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How is CountDownLatch used in Java Multithreading?
Can someone help me to understand what Java CountDownLatch is and when to use it?
12 Answers
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What's the advantage of a Java enum versus a class with public static final fields?
I am very familiar with C# but starting to work more in Java. I expected to learn that enums in Java were basically equivalent to those in C# but apparently this is not the case. Initially I was excited to learn that Java enums could contain multiple pieces of data which seems very advantageous ( ht...
round up to 2 decimal places in java? [duplicate]
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did you import java.text.DecimalFormat; ?
– amitchhajer
Jul 28 '12 at 13:42
2
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Java: method to get position of a match in a String?
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text.indexOf(match);
See the String javadoc
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Performing user authentication in Java EE / JSF using j_security_check
...web application making use of JSF 2.0 (and if any components do exist) and Java EE 6 core mechanisms (login/check permissions/logouts) with user information hold in a JPA entity. The Oracle Java EE tutorial is a bit sparse on this (only handles servlets).
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How to convert Milliseconds to “X mins, x seconds” in Java?
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Use the java.util.concurrent.TimeUnit class:
String.format("%d min, %d sec",
TimeUnit.MILLISECONDS.toMinutes(millis),
TimeUnit.MILLISECONDS.toSeconds(millis) -
TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes...
Is System.nanoTime() completely useless?
As documented in the blog post Beware of System.nanoTime() in Java , on x86 systems, Java's System.nanoTime() returns the time value using a CPU specific counter. Now consider the following case I use to measure time of a call:
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How do I initialize a byte array in Java?
I have to store some constant values (UUIDs) in byte array form in java, and I'm wondering what the best way to initialize those static arrays would be. This is how I'm currently doing it, but I feel like there must be a better way.
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Java serialization: readObject() vs. readResolve()
The book Effective Java and other sources provide a pretty good explanation on how and when to use the readObject() method when working with serializable Java classes. The readResolve() method, on the other hand, remains a bit of a mystery. Basically all documents I found either mention only one o...
How can I send an email by Java application using GMail, Yahoo, or Hotmail?
Is it possible to send an email from my Java application using a GMail account? I have configured my company mail server with Java app to send email, but that's not going to cut it when I distribute the application. Answers with any of using Hotmail, Yahoo or GMail are acceptable.
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