java-7

问题 Java 7 has been out for a while now, but I cannot find any good resources on the configuration of the garbage collectors , specifically the new G1 collector . My questions: Is G1 the default collector in Java 7 and if not how do I activate G1? What optional settings does g1 have in Java7? Were there any changes made to other collectors like cms or the parallel collector in Java 7? Where can I find good documentation on garbage collection in Java 7? 回答1: The G1 garbage collector is not the

问题 I just encountered a strange error when switching the JDK version of a new Project of mine from 7u45 to 8u20. A harmless LogManager declaration at the beginning of my class is being refused with the following error: The type java.lang.reflect.AnnotatedElement cannot be resolved. It is indirectly referenced from required .class files This is the code: public class Class1 { private static Logger log = LogManager.getLogger(Class1.class); ... Eclipse proposes me to configure the build path, but I

问题 I have designed a javafx application which works fine in jdk 7. When I try to run it in java 8 I am getting the below exceptions: javafx.fxml.LoadException: at javafx.fxml.FXMLLoader.constructLoadException(FXMLLoader.java:2617) at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2595) at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2441) at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3230) at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3191) at javafx.fxml.FXMLLoader.loadImpl

问题 I have designed a javafx application which works fine in jdk 7. When I try to run it in java 8 I am getting the below exceptions: javafx.fxml.LoadException: at javafx.fxml.FXMLLoader.constructLoadException(FXMLLoader.java:2617) at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2595) at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2441) at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3230) at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3191) at javafx.fxml.FXMLLoader.loadImpl

问题 I know of the Apache Commons IO library for file directory processing in Java. However, List all files from a directory recursively with Java talks about native support in Java 7. Does anyone have experience on how to recursively list/read files in a directory using Java 7? 回答1: There's a tutorial on it. Basically you implement a Visitor which can then be called as directories are entered, exited, and files are encountered. There is support for determining if files are symbolic links, and

问题 I have to implement a Server which should accept more connections. Without any deeper thoughts i decided to use the new JAVA NIO.2 classes. My current approach is: final Semaphore wait = new Semaphore(1); while(true){ wait.acquire(); this.asyncSocket.accept(null, new CompletionHandler<AsynchronousSocketChannel, Void>() { @Override public void completed(AsynchronousSocketChannel result, Void attachment) { wait.release(); asyncSocket.accept(null, this); ... } ... } } if i don't add the

问题 After installation of JDK kit in Windows Server 64 bit I discovered there is no client folder in C:\Program Files\Java\jre7\bin , its directory structure according to http://www.oracle.com/technetwork/java/javase/jre-7-readme-430162.html ( If it is correct then what about the registry entry ) Is this a bug? 来源： https://stackoverflow.com/questions/22318204/no-client-in-c-program-files-java-jre7-bin-in-jdk-7u51-windows-x64

问题 Hi I'm trying to check if the currentime is > , say, 14:00. Does anyone know how to do this? This is what I have: SimpleDateFormat dateFormat = new SimpleDateFormat("yyyyMMdd HH:mm"); Somehow I guess I need to now create a Date object and use this dateformat? I know the current time is: date= new Date(); and in the above format it would be return dateFormat.format(date); So can anyone help - much appreciated. (am using Java 7 btw) 回答1: Try below code, it should work. Date date = new Date() ;

问题 why does this: import java.util.*; public class my { public static void main(String[] a) { TreeMap<TreeSet<Integer>, String> map = new TreeMap<TreeSet<Integer>, String>(); TreeSet<Integer> set = new TreeSet<Integer>(); map.put(set, "lol"); } } work in Java 6? I mean that by specification putting TreeSet as a key of TreeMap without proper Comparator should lead to ClassCastException but it doesn't when running under Java 6. Was it a bug or there were some specification changes in Java 7 that

问题 I have a Jersey application running on Glassfish 4 (4.1 build 13), JDK 1.7 update 67 and AWS Linux AMI and I'm noticing that after some hours running it, CPU usage goes up and stays up even though clients are stopped. Running "top -H" identifies 2 http-listener-1-kernel threads with high CPU usage (from a total of 16). I then took a thread dump to check these two threads: "http-listener-1-kernel(3) SelectorRunner" daemon prio=10 tid=0x00007fbc68251000 nid=0xaee runnable [0x00007fbcb55ce000]