Java 截取字符串 split 方法与 substring 方法简单比较

public void split() {
    String str = "org.springframework.boot.test.context.SpringBootTest";
    String name = str.split("org.springframework.boot.")[1].split("\\.")[0];
}

public void substring() {
    String str = "org.springframework.boot.test.context.SpringBootTest";
    String name = str.substring(str.indexOf(".", "org.springframework".length()) + 1, str.indexOf(".", "org.springframework".length() + 1));
}

@Test
public void test02() {
    long start = System.currentTimeMillis();
    System.out.println("split 开始时间" + start);
    for (int i = 0; i < 100000; i++) {
        split();
    }
    long middle = System.currentTimeMillis();
    System.out.println("split 结束时间" + middle);
    System.out.println("split 耗时" + (middle - start) + "毫秒");
    System.out.println("substring 开始时间" + middle);
    for (int i = 0; i < 100000; i++) {
        substring();
    }
    long end = System.currentTimeMillis();
    System.out.println("substring 结束时间" + end);
    System.out.println("substring 耗时" + (end - middle) + "毫秒");
}

split 开始时间1648630532312
split 结束时间1648630532425
split 耗时113毫秒
substring 开始时间1648630532425
substring 结束时间1648630532429
substring 耗时4毫秒