Those who have used python should know that multiple lines of strings can be defined in python, which can be written like this:
multiline_str="""
first row
second line
...
"""Looks great, other languages like javascript have similarities:
let multiline_str=`
first row
second line
...
`However, our own java has no such syntax! So in Java you can only write "multi-line" strings like this:
String multiline_str="first line \n" +
"Second line \n" +
"...";
Look at how much… very silly feeling! (a bunch of newline and +)
Can it really only compromise this way? Do not!
Please see the implementation below:
Online code demo address: http://codingair.com/ex/code2.html?t=1535091572137&interface=146&projectId=17
Yes, you are not mistaken, it is indeed a "multi-line string" function implemented in java multi-line comments, this is a trick (small trick, not compiler level implementation), but it is very practical!
Imagine if your sql can be written like this:
Think again, you can write shell commands directly like this:
Everything is too cool, there are wood!
You can experience more features at this site: [http://codingair.com] (http://codingair.com)
Secret moment!
So how is this small trick implemented? Directly attach the source code of the S function in the above example:
/**
* Multi-line string
* Into the parentheses, use /* ....* / form comments
*
* @return
*/
Public static String S() {
String javaSource = threadLocal.get();
Try {
StackTraceElement element = new RuntimeException().getStackTrace()[1];
Byte[] bytes = javaSource.getBytes("UTF-8");
String s = convertStreamToString(new ByteArrayInputStream(bytes, 0, bytes.length), element.getLineNumber());
Return s.substring(s.indexOf("/*") + 2, s.indexOf("*/"));
} catch (Exception e) {
e.printStackTrace();
}
Return null;
}Explain that you will notice that the first line of the function has such a line of code:
String javaSource = threadLocal.get();That’s right, here is the source code for the class in which the S function is called, passed through the ThreadLocal object.
At this point, is there a feeling of great understanding? ! You can go to this website to experience more features: https://lambda.zhouzhipeng.com/ If you have any questions or concerns, please leave a comment below the blog.
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