I'm reading the Book Java Concurrency in Practice. In chapter 15, they are talking about the nonblocking algorithms and the compare-and-swap (CAS) method. It is written that CAS perform much better than the locking methods. I want to ask the people who already worked with both of these concepts and would like to hear when you are preferring which one of these concepts? Is it really so mu
我正在阅读Book Java Concurrency in Practice。 在第15章中，他们正在讨论非阻塞算法和比较与交换（CAS）方法。 据写道，CAS性能比锁定方法好得多。 我想问问那些已经与这两个概念合作过的人，并且希望听到您何时更喜欢这些概念中的哪一个？ 它真的太快了吗？ 对我而言，锁的使用更加清晰易懂，甚至更好维护（如果我错了，请纠正我的错误）。 我们是否真的应该专注于创建与CAS相关的并发代码而不是锁，以获得更好的性能
My question is what is a good way to implement upgrading outdated objects? For example say you have a class like this: public class Foo() implements Serializable { int a; String b; } and then you serialize this object. Then later on you add more functionality to your class by say adding: ... int c; ... You still want to retain the information that is in the serialized object but I
我的问题是什么是实现升级过时对象的好方法？ 例如，假设你有这样的课程： public class Foo() implements Serializable { int a; String b; } 然后你序列化这个对象。 然后，稍后通过添加以下内容，可以为课程添加更多功能： ... int c; ... 您仍然希望保留序列化对象中的信息，但我知道如果您试图反序列化它，就会出现冲突。 那么有没有办法（可能通过检查serialVersionUID）为int c设置一个值，知道它不会存
I have yet another Java question :) I have read this thread, where it explains it clearly, but I have two bi-dimensional arrays that I would like to copy. I understand that this piece of code int[] array1and2 = new int[array1.length + array2.length]; System.arraycopy(array1, 0, array1and2, 0, array1.length); System.arraycopy(array2, 0, array1and2, array1.length, array2.length); But my quest
我还有另一个Java问题:) 我已经阅读了这个线程，它在那里解释清楚，但我有两个我想复制的二维数组。 我明白这段代码 int[] array1and2 = new int[array1.length + array2.length]; System.arraycopy(array1, 0, array1and2, 0, array1.length); System.arraycopy(array2, 0, array1and2, array1.length, array2.length); 但我的问题是，我如何将它与两个数组合并在一起 int a1[][] = new int [3][3]; int b1[][] = new int
In my bouncing ball program, it asks the user to insert a number of balls which will be displayed on the screen and will start at the top of the canvas then drop and bounce on a line on the bottom of the canvas. When finished = true, the animation will stop. So far the animation stops once the X position of the first ball goes past 550. How do I make the animation end once the X position of EV
在弹跳球程序中，它要求用户插入一些将显示在屏幕上的球，并将从画布顶部开始，然后在画布底部的一条线上落下并弹起。 完成= true时，动画将停止。 到目前为止，一旦第一个球的X位置超过550，动画就会停止。一旦每个球的X位置超过550，我该如何让动画结束？ public void multiBounce(int numBalls) { BouncingBall[] balls; balls = new BouncingBall[numBalls]; int x = 50; int y = 150; for (int i
I use the following code to match the user touch to a ball object's position, so when the user touches the ball it bounce back up. Code: int x1 = Gdx.input.getX(); int y1 = Gdx.input.getY(); Vector3 input = new Vector3(x1, y1, 0); cam.unproject(input); if(ball.getBoundingCircle().contains(input.x, input.y)) { ballBounce(); } But I have a problem with the touch. If the user touches a cert
我使用下面的代码来将用户触摸与球对象的位置进行匹配，所以当用户触摸球时它会反弹回来。 码： int x1 = Gdx.input.getX(); int y1 = Gdx.input.getY(); Vector3 input = new Vector3(x1, y1, 0); cam.unproject(input); if(ball.getBoundingCircle().contains(input.x, input.y)) { ballBounce(); } 但是我的触摸有问题。 如果用户触摸屏幕上的某个位置一会儿，并且一个球（稍后出现一段时间）即将到达用户触摸的位置，球
