Tag Archives: Java

The costs of String concatenation (+) or what String appending really does

String concatenation (e.g. “fu” + “bar”) are for most developers a mystery what it really does. The simple case Something like will usually be appended at compile time. So if you decompile this you see: The final case What happens … Continue reading

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Java Performance Tuning with maximizing Integer.valueOf(int)

With http://java.sun.com/javase/6/docs/api/java/lang/Integer.html#valueOf%28int%29 or auto boxing(uses internal a valueOf too) the cached Integer values will be used if they are between -127 and +128. Now I found coincidentally(by looking at the source) on a Java feature or more exactly on a … Continue reading

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SimpleDateFormat in multithreaded environment

SimpleDateFormat is wide known in Java as the default tool to convert a String to a (java.util.)Date and vice versa. Usually you would think you can make a SimpleDateFormat static, like: Because we think, that the formatter just contains the … Continue reading

Posted in Formatting, Java, Multi threading | Tagged , , , , | 1 Comment