Reaching a resource of the file system

Through FileSystemItem you can reach a resource of the file system even if it is contained in a nested supported (zip, jar, war, ear, jmod) compressed archive and obtain the content of it or other informations such as if it is a folder or a file or a compressed archive or if it is a compressed entry or obtain, if it is a folder or a compressed archive, the direct children or all nested children or a filtered collection of them. To start we need to add the following dependency to our pom.xml:

<dependency>
    <groupId>org.burningwave</groupId>
    <artifactId>core</artifactId>
    <version>12.64.3</version>
</dependency>

… And to use Burningwave Core as a Java module, add the following to your module-info.java:

requires org.burningwave.core;

Let’s take look at the code now: :

package org.burningwave.core.examples.filesystemitem;

import org.burningwave.core.assembler.ComponentContainer;
import org.burningwave.core.io.FileSystemItem;

public class ResourceReacher {
    
    private static void execute() {
        //Obtaining FileSystemItem through absolute path
        FileSystemItem fSI = FileSystemItem.ofPath("C:/Program Files (x86)");
       
        
        FileSystemItem firstFolderFound = null;
        
        //Obtaining direct children
        for (FileSystemItem child : fSI.getChildren()) {
            System.out.println("child name:" + child.getAbsolutePath());
            if (firstFolderFound == null && child.isFolder()) {
                 System.out.println(child.getAbsolutePath() + " is a folder: " + child.isFolder());
                 firstFolderFound = child;
            }
        }
        
        //Filtering all nested children for extension
        for (FileSystemItem child : firstFolderFound.findInAllChildren(
            FileSystemItem.Criteria.forAllFileThat(fSIC -> 
                "txt".equals(fSIC.getExtension()) || "exe".equals(fSIC.getExtension()))
            )
        ){
            System.out.println("child name: " + child.getName() + " - child parent: " + child.getParent().getName());
            //copy the file to a folder
            child.copyTo(System.getProperty("user.home") + "/Desktop/copy");
        }
        
        //Obtaining a FileSystemItem through a relative path (in this case we are obtaining a reference to a jar
        //contained in an ear that is contained in a zip
        fSI = ComponentContainer.getInstance().getPathHelper().getResource(
            "/../../src/test/external-resources/libs-for-test.zip/ESC-Lib.ear/APP-INF/lib/jaxb-xjc-2.1.7.jar"
        );
        
        System.out.println("is an archive:" + fSI.isArchive());
        
        //This method return true if the file or folder is located inside a compressed archive
        System.out.println("is compressed:" + fSI.isCompressed());
        
        //this clear cache
        fSI.refresh(true);
        
        //Obtaining direct children
        for (FileSystemItem child : fSI.getChildren()) {
            System.out.println("child name:" + child.getAbsolutePath());
        }
        
        //Obtaining all nested children
        for (FileSystemItem child : fSI.getAllChildren()) {
            System.out.println("child name:" + child.getAbsolutePath());
        }
        
        //Obtaining the content of the resource (once the content is loaded it will be cached)
        fSI.toByteBuffer();
    }
    
    public static void main(String[] args) {
        execute();
    }
    
}

As you can see in the box above, you can retrieve a FileSystemItem through an absolute path or through a relative path referred to your classpath by using the PathHelper. FileSystemItems are cached and there will only be one instance of them for an absolute path and you can also clear the cache e reload all informations of a FileSystemItem. In the example below we show how to retrieve and use a FileSystemItem.