差異處
這裏顯示兩個版本的差異處。
| 下次修改 | 前次修改 下次修改 Both sides next revision | ||
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java:guava:cache:helloworld [2016/04/13 13:40] tony 建立 |
java:guava:cache:helloworld [2016/04/13 23:30] tony |
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| 行 1: | 行 1: | ||
| {{tag>java guava}} | {{tag>java guava}} | ||
| ====== Guava Cache Hello World ====== | ====== Guava Cache Hello World ====== | ||
| + | ===== Introduction ===== | ||
| + | 大部分應用程式都會透過Cache機制，去增加效能或暫時性的備援。Guava提供了簡單的Cache實做，讓你不用替資源回收或同步問題煩惱。 | ||
| ===== How to? ===== | ===== How to? ===== | ||
| + | 我們可以透過CacheBuilder去設定Cache的條件。在build時，你可以選擇要預先提供服務實做，或是在get時提供: | ||
| <code java> | <code java> | ||
| package org.tonylin.practice.guava.cache; | package org.tonylin.practice.guava.cache; | ||
| 行 15: | 行 18: | ||
| public class TestCache { | public class TestCache { | ||
| + | @Test | ||
| + | public void testCache() throws Exception { | ||
| + | Cache<String, String> cache = CacheBuilder.newBuilder() | ||
| + | .maximumSize(10) | ||
| + | .expireAfterAccess(5, TimeUnit.SECONDS) | ||
| + | .expireAfterWrite(5, TimeUnit.SECONDS) | ||
| + | .softValues() | ||
| + | .build(); | ||
| + | |||
| + | Assert.assertEquals("0", cache.get("test1", ()->{return "0";})); | ||
| + | Thread.sleep(4000); | ||
| + | Assert.assertEquals("0", cache.get("test1", ()->{return "1";})); | ||
| + | Thread.sleep(2000); | ||
| + | Assert.assertNull(cache.getIfPresent("test1")); | ||
| + | Assert.assertEquals("2", cache.get("test1", ()->{return "2";})); | ||
| + | } | ||
| @Test | @Test | ||
| public void test() throws Exception { | public void test() throws Exception { | ||
