java 位运算 取反（代码库）

System.out.println(5 & (~1));

 

比如，通过二进制位运算实现权限设置

newAuth.getAuthority() 为表示权限的数字，attEnum.getIndex() 指的是某一个权限的位数，代码如下

if(flag) {
    Long tmp = newAuth.getAuthority() | attEnum.getIndex();
    newAuth.setAuthority(tmp);
} else {
    Long tmp=newAuth.getAuthority() & (~attEnum.getIndex());
    newAuth.setAuthority(tmp);
}

public enum AuthorityAttributeEnum {
    NAME(1), MOBILE(2), EMAIL(4);
    private int index;
    // 构造方法
    AuthorityAttributeEnum(int index) {
        this.index = index;
    }
    public int getIndex() {
        return index;
    }
    public void setIndex(int index) {
        this.index = index;
    }
}

 

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