How to convert a String into an ArrayList?

Try something like
List myList = new ArrayList(Arrays.asList(s.split(“,”)));

Arrays.asList documentation
String.split documentation
ArrayList(Collection) constructor documentation

Demo:
String s = “lorem,ipsum,dolor,sit,amet”;

List myList = new ArrayList(Arrays.asList(s.split(“,”)));

System.out.println(myList); // prints [lorem, ipsum, dolor, sit, amet]

This post has been rewritten as an article here.

String s1=”[a,b,c,d]”;
String replace = s1.replace(“[“,””);
System.out.println(replace);
String replace1 = replace.replace(“]”,””);
System.out.println(replace1);
List myList = new ArrayList(Arrays.asList(replace1.split(“,”)));
System.out.println(myList.toString());