Various Java trips and tricks

This blog will list some nice tips and tricks that is good to know.

Classpath resource to java.net.URL

To get a java.net.URL from a classpath resource do:

 URL url = getClass().getClassLoader().getResource("some.file");  

Classpath resource to java.io.InputStream

 To get a java.io.InputStream from a classpath resource do:

 InputStream resourceAsStream = getClass().getClassLoader().getResourceAsStream();  

Classpath resource to java.io.File

 To get a java.io.File from a classpath resource do:

 File file = new File(this.getClass().getResource("some.file").toURI());  

Iterate through a Map

 for (Map.Entry<String, String> entry : map.entrySet()) {  
   System.out.println(entry.getKey() + "/" + entry.getValue());  
 }  

Find current root directory

 File rootDirectory = new File(System.getProperty("user.dir"));