In Java, I want to convert a double to an integer, I know if you do this: double x = 1.5; int y = (int)x; you get y=1. If you do this: int y = (int)Math.round(x); You'll likely get 2. However, I am wondering: since double representations of integers sometimes look like 1.9999999998 or something, is there a possibility that casting a double created via Math.round() will still result in a
在Java中，我想将double转换为整数，我知道如果你这样做： double x = 1.5; int y = (int)x; 你得到y = 1。 如果你这样做： int y = (int)Math.round(x); 你可能会得到2.但是，我想知道：因为整数的双重表示有时看起来像1.9999999998什么的，是否有可能通过Math.round（）创建一个double仍然会导致截断的数字，而不是比我们正在寻找的四舍五入的数字（例如：代码中的1代替2代表）？ （是的，我的意思是这样的：x是否有任
I am trying to write a simple application that gets updated. For this I need a simple function that can download a file and show the current progress in a ProgressDialog . I know how to do the ProgressDialog , but I'm not sure how to display the current progress and how to download the file in the first place. There are many ways to download files. Following I will post most common ways;
我正在尝试编写一个更新的简单应用程序。 为此，我需要一个简单的函数，可以下载一个文件并在ProgressDialog显示当前的ProgressDialog 。 我知道如何做ProgressDialog ，但我不确定如何显示当前进度以及如何首先下载文件。 有很多方法可以下载文件。 以下我将发布最常见的方式; 您需要决定哪种方法更适合您的应用。 1.使用AsyncTask并在对话框中显示下载进度 此方法将允许您执行一些后台进程并同时更新UI（在这种情况
Imagine I've got a class with 10 methods and I need to instantiate 10 objects from the class. The question is: Will JVM allocate 10 different memory spaces for 10 instances at object creation time (I mean at the time I call the constructor ie new MyClass(); ? or it will load the class definition once in memory and each instance while calling each of those 10 methods, at run time, JVM will al
想象一下，我有10个方法的类，我需要从类中实例化10个对象。 问题是： 在创建对象时，JVM会为10个实例分配10个不同的内存空间（我的意思是在我调用构造函数的时候，例如new MyClass（）;或者它将在调用内存时调用一次类定义，这10种方法中的每一种，在运行时，JVM都会分配内存？ 为了消除一些误解，我的问题是在创建一个对象时，我知道所有的数据成员都是在堆内存中分配的，但我不确定尚未调用的方法是否在内存中分配给每个对
i am trying to execute a task at a fixed rate using the @Scheduled annotation in java spring. however, it seems that by default spring will not execute a fixedRate task at a fixed rate if the task is slower than the rate. is there some setting i can add to my spring configuration to change this behavior? example : @Service public class MyTask{ @Scheduled(fixedRate = 1000) public void
我正尝试在java spring中使用@Scheduled注释以固定的速率执行任务。 然而，如果任务比速率慢，默认情况下，spring不会以固定速率执行fixedRate任务。 是否有一些设置可以添加到我的弹簧配置中以更改此行为？ 例如 ： @Service public class MyTask{ @Scheduled(fixedRate = 1000) public void doIt(){ // this sometimes takes >1000ms, in which case the next execution is late ... } }
I want to count the different elements of a stream and am wondering why Stream<String> stream = Stream.of("a", "b", "a", "c", "c", "a", "a", "d"); Map<String, Integer> counter1 = stream.collect(Collectors.toMap(s -> s, 1, Integer::sum)); doesn't work. Eclipse tells me The method toMap(Function, Function, BinaryOperator) in the type Collectors is not applicable for the argu
我想统计一个流的不同元素，我想知道为什么 Stream<String> stream = Stream.of("a", "b", "a", "c", "c", "a", "a", "d"); Map<String, Integer> counter1 = stream.collect(Collectors.toMap(s -> s, 1, Integer::sum)); 不起作用。 Eclipse告诉我 类型Collectors中的Map（Function，Function，BinaryOperator）方法不适用于参数（（s） - > {}，int，Integer :: sum） 顺便说一下，我知道这个解决方