Is there a way to iterate over Java SparseArray (for Android) ? I used sparsearray to easily get values by index. I could not find one. Seems I found the solution. I hadn't properly noticed the keyAt(index) function. So I'll go with something like this: for(int i = 0; i < sparseArray.size(); i++) { int key = sparseArray.keyAt(i); // get the object by the key. Object ob
有没有办法来迭代Java SparseArray（Android版）？ 我用sparsearray很容易通过索引获取值。 我找不到一个。 似乎我找到了解决方案。 我没有正确注意到keyAt(index)函数。 所以我会像这样去做： for(int i = 0; i < sparseArray.size(); i++) { int key = sparseArray.keyAt(i); // get the object by the key. Object obj = sparseArray.get(key); } 如果您不关心这些键，那么可以在遍历稀疏数组时直接使用va
i have a folder in the GoogleDrive. Its named 'lgc'. In it, i have a file info. I know the ID of the folder, but i dont know the ID of 'info' text file in it. I want to UPDATE the content of 'info' file, Conditions to update: I dont want to change file name or title, only wanting to change its contents. I dont want to use File ID for 'info' file. Using sea
我在GoogleDrive中有一个文件夹。 它的名字叫做'lgc'。 其中，我有一个文件信息。 我知道该文件夹的ID，但我不知道其中的'info'文本文件的ID。 我想更新'info'文件的内容，更新条件： 我不想更改文件名或标题，只想更改其内容。 我不想使用'信息'文件的文件ID。 使用搜索查询，只会导致名称为'info'的文件。 那么，如何找到没有ID的文件，以及如何更新它？ 我看了Google De
I have been developing web application checking if there were any changes in Google Drive files. It takes care about several folders and use Google Drive API changes. So far I am trying to get all files from watched folders, save their state (name, parent folder, etc.), get list of changes from GDrive API, then looking for changes with matching FileId and finally compare state before and after
我一直在开发Web应用程序，检查Google Drive文件是否有任何更改。 它需要关注几个文件夹并使用Google Drive API更改。 到目前为止，我试图从监视的文件夹中获取所有文件，保存它们的状态（名称，父文件夹等），从GDrive API获取更改列表，然后查找匹配的FileId的更改，最后比较更改前后的状态。 我想知道是否有更简单的方法来确定一种更改（移动/删除文件，更改名称）？ 更改要么是删除（ deleted将设置为true ），要么是
Hi >Whats should be the output of the following code and why? >the output turned out to be 131713.Below is the code. the object >references are interchanging so the values are changing. enter code here public class Test { int age; String name; Test(int age,String name){ this.age=age; this.name=name; } public static void main(String[] args){ Test t1 = new Test(17,"A"); Test t2 = new
你好 >Whats should be the output of the following code and why? >the output turned out to be 131713.Below is the code. the object >references are interchanging so the values are changing. enter code here 公共类Test {int age; 字符串名称; Test(int age,String name){ this.age=age; this.name=name; } public static void main（String [] args）{ Test t1 = new Test(17,"A"); Test t2 = new Tes
Created a new class to test something with AES in CBC and CTR mode. So with this code, CTR is working fine, but CBC returns empty arrays. Not sure why this happens, hope somebody can explain that. import org.junit.Before; import org.junit.Test; import javax.crypto.BadPaddingException; import javax.crypto.Cipher; import javax.crypto.IllegalBlockSizeException; import javax.crypto.spec.IvParamet
创建了一个新类，用CBC和CTR模式下的AES进行测试。 因此，使用此代码，CTR工作正常，但CBC会返回空数组。 不知道为什么会发生这种情况，希望有人能解释这一点。 import org.junit.Before; import org.junit.Test; import javax.crypto.BadPaddingException; import javax.crypto.Cipher; import javax.crypto.IllegalBlockSizeException; import javax.crypto.spec.IvParameterSpec; import javax.crypto.spec.SecretKeySpec;