Java Parser class to use with java azure function

FormDataParser.java

package com.example.util;

import org.apache.tomcat.util.http.fileupload.MultipartStream;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.*;

// Inspired by this post - https://stackoverflow.com/a/60882449/363867
public class FormDataParser {
    private String contentType = "multipart/form-data";
    private String body;

    private Map<String, Object> formFields = new HashMap<String, Object>();
    public FormDataParser(String body, String contentType){
        this.body = body;
        this.contentType = contentType;
        if(!body.isEmpty()){
            parseBody(body);
        }
    }

    private void parseBody(String body){
        try {
            String boundary = contentType.split(";")[1].split("=")[1];

            int bufSize = 1024;
            InputStream in = new ByteArrayInputStream(body.getBytes()); // Convert body to an input stream
            MultipartStream multipartStream  = new MultipartStream(in, boundary.getBytes(), bufSize, null); // Using MultipartStream to parse body input stream
            boolean nextPart = false;
            nextPart = multipartStream.skipPreamble();
            while (nextPart) {
                String header = multipartStream.readHeaders();
                String name = parseMimeHeader(header, "name=");
                //  multipartStream.readBodyData(System.out);

                if(header.indexOf("filename=") != -1){
                    parseFileMime(name, header);
                }

                ByteArrayOutputStream output = new ByteArrayOutputStream();
                multipartStream.readBodyData(output);
                String value=output.toString("UTF-8");
                setValue(name, value);

                nextPart = multipartStream.readBoundary();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private String parseMimeHeader(String header, String name){
        String fieldName = "";
        try{
            String[] headers = header.replace(";", "\r\n").split("\r\n");
            for(String mime: headers){
                System.out.println(mime);
                mime = mime.trim();
                int start =mime.indexOf(name);
                if(start != -1){
                    start = mime.indexOf(name) + name.length()+1;
                    int end = mime.indexOf("\"", start);
                    fieldName = end != -1?mime.substring(start, end): mime.substring(start);
                    break;
                }
            }
        }catch (Exception e) {
            e.getStackTrace();
        }
        return fieldName;
    }

    //if there is file, parse extra information like filename and mimetype of the file
    private void parseFileMime(String fileFieldName, String header) {

        String filename = parseMimeHeader(header, "filename=");
        String contentType = parseMimeHeader(header, "Content-Type:");

        setValue(fileFieldName+"-filename", filename);
        setValue(fileFieldName+"-Content-Type", contentType.trim());

    }

    private void setValue(String fieldName, String fieldValue){
        formFields.put(fieldName, fieldValue);
    }

    public String get(String fieldName){
        return (String) formFields.get(fieldName);
    }
}

//to use this in azure function
/*
            String contentType = request.getHeaders().get("content-type");
            String body = request.getBody().get();
            FormDataParser formDataParser = new FormDataParser(body, contentType);

            String name = formDataParser.get("name");

 */