随机数产生(1w内不重复)，随机数产生1w重复,package roo.

随机数产生(1w内不重复)，随机数产生1w重复,package roo.

package roo.util;import java.util.ArrayList;import java.util.List;/** * @author YZM */public final class IDGenerator {    private static int ID_LEN = 9;    private static IDGenerator generator = new IDGenerator();    /**     * private and only constructor     */    private IDGenerator() {    }    /**     * @return Generator     */    public static IDGenerator getInstance() {        if (generator == null)            generator = new IDGenerator();        return generator;    }    /**     * @return the iD     *      */    public int getID() {        int root = (int) Math.pow(10, ID_LEN);        int id = 0;        do {            long tmp = Math.abs(Double.doubleToLongBits(Math.random()));            id = (int) (tmp % root);        } while (id < (root / 10));        // System.out.println(id);        return id;    }    /**     * @return the iD_LEN     */    public static int getID_LEN() {        return ID_LEN;    }    /**     * @param iD_LEN     *            the iD_LEN to set     */    public static void setID_LEN(int iD_LEN) {        ID_LEN = iD_LEN;    }    public static void main(String[] args) {        List<Integer> list = new ArrayList<Integer>();        int x;        for (int i = 0; i < 10000; i++) {            // System.out.println(generator.getID());            x = generator.getID();            if (!list.contains(x))                list.add(x);            else                System.out.println(x);        }    }}//该片段来自于http://byrx.net