What happens after a method is called in Java

This looks like a silly question but I found it is hard to get it right. I have asked different people but couldn't get an ideal answer. I want to know what happens after we call a normal method in Java (Provided in a single threaded environment). My understanding is that: All current stack variables are poped-up and stored somewhere (where?) The current method call halts The argum

在Java中调用方法后会发生什么

这看起来像一个愚蠢的问题,但我发现很难做到这一点。 我问过不同的人,但无法得到理想的答案。 我想知道在Java中调用常规方法(在单线程环境中提供)后会发生什么。 我的理解是: 所有当前的堆栈变量都被加载并存储在某处(其中?) 当前方法调用暂停 新调用的方法的参数被推送到堆栈 方法代码运行 方法完成运行后,堆栈将再次清空,旧的堆栈内容将再次恢复。 (如果函数返回一个值会发生什么?)。 代码继续

Android: Take Photo Without User Interface

I am interested in writing an app for android where after a certain event in the app a photo is automatically taken using the camera on the android. Things I need: No Preview of photo No Button for User to press to take the photo Just run the operation to take a photo and store it to the album. here is some code i tried from a tutorial online: public void snap(){ mCamera = Camer

Android:无需用户界面拍照

我有兴趣为Android编写一个应用程序,在应用程序中的某个事件之后,使用android上的相机自动拍摄照片。 我需要的东西: 没有预览照片 用户无按钮拍照 只需运行该操作即可拍摄照片并将其存储到相册中。 这里是我从网上的一个教程尝试的一些代码: public void snap(){ mCamera = Camera.open(); SurfaceView sv = new SurfaceView(getApplicationContext()); try { mCamera.s

How to get the sum of two n

Adding two n-dimensional arrays in Java addVectors Two 1-dimensional arrays / vectors in Java can be added like this: public static int[] addVectors( int[] a, int[] b ) { int[] c = new int[a.length]; for ( int i = 0; i < a.length; i++ ) { c[i] = a[i] + b[i]; } return c; } addMatrices Two 2-dimensional arrays / matrices in Java can be added like this: publ

如何得到两个人的总和

在Java中添加两个n维数组 addVectors Java中的两个1维数组/矢量可以像这样添加: public static int[] addVectors( int[] a, int[] b ) { int[] c = new int[a.length]; for ( int i = 0; i < a.length; i++ ) { c[i] = a[i] + b[i]; } return c; } addMatrices Java中的两个二维数组/矩阵可以像这样添加: public static int[][] addMatrices( int[][] a, int[][] b ) { int[][]

HTMLUnit : super slow execution?

I have been using HTMLUnit . It suits my requirements well. But it seems to be extremely slow. for example : I have automated the following scenario using HTMLUnit Goto Google page Enter some text Click on the search button Get the title of the results page Click on the first result. Code : long t1=System.currentTimeMillis(); Logger logger=Logger.getLogger(""); logger.setLevel(Level.OFF); W

HTMLUnit:超慢执行?

我一直在使用HTMLUnit。 它很适合我的要求。 但它似乎非常缓慢。 例如:我已经使用HTMLUnit自动化了以下场景 Goto Google page Enter some text Click on the search button Get the title of the results page Click on the first result. 代码: long t1=System.currentTimeMillis(); Logger logger=Logger.getLogger(""); logger.setLevel(Level.OFF); WebClient webClient=createWebClient(); WebRequest webReq=new We

How edit/change View from layout in RemoteView or create RemoteView from View?

I create widget for Android application (in Java, of course). I have classic RemoteViews created from layout (using layout id) RemoteViews rv = new RemoteViews(context.getPackageName(), R.layout.view); and I need edit or change view (identify by id). In classic View is it easy, using findViewById function. View v = ... //inflate layout R.layout.view View my = v.findViewById(R.id.myViewId); p

如何编辑/更改RemoteView中的布局视图或从View创建RemoteView?

