Relative path and absolute path

Slashes and dots indicate relative and absolute paths

Absolute path ： It's the path from the drive letter

Relative paths ： Is the path starting from the current path

/ It's the root directory （ stay Javaweb Can be combined with the absolute path inside the project as a relative path ）

./ Is the current directory （ Or start with nothing ）

“…/” To represent a higher level directory ,

Absolute path

JavaWeb Relative path in

Relative paths are divided into paths that start with a diagonal bar and paths that do not start with a diagonal bar

• Path starting with diagonal bar ： Baseline path （ The root path ） Relative path of
• A path that does not begin with a diagonal bar ： The relative path of the current directory

Depending on the location of the file where the path is located , Divided into two ： Foreground path and background path .

A、 Foreground reference path

The so-called foreground path refers to , The path contained in the code executed by the browser .

for example ,html、css、js In the path , And jsp The path of the static part in .

 image  html  And  jsp  In the static part of <img src=" "/>、<a href=" "></a>、<form action=" "></form> etc. ; image  css  Medium  background:img("") etc. ; image  js  Medium window.location.href=" " etc. , All belong to the foreground path .

The reference path of the foreground path is Web The root path of the server , namely http://127.0.0.1:8080/

B、 Background reference path

The so-called background path refers to , The server parses the executed code and the path contained in the file .

for example ,java The path in the code 、jsp File dynamic part （java Code block ） In the path 、xml Path in file （xml The document is to be java The code is loaded into memory , And by the java Code parsing ） etc. .

The reference path of the background path is Web Root path of application . Such as http://127.0.0.1:8080/primary/ (primary yes Web Applied project name )

HTML and JSP Benchmark difference of relative path

In the default HTML Page and JSP The benchmark of relative path in the page is different .

stay HTML in base The label is used to know the benchmark of the relative path （ default HTML Page does not base label , At this time, the relative path is the path relative to the current page ）

stay jsp It automatically adds one to us base Label and specify that the benchmark is the project path , Therefore, the relative path we write in any directory is based on the project path .