TreePrinter

To add this library to your project, click on JitPack badge. You can also manually add Jar file, you can find jar file in release section.

Demo: I have created two classes for printing FilesStructure.

1.FileTreePrinter

public class Main {

    public static void main(String[] args) {

        File file=new File("./src");

        FileTreePrinter treePrinter=new FileTreePrinter(file);
        treePrinter.visitAndPrint();
        //  or
        //  StringBuilder sb=treePrinter.visitAndReturn();
        //  sout(sb);
    }
}

This code will produce below output.

src
├─main
│  ├─java
│  │  └─com
│  │     ├─demo
│  │     │  └─Main.java
│  │     └─devik
│  │        ├─Color.java
│  │        ├─file
│  │        │  ├─FileTreePrinter.java
│  │        │  └─FileTreePrinterColored.java
│  │        └─TreePrinter.java
│  └─resources
└─test
   └─java

2.FileTreePrinterColored

public class Main {

    public static void main(String[] args) {

        File file=new File("./src");

        FileTreePrinterColored treePrinter=new FileTreePrinterColored(file);
        treePrinter.visitAndPrint();
        //  or
        //  StringBuilder sb=treePrinter.visitAndReturn();
        //  System.out.println(sb);
    }
}

This code will produce below output.

Also in case of FileTreePrinterColored you can set custom colors.

public class Main {

    public static void main(String[] args) {

        File file=new File("./src");

        FileTreePrinterColored treePrinter=new FileTreePrinterColored(file);
        
        treePrinter.setFolderColor(Color.RED);
        treePrinter.setHiddenFolderColor(Color);
        treePrinter.setExecutableFileColor(Color);
        treePrinter.setNonExecutableFileColor(Color);
        //or
        treePrinter.setNonExecutableFileColor(Color.valueOf("color asci"));

        
        treePrinter.visitAndPrint();
        //  or
        //  StringBuilder sb=treePrinter.visitAndReturn();
        //  System.out.println(sb);
    }
}

If you want to print other than file tree than you can use TreePrinter abstract class. In that case you need to implement three methods.

 Object obj;
        TreePrinter treePrinter=new TreePrinter(obj) {
            @Override
            public Object[] getChild(Object obj) {
                return new Object[0];
            }

            @Override
            public String getValue(Object obj) {
                return null;
            }

            @Override
            public boolean isLeaf(Object obj) {
                return false;
            }
        };
        // Here obj is the root of TreeStructure.

for ie. if you want to print BinaryTree than you can do something like below...

Object obj; //here obj is root of Binary tree
       TreePrinter treePrinter=new TreePrinter(obj) {
           @Override
           public Object[] getChild(Object obj) {
               Node node=(Node)obj;
               return new Object[]{node.left,node.right};
           }

           @Override
           public String getValue(Object obj) {
               return ((Node)obj).getValue();
           }

           @Override
           public boolean isLeaf(Object obj) {
              Node node=(Node)obj;
               return node.left==null && node.right==null;
           }
       };
       // Here obj is the root of TreeStructure.