Consider the following code

String[] s = new String[]{""};  
List<String> list = Arrays.asList(s);  
list.clear();  

All looks good, right? When you run it you get:

java.lang.UnsupportedOperationException  
    at java.util.AbstractList.remove(AbstractList.java:144)  
    at java.util.AbstractList$Itr.remove(AbstractList.java:360)  
    at java.util.AbstractList.removeRange(AbstractList.java:559)  
    at java.util.AbstractList.clear(AbstractList.java:217)  

This is because Arrays.asList(array) returns a fixed-size list backed by the specified array. Fixed-size being the operative word.