JVM环境检查

最新推荐文章于 2025-01-07 18:22:01 发布

原创最新推荐文章于 2025-01-07 18:22:01 发布 · 1k 阅读

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#jvm #collections #jdk #null

boolean getGeneratedKeysSupport; try { Statement.class.getMethod("getGeneratedKeys", null); getGeneratedKeysSupport = true; } catch (NoSuchMethodException nsme) { getGeneratedKeysSupport = false; } JVM_SUPPORTS_GET_GENERATED_KEYS = getGeneratedKeysSupport; if (!JVM_SUPPORTS_GET_GENERATED_KEYS) log.info("JVM does not support Statement.getGeneratedKeys()"); boolean linkedHashSupport; try { Class.forName("java.util.LinkedHashSet"); linkedHashSupport = true; } catch (ClassNotFoundException cnfe) { linkedHashSupport = false; } JVM_SUPPORTS_LINKED_HASH_COLLECTIONS = linkedHashSupport; if (!JVM_SUPPORTS_LINKED_HASH_COLLECTIONS) log.info("JVM does not support LinkedHasMap, LinkedHashSet - ordered maps and sets disabled"); JVM_HAS_TIMESTAMP_BUG = new Timestamp(123456789).getTime() != 123456789; if (JVM_HAS_TIMESTAMP_BUG) log.info("using workaround for JVM bug in java.sql.Timestamp"); Timestamp t = new Timestamp(0); t.setNanos(5 * 1000000); JVM_HAS_JDK14_TIMESTAMP = t.getTime() == 5; if (JVM_HAS_JDK14_TIMESTAMP) { log.info("using JDK 1.4 java.sql.Timestamp handling"); } else { log.info("using pre JDK 1.4 java.sql.Timestamp handling"); }