使用Comparator实现自定义排序

package map;



/**

 * Created by benjamin on 11/5/15.

 */

public class Person {

    String firstName,lastName;

    char sex;

    Integer age;



    public Person(String firstName, String lastName, char sex, Integer age) {

        this.firstName = firstName;

        this.lastName = lastName;

        this.sex = sex;

        this.age = age;

    }



    public String getFirstName() {

        return firstName;

    }



    public void setFirstName(String firstName) {

        this.firstName = firstName;

    }



    public String getLastName() {

        return lastName;

    }



    public void setLastName(String lastName) {

        this.lastName = lastName;

    }



    public char getSex() {

        return sex;

    }



    public void setSex(char sex) {

        this.sex = sex;

    }



    public Integer getAge() {

        return age;

    }



    public void setAge(Integer age) {

        this.age = age;

    }

}

package map;



/**

 * Created by benjamin on 11/5/15.

 */





import java.util.Comparator;



/**

 * 谁的拼音靠前,谁就排前面.

 * 然后对名字进行排序.如果同名,女性排前面.

 * 如果名字和性别都相同,年龄小的排前面.

 *

 *

 * int compare(Object o1, Object o2)返回一个基本的数据类型

 * 如果要按照升序排序

 * 则o1 < o2, return -1; equals return 0;  o1 > 02 return 1;

 * 如果要按照降序排序

 * 则01 < 02, return 1;  equals return 0;  o1 > o2 return -1;

 *

 */

public class Comparators {

    /**

     * 获取合适的比较器

     * @return

     */

    public static Comparator getComparator() {

        return new Comparator() {

            @Override

            public int compare(Object o1, Object o2) {

                if(o1 instanceof String) {

                    return compare((String)o1, (String)o2);

                } else if(o1 instanceof Integer) {

                    return compare((Integer)o1, (Integer)o2);

                } else if(o1 instanceof Person) {

                    return comparePerson((Person) o1, (Person) o2);

                } else {

                    System.out.println("未找到合适的比较器");

                    return 1;

                }

            }

        };

    }



    private static int compare(String o1, String o2) {

        int len1 = o1.length();

        int len2 = o2.length();

        int min = Math.min(len1, len2);

        char v1[] = o1.toCharArray();

        char v2[] = o2.toCharArray();

        int pos = 0;

        //循环得到名字的排序

        while(--min != 0) {

            char c1 = v1[pos];

            char c2 = v2[pos];

            if (c1 != c2) {

                return c1 - c2;

            }

            pos ++;

        }

        return len1 - len2;

    }



    /**

     * 比较年龄

     * @param o1

     * @param o2

     * @return

     */

    private static int compare(Integer o1, Integer o2) {

        int val1 = o1.intValue();

        int val2 = o2.intValue();

        return val1 < val2 ? -1 : (val1 == val2 ? 0 : 1);

    }



    /**

     * 比较性别

     * @param o1

     * @param o2

     * @return

     */

    private static int compare(char o1, char o2) {

        return ((o1 == o2) ? 0 : (o1 == '男' ? 1 : -1));

    }



    /**

     * 比较Person

     * @param o1

     * @param o2

     * @return

     */

    private static int comparePerson(Person o1, Person o2) {

        String firstName1 = o1.getFirstName();

        String firstName2 = o2.getFirstName();

        String lastName1 = o1.getLastName();

        String lastName2 = o2.getLastName();

        char sex1 = o1.getSex();

        char sex2 = o2.getSex();

        Integer age1 = o1.getAge();

        Integer age2 = o2.getAge();

        return (compare(firstName1, firstName2) == 0 ?

                (compare(lastName1, lastName2) == 0 ?

                (compare(sex1, sex2) == 0 ?

                (compare(age1, age2) == 0 ? 0 :

                compare(age1, age2)) :

                compare(sex1, sex2)) :

                compare(lastName1, lastName2)) :

                compare(firstName1, firstName2));

    }



}

排序前=ouyang feng 男 27

排序前=zhuang gw 男 27

排序前=deng jx 男 28

排序前=deng jx 女 27



----------------------------------------------------

排序前=deng jx 女 27

排序前=deng jx 男 28

排序前=ouyang feng 男 27

排序前=zhuang gw 男 27