Due to this annoying Android limitation I need users to reinstall my application so the manifest permissions are detected by other applications. This is already going to be frustrating for the user, but in addition, I cannot see a way to reinstall my application from the apk stored in /data/app and I would therefore have to download the same version to the storage card before firing the usual i
由于这个恼人的Android限制，我需要用户重新安装我的应用程序，以便其他应用程序可以检测到清单权限。 这对用户来说已经是令人沮丧的事了，但是除此之外，我无法从存储在/ data / app中的apk中重新安装我的应用程序，因此我必须在启动之前将相同版本下载到存储卡通常的安装意图。 我急切地等待有人告诉我我错过了明显的东西！ 我画了一张空白的... 提前致谢。 如果您希望看到问题解决，请为此问题做明星演示！ 干杯。
There's this library I created to report exceptions via email. It works well with the Android Java project but fails with Android Kotlin. When I add the compile script for the libary (compile 'com.theah64.bugmailer:bugmailer:1.1.9') and tries to build the APK, am getting below error. Error:Execution failed for task ':app:transformDexArchiveWithExternalLibsDexMergerForDebug'. > c
我创建了这个库来通过电子邮件报告异常情况。 它适用于Android Java项目，但Android Kotlin失败。 当我为该库添加编译脚本(compile 'com.theah64.bugmailer:bugmailer:1.1.9')并尝试构建APK时，出现错误。 Error:Execution failed for task ':app:transformDexArchiveWithExternalLibsDexMergerForDebug'. > com.android.builder.dexing.DexArchiveMergerException: Unable to merge dex 这是我的应用程序的build
My App is not bringing up an error: Error:Execution failed for task ':app:transformDexArchiveWithExternalLibsDexMergerForDebug'. java.lang.RuntimeException: com.android.builder.dexing.DexArchiveMergerException: Unable to merge dex This is y build gradle: apply plugin: 'com.android.application' android { compileSdkVersion 26 defaultConfig { applicationId "app.monmos" minSdk
我的应用程序不会引发错误： 错误：执行任务'：app：transformDexArchiveWithExternalLibsDexMergerForDebug'失败。 java.lang.RuntimeException：com.android.builder.dexing.DexArchiveMergerException：无法合并dex 这是y构建gradle： apply plugin: 'com.android.application' android { compileSdkVersion 26 defaultConfig { applicationId "app.monmos" minSdkVersion 21 targetSdkVersion 26
I just created a blank activity from File > New > Activity. Its MainActivity.java is editable, same for menu_main.xml, but the activity_main.xml layout file cannot be opened. There is no error message, no sign that anything is happening at all, nothing. I also tried removing the activity and creating it again. Android Studio is updated to the latest version (1.2.1.1) and I tried openin
我刚刚从文件>新建>活动中创建了一个空白活动。 它的MainActivity.java是可编辑的，对于menu_main.xml也是如此，但是无法打开activity_main.xml布局文件。 没有错误信息，没有迹象表明任何事情都发生了，什么也没有。 我也尝试删除活动并重新创建它。 Android Studio已更新到最新版本（1.2.1.1），我尝试打开并关闭它。 我在Mac OS X 10.10.3上运行它，并且该文件存在于IDE所说的文件系统上。 有没有人有过这个问
I was looking at the example implementation of Publisher (AsyncIterablePublisher.java) of the reactive-streams spec when I stumbled into something that I don't understand why it was done that way. static interface Signal {}; enum Cancel implements Signal { Instance; }; enum Subscribe implements Signal { Instance; }; enum Send implements Signal { Instance; }; Being realistic that I'm not
当我偶然发现一些我不明白为什么会这样做的事情时，我正在研究reactive-streams规范的Publisher（AsyncIterablePublisher.java）的示例实现。 static interface Signal {}; enum Cancel implements Signal { Instance; }; enum Subscribe implements Signal { Instance; }; enum Send implements Signal { Instance; }; 我不是写这个高级程序员的现实人物，我确信有这样做的理由。 但我也无法解释为什么它会比这样做更好（这