我为Android应用程序创建了一个小部件(当然是用Java)。 我有从布局创建的经典RemoteViews(使用布局ID) RemoteViews rv = new RemoteViews(context.getPackageName(), R.layout.view); 我需要编辑或更改视图(通过ID标识)。 在经典View中很容易,使用findViewById函数。 View v = ... //inflate layout R.layout.view View my = v.findViewById(R.id.myViewId); processView(my); //filling view 但它在RemoteViews中

How to capitalize the first character of each word in a string

Is there a function built into Java that capitalizes the first character of each word in a String, and does not affect the others? Examples: jon skeet -> Jon Skeet miles o'Brien -> Miles O'Brien (B remains capital, this rules out Title Case) old mcdonald -> Old Mcdonald * *( Old McDonald would be find too, but I don't expect it to be THAT smart.) A quick look at t

如何大写字符串中每个单词的第一个字符

Java中内置了一个函数,用于将每个单词的第一个字符转换为字符串,并且不影响其他字符? 例子: jon skeet - > Jon Skeet miles o'Brien - > Miles O'Brien (B保留资本,这排除了标题案例) old mcdonald - > Old Mcdonald * *( Old McDonald也可以找到,但我不认为它很聪明。) 快速浏览一下Java String Documentation,只会揭示toUpperCase()和toLowerCase() ,这当然不会提供所需的行为。 当

Mock private method in the same class that is being tested

I have a Java class named, MyClass , that I want to test with JUnit. The public method, methodA , that I want to test calls a private method, methodB , in the same class to determine which conditional path to follow. My goal is to write JUnit tests for the different paths in methodA . Also, methodB calls a service, so I do not want it to actually be executed when I run the JUnit tests. What

在正在测试的同一类中模拟私有方法

我有一个名为MyClass的Java类,我想用JUnit进行测试。 公共方法methodA ,我想测试调用私有方法, methodB ,在同级别来确定要遵循的条件路径。 我的目标是为methodA的不同路径编写JUnit测试。 此外, methodB调用一个服务,所以我不希望它在我运行JUnit测试时被实际执行。 模拟methodB并控制其返回以便我可以测试'methodA'的不同路径的最佳方法是什么? 我更喜欢在写模拟时使用JMockit,所以我特别感兴趣的是适

Hashmap and how this works behind the scene

This question already has an answer here: How does Java HashMap store entries internally 3 answers Please also note, there are several ways HashMap can implement hash codes collision resolution, not only utilizing linked list as you mentioned Java's HashMap implementation does not only use LinkedList strategy to handle key-values with same key.hashCode() values. Also, you may want to

散列图以及它如何在幕后工作

这个问题在这里已经有了答案: Java HashMap如何在内部存储条目3个答案 另请注意,HashMap可以通过多种方式实现哈希码冲突解决方案,不仅可以像您提到的那样利用链接列表 Java的HashMap实现不仅使用LinkedList策略来处理具有相同key.hashCode()值的键值。 另外,你可能想阅读这篇文章 是的,你的理解是正确的。 请注意,单个桶分配了许多哈希码:在新的HashMap中共有16个桶,每个桶分配了总共232/16 = 228个哈希码。

Java equivalent for CultureInfo.InvariantCulture Property in C#

Yes,I am new to java and this question is asked in some other links in stackoverflow ( Java equivalent of Invariant Culture). But still there is no conclusion stating that, There is no equivalent in java to do this There is an alternative Also what will the below statement do in java. Locale invariant = new Locale("","",""); Am interested in the above statement because in C# the below co

C#中CultureInfo.InvariantCulture属性的Java等价物

是的,我是新来的Java和这个问题在一些其他链接在stackoverflow(Java相当于不变的文化)。 但仍然没有结论说明, 在java中没有这样做的等价物 有一个选择 下面的语句在java中会做什么? Locale invariant = new Locale("","",""); 我对上述语句感兴趣,因为在C#中,下面的代码将带来Invariant文化设置。 CultureInfo Invc = New CultureInfo(""); 我想知道这是否有可能在java中具有不变的文化设置,是否可以通过任

java.lang.OutOfMemoryError: GC overhead limit exceeded excel reader

I am getting a java.lang.OutOfMemoryError: GC overhead limit exceeded exception when I try to run the program below. This program's main method access' a specified directory and iterates over all the files that contain .xlsx. This works fine as I tested it before any of the other logic. And the method it is calling xlsx which basically converts the xlsx file into csv and appends it to

java.lang.OutOfMemoryError:超出了Excel阅读器的GC开销限制

我得到一个java.lang.OutOfMemoryError:当我尝试运行下面的程序时GC溢出限制超出异常。 该程序的主要方法访问'指定的目录并迭代包含.xlsx的所有文件。 这工作正常,因为我在任何其他逻辑之前测试它。 它调用xlsx的方法基本上可以将xlsx文件转换为csv,并将其附加到现有的文件中。 但是当我把它放在for循环中时,这是当我得到这个异常。 我猜测它有一个冲突,当它打开xlsx并将其转换为csv并打开第二个时间时,也许我必