Java 静态方法获取当前类

Java中静态方法不依赖于具体的实例存在，所有不能直接使用this指针，需要别的方式间接的获取到类名。

方法

1. 方法1：通过SecurityManager的保护方法getClassContext()

private static String test1() {
        return new SecurityManager() {
            public String getClassName() {
                return getClassContext()[1].getName();
            }
        }.getClassName();
    }

2. 方法2：通过Throwable的方法getStackTrace()

private static String test2() {
        return new Throwable().getStackTrace()[1].getClassName();
    }

3. 方法3：通过Thread.currentThread的方法getStackTrace()

private static String test3() {
        return Thread.currentThread().getStackTrace()[1].getClassName();
    }

4. 方法4：通过分析匿名类名称()

private static String test4() {
        return new Object() {
            public String getClassName() {
                String clazzName = this.getClass().getName();
                return clazzName.substring(0, clazzName.lastIndexOf('$'));
            }
        }.getClassName();
    }

性能

分别调用100w次测试性能

public static void main(String[] args) {
        long start, end;
        int total = 1000000;
        String className = null;

        start = System.currentTimeMillis();
        for (int i = 0; i < total; i++) {
            className = Main.test1();
        }
        end = System.currentTimeMillis();
        System.out.println("test1: " + className + "time: " + (end - start) + " ms");

        start = System.currentTimeMillis();
        for (int i = 0; i < total; i++) {
            Main.test2();
        }
        end = System.currentTimeMillis();
        System.out.println("test2: " + className + "time: " + (end - start) + " ms");

        start = System.currentTimeMillis();
        for (int i = 0; i < total; i++) {
            Main.test3();
        }
        end = System.currentTimeMillis();
        System.out.println("test3: " + className + "time: " + (end - start) + " ms");

        start = System.currentTimeMillis();
        for (int i = 0; i < total; i++) {
            Main.test4();
        }
        end = System.currentTimeMillis();
        System.out.println("test4: " + className + "time: " + (end - start) + " ms");
    }

测试结果: 直接分析匿名内部类名字性能最高

test1: com.rainlf.mult.Maintime: 463 ms
test2: com.rainlf.mult.Maintime: 1840 ms
test3: com.rainlf.mult.Maintime: 2193 ms
test4: com.rainlf.mult.Maintime: 21 ms