1607084207 张阳

[annyangya]

package Sort.src.BaseSort;

public class BaseSort {
public void sort(int []a)
{
System.out.println("排序算法");
}
}

package Sort.src.BaseSort;

public class InsertSort extends BaseSort{
public void sort(int []a,int n)
{
for(int i=0;i<n;i++)
{
for(int j=i;j>0;j--)
{
if(a[j]<a[j-1])
{
swap(a,j,j-1);
}
else
break;
}
}
}
public void swap(int []a,int i,int j)
{
int temp=a[i];
a[i]=a[j];
a[j]=temp;
}

}
package Sort.src.BaseSort;

public class QuickSort extends BaseSort{
public int getElem(int []a,int l,int r)
{
int j=l;
for(int i=l+1;i<=r;i++)
{
if(a[i]<a[j])
{
swap(a,j+1,i);
}
}
return j;
}
public void swap(int []a,int i,int j)
{
int temp=a[i];
a[i]=a[j];
a[j]=temp;
}
public void sort(int []a,int n)
{
int m=getElem(a,0,n-1);
getElem(a,0,m-1);
getElem(a,m+1,n-1);
}
}
package Sort.src.BaseSort;

public class SelectSort extends BaseSort {
public void sort(int []a,int n)
{
for(int i=0;i<n;i++)
{
int min=i;
for(int j=i+1;j<n;j++)
{
if(a[min]>a[j])
{
min=j;
}
}
swap(a,i,min);
}
}
public void swap(int []a,int i,int j)
{
int temp=a[i];
a[i]=a[j];
a[j]=temp;
}
}
package Sort.src.BaseSort;

import java.util.Scanner;

public class Text {

public static void main(String[] args) {
int[] a=new int[10];
Scanner scanner=new Scanner(System.in);
for(int i=0;i<10;i++)
{
a[i]=scanner.nextInt();
}
System.out.println("选择排序：");
SelectSort one=new SelectSort();
one.sort(a,10);
for(int i=0;i<10;i++)
{
System.out.print(a[i]+",");
}
System.out.println();
System.out.println("选择排序：");
InsertSort two=new InsertSort();
two.sort(a,10);
for(int i=0;i<10;i++)
{
System.out.print(a[i]+",");
}
System.out.println();
System.out.println("快速排序：");
QuickSort three=new QuickSort();
three.sort(a,10);
for(int i=0;i<10;i++)
{
System.out.print(a[i]+",");
}
System.out.println();

}
}

[annyangya]

第二次作业

单例模式：只能产生一个实例

`package Design.src.People;

public class People {
private int age;
private String name;
private double weight;

private People()//构造方法必须是private访问权限，禁止从类外部调用构造方法，只能产生一个实例
{
	
}

private People(int age, String name, double weight) {
	super();
	this.age = age;
	this.name = name;
	this.weight = weight;
}
public int getAge() {
	return age;
}
public void setAge(int age) {
	this.age = age;
}
public String getName() {
	return name;
}
public void setName(String name) {
	this.name = name;
}
public double getWeight() {
	return weight;
}
public void setWeight(double weight) {
	this.weight = weight;
}

private static People people1=new People(12,"ann",45.6);
public static People getPeople1()//通过该方法可以从类外部访问到类的实例
{
	return people1;
}
private static People people2=new People();
public static People getPeople2()
{
	return people2;
}
public String toString()
{
	return "\n姓名："+this.getName()+"\n年龄："+this.getName()+"\n体重："+this.getWeight();
}

}
package Design.src.People;

public class PeopleText {

public static void main(String[] args) {
	People a=People.getPeople1();//调用该方法时，生成了唯一的一个实例
	System.out.println("a的个人信息为："+a);
	People b=People.getPeople1();
	System.out.println("b的个人信息为："+b);
	People c=People.getPeople2();
	People d=People.getPeople2();
	System.out.println("c==d的结果为："+(c==d));//判断两个实例是否相等
	System.out.println("c的个人信息为："+c);
	

