java - Hash Map entries collision -

i trying code snippet

map headers=new hashmap(); headers.put("x-capillary-relay","abcd"); headers.put("message-id","abcd"); 

now when get either of keys working fine. seeing strange phenomenon on eclipse debugger. when debug , go inside variables , check inside table entry @ first see this

->table --->[4] ------>key:x-capillary-relay ........... 

however after debugging across 2nd line get

->table --->[4] ------>key:message-id ........... 

instead of creating new entry overwrites on existing key. other key overwrite not occur. size of map shown 2. , get works both keys. reason behind discrepancy in eclipse debugger. eclipse problem? or hashing problem. hashcode different 2 keys.

the hashcode of keys not used is.

it applied 2 transformations (at least based on java 6 code):

static int hash(int h) {     // function ensures hashcodes differ     // constant multiples @ each bit position have bounded     // number of collisions (approximately 8 @ default load factor).     h ^= (h >>> 20) ^ (h >>> 12);     return h ^ (h >>> 7) ^ (h >>> 4); } 

and

/**  * returns index hash code h.  */ static int indexfor(int h, int length) {     return h & (length-1); } 

since length initial capacity of hashmap (16 default), 4 both keys :

system.out.println (hash("x-capillary-relay".hashcode ())&(16-1)); system.out.println (hash("message-id".hashcode ())&(16-1)); 

therefore both entries stored in linked list in same bucket of map (index 4 of table array, can see in debugger). fact debugger shows 1 of them doesn't mean other overwritten. means see key of first entry of linked list, , each new entry added head of list.