What is the native keyword in Java for?

While playing this puzzle (It's a Java keyword trivia game), I came across the native keyword. What is the native keyword in Java used for? native关键字应用于一种方法,以指示该方法使用JNI(Java Native Interface)以本机代码实现。 It marks a method, that it will be implemented in other languages, not in Java. It works together with JNI (Java Native Interface). Native methods were used i

Java中的native关键字是什么?

当玩这个谜题(这是一个Java关键字琐事游戏)时,我遇到了native关键字。 Java中使用的native关键字是什么? native关键字应用于一种方法,以指示该方法使用JNI(Java Native Interface)以本机代码实现。 它标志着一种方法,它将以其他语言实现,而不是Java。 它与JNI(Java本地接口)一起工作。 过去使用本地方法来编写性能关键部分,但是Java变得更快,现在不太常见。 当时需要本地方法 您需要从Java调用其他语言

What is the equivalent of the C# 'var' keyword in Java?

One use of the var keyword in C# is implicit type declaration. What is the Java equivalent syntax for var? There is none. Alas, you have to type out the full type name. Edit 6 years after being posted, to collect some of the comments from below: The reason C# has the var keyword is because it's possible to have Types that have no name in .NET. Eg: var myData = new { a = 1, b = "2" }

Java中C#'var'关键字的等价物是什么?

在C#中使用var关键字是隐式类型声明。 什么是var的Java等价语法? 空无一人。 唉,你必须输入完整的类型名称。 在发布6年后编辑,收集下面的一些评论: C#具有var关键字的原因是因为可能有.NET中没有名称的类型。 例如: var myData = new { a = 1, b = "2" }; 在这种情况下,将不可能给myData一个正确的类型。 6年前,这在Java中是不可能的(所有类型都有名称,即使它们非常冗长而且不流畅)。 我不知道这是否同

Why is a static method considered a method?

I'm writing an explanation for some code for a course, and have been accidentally using the words method and function interchangeably. I decided to go back over and fix the wording, but ran into a hole in my understanding. From what I understand, a subroutine is a function if it doesn't act on an instance of a class (its effect is restricted to its explicit input/output), and is a meth

为什么静态方法被认为是一种方法?

我正在为一门课程的一些代码写一篇解释,并且已经意外地使用了单词method和function 。 我决定回去修改措辞,但在我的理解中遇到了一个漏洞。 据我所知,一个子程序是一个function如果它不作用于一个类的实例(其效果仅限于其明确的输入/输出),并且是一个method如果它在类的一个实例上运行可能会对不纯的实例产生副作用)。 这里有一个很好的讨论这个话题。 请注意,通过接受的答案的定义,静态method实际上应该是一个函

Problem using the nextLine() and hasNextLine() methods of Scanner

I have a log file containing the following data: Shortest path(2)::RV3280-RV0973C-RV2888C Shortest path(1)::RV3280-RV2502C Shortest path(2)::RV3280-RV2501C-RV1263 Shortest path(2)::RV2363-Rv3285-RV3280 From each line, i require the number within the brackets, name of the first protein (RV3280 in the first line) and the name of the last protein (RV2888C in the first line). I have writt

使用Scanner的nextLine()和hasNextLine()方法时出现问题

我有一个包含以下数据的日志文件: 最短路径(2):: RV3280-RV0973C-RV2888C 最短路径(1):: RV3280-RV2502C 最短路径(2):: RV3280-RV2501C-RV1263 最短路径(2):: RV2363-Rv3285-RV3280 从每一行中,我需要括号内的数字,第一个蛋白质的名称(第一行中的RV3280)和最后一个蛋白质(第一行中的RV2888C)的名称。 我已经使用Scanner对象为此编写了代码。 try{ Scanner s = new Scanner(new File(

Difference between Authenticode, SPC and Java CodeSign?

Most CAs are selling code signing certificates in different "products", like Verisign or Certum: Microsoft Authenticode - "Allows you to sign EXE, OCX, DLL, bla..." Java CodeSign - "Allows you to sign Java code" Software Publisher Certificate - "Allows you to sign software" Well, I am REALLY confused about this. What is the difference between all t

Authenticode,SPC和Java CodeSign之间的区别?

大多数CA在不同的“产品”中销售代码签名证书,例如Verisign或Certum: Microsoft Authenticode - “允许您签署EXE,OCX,DLL,bla ...” Java CodeSign - “允许您签署Java代码” 软件出版商证书 - “允许您签署软件” 那么,我真的很困惑这一点。 所有这些产品之间有什么区别 - 除了PRICE? 自从我好奇之后,我问Verisign和其他CA几次,但没有回答。 我从Certum CA获得Authenticode证书。 我将它注册到Internet Explore

Programmatically Hide/Show Android Soft Keyboard

Possible Duplicate: Close/hide the Android Soft Keyboard First thing first I already saw this thread. I tried accepted methods given there..But nothing worked for me.. I have two screens in my app. First one have 2 EditText's - One for username and one for password Second one have one ListView, and an EditText - to filter the listView In my first screen, I want username EditText

以编程方式隐藏/显示Android软键盘

可能重复: 关闭/隐藏Android软键盘 首先我已经看到这个线程。 我尝试了在那里接受的方法..但没有为我工作.. 我的应用程序中有两个屏幕。 首先有两个EditText - 一个用于用户名,一个用于密码 第二个有一个ListView和一个EditText - 来过滤listView 在我的第一个屏幕上,我希望用户名EditText专注于启动和键盘应该是可见的 ..这是我的实现(通过删除不必要/不相关的代码简化).. app_login.xml <LinearLayou

Difference between HashMap, LinkedHashMap and TreeMap

What is the difference between HashMap , LinkedHashMap and TreeMap in Java? I don't see any difference in the output as all the three has keySet and values . What are Hashtable s? Map m1 = new HashMap(); m1.put("map", "HashMap"); m1.put("schildt", "java2"); m1.put("mathew", "Hyden"); m1.put("schildt", "java2s"); print(m1.keySet()); print(m1.values()); SortedMap sm = new TreeMap(); sm.pu

HashMap,LinkedHashMap和TreeMap之间的区别

Java中的HashMap , LinkedHashMap和TreeMap什么区别? 我没有看到输出中的任何差异,因为所有三个都有keySet和values 。 什么是Hashtable ? Map m1 = new HashMap(); m1.put("map", "HashMap"); m1.put("schildt", "java2"); m1.put("mathew", "Hyden"); m1.put("schildt", "java2s"); print(m1.keySet()); print(m1.values()); SortedMap sm = new TreeMap(); sm.put("map", "TreeMap"); sm.put("schildt", "java2"); sm

Difference between wait() and sleep()

What is the difference between a wait() and sleep() in Threads? Is my understanding that a wait() -ing Thread is still in running mode and uses CPU cycles but a sleep() -ing does not consume any CPU cycles correct? Why do we have both wait() and sleep() : how does their implementation vary at a lower level? A wait can be "woken up" by another thread calling notify on the monitor w

wait()和sleep()之间的区别

线程中的wait()和sleep()有什么区别? 我的理解是wait() ing线程仍处于运行模式并使用CPU周期,但sleep()不会消耗任何CPU周期正确吗? 为什么我们同时wait()和sleep() :它们的实现在较低的层次上如何变化? 一个wait可以被另一个线程唤醒,这个线程正在等待的监视器上notify ,而sleep不能。 wait (和notify )也必须在监视器对象上synchronized的块中发生,而sleep不会: Object mon = ...; synchronized (mon) {

"implements Runnable" vs. "extends Thread"

From what time I've spent with threads in Java, I've found these two ways to write threads: With implements Runnable : public class MyRunnable implements Runnable { public void run() { //Code } } //Started with a "new Thread(new MyRunnable()).start()" call Or, with extends Thread : public class MyThread extends Thread { public MyThread() { super("MyThread"

“实现Runnable”与“扩展线程”

从我在Java中使用线程的时间开始,我发现了这两种编写线程的方法: 使用可运行的implements Runnable : public class MyRunnable implements Runnable { public void run() { //Code } } //Started with a "new Thread(new MyRunnable()).start()" call 或者,通过extends Thread : public class MyThread extends Thread { public MyThread() { super("MyThread"); } public void ru

Java inner class and static nested class

What is the main difference between an inner class and a static nested class in Java? Does design / implementation play a role in choosing one of these? From the Java Tutorial: Nested classes are divided into two categories: static and non-static. Nested classes that are declared static are simply called static nested classes. Non-static nested classes are called inner classes. Static ne

Java内部类和静态嵌套类

Java中的内部类和静态嵌套类之间的主要区别是什么? 设计/实施在选择其中一种方面起作用吗? 从Java教程: 嵌套类分为两类:静态和非静态。 被声明为静态的嵌套类简单地称为静态嵌套类。 非静态嵌套类称为内部类。 静态嵌套类可以使用封闭类名来访问: OuterClass.StaticNestedClass 例如,要为静态嵌套类创建对象,请使用以下语法: OuterClass.StaticNestedClass nestedObject = new OuterClass.StaticNestedClass(