gu.sql2java.ArraySupport Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of sql2java-base Show documentation
sql2java common class package
The newest version!
package gu.sql2java;

import static com.google.common.base.Preconditions.checkArgument;

import com.google.common.io.BaseEncoding;

public class ArraySupport {
	private static final String HEX_REGEX  = "^([a-fA-F0-9]{2})+$";
	/**
	 * 字符串验证器,根据正则表达式判断字符串是否为十六进制(HEX)字符串
	 * 输入为null或空或正则表达式不匹配则返回false
	 */
	private static final boolean validHEX(String input){
		return input != null && (input.length()&1) == 0 && input.matches(HEX_REGEX);
	}
	/**
	 * cast byte array to HEX string
	 * 
	 * @param input
	 * @return hex string or  null if not byte[]
	 */
	public static final String toHex(byte[] input) {
		if (input instanceof byte[]){
			return BaseEncoding.base16().encode(input);
		}
		return null;
	}

	/**
	 * cast integral Number to HEX string
	 * @param input
	 * @return hex string or  null if not Number
	 * @since 4.2.0
	 */
	public static final String toHex(Number input){
		if(input instanceof Integer) {
			return String.format("%08X",input.intValue());
		}else if(input instanceof Long) {
			return String.format("%016X",input.longValue());
		}else if(input instanceof Short) {
			return String.format("%04X",input.shortValue());
		}else if(input instanceof Byte) {
			return String.format("%02X",input.byteValue());
		}else if(null != input) {
			return String.format("%08X",input.intValue());
		}
		return null;
	}

	/**
	 * cast byte array or number to HEX string

	 * @param input
	 * @return hex string or  null if not byte[] or Number.
	 * @since 4.2.0
	 */
	public static final String toHex(Object input) {
	    if (input instanceof byte[]){
	    	return toHex((byte[])input);
	    }else if(input instanceof Number) {
	    	return toHex((Number)input);
	    }else if(input instanceof String) {
	    	String s = (String)input;
	    	if(validHEX(s)) {
	    		return s;
	    	}
	    }
	    return null;
	}
	/**
	 * cast HEX string to byte array
	 * @param input
	 * @return {@code null} if {@code input} is null
	 */
	public static final byte[] fromHex(String input){
		if (null == input){
			return null;
		}
		return BaseEncoding.base16().decode(input);
	}
	/**
     * cast HEX string to byte array,copy to this destination,same length required with {@code dest}
     * @param hex
     * @param dest
     */
    public static void copyToByteArray(String hex, byte[] dest){
    	checkArgument(null != hex && null != dest,"hex or dest is null");
    	byte[] src = fromHex(hex);
    	checkArgument(src.length == dest.length,"INVALID HEX String length, %s required",dest.length);
        System.arraycopy(src, 0, dest, 0, src.length);
    }

    /**
     * return {@code true} if bit specialized by {@code index} in  byte array {@code bits} is 1,otherwise {@code false}
     * @param bits
     * @param index
     * @since 4.0.0
     */
    public static final boolean bitCheck(byte[]bits,int index){
    	return 0 != (bits[bits.length - 1 - (index>>3)]&(byte)(1<<(index&0x07)));
    }

	/**
	 * return {@code true} if bit specialized by {@code index} in HEX string
	 * {@code hex} is 1, otherwise {@code false} 

	 * return {@code false} if {@code index} is {@code null} or out of range
	 * 
	 * @param hex
	 * @param index
	 * @since 5.3.0
	 */
	public static final boolean bitCheck(String hex, int index) {
		byte[] bits = fromHex(hex);
		return (null == bits || index >= bits.length || index < 0) ? false : bitCheck(bits, index);
	}

    /**
     * set bit specialized by {@code index} in  byte array {@code bits} to 1
     * @param bits
     * @param index
     * @return always {@code bits}
     * @since 4.0.0
     */
    public static final byte[] bitSet(byte[] bits,int index){
    	bits[bits.length - 1 - (index>>3)] |= (byte)(1<<(index&0x07));
    	return bits;
    }
    /**
     * set bit specialized by {@code index} in  byte array {@code bits} to 0
     * @param bits
     * @param index
     * @return always {@code bits}
     * @since 4.0.0
     */
    public static final byte[] bitReset(byte[] bits,int index){
        bits[bits.length - 1 - (index>>3)] &= (byte)(~(1<<(index&0x07)));
        return bits;
    }
    /**
     * set bit specialized by {@code index} in  byte array {@code bits} to 0 if {@code set1} is {@code true},otherwise set to 0
     * @param bits
     * @param index
     * @param set1
     * @return always {@code bits}
     * @since 4.0.0
     */
    public static final byte[] bitSet(byte[] bits,int index,boolean set1){
        return set1 ? bitSet(bits, index) : bitReset(bits, index);
    }
}