以下是使用Collections.shuffle()方法实现随机获取元素的示例代码: 代码语言:java AI代码解释 importjava.util.Collections;importjava.util.List;publicclassRandomElementSelector{publicstatic<T>TgetRandomElement(List<T>list){if(list==null||list.isEmpty()){thrownewIllegalArgumentException("List cannot be null...
1. 初窥门径：List.of publicinterfaceList<E> extendsCollection<E> {/** * Returns an unmodifiable list containing zero elements. * * See Unmodifiable Lists for details. * * @param <E> the {@code List}'s element type * @return an empty {@code List} * * @since...
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'courseMapper' defined in file [E:\IDEAProject\Education\edu-course-boot\target\classes\com\laoli\mapper\CourseMapper.class]: Unsatisfied dependency expressed through bean property 'sqlSessionFactory'...
AI代码解释 importjava.util.List;importjava.util.HashMap;importjava.util.stream.Collectors;publicclassListToMapExample{publicstaticvoidmain(String[]args){// 创建一个User对象的列表List<User>userList=List.of(newUser(1,"Alice"),newUser(2,"Bob"),newUser(3,"Charlie"));// 使用Stream API将List转...
程序在list.add(“1”)处,抛出异常:UnsupportedOperationException。 原因解析:Arrays.asList(strArray)返回值是java.util.Arrays类中一个私有静态内部类java.util.Arrays.ArrayList,它并非java.util.ArrayList类。java.util.Arrays.ArrayList类具有 set(),get(),contains()等方法,但是不具有添加add()或删除remove()方...
java.lang.NullPointerException异常是由于在使用Collectors.toList()方法时,流中存在null值导致的。为了避免这个异常的抛出,我们可以在使用Collectors.toList()方法之前,先使用filter方法过滤掉null值。 Java 8的Stream API和Collectors类为我们提供了强大的数据处理和集合收集功能。然而,在使用这些功能时,我们需要注意处理...
printStackTrace(); } } public void m() throws CheckedException { } twr Inserts a statement in a try-with-resources block (Java 7 or higher is required). public class Foo { void m() { getStream().twr } AutoCloseable getStream() { return null; } } public class Foo { void m() {...
importjava.util.LinkedList;importjava.util.Scanner;importjava.lang.Exception;publicclassKTVByLinkedList {publicstaticvoidmain(String[] args) {//TODO Auto-generated method stubSystem.out.println("---欢迎来到点歌界面---"); System.out.println("0.添加歌曲至列表"); System...
lang.NumberFormatException: For input string: "false" at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65) at java.lang.Long.parseLong(Long.java:589) at java.lang.Long.valueOf(Long.java:803) at com.atlassian.jira.security.login.LoginS...
instanceof on catch parameter Disabled Warning java.lang.Error not rethrown Disabled Warning java.lang.ThreadDeath not rethrown Disabled Warning Nested try statement Disabled Warning Non-final field of exception class Disabled Warning null thrown Disabled Warning Overly broad catch block Disabled Warning Ov...