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我编写了以下代码来对 SLF4J（带有 Logback 绑定）的查找性能进行基准测试：

public final class LoggerTest {

    private static final Logger staticLogger = LoggerFactory.getLogger(LoggerTest.class);

    public static void main(final String[] args) {
        warmUp(50000);

        final int iterations = 1000000;

        final long t1 = staticExecutionTime(iterations);
        System.out.printf("Static time     : %d%n", t1);


        final long t2 = nontStaticExecutionTime(iterations);
        System.out.printf("Non Static time : %d%n", t2);
    }

    private static void warmUp(final int iterations) {
        executeStatic(iterations);
        executeNonStatic(iterations);
    }

    private static long staticExecutionTime(final int iterations) {
        final long s1 = System.nanoTime();
        executeNonStatic(iterations);
        final long e1 = System.nanoTime();
        return e1 - s1;
    }

    private static void executeStatic(final int iterations) {
        for (int i = 0; i < iterations; i++) {
            staticLogger.trace("Do nothing!");
            staticLogger.debug("Do nothing!");
        }
    }

    private static long nontStaticExecutionTime(final int iterations) {
        final long s2 = System.nanoTime();
        executeNonStatic(iterations);
        final long e2 = System.nanoTime();
        return e2 - s2;
    }

    private static void executeNonStatic(final int iterations) {
        for (int i = 0; i < iterations; i++) {
            final Logger localLogger = LoggerFactory.getLogger(LoggerTest.class);
            localLogger.trace("Do nothing!");
            localLogger.debug("Do nothing!");
        }
    }

}

正如您在一个场景中看到的那样，我使用了一个在类加载期间初始化的静态记录器，而在另一种场景中，我每次都查找记录器。

我原以为使用静态记录器会更快，但是这两种情况几乎都花费了相同的时间，而且令人惊讶的是，非静态情况通常会快一点。

任何机构都可以描述这一点吗？

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1 回答 1

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你的方法

private static long staticExecutionTime(final int iterations) {
        final long s1 = System.nanoTime();
        executeNonStatic(iterations);
        final long e1 = System.nanoTime();
        return e1 - s1;
    }

正在执行错误的内部方法：p

它应该调用executeStatic(iterations);而不是executeNonStatic(iterations);

纠正它，你会得到不同的图片:)

于 2013-10-24T18:26:06.713 回答