EhCache：什麼是用於密鑰身份？

Question

EhCache似乎對用作內存緩存鍵的對象沒有限制，對磁盤/分佈式緩存只有Serializable。 （http://ehcache.org/apidocs/net/sf/ehcache/Element.html）

那麼，密鑰對象的哪個屬性在內部用於檢查密鑰是否與存儲密鑰匹配？如果有什麼方法可以用來提供我自己的身份識別方法？

Answer 1

所以EHCache使用等於/ hashCode爲鍵身份。

我做了一些測試：

private static final class TestKey implements Serializable { 

    boolean equals; 
    int hash; 

    TestKey(boolean equals, int hash){ 
     this.equals = equals; 
     this.hash = hash; 
    } 

    @Override 
    public boolean equals(Object other){ return equals; } 

    @Override 
    public int hashCode(){ return hash; } 
} 




public void testIdentity() throws Exception { 

    // A simple wrapper around EHCache which does the configuration 
    // and provides a map like interface 
    CacheEHCache<TestKey,String> cache = CacheEHCache.instance(
      new File("/tmp/ehcache"), "testcache", 10); 

    // May contain content from last run 
    cache.clear(); 

    // equals and hash matches 
    TestKey k11 = new TestKey(true, 1); 

    cache.put(k11, "Test11"); 

    assertEquals(cache.size(), 1); 
    assertTrue(cache.containsKey(k11)); 

    cache.remove(k11); 
    assertEquals(cache.size(), 0); 

    // doesn't equal but hash matches 
    TestKey k21 = new TestKey(false, 1); 

    cache.put(k21, "Test21"); 
    assertEquals(cache.size(), 1); 
    assertFalse(cache.containsKey(k21)); 

    // This is interesting: Clear needs to find the objects to clear 
    // So we must patch it. 
    k21.equals = true; 
    cache.clear(); 
    assertEquals(cache.size(), 0); 

    // equals but hash missmatches 
    TestKey k31 = new TestKey(true, 1); 
    TestKey k32 = new TestKey(true, 2); 
    cache.put(k31, "Test21"); 
    assertEquals(cache.size(), 1); 
    assertTrue(cache.containsKey(k31)); 
    assertFalse(cache.containsKey(k32)); 
    cache.clear(); 
}