Java regular two-time escape

What does the regular expression "\\[([^\\]]+) \ \ \]" In Java mean? What are the two escape characters to express?

Characters such as "[" in regular expressions have special meanings, so they need to be written as "\[". But "\" itself is also a special meaning of the escape character.

So "\[" needs to be written as "\\[". "\" needs to be escaped first

In regular brackets denote a character set, to indicate that the bracket character must be escaped

The contents of the parentheses in the entire regular match
The \\[at the beginning matches the "[" character
The tail \ \] matches the "]" character
The Middle [([^\\]]+), which represents all non-"]" characters consisting of a string

Java regular two-time escape