如何在java中切换类 [英] How to switch the class in java
本文介绍了如何在java中切换类的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
Hello编码器，我想将switch语句重构为枚举类。代码的结果：创建一个盒子并将粒子放入盒子内，然后让粒子自由移动，如果两个粒子碰撞，新的粒子将被添加到盒子内。帮助我们一些提示。还有一个，我知道当我在这里粘贴我的代码时（我问我的团队他们同意了），它会被另一个人轻易复制。我怎么能防止这种情况？谢谢。
我尝试过：
盒子类：
import java.util.Random;
公共类框{
private final int WIDTH = 25;
private final int HEIGHT = 6;
private final int PARTICLE_MAX = 300;
私人静电箱;
private particle [] particleList = new particle [PARTICLE_MAX];
private Random r = new Random（）;
private box（）{
for（int i = 0; i< 3; i ++）{
addNewParticle（）;
}
}
public int getWidth（）{
返回WIDTH;
}
public int getHeight（）{
return HEIGHT;
}
public int getParticleMax（）{
return PARTICLE_MAX;
}
公共静态框getInstance（）{
if（box == null）
box = new box（）;
返回框;
}
public void makeParticlesMove（）{
int n;
for（particle particle：particleList）{
if（particle！= null）{
n = r.nextInt（8）+1;
switch（n）{
case 1：if（particle.getY（） - 1> 0）{
particle.north（）;
}
休息;
case 2：if（particle.getY（） - 1> 0&& particle.getX（）+ 1< WIDTH-1）{
particle.northeast（）;
}
休息;
case 3：if（particle.getX（）+ 1< WIDTH-1）{
particle.east（）;
}
休息;
case 4：if（particle.getY（）+ 1< HEIGHT-1&& particle.getX（）+ 1< WIDTH-1）{
particle.southeast（）;
}
休息;
case 5：if（particle.getY（）+ 1< HEIGHT-1）{
particle.south（）;
}
休息;
case 6：if（particle.getY（）+ 1< HEIGHT-1&& particle.getX（） - 1> 0）{
particle.southwest（）;
}
休息;
case 7：if（particle.getX（） - 1> 0）{
particle.west（）;
}
休息;
case 8：if（particle.getY（） - 1> 0&& particle.getX（） - 1> 0）{
particle.northwest（）;
}
休息;
}
}
}
collisionCheck（）;
}
public int particleCount（）{
int p = 0;
for（particle particle：particleList）{
if（particle！= null）{
p ++;
}
}
返回p;
}
public void showParticles（）{
char [] [] map = new char [WIDTH] [HEIGHT];
for（particle p：particleList）{
if（p！= null）{
int x = p.getX（）;
int y = p.getY（）;
map [x] [y] ='*';
}
}
for（int i = 0; i< WIDTH; i ++）
System.out.print（ - ）;
System.out.println（）;
for（int j = 1; j< HEIGHT-1; j ++）{
System.out.print（|）;
for（int c = 1; c< WIDTH-1; c ++）{
if（map [c] [j] =='*'）
System.out.print（ *）;
else
System.out.print（）;
}
System.out.println（|）;
}
for（int i = 0; i< WIDTH; i ++）
System.out.print（ - ）;
System.out.println（）;
}
public void collisionCheck（）{
boolean [] [] map = new boolean [WIDTH] [HEIGHT];
for（int i = 0; i< HEIGHT; i ++）{
for（int j = 0; j< WIDTH; j ++）
map [j] [i] = false;
}
for（粒子p：particleList）{
if（p！= null）{
int x = p.getX（）;
int y = p.getY（）;
if（map [x] [y]）{
System.out.println（Collided !!!!）;
addNewParticle（）;
}
其他
map [x] [y] = true;
}
}
}
public void addNewParticle（）{
for（int i = 0; i< PARTICLE_MAX; i ++）{
if（particleList [i] == null）{
particleList [i] = new particle（r.nextInt（WIDTH-2）+ 1，r.nextInt（HEIGHT-2）+1）;
休息;
}
}
}
}
粒子类：
public class Particle {
private int x;
private int y;
public Particle（int x，int y）{
this.x = x;
this.y = y;
}
public void setX（int x）{
this.x = x;
}
public void setY（int y）{
this.y = y;
}
public int getX（）{
return x;
}
public int getY（）{
return y;
}
public void north（）{
y- = 1;
}
public void northeast（）{
y- = 1;
x + = 1;
}
public void east（）{
x + = 1;
}
public void southeast（）{
y + = 1;
x + = 1;
}
public void south（）{
y + = 1;
}
public void southwest（）{
y + = 1;
x- = 1;
}
public void west（）{
x- = 1;
}
public void northwest（）{
y- = 1;
x- = 1;
}
}
测试：
公共类主要{
public static void main（String [] args）{
Box b = Box.getInstance（）;
do {
System.out.println（粒子数：+ b.particleCount（））;
b.makeParticlesMove（）;
b.showParticles（）;
try {
Thread.sleep（300）;
} catch（例外e）{
System.out.println（e）;
}
} while（b.particleCount（）< b.getParticleMax（））;
}
}
解决方案
您可以定义枚举类似于：
enum 方向{
无效（ - 1 ），
北（ 0 ），
NorthEast（ 1 ），
南（ 2 ），
...
...
