在java中的长问题中移动最高有效位

Question

[JAVA] 从特定索引处的长变量中清除一点时，我遇到了一个小问题。

该方法几乎适用于所有事情，但是当我尝试清除（设置为 0）msb（最高有效位）时失败。

public static long clear(long bitSet, int bitIndex) {

    bitSet &= ~(1L << bitIndex);


    return bitSet;
}

我真的无法解决这个错误......

我在这里做错了什么？

非常感谢任何帮助！提前谢谢！！！

例子：如果你输入 524552L 它输出 264L

二进制（相同示例）：10000000000100001000 --> 100001000

虽然它应该输出 --> 00000000000100001000

Answer 1

试试这个。

public static final long setBits(final long store, final int startBitIndex, final int bitQuantity, final boolean MSBFormat, final boolean setBit)
{
        if(startBitIndex < 0 || startBitIndex > 63) throw new IndexOutOfBoundsException("startBitIndex must be at least 0 and cannot larger than 63.");
        if(bitQuantity < 0 || bitQuantity > 64) throw new IllegalArgumentException("bitQuantity must be at least 0 and cannot be larger than 64.");
        //Do not throw IndexOfOutBoundsException for bitQuantity > (64 - startBitIndex). Tolerate. Nothing's gained from that. Its binary after all.
        if(bitQuantity == 0) return store;
        if(MSBFormat && setBit) return ((startBitIndex > 31 ? store & 0xFFFFFFFF00000000L : ((((store >> 32) & 0xFFFFFFFFL) | ((0xFFFFFFFFL >> (32 - Math.min(bitQuantity, 32 - startBitIndex))) << Math.max(0, 32 - startBitIndex - bitQuantity))) << 32)) //left side
            | (startBitIndex + bitQuantity < 33 ? store & 0xFFFFFFFFL : ((store & 0xFFFFFFFFL) | ((0xFFFFFFFFL >> (32 - Math.min(bitQuantity, Math.min(32, 64 - startBitIndex)))) << Math.max(0, 32 - (bitQuantity - (32 - startBitIndex))))))); //right side
        if(MSBFormat) return ((startBitIndex > 31 ? store & 0xFFFFFFFF00000000L : ((((store >> 32) & 0xFFFFFFFFL) & ~((0xFFFFFFFFL >> (32 - Math.min(bitQuantity, 32 - startBitIndex))) << Math.max(0, 32 - startBitIndex - bitQuantity))) << 32)) //left side
            | (startBitIndex + bitQuantity < 33 ? store & 0xFFFFFFFFL : ((store & 0xFFFFFFFFL) & ~((0xFFFFFFFFL >> (32 - Math.min(bitQuantity, Math.min(32, 64 - startBitIndex)))) << Math.max(0, 32 - (bitQuantity - (32 - startBitIndex))))))); //right side
        if(setBit) return ((startBitIndex > 31 ? store & 0xFFFFFFFFL : (store & 0xFFFFFFFFL) | ((0xFFFFFFFFL >> (32 - Math.min(bitQuantity, 32 - startBitIndex))) << startBitIndex)) //right side
            | (startBitIndex + bitQuantity < 33 ? store & 0xFFFFFFFF00000000L : ((((store >> 32) & 0xFFFFFFFFL) | (0xFFFFFFFFL >> (32 - Math.min(bitQuantity, Math.min(32, bitQuantity + startBitIndex - 32))))) << 32))); //left side
        return ((startBitIndex > 31 ? store & 0xFFFFFFFFL : (store & 0xFFFFFFFFL) & ~((0xFFFFFFFFL >> (32 - Math.min(bitQuantity, 32 - startBitIndex))) << startBitIndex)) //right side
            | (startBitIndex + bitQuantity < 33 ? store & 0xFFFFFFFF00000000L : ((((store >> 32) & 0xFFFFFFFFL) & ~(0xFFFFFFFFL >> (32 - Math.min(bitQuantity, Math.min(32, bitQuantity + startBitIndex - 32))))) << 32))); //left side
}       
    
public static final long setMSBits(final long store, final int startBitIndex, final int bitQuantity)
{
    return setBits(store, startBitIndex, bitQuantity, true, true);
}

public static final long clearMSBits(final long store, final int startBitIndex, final int bitQuantity)
{
    return setBits(store, startBitIndex, bitQuantity, true, false);
}

public static final long setLSBits(final long store, final int startBitIndex, final int bitQuantity)
{
    return setBits(store, startBitIndex, bitQuantity, false, true);
}

public static final long clearLSBits(final long store, final int startBitIndex, final int bitQuantity)
{
    return setBits(store, startBitIndex, bitQuantity, false, false);
}