java-8

问题 I'm using Play 2.4.0 and I've been trying to follow the tutorial from the main page: https://playframework.com/ which is for Play 2.3 and after solving a couple of issues regarding changes in the Ebean ORM from version 2.3 to 2.4, I'm stuck with the following error: Compilation error value at is not a member of controllers.ReverseAssets My index.scala.html : @(message: String) @main("Welcome to Play") { <script type='text/javascript' src="@routes.Assets.at("javascripts/index.js")"></script>

问题 To better understand the new stream API I'm trying to convert some old code, but I'm stuck on this one. public Collection<? extends File> asDestSet() { HashMap<IFileSourceInfo, Set<File>> map = new HashMap<IFileSourceInfo, Set<File>>(); //... Set<File> result = new HashSet<File>(); for (Set<File> v : map.values()) { result.addAll(v); } return result; } I can't seem to create a valid Collector for it: public Collection<? extends File> asDestSet() { HashMap<IFileSourceInfo, Set<File>> map = new

问题 To better understand the new stream API I'm trying to convert some old code, but I'm stuck on this one. public Collection<? extends File> asDestSet() { HashMap<IFileSourceInfo, Set<File>> map = new HashMap<IFileSourceInfo, Set<File>>(); //... Set<File> result = new HashSet<File>(); for (Set<File> v : map.values()) { result.addAll(v); } return result; } I can't seem to create a valid Collector for it: public Collection<? extends File> asDestSet() { HashMap<IFileSourceInfo, Set<File>> map = new

问题 I am using JDK8 (tried it on my Eclipse workspace with Win x64 u25 JDK + on Linux launched by Jenkins - jdk-8u20-linux-x64, same problem for both). I have multi-module Maven project (I am launching Maven goal "javadoc:aggregate" from a main module with packaging type "pom"). Pom build section looks like this: <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <configuration> <source>1.8</source> <target>1.8</target> <

问题 I am using JDK8 (tried it on my Eclipse workspace with Win x64 u25 JDK + on Linux launched by Jenkins - jdk-8u20-linux-x64, same problem for both). I have multi-module Maven project (I am launching Maven goal "javadoc:aggregate" from a main module with packaging type "pom"). Pom build section looks like this: <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <configuration> <source>1.8</source> <target>1.8</target> <

问题 Now with announcement of Jack Google clarified the foreseeable future of Java in relation to Android. But what are the implications to Scala and other JVM-based languages developers. In particular: Scala does it's magic due to own compiler that produces Java bytecode. But Jack toolchain doesn't deal with bytecode. Will generated bytecode gain any optimization benefits of Jack processing? Starting from Scala 12 only Java 8+ is supported. That is the generated bytecode is Java 8+ too. Can Jack

问题 In JDK 8: public static int numberOfLeadingZeros(int i) { if (i == 0) return 32; int n = 1; // if the first leftest one bit occurs in the low 16 bits if (i >>> 16 == 0) { n += 16; i <<= 16; } if (i >>> 24 == 0) { n += 8; i <<= 8; } if (i >>> 28 == 0) { n += 4; i <<= 4; } if (i >>> 30 == 0) { n += 2; i <<= 2; } n -= i >>> 31; return n; } By judging if the leftest first one bit is in the low x bits. public static int numberOfTrailingZeros(int i) { int y; if (i == 0) return 32; int n = 31; // if

问题 I have a javafx TableView and I want custom controls inside the columns. Say I want a TextField in column1 and ComboBox in column2 and DatePicker in column3 . I know that I should create a class that extends TableCell and override the updateItem() method.... But I read that specifically for this purpose we have default classes like ComboBoxTableCell , TextFieldTableCell etc in the cell package and it is recommended to use them. So I'm able to achieve this with the below code.

问题 I came across following paragraph while reading about java 8 default methods from here: If any class in the hierarchy has a method with same signature, then default methods become irrelevant. A default method cannot override a method from java.lang.Object. The reasoning is very simple, it’s because Object is the base class for all the java classes. So even if we have Object class methods defined as default methods in interfaces, it will be useless because Object class method will always be

问题 I upgraded jdk to version 7_45. After compiling and executing the jar, which works fine, i packed it into an application bundle. But unfortunately i get this error message "LSOpenURLsWithRole() failed with error -10810 for the file /Users/.../MyApp.app". The same problem with the jdk 8 Early Access. I also. tried different setting in the info.plist for the "JVMVersion" key Since the jar itself works fine, i could do a workaround by replacing the JavaApplicationStub with my own executable