}

}

`

为什么有了接口还要使用抽象类

1.一个类可以实现多个接口，同时要实现接口里所有的方法，但是一个类只能继承一个类，不能是多继承
2.一个类继承了另一个抽象类后，可以不用实现该抽象类中所有的方法，但是这个类必须也要是抽象类
3.接口中规定了必须有某些方法，如果一个类实现了该接口，也就是说要实现这个接口中规定的方法
4.一个类继承另一个抽象类时，不需要必须实现哪一个方法

[annyangya]

第三次培训

Foreach

`package BianLi;

import java.util.Collection;
import java.util.HashSet;

public class Foreach {

public static void main(String[] args) {
	Collection book=new HashSet();
	book.add("book1");
	book.add("book2");
	book.add("book3");

// for(Object obj:book)
// {
// //System.out.println(obj);
// String a=(String)obj;
// System.out.println(a);
// }
for(Object obj:book)
{
System.out.println(obj);
}
}

}
`

Iterator

`package Demo1.src.Collection;

public class catSet {
private String name;
private int month;
private String species;
private double weight;
public catSet(String name, int month, String species, double weight) {
super();
this.name = name;
this.month = month;
this.species = species;
this.weight = weight;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getMonth() {
return month;
}
public void setMonth(int month) {
this.month = month;
}
public String getSpecies() {
return species;
}
public void setSpecies(String species) {
this.species = species;
}
public double getWeight() {
return weight;
}
public void setWeight(double weight) {
this.weight = weight;
}

public String toString()
{
	return "姓名："+this.getName()+"\t年龄："+this.getMonth()+"\t种类："+this.getSpecies()+"\t体重："+this.getWeight();
}
@Override
public int hashCode() {
	final int prime = 31;
	int result = 1;
	result = prime * result + month;
	result = prime * result + ((name == null) ? 0 : name.hashCode());
	result = prime * result + ((species == null) ? 0 : species.hashCode());
	long temp;
	temp = Double.doubleToLongBits(weight);
	result = prime * result + (int) (temp ^ (temp >>> 32));
	return result;
}
@Override
public boolean equals(Object obj) {
	if(this==obj)
		return true;
	if(obj.getClass()==catSet.class)
	{
		catSet cat=(catSet)obj;
		//return cat.getName().equals(name)&&cat.getMonth().equals(month)&&cat.getSpecies().equals(species)&&cat.getWeight().equals(weight);
		return cat.getName().equals(name)&&(cat.getMonth()==month)&&cat.getSpecies().equals(species)&&(cat.getWeight()==weight);
	}
	return false;
	
}

}
package Demo1.src.Collection;

import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;

public class catSetText {

public static void main(String[] args) {
	catSet huahua=new catSet("花花",1,"短毛猫",2.3);
	catSet honghong=new catSet("红红",4,"田园猫",3.4);
	catSet mingming=new catSet("明明",2,"斑点猫",2);
	Set<catSet> set=new HashSet<catSet>();
	set.add(huahua);
	set.add(honghong);
	set.add(mingming);
	Iterator it=set.iterator();
	System.out.println("小猫的信息为：");
	while(it.hasNext())
	{
		System.out.println(it.next());//要重写toString方法，否则输出的是地址值
	}
	catSet honghong2=new catSet("红红",4,"田园猫",3.4);
	set.add(honghong2);
	Iterator it2=set.iterator();
	System.out.println("增加红红二号的结果：");
	while(it2.hasNext())
	{
		System.out.println(it2.next());//添加信息相同的猫没有报错，所以要重写equals方法判断猫的信息是否相同
		
	}
	catSet huahua2=new catSet("花花二号",3,"田园猫",4.5);
	set.add(huahua2);
	set.remove(huahua);
	if(set.contains(huahua))
		System.out.println("花花找到了");
	else
		System.out.println("花花没找到");
	Iterator it3=set.iterator();
	while(it.hasNext())
	{
		System.out.println(it.next());
	}

}

}
`

lambda

package BianLi;

import java.util.HashSet;
import java.util.Set;

public class lambda {

public static void main(String[] args) {
	Set books=new HashSet();
	books.add("java book");
	books.add("c book");
	books.add("c# book");
	System.out.println("遍历结果：");
	books.forEach(obj->System.out.println(obj));

}

}