Develop Reference

Relative path in resources folder for README.md file

I am trying to add some images on README.file in my Spring Boot app as shown below:
### Diagram
<img src="D:\my-project\src\main\resources\images\entity-diagram.png" width="600"/>
However, I need to set this path as relative. But I could not set by directly referring resources folder in a smart way something e.g.:
<img src="~\images\entity-diagram.png" width="1000"/>
So, how can I give reference to the resources folder smartly?

if README.md is parallel to pom.xml (AKA "basedir"):
<img src="./src/main/resources/images/entity-diagram.png" width="600"/>

How access uploaded file in spring framework

I am new to Spring framework in spring site There is tutorial at https://spring.io/guides/gs/uploading-files/ that upload file to the root folder "upload-dir" (this folder is beside src root folder)
questions:
How can I access and show image in browser (or access it in thymeleaf by th:src="#{}" syntax) -
by browsing to localhost:8080/files/first.jpg because of controller it give me download link.
should I always upload file to folder that beside src folder for example I want to upload file to "src/main/resources/static/file" is it possible?

When accessing files in your code, Spring will (by default) assume that the src/main/resources is the parent directory. If you are planning on accessing the files that are uploaded, then I would use src/main/resources (or a subdirectory of this location) as the upload path. This way, you can simply access them in Thymeleaf as such:
Location: src/main/resources/picture.jpg
Thymeleaf: th:src="#{picture.jpg}"
Or if the file exists in a subdirectory:
Location: src/main/resources/somedir/picture.jpg
Thymeleaf: th:src="#{somedir/picture.jpg}"
If you are storing the file(s) elsewhere, then you can also access them using various prefixes like classpath or file, i.e.:
classpath:com/myapp/config.xml
See more about Resources in Spring here:
http://docs.spring.io/spring/docs/current/spring-framework-reference/html/resources.html
Hope this helps!

Load config file from a war

I have a Maven project that I'm trying to package as both a war and a jar. As part of my application / servlet initialisation (depending on whether I'm running the jar or the war), I need to read a file called server.ini. I've put the file in src/main/resources/server.ini and am trying to load it like so:
System.class.getResourceAsStream("server.ini");
However, this always results in null. What am I doing wrong?

The server.ini file should be in the root of a resources directory.
By placing it in the webapp you're making the file available via http, but you need it accessible on the classpath, which means that you should place it in the resources directory.

There's a good chance web.xml or context.xml is better suited to what you're trying to do, but...
Try putting server.ini in WEB-INF/classes, or do something like this.

The issue was that I was using the System classloader with an unqualified path, so it was expecting to find my server.ini in the java.lang package.
Since my file is in src/main/resources, I should just use the classloader of my current class, with an absolute path:
getClass().getResourceAsStream("/server.ini")
This works in both the war and the jar.
The "Preferred way of loading resources in Java" question has a great explanation of resource loading.

How to read a directory in webapp folder of Maven web application

I'm working in maven web application. I need to read a directory(For ex: Files) in my webapp folder as follows,
Java.io.File file = new Java.io.File("path");
But I don't know how to specify the path of the directory here.

You shouldn't give local path addresses. Path should be a relative address, e.g. /files/images under your web archive (.war) folder.
To use relative paths properly, I suggest you to add your target folder to the resources definiton of POM.xml, check out these pages
http://www.mkyong.com/maven/how-to-change-maven-resources-folder-location/
http://maven.apache.org/guides/introduction/introduction-to-the-standard-directory-layout.html
You can refer to resources folder easily with something like this:
this.class.getResource("Mydirectory/SubDirectory");

When in doubt how relatives paths work, it's always best to do something like that:
System.out.println(new File("/my/desired/directory").getAbsolutePath());
This will print out the path in which classpath will look for the files.
Assuming:
servlet container webapps dir is located in: /var/lib/tomcat6/webapps
your webapp is called my-webapp.war
You should see the following output: /var/lib/tomcat6/webapps/my-webapp/my/desired/directory
Another pointer: you have mentioned that you are looking for webapp directory. I hope you know that this directory will not end up in *.war - it's contents will.

War files are not always expanded when they are deployed to an app server, so it's possible that a relative path won't exist in a filesystem at all.
Best bets are to use getResource from the class loader, which will return things in the class path (the WEB-INF/lib directory, etc), or to use the getResource() method of ServletContext to find things in the web application itself.

How to change location of static file in WAR archive?

By default static files are located in WEB-INF directory (accessible as /images/logo.png):
foo.war
WEB-INF
web.xml
images
logo.png
I want to change the structure and use this one instead (still accessible as /images/logo.png):
foo.war
WEB-INF
web.xml
static
images
logo.png
How can I do this with web.xml?

The container will repsond with a 404 NOT FOUND error if you directly access the files under WEB-INF using HTTP GET .
But now , you said you can access WEB-INF/images/logo.png by /images/logo.png , so I think your web application most probably achieve this result by some URLRewriteFilter mechainsim or by some Java code in the servlet level (eg a filter) , or by your web application 's framework . I suggest you to check your web application to see what mechanism causes this behvaior now and configurate to your desired result accordingly.

According to http://java.sun.com/j2ee/tutorial/1_3-fcs/doc/WCC3.html,:
A WAR has a specific directory
structure. The top-level directory of
a WAR is the document root of the
application. The document root is
where JSP pages, client-side classes
and archives, and static Web resources
are stored.
The document root contains a
subdirectory called WEB-INF, which
contains the following files and
directories:
web.xml: The Web application
deployment descriptor Tag library
descriptor files (see Tag Library
Descriptors) classes: A directory
that contains server-side classes:
servlets, utility classes, and
JavaBeans components lib: A
directory that contains JAR archives
of libraries (tag libraries and any
utility libraries called by
server-side classes).
You can also create
application-specific subdirectories
(that is, package directories) in
either the document root or the
WEB-INF/classes directory.
So the default behavior is what you're looking for. Is your document root set incorrectly to serve content from WEB-INF?

You may use a filter or URLRewriteFilter to point /images/* to /static/images/*.
If you just want your folder structure to be /static/images for development time organization purposes, but the deployment URL to be /images -- you may need to alter your build script to copy /static/** to /.
I personally would not bother whether my static files are referred as /static/images or /images -- because they would be referred in my code (only), which I have control over.
If you are using these files in CSS and that's why you wanted the path to stay the same... better keep the images under /static/css/images and have the images that are referred in the CSS here. In this way, no matter where you move your CSS folder, you would not bother spoiling your CSS.