java位操作和逻辑操作

1.java的位运算符

/**
 * 计算机对有符号数（包括浮点数）的表示有三种方法：原码、反码和补码， 补码=反码+1。 在 二进制里，是用 0 和 1
 * 来表示正负的，最高位为符号位，最高位为 1 代表负数，最高位为 0 代表正数。
 * 
 * @author Administrator
 * 
 */
public class ShiftOperator {

	public static void main(String[] args) {
		leftMove();
		rightMove();
		unSignRightMove();
	}

	/**
	 * 左移位运算符（<<）能将运算符左边的运算对象向左移动运算符右侧指定的位数（在低位补 0）
	 * 
	 * 负数的情况:十进制如何转为二进制 1.先将-5的绝对值转换成二进制，即为0000 0101 2.然后求该二进制的反码，即为 1111 1010
	 * 3.最后将反码加1，即为：1111 1011
	 * Integer是32位(bit)的,所以结果是：11111111111111111111111111111011
	 */
	public static void leftMove() {
		System.out.println("左移运算符");
		int start_1 = 5;
		System.out.println(start_1 + ":" + Integer.toBinaryString(start_1));
		int end_1 = 5 << 2;
		System.out.println(end_1 + ":" + Integer.toBinaryString(end_1));

		int start_2 = -5;
		System.out.println(start_2 + ":" + Integer.toBinaryString(start_2));
		int end_2 = -5 << 2;
		System.out.println(end_2 + ":" + Integer.toBinaryString(end_2));
	}

	/**
	 * "有符号"右移位运算符(>>)则将运算符左边的运算对象向右移动运算符右侧指定的位数 若值为正，则在高位插入0；若值为负，则在高位插入1
	 */
	public static void rightMove() {
		System.out.println("(有符号)右移位运算符运算符");
		int start_1 = 5;
		System.out.println(start_1 + ":" + Integer.toBinaryString(start_1));
		int end_1 = 5 >> 2;
		System.out.println(end_1 + ":" + Integer.toBinaryString(end_1));

		int start_2 = -5;
		System.out.println(start_2 + ":" + Integer.toBinaryString(start_2));
		int end_2 = -5 >> 2;
		System.out.println(end_2 + ":" + Integer.toBinaryString(end_2));
	}

	/**
	 * 右移位运算符(>>>):零填充高位
	 */
	public static void unSignRightMove() {
		System.out.println("右移位运算符运算符");
		int start_1 = 5;
		System.out.println(start_1 + ":" + Integer.toBinaryString(start_1));
		int end_1 = 5 >>> 2;
		System.out.println(end_1 + ":" + Integer.toBinaryString(end_1));

		int start_2 = -5;
		System.out.println(start_2 + ":" + Integer.toBinaryString(start_2));
		int end_2 = -5 >>> 2;
		System.out.println(end_2 + ":" + Integer.toBinaryString(end_2));
	}
}

2.java逻辑操作符

/**
 * & 与；| 或；~ 非（也叫做求反）；^ 异或
 * 
 * @author Administrator
 * 
 */
public class LogicOperator {

	public static final String INT_ZENO = "00000000000000000000000000000000";

	public static void main(String[] args) {
		operator_1();
		operator_2();
		operator_3();
		operator_4();
	}

	/**
	 * 两个都为 1时才为1，否则为0
	 */
	public static void operator_1() {
		System.out.println("与运算符(&)");
		int first_1 = 5;
		int second_1 = 3;
		System.out.println(first_1 + ":"
				+ getFullBinary(Integer.toBinaryString(first_1)));
		System.out.println(second_1 + ":"
				+ getFullBinary(Integer.toBinaryString(second_1)));
		int result_1 = 5 & 3;
		System.out.println(result_1 + ":"
				+ getFullBinary(Integer.toBinaryString(result_1)));

		int first_2 = -5;
		int second_2 = 3;
		System.out.println(first_2 + ":"
				+ getFullBinary(Integer.toBinaryString(first_2)));
		System.out.println(" " + second_2 + ":"
				+ getFullBinary(Integer.toBinaryString(second_2)));
		int result_2 = -5 & 3;
		System.out.println(" " + result_2 + ":"
				+ getFullBinary(Integer.toBinaryString(result_2)));
	}

	/**
	 * 只要有一个为1，结果为1
	 */
	public static void operator_2() {
		System.out.println("或运算符(|)");
		int first_1 = 5;
		int second_1 = 3;
		System.out.println(first_1 + ":"
				+ getFullBinary(Integer.toBinaryString(first_1)));
		System.out.println(second_1 + ":"
				+ getFullBinary(Integer.toBinaryString(second_1)));
		int result_1 = 5 | 3;
		System.out.println(result_1 + ":"
				+ getFullBinary(Integer.toBinaryString(result_1)));

		int first_2 = -5;
		int second_2 = 3;
		System.out.println(first_2 + ":"
				+ getFullBinary(Integer.toBinaryString(first_2)));
		System.out.println(" " + second_2 + ":"
				+ getFullBinary(Integer.toBinaryString(second_2)));
		int result_2 = -5 | 3;
		System.out.println(result_2 + ":"
				+ getFullBinary(Integer.toBinaryString(result_2)));
	}

	/**
	 * 1变为0,0变为1
	 */
	public static void operator_3() {
		System.out.println("非运算符(~)");
		int first_1 = 5;
		System.out.println(" " + first_1 + ":"
				+ getFullBinary(Integer.toBinaryString(first_1)));
		int result_1 = ~5;
		System.out.println(result_1 + ":"
				+ getFullBinary(Integer.toBinaryString(result_1)));
	}

	/**
	 * 两个相同时为1，不同时为0
	 */
	public static void operator_4() {
		System.out.println("异或运算符(^)");
		int first_1 = 5;
		int second_1 = 3;
		System.out.println(first_1 + ":"
				+ getFullBinary(Integer.toBinaryString(first_1)));
		System.out.println(second_1 + ":"
				+ getFullBinary(Integer.toBinaryString(second_1)));
		int result_1 = 5 ^ 3;
		System.out.println(result_1 + ":"
				+ getFullBinary(Integer.toBinaryString(result_1)));

		int first_2 = -5;
		int second_2 = 3;
		System.out.println(first_2 + ":"
				+ getFullBinary(Integer.toBinaryString(first_2)));
		System.out.println(" " + second_2 + ":"
				+ getFullBinary(Integer.toBinaryString(second_2)));
		int result_2 = -5 ^ 3;
		System.out.println(result_2 + ":"
				+ getFullBinary(Integer.toBinaryString(result_2)));
	}

	private static String getFullBinary(String binaryString) {
		return INT_ZENO.substring(binaryString.length()) + binaryString;
	}

}