performance

Efficiency of Java “Double Brace Initialization”?

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Here’s the problem when I get too carried away with anonymous inner classes: 2009/05/27 16:35 1,602 DemoApp2$1.class 2009/05/27 16:35 1,976 DemoApp2$10.class 2009/05/27 16:35 1,919 DemoApp2$11.class 2009/05/27 16:35 2,404 DemoApp2$12.class 2009/05/27 16:35 1,197 DemoApp2$13.class /* snip */ 2009/05/27 16:35 1,953 DemoApp2$30.class 2009/05/27 16:35 1,910 DemoApp2$31.class 2009/05/27 16:35 2,007 DemoApp2$32.class 2009/05/27 16:35 926 DemoApp2$33$1$1.class 2009/05/27 16:35 4,104 … Read more

How can I read a large text file line by line using Java?

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A common pattern is to use try (BufferedReader br = new BufferedReader(new FileReader(file))) { String line; while ((line = br.readLine()) != null) { // process the line. } } You can read the data faster if you assume there is no character encoding. e.g. ASCII-7 but it won’t make much difference. It is highly likely … Read more

StringBuilder vs String concatenation in toString() in Java

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Version 1 is preferable because it is shorter and the compiler will in fact turn it into version 2 – no performance difference whatsoever. More importantly given we have only 3 properties it might not make a difference, but at what point do you switch from concat to builder? At the point where you’re concatenating … Read more