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Java ResultSet how to check if there are any results
... "forward only".
Compare the two throw sections:
http://docs.oracle.com/javase/7/docs/api/java/sql/ResultSet.html#isBeforeFirst()
http://docs.oracle.com/javase/7/docs/api/java/sql/ResultSet.html#first()
Okay, basically this means that you should use "isBeforeFirst" as long as you have a "forward...
Are non-synchronised static methods thread safe if they don't modify static class variables?
...you find one, its not thread safe.
Please be also aware, that most of the Java 1.5 Collection classes are not threadsafe, except those where stated, like ConcurrentHashMap.
And if you really want to dive into this, have a close look at the volatile keyword and ALL its side effects. Have a look at...
Ant: How to execute a command for each file in directory?
...t dir="${server.src}" casesensitive="yes">
<include name="**/*.java"/>
<exclude name="**/*Test*"/>
</fileset>
</foreach>
</target>
<target name="bar">
<echo message="${theFile}"/>
</target>
This will antcall the target "bar" w...
Convert Iterable to Stream using Java 8 JDK
I have an interface which returns java.lang.Iterable<T> .
9 Answers
9
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What is
... type has to implement comparable of itself or its superclass. So consider java.util.Date. It implements Comparable<Date>. But what about java.sql.Date? It implements Comparable<java.util.Date> as well.
Without the super signature, SortedList would not be able accept the type of java.sq...
How do you make a web application in Clojure? [closed]
... strange question to the huge majority of programmers that work daily with Java. I don't. I know Java-the-language, because I worked on Java projects, but not Java-the-world. I never made a web app from scratch in Java. If I have to do it with Python, Ruby, I know where to go (Django or Rails), but ...
Utility classes are evil? [closed]
...ity classes to group a number of methods together — an example being the java.util.Collections class which provides a number of utilities that can be used on any Java Collection. These aren't specific to one particular type of Collection, but instead implement algorithms that can be used on any Co...
Difference between & and && in Java? [duplicate]
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Why is creating a Thread said to be expensive?
The Java tutorials say that creating a Thread is expensive. But why exactly is it expensive? What exactly is happening when a Java Thread is created that makes its creation expensive? I'm taking the statement as true, but I'm just interested in mechanics of Thread creation in JVM.
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What is the easiest way to ignore a JPA field during persistence?
...he JPA annotation marking a field as not persistable
transient keyword in java. Beware - using this keyword, will prevent the field to be used with any serialization mechanism from java. So, if the field must be serialized you'd better use just the @Transient annotation.
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