java-7

This is a test about thread priority. The code is from Thinking in Java p.809 import java.util.concurrent.*; public class SimplePriorities implements Runnable { private int countDown = 5; private volatile double d; // No optimization private int priority; public SimplePriorities(int priority) { this.priority = priority; } public String toString() { return Thread.currentThread() + ": " + countDown; } public void run() { Thread.currentThread().setPriority(priority); while (true) { // An expensive, interruptable operation: for (int i = 1; i < 10000000; i++) { d += (Math.PI + Math.E) / (double) i;

Until Java 6, we had a constant time substring on String . In Java 7, why did they decide to go with copying char array - and degrading to linear time complexity - when something like StringBuilder was exactly meant for that? Why they decided is discussed in Oracle bug #4513622 : (str) keeping a substring of a field prevents GC for object : When you call String.substring as in the example, a new character array for storage is not allocated. It uses the character array of the original String. Thus, the character array backing the the original String can not be GC'd until the substring's

I am trying to enable TLS 1.2 in my web app which uses JBoss 6.4 and Java 1.7. I have -Dhttp.protocols = TLSv1.2 in my application environment but it doesn't seem to work for me. Is there anything I could do to enable TLS 1.2? I wrote a simple program context = SSLContext.getInstance("TLSv1.2"); context.init(null,null,null); SSLContext.setDefault(context); SSLSocketFactory factory = (SSLSocketFactory)context.getSocketFactory(); SSLSocket socket = (SSLSocket)factory.createSocket(); protocols = socket.getEnabledProtocols(); After running this program within the app the TLS 1.2 gets enabled. I do

I am trying out the new Gmail API and the samples use the classes in the java.nio.file package, e.i. Files and FileSystems . These classes was introduced in Java jdk 1.7 for the record, and since I am running jdk 1.7.0_65 in my Android app I have no idea why Android Studio cannot find these classes. The imports are: import java.nio.file.FileSystems; import java.nio.file.Files; My build.gradle file of course tells the system to use v. 1.7 like this android { compileSdkVersion 19 buildToolsVersion '20' ... compileOptions { sourceCompatibility JavaVersion.VERSION_1_7 targetCompatibility

This question already has an answer here: Java Jar file: use resource errors: URI is not hierarchical 6 answers I have files in resource folder. For example if I need to get file from resource folder, I do like that: File myFile= new File(MyClass.class.getResource(/myFile.jpg).toURI()); System.out.println(MyClass.class.getResource(/myFile.jpg).getPath()); I've tested and everything works ! The path is /D:/java/projects/.../classes/X/Y/Z/myFile.jpg But , If I create jar file, using , Maven : mvn package ...and then start my app: java -jar MyJar.jar I have that following error: Exception in

I made a color palette with a jPanel and a JLabel array in it. At first it worked well, but then i put some other jLabels out of the JPanel and added them some events. Now I keep getting this error: Exception in thread "AWT-EventQueue-0" java.lang.IllegalArgumentException: Comparison method violates its general contract! at java.util.TimSort.mergeLo(TimSort.java:747) at java.util.TimSort.mergeAt(TimSort.java:483) at java.util.TimSort.mergeCollapse(TimSort.java:410) at java.util.TimSort.sort(TimSort.java:214) at java.util.TimSort.sort(TimSort.java:173) at java.util.Arrays.sort(Arrays.java:659)