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Java: how do I get a class literal from a generic type?
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You can't due to type erasure.
Java generics are little more than syntactic sugar for Object casts. To demonstrate:
List<Integer> list1 = new ArrayList<Integer>();
List<String> list2 = (List<String>)list1;
list2.add("foo"); // perf...
compareTo() vs. equals()
When testing for equality of String 's in Java I have always used equals() because to me this seems to be the most natural method for it. After all, its name already says what it is intended to do. However, a colleague of mine recently told me had been taught to use compareTo() == 0 instead of ...
Java 8 method references: provide a Supplier capable of supplying a parameterized result
...ise you will get an error message like MyException cannot be converted to java.lang.RuntimeException
Update:- This was an issue with an older version of JDK. I don't see this issue with the latest versions.
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Convert JsonNode into POJO
...he official documentation for that call: http://jackson.codehaus.org/1.7.9/javadoc/org/codehaus/jackson/map/ObjectMapper.html#readValue(java.lang.String, java.lang.Class)
You can also define a custom deserializer when you instantiate the ObjectMapper:
http://wiki.fasterxml.com/JacksonHowToCustomDes...
Is List a subclass of List? Why are Java generics not implicitly polymorphic?
I'm a bit confused about how Java generics handle inheritance / polymorphism.
17 Answers
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Why does InetAddress.isReachable return false, when I can ping the IP address?
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Here are other, similar questions :
Detect internet Connection using Java
How do I test the availability of the internet in Java?
And even a reported bug on this same matter :
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4921816
Part 1 : A reproducible example of the problem
Note t...
How to obtain the start time and end time of a day?
...lusive while the ending is exclusive.
The current date-time frameworks of Java (java.util.Date/Calendar and Joda-Time) both use milliseconds from the epoch. But in Java 8, the new JSR 310 java.time.* classes use nanoseconds resolution. Any code you wrote based on forcing the milliseconds count of l...
What is the difference between 'java', 'javaw', and 'javaws'?
What is the difference between java , javaw , and javaws ?
5 Answers
5
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Draw in Canvas by finger, Android
...DIUS = 32;
private int floatToByte(float x) {
int n = java.lang.Math.round(x);
return n;
}
private int pinToByte(int n) {
if (n < 0) {
n = 0;
} else if (n > 255) {
n = 255;
}
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How can I use pointers in Java?
I know Java doesn't have pointers, but I heard that Java programs can be created with pointers and that this can be done by the few who are experts in java. Is it true?
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