Design patterns(Composite and Decorator) Java

You are required to develop a simplified HTML+JavaScript+CSS parser using the Document Object Model (DOM) concept. The project will have three files, a pure HTML file, a JavaScript-like file, and a CSS-like file. Your task is to parse these files and create a new HTML file based on the JavaScript commands and CSS-like file. The parser will be made using JAVA which should satisfy 2 design pattern that is Composite and Decorator which are mandatory, and both the patterns should be satisfied in the single project. These patterns should be integrated into your solution. This is the heart of the project it should be developed considering Design patterns. Take this project only if you know Java Design patterns.