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Java 8 NullPointerException in Collectors.toMap
The Java 8 Collectors.toMap throws a NullPointerException if one of the values is 'null'. I don't understand this behaviour, maps can contain null pointers as value without any problems. Is there a good reason why values cannot be null for Collectors.toMap ?
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Ruby on Rails and Rake problems: uninitialized constant Rake::DSL
...e .9.0 breaks Rails and several other things, you need to:
gem "rake", "0.8.7"
in your Gemfile.
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Listing only directories in UNIX
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answered Sep 8 '10 at 11:45
David HancockDavid Hancock
13.9k44 gold badges3737 silver badges4343 bronze badges
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Get folder name from full file path
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answered Mar 8 '11 at 6:54
Alex PacurarAlex Pacurar
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Grouped LIMIT in PostgreSQL: show the first N rows for each group?
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New solution (PostgreSQL 8.4)
SELECT
*
FROM (
SELECT
ROW_NUMBER() OVER (PARTITION BY...
What's the difference between ASCII and Unicode?
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ASCII defines 128 characters, which map to the numbers 0–127. Unicode defines (less than) 221 characters, which, similarly, map to numbers 0–221 (though not all numbers are currently assigned, and some are reserved).
Unicode is a supers...
How to make the tab character 4 spaces instead of 8 spaces in nano?
When I press TAB in nano editor, the cursor will jump with 8 spaces like this:
6 Answers
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Removing Java 8 JDK from Mac
So I installed the beta of JDK 8 a while ago to look at some of the examples. I thought for sure by now, it's easy to change between versions.
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