一句话概括：循环每次从未排序里选择一个最小或的最大的元素依次放好，直到最后（没有未排序的了）。

1.int型数组选择排序

import java.util.Random;public class test1 {		private static int a[];	public static void main(String[] args) {		produceData(10,1,10);		print();		sort();		print();			}	//产生数据	private static void produceData(int n,int min,int max ) {				a = new int[n];				Random random = new Random();				for(int i= 0;i
    
     a[j])					minindx = j;			}						int tmp =  a[minindx];			a[minindx] = a[i];			a[i] = tmp;					}			}	private static void print() {				int n = a.length;				for(int i=0;i
    

2.使用Comparable接口实现各种数据类型排序

自定义的Student类:

import java.util.Comparator;public class Student implements Comparable
    
     {		public String name;	public int score;				public Student(String name, int score) {		super();		this.name = name;		this.score = score;	}	public String getName() {		return name;	}	public void setName(String name) {		this.name = name;	}	public int getScore() {		return score;	}	public void setScore(int score) {		this.score = score;	}	@Override	public String toString() {		return "Student [name=" + name + ", score=" + score + "]";	}	@Override	public int compareTo(Student o) {		if(this.getScore()>o.getScore())			return 1;		else if(this.getScore()
    

排序算法

import java.util.Comparator;import java.util.Random;public class test1 {		public static void main(String[] args) {		Student[] stus = produceData();		print(stus);//打印原来顺序		sort(stus);		print(stus);				//比较Double类型（也实现了Comparable接口）		Double[] d = {3.14,3.11,3.99};		sort(d);		print(d);			}	//产生数据	private static Student[] produceData() {				Student[] stus = new Student[4];		stus[0] = new Student("A",66);		stus[1] = new Student("B",90);		stus[2] = new Student("C",80);		stus[3] = new Student("D",100);				return stus;			}	//排序	private static void sort(Comparable[] arry) {		int n = arry.length;				for(int i=0;i

3.编写一个类来测试排序算法运行时间(利用反射和系统时间实现)

import java.lang.reflect.Method;public class SortTestHelper {	public static void testSort(String sortClassName,Comparable[] arry)	{		try {						//告诉类名即可获取class对象			Class sortClass =  Class.forName(sortClassName);			//指明方法名和参数列表就可以获取			//getDeclaredMethod()获取的是类自身声明的所有方法，包含public、protected和private方法。	　　			//getMethod()获取的是类的所有共有方法，这就包括自身的所有public方法，和从基类继承的、从接口实现的所有public方法。			Method sortMethod = sortClass.getDeclaredMethod("sort", new Class[]{Comparable[].class});			Object[] params = new Object[]{arry};						long startTime = System.currentTimeMillis();						//第一个参数是调用哪个对象实例的此方法，静态就写null，第二个为方法参数			sortMethod.invoke(null, params);						long overTime = System.currentTimeMillis();						System.out.println("耗时："+(overTime-startTime+" ms!"));						judgeSorted(arry);					} catch (Exception e) {			e.printStackTrace();		}	}	private static void judgeSorted(Comparable[] arry) {				for (int i = 0; i < arry.length-1; i++) {			if(arry[i].compareTo(arry[i+1])<0)			{				System.out.println("排序失败!");				return;			}		}		System.out.println("排序成功!");			}		public static void print(Object[] data) {				int n = data.length;				for(int i=0;i
    
     max;				Integer[] data = new Integer[n];				for (int i = 0; i < data.length; i++) {			data[i] = new Integer((int)(Math.random()*(max-min+1))+min);		}				return data;			}	}