ...