In Delphi I can do the following with a boolean variable: If NOT bValue then begin //do some stuff end; Does the equivalent in Java use the !? If !(bValue) { //do some stuff } Yes, but inside the bracket: if (!bValue) { } You'd normally not use any sort of data type prefix in Java as well, so it would more likely be something like: if (!isGreen) { // or some other meaningful variab
在Delphi中，我可以用一个布尔变量来完成以下工作： If NOT bValue then begin //do some stuff end; Java中的等价物是否使用！？ If !(bValue) { //do some stuff } 是的，但在括号内： if (!bValue) { } 您通常不会在Java中使用任何类型的数据类型前缀，因此它更可能是这样的： if (!isGreen) { // or some other meaningful variable name } 你很近; 正确的语法是： if (!bValue) { //do some stuff } 整个
Here is the code segments Can you explain why outputs are varying 1) public static ShortCkt { public static void main(String args[]) { int i = 0; boolean t = true; boolean f = false, b; b = (t && ((i++) == 0)); b = (f && ((i+=2) > 0)); System.out.println(i); } } output in this case is 1 2) public static Shor
这是代码段 你能解释为什么产出会变化吗？ 1） public static ShortCkt { public static void main(String args[]) { int i = 0; boolean t = true; boolean f = false, b; b = (t && ((i++) == 0)); b = (f && ((i+=2) > 0)); System.out.println(i); } } 这种情况下的输出是1 2） public static ShortCkt { public static void
In other words, do the following two statements behave the same way? isFoobared = isFoobared && methodWithSideEffects(); isFoobared &= methodWithSideEffects(); I realize I could just write up a test, but someone might know this offhand, and others might find the answer useful. No, |= and &= do not shortcircuit, because they are the compound assignment version of & and | ,
换句话说，以下两个陈述的行为方式是一样的吗？ isFoobared = isFoobared && methodWithSideEffects(); isFoobared &= methodWithSideEffects(); 我意识到我可以写一个测试，但有人可能会知道这一点，其他人可能会发现有用的答案。 不， |=和&=不会短路，因为它们是&和|的复合赋值版本 ，它不会短路。 JLS 15.26.2复合赋值运算符 E1 op= E2形式的复合赋值表达式等价于E1 = (T)((E1) op (E2)) ，其
Recently I saw a code using this: boolean val = something(); val |= somethingElse(); Interesting part is |= (binary like) operator made on boolean primitive type. It surprised me that |= exist for boolean, as if it was integer type, and searched Java specification for this operator, but could not find any. I'd be curious if right operand is evaluated if left value already is true. Can
最近我看到一个代码使用这个： boolean val = something(); val |= somethingElse(); 有趣的部分是在布尔基元类型上生成的| =（二进制样）运算符。 令我惊讶的是，| =存在布尔值，就好像它是整数类型一样，并且搜索此运算符的Java规范，但找不到任何。 我很好奇，如果右操作数被评估，如果左值已经是真的。 有人能指出我对此的Java规范吗？ 从JLS： 15.26.2。 复合分配算子 E1 op= E2形式的复合赋值表达式等价于E
This question already has an answer here: Shortcut “or-assignment” (|=) operator in Java 8 answers 这是对声明的简短陈述： noti.flags = noti.flags | Notification.FLAG_AUTO_CANCEL; It's a Bitwise OR operator used as assignment noti.flags |= Notification.FLAG_AUTO_CANCEL; is the same of noti.flags = noti.flags | Notification.FLAG_AUTO_CANCEL It's the assignment version of the Bitwise
这个问题在这里已经有了答案： Java 8中的快捷方式“or-assignment”（| =）运算符会回答 这是对声明的简短陈述： noti.flags = noti.flags | Notification.FLAG_AUTO_CANCEL; 这是一个用作赋值的按位或运算符 noti.flags |= Notification.FLAG_AUTO_CANCEL; 是一样的 noti.flags = noti.flags | Notification.FLAG_AUTO_CANCEL 它是Bitwise Or运算符的赋值版本，即： noti.flags = noti.flags | Notification.FLAG_AUTO_
Possible Duplicate: Shortcut “or-assignment” (|=) operator in Java I found the following example code in the Android SDK docs: boolean retValue = false; retValue |= mActionBarHelper.onCreateOptionsMenu(menu); retValue |= super.onCreateOptionsMenu(menu); Can anyone show me equivalent code, to demonstrate what this does? Note: I assume the method calls return a boolean value, so
可能重复： Java中的快捷方式“or-assignment”（| =）运算符 我在Android SDK文档中找到以下示例代码： boolean retValue = false; retValue |= mActionBarHelper.onCreateOptionsMenu(menu); retValue |= super.onCreateOptionsMenu(menu); 任何人都可以向我展示相当的代码，以证明这是什么？ 注：我假设方法调用返回一个布尔值，所以我喜欢看一个例子，这看起来像一个if-else结构。 速记为我or与我分配给
This question already has an answer here: Shortcut “or-assignment” (|=) operator in Java 8 answers What does “|=” mean? (pipe equal operator) 6 answers noti.flags |= Notification.FLAG_AUTO_CANCEL; means noti.flags = noti.flags | Notification.FLAG_AUTO_CANCEL; where | is the Bit wise OR operator | is the bit a bit or operator |= is noti.flags = noti.flags | Notification.FLAG_AUTO_C
这个问题在这里已经有了答案： Java 8中的快捷方式“or-assignment”（| =）运算符会回答 “| =”是什么意思？ （管道相同的操作员）6个答案 noti.flags |= Notification.FLAG_AUTO_CANCEL; 手段 noti.flags = noti.flags | Notification.FLAG_AUTO_CANCEL; 在哪里| 是Bit wise OR operator | 是一点点还是操作员 | =是noti.flags = noti.flags | Notification.FLAG_AUTO_CANCEL; noti.flags | = Notification.FLA
I have so input <input type="date" name="date"> How to read from this input to java object of class java.util.Date? PS Date date is a field of my Bean, which I read so: @RequestMapping("/updateVacancy") public String updateVacancy(@ModelAttribute("vacancy") Vacancy vacancy){ vacancyService.update(vacancy); return "VacancyDetails"; } You may receive date as te
我有这样的意见 <input type="date" name="date"> 如何从此输入读取java.util.Date类的java对象？ PS日期日期是我的Bean的一个字段，我这样读： @RequestMapping("/updateVacancy") public String updateVacancy(@ModelAttribute("vacancy") Vacancy vacancy){ vacancyService.update(vacancy); return "VacancyDetails"; } 您可能会收到日期文本，然后将其解析为java.util.Date 例如像
We need to implement a graceful shutdown mechanism into our Servlet application. EDIT: We want to make it simple as possible, which would be handling a kill signal sent via operating system's function. This would allow system admins to use built in shell utilities (kill or taskkill on Windows), otherwise they would have to install another utility just to "talk" with server. Thi
我们需要在我们的Servlet应用程序中实现一个正常的关闭机制。 编辑：我们希望尽可能简单，这将处理通过操作系统功能发送的杀死信号。 这将允许系统管理员使用内置的shell实用程序（在Windows上终止或taskkill），否则他们将不得不安装另一个实用程序来与服务器“交谈”。 该机制分两个阶段进行： 在关闭请求时，拒绝某些关键活动 阻止直到先前启动的关键动作完成; 这些可能需要几个小时 阶段＃1在我们的DAO层中实现。
I need to get the total ram size of the computer using java. I've tried this: package test; import java.lang.management.ManagementFactory; public class test1 { public static void main(String[] args) { com.sun.management.OperatingSystemMXBean mxbean = (com.sun.management.OperatingSystemMXBean) ManagementFactory.getOperatingSystemMXBean(); float a = mxbea
我需要使用java来获得计算机的总RAM大小。 我试过这个： package test; import java.lang.management.ManagementFactory; public class test1 { public static void main(String[] args) { com.sun.management.OperatingSystemMXBean mxbean = (com.sun.management.OperatingSystemMXBean) ManagementFactory.getOperatingSystemMXBean(); float a = mxbean.getTotalPhysicalMemorySize(