import java.io.*;
class RenameFiles 
{
    public static String getFileNameWithoutExtension(String fileName) {
          File file = new File(fileName);
          int index = file.getName().lastIndexOf('.');
          if (index>0&& index <= file.getName().length() - 2 ) {
            System.out.println("Filename without Extension: "+file.getName().substring(0, index));
          }  
          return "";
    } 
    public static void main(String[] args){
        String files[]={"c:/1Angelrose0705$.jpg","c:/2Angelrose0705$.jpg","c:/3Angelrose0705$.jpg","c:/4Angelrose0705$.jpg"};
        File oldfile[]=new File[files.length];
        String st[]=new String[files.length];
        for(int i=0;i<oldfile.length;i++){
        oldfile[i]=new File(files[i]);
        int index = oldfile[i].getName().lastIndexOf('.');
          if (index>0&& index <= oldfile[i].getName().length() - 2 ) {
           st[i]=oldfile[i].getName().substring(0, index);
          } 
        }
        File newfile[] = new File[files.length];
        String filename[]=new String[files.length];
        for(int i=0;i<files.length;i++){
        filename[i]=st[i].replace("Angelrose0705$","RohitBBorse");
        newfile[i]=new File(filename[i]+".jpg");
        }

        for(int i=0;i<files.length;i++){
           boolean Rename = oldfile[i].renameTo(newfile[i]);
           if(Rename){
               System.out.println("Renamed Successfully!");
           }
        }
    }
}

Thanks friend :)