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Java Timer vs ExecutorService?
I have code where I schedule a task using java.util.Timer . I was looking around and saw ExecutorService can do the same. So this question here, have you used Timer and ExecutorService to schedule tasks, what is the benefit of one using over another?
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Variable length (Dynamic) Arrays in Java
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Yes: use ArrayList.
In Java, "normal" arrays are fixed-size. You have to give them a size and can't expand them or contract them. To change the size, you have to make a new array and copy the data you want - which is inefficient and a pain for you...
How to fix: “No suitable driver found for jdbc:mysql://localhost/dbname” error when using pools? [du
....jar && wget http://central.maven.org/maven2/mysql/mysql-connector-java/5.1.27/mysql-connector-java-5.1.27.jar
– jmojico
Dec 17 '19 at 16:38
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How can I get System variable value in Java?
...s either the current value of a system wide variable or a user variable in Java, see below:
String javaHome = System.getenv("JAVA_HOME");
For more information on environment variables see this wikipedia page.
Also make sure the environment variable you are trying to read is properly set before i...
How to call a method with a separate thread in Java?
...t = new Thread(myRunnable)
t.start();
}
}
Take a look at Java's concurrency tutorial to get started.
If your method is going to be called frequently, then it may not be worth creating a new thread each time, as this is an expensive operation. It would probably be best to use a thr...
How to generate UML diagrams (especially sequence diagrams) from Java code?
...w can I generate UML diagrams (especially sequence diagrams) from existing Java code?
16 Answers
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How to install JSTL? The absolute uri: http://java.sun.com/jstl/core cannot be resolved
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org.apache.jasper.JasperException: The absolute uri: http://java.sun.com/jstl/core cannot be resolved in either web.xml or the jar files deployed with this application
That URI is for JSTL 1.0, but you're actually using JSTL 1.2 which uses URIs with an additional /jsp path (because ...
Calculate date/time difference in java [duplicate]
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I would prefer to use suggested java.util.concurrent.TimeUnit class.
long diff = d2.getTime() - d1.getTime();//as given
long seconds = TimeUnit.MILLISECONDS.toSeconds(diff);
long minutes = TimeUnit.MILLISECONDS.toMinutes(diff);
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Java default constructor
...ast one constructor, the default constructor is not generated.
Reference: Java Language Specification
If a class contains no constructor declarations, then a default constructor with no formal parameters and no throws clause is implicitly declared.
Clarification
Technically it is not the co...
Quickest way to convert XML to JSON in Java [closed]
What are some good tools for quickly and easily converting XML to JSON in Java?
6 Answers
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