Collection.max(List,new Comparator)的學習

package org.apache.java.lib.test;

import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

public class QueueTest {

    public static void main(String[] args) {

        List<Student> studentList = new ArrayList<Student>();
        studentList.add(new Student("zhangs", "2"));
        studentList.add(new Student("lisi", "1"));
        studentList.add(new Student("wangwu", "3"));

        Student student = getMaxObject(studentList);
        System.out.println(student.getName());
        System.out.println(student.getNumber());
    }

    /**
     * 返回容器中最大的元素（經過比較器）
     * 
     * @param objList
     *            容器
     * @return 最大的元素
     * 
     */
    public static <T> T getMaxObject(List<T> objList) {

        if (objList == null || objList.size() == 0) {
            return null;
        }

        return Collections.max(objList, new Comparator<T>() {
            public int compare(T o1, T o2) {
                int equalValue = 0;
                try {

                    Field o1Field = o1.getClass().getDeclaredField("number");
                    o1Field.setAccessible(true);
                    Field o2Filed = o2.getClass().getDeclaredField("number");
                    o2Filed.setAccessible(true);

                    equalValue = Integer.parseInt(String.valueOf(o1Field.get(o1))) < Integer
                            .parseInt(String.valueOf(o2Filed.get(o2))) ? -1 : 1;

                } catch (Exception e) {
                    System.out.println("你傳輸的數據有問題！");
                    e.printStackTrace();
                    return equalValue;
                }

                return equalValue;
            }
        });
    }

}