JDK 1.8

import lombok.extern.slf4j.Slf4j;import org.junit.Test;@Slf4jpublic class SwitchTest {    @Test    public void givenByte_then() {        Byte flag = 1;        switchMethod(flag);        flag = 2;        switchMethod(flag);        flag = 3;        switchMethod(flag);    }    /**     * 如果switch表达式是Byte类型，     * case后面的数字也会自动转型为Byte类型     *     * @param flag     */    private void switchMethod(Byte flag) {        switch (flag) {            case 1:                log.info("is 1");                break;            case 2:                log.info("is 2");                break;            default:                log.info("not match. value:" + flag);        }        log.info("success:" + flag);    }}