How java extracts expressions

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Extract expression

In the process of software development, it is easy for programmers to make code do some "repetitive work" intentionally or unintentionally. In most cases, these "repetitive work" do not pose a great threat to performance because of the running of the computer. However, if the performance of the system is brought into play, it is quite meaningful to extract these "repetitive work".

Take a look at the following test cases:

@ Test public void test () {long start = System.currentTimeMillis (); ArrayList list = new ArrayList (); for (int I = 0polii