SouthEast（ 7 ）;
private int val;
private static Map< int，Direction> intToTypeMap;
private Direction（ int v）{
此 .val = v;
this .addToMap（v）;
}
public int getValue（）{
return this .val;
}
private void addToMap（ int v）{
if （intToTypeMap == null）{
intToTypeMap = new TreeMap< int，Direction>（）;
}
intToTypeMap.put（v， this ）;
}
public static 方向fromInt（ int v）{
Direction type = intToTypeMap.get（Integer.valueOf（v））;
if （type == null）{
return Direction.Invalid;
}
返回类型;
}
}
在上面的枚举之后，你可以改变你的开关语句，如下所示：
。 。 。
。 。 。
for（粒子：particleList）{
if（particle！= null）{
switch（Direction.fromtInt（r.nextInt（8）））{
case North： if（particle.getY（） - 1> 0）{
particle.north（）;
}
休息;
。 。 。
。 。
Hello coders, I want to refactor the switch statement to a enum class. The result of the code: creates a box and put particles inside the box, then make particles move freely and if two particles collide a new particle will be added inside the box. Help us some hints to do. One more, I knew when I pasted my code in here (I asked my team and they agreed), it will be copied easily by another person. How can I prevent that? Thanks.
What I have tried:
Box class:
import java.util.Random;
public class box{
private final int WIDTH = 25;
private final int HEIGHT = 6;
private final int PARTICLE_MAX = 300;
private static box box;
private particle[] particleList = new particle[PARTICLE_MAX];
private Random r = new Random();
private box(){
for(int i = 0; i<3;i++){
addNewParticle();
}
}
public int getWidth(){
return WIDTH;
}
public int getHeight(){
return HEIGHT;
}
public int getParticleMax(){
return PARTICLE_MAX;
}
public static box getInstance(){
if(box == null)
box = new box();
return box;
}
public void makeParticlesMove(){
int n;
for(particle particle:particleList){
if(particle != null){
n = r.nextInt(8)+1;
switch(n){
case 1: if(particle.getY()-1 > 0){
particle.north();
}
break;
case 2: if(particle.getY()-1 > 0 && particle.getX()+1 < WIDTH-1){
particle.northeast();
}
break;
case 3: if(particle.getX()+1 < WIDTH-1){
particle.east();
}
break;
case 4: if(particle.getY()+1 < HEIGHT-1 && particle.getX()+1 < WIDTH-1){
particle.southeast();
}
break;
case 5: if(particle.getY()+1 < HEIGHT-1){
particle.south();
}
break;
case 6: if(particle.getY()+1 < HEIGHT-1 && particle.getX()-1 > 0){
particle.southwest();
}
break;
case 7: if(particle.getX()-1 > 0){
particle.west();
}
break;
case 8: if(particle.getY()-1 > 0 && particle.getX()-1 > 0){
particle.northwest();
}
break;
}
}
}
collisionCheck();
}
public int particleCount(){
int p = 0;
for(particle particle:particleList){
if(particle !=null){
p++;
}
}
return p;
}
public void showParticles(){
char[][] map = new char[WIDTH][HEIGHT];
for(particle p:particleList){
if(p != null){
int x = p.getX();
int y = p.getY();
map[x][y] = '*';
}
}
for(int i = 0; i < WIDTH; i++)
System.out.print("-");
System.out.println();
for(int j = 1; j < HEIGHT-1; j++){
System.out.print("|");
for(int c = 1; c < WIDTH-1; c++){
if(map[c][j] == '*')
System.out.print("*");
else
System.out.print(" ");
}
System.out.println("|");
}
for(int i = 0; i < WIDTH; i++)
System.out.print("-");
System.out.println();
}
public void collisionCheck(){
boolean[][] map = new boolean[WIDTH][HEIGHT];
for(int i =0; i<HEIGHT; i++){
for(int j = 0; j<WIDTH; j++)
map[j][i] = false;
}
for(particle p:particleList){
if(p != null){
int x = p.getX();
int y = p.getY();
if(map[x][y]) {
System.out.println("Collided!!!!");
addNewParticle();
}
else
map[x][y] = true;
}
}
}
public void addNewParticle(){
for(int i = 0; i < PARTICLE_MAX; i++){
if(particleList[i] == null){
particleList[i] = new particle(r.nextInt(WIDTH-2)+1, r.nextInt(HEIGHT-2)+1);
break;
}
}
}
}
particle class:
public class Particle{
private int x;
private int y;
public Particle(int x, int y){
this.x = x;
this.y = y;
}
public void setX(int x){
this.x = x;
}
public void setY(int y){
this.y = y;
}
public int getX(){
return x;
}
public int getY(){
return y;
}
public void north(){
y-=1;
}
public void northeast(){
y-=1;
x+=1;
}
public void east(){
x+=1;
}
public void southeast(){
y+=1;
x+=1;
}
public void south(){
y+=1;
}
public void southwest(){
y+=1;
x-=1;
}
public void west(){
x-=1;
}
public void northwest(){
y-=1;
x-=1;
}
}
test:
public class Main{
public static void main(String[] args){
Box b = Box.getInstance();
do{
System.out.println("Particle count: " + b.particleCount());
b.makeParticlesMove();
b.showParticles();
try{
Thread.sleep(300);
}catch (Exception e){
System.out.println(e);
}
}while(b.particleCount() < b.getParticleMax());
}
} 解决方案
You can define an enum something like:
enum Direction { Invalid(-1), North(0), NorthEast(1), South(2), ... ... SouthEast(7); private int val; private static Map<int, Direction> intToTypeMap; private Direction(int v) { this.val = v; this.addToMap(v); } public int getValue() { return this.val; } private void addToMap(int v) { if (intToTypeMap == null) { intToTypeMap = new TreeMap<int, Direction>(); } intToTypeMap.put(v, this); } public static Direction fromInt(int v) { Direction type = intToTypeMap.get(Integer.valueOf(v)); if (type == null) { return Direction.Invalid; } return type; } }
After above enum, you can change your switch statement something like as below:
. . . . . . for (particle particle:particleList) { if(particle != null){ switch(Direction.fromtInt(r.nextInt(8))){ case North: if(particle.getY()-1 > 0){ particle.north(); } break; . . . . . .
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