这是java中的推箱子游戏。我尝试执行移动时遇到错误。任何人都可以指出我必须做出的改变才能使其发挥作用？
以下是我遇到的错误
java.lang.StringIndexOutOfBoundsException：字符串索引超出范围：49
at java.lang.String.charAt（Unknown Source）
在State.stateString（State.java:32）
at State。（State.java:15）
at boxpushing.perform（boxpushing.java:14）
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.ArrayList;
public class State{
private int posX;
private int posY;
private ArrayList<Integer> goalX;
private ArrayList<Integer> goalY;
private char[][] state;
public State(String s){
state=stateString(s);
goalX=new ArrayList<Integer>();
goalY=new ArrayList<Integer>();
locatePositionPlayerAndTargets();
}
public char [][] stateString(String s){
//need to put the state string into respective array position
int width = s.indexOf("\n"); //to find how many number of rows below.
int height = s.length() / width;
char newState[][] = new char[height][width];
int index = 0;
for (int i = 0; i <height; i++){
for(int j = 0; j< width; j++){
newState[i][j]=s.charAt(index);
index++;
}
index++;
}
return newState;
}
public char[][] getState(){
return state;
}
private void locatePositionPlayerAndTargets(){
//for player on target, target and crate on target
for (int i=0; i< state.length; i++){
for(int j=0; j<state[0].length; j++){
if(state[i][j] == 'P'){
posX=j;
posY=i;
} else if (state[i][j] == '+' || state[i][j] == 'o' || state[i][j] == '@' ){
goalX.add(j); //save the goal/targets values (X and Y position)
goalY.add(i);
}
}
}
}
public ArrayList<Integer> getGoalY(){
return goalY; //return the goal/target Y's position
}
public ArrayList<Integer> getGoalX(){
return goalX; //return the goal/target X's position
}
public int getPosX(){
return posX;
}
public int getPosY(){
return posY;
}
public void setChar(int y, int x, char c){
//to save the current element on that particular coordinates/position
state[y][x] = c;
}
public char getChar(int y, int x){
//will return what is on that particular coordinates/position
return state[y][x];
}
//To replace the symbol/character after player move is initiated
public void replacePlayerOnMove(int dy, int dx){
// to get the char value on the current position
char charOnPos = state[posY][posX];
switch(charOnPos){
case '+':
//if current position has 'playerOnTarget' replace with target
setChar(posY,posX, 'o');
break;
case '@':
//if current position has 'crateontarget' replace with playeronTarget
setChar(posY,posX, '+');
break;
case 'P':
//if current position has 'player' replace with background
setChar(posY,posX, '.');
break;
}
posX += dx;
posY += dy;
}
//To replace the symbol/character player is pushing the crate
public void replacePlayerOnPush(int dy, int dx){
char charOnPos = state[posY][posX];
switch(charOnPos){
case '@':
//if current position has 'crateOnTarget' replace with 'playerontarget'
setChar(posY,posX, '+');
break;
case '*':
//if current position has 'crate' replace with player
setChar(posY,posX, 'P');
break;
}
}
//To replace the symbol/character when crate is moved
public void replaceCrateOnMove(int dy, int dx, char c){
switch(c){
case 'o':
setChar(posY,posX, '@');
break;
case '.':
setChar(posY,posX, '*');
break;
}
}
public boolean checkValidMove(int dx, int dy){
try{ // need to use try and catch as this might not work / error might occur furthe debugging needed
int tmpX = getPosX()+dx;
int tmpY = getPosY()+dy;
// this is for index out of bound array checks
// then also check for crate / wall for pushing iniatiation
char newPosition = getChar(tmpY, tmpX);
if (newPosition == '*' || newPosition == '@'){
return checkValidPush(dx,dy);
} else if (newPosition == '#'){
return false;
} else {
return true;
}
} catch (ArrayIndexOutOfBoundsException e){
//if outofbound occurs just return false (possible end of boundary/map)
return false;
} catch (Exception e){
System.out.println("Error Occur tadaaaa..Yeehaa =( ");
return false;
}
}
public boolean checkValidPush(int dx, int dy){
int tmpPushX = getPosX() + dx*2; //new position of crate (x coordinates)
int tmpPushY = getPosY() + dy*2; //new position of crate (x coordinates)
char newCratePosition = getChar(tmpPushY,tmpPushX);
if (newCratePosition != '#' && newCratePosition != '*' && newCratePosition != '@'){
return true;
} else {
return false; //crate new position is invalid (possible collision might occur)
}
}
public void cratePush(int my, int mx){
//new position of crate after moved
int newCratePosX = posX+mx*2;
int newCratePosY = posY+my*2;
//get current symbol / item on the new position above
char c = getChar(newCratePosY, newCratePosX);
//replace box with the symbol / item above.
replaceCrateOnMove(newCratePosY, newCratePosX, c);
}
public void playerMove(int mx, int my){
if (checkValidMove(mx, my)){
int tmpNewX = posX+mx;
int tmpNewY = posY+my;
char newPosition = getChar(tmpNewY, tmpNewX);
switch(newPosition){
case '@':
cratePush(my,mx);
replacePlayerOnMove(my,mx);
replacePlayerOnPush(my,mx);
return;
case '*':
cratePush(my,mx);
replacePlayerOnMove(my,mx);
replacePlayerOnPush(my,mx);
return;
case '.':
setChar(tmpNewY,tmpNewX,'P');
replacePlayerOnMove(my,mx);
return;
case 'o':
setChar(tmpNewY,tmpNewX,'+');
replacePlayerOnMove(my,mx);
return;
default:
System.out.println("The move is not valid");
return;
}
}
}
public String toString(){
String printString = "";
for (int i=0; i<state.length; i++){
for (int j=0; j<state[0].length; j++){
printString += state[i][j];
}
printString += "\n";
}
return printString;
}
}
以下是boxpushing代码
public class boxpushing {
private final static char player = 'P';
private final static char playerOnTarget = '+';
private final static char wall = '#';
private final static char crate = '*';
private final static char crateOnTarget= '@';
private final static char target = 'o';
private final static char background = '.';
private State currentState;
public String perform(String state, char move){
currentState = new State(state);
performMove(move);
System.out.println("Before");
System.out.println(state);
System.out.println("");
return currentState.toString();
}
public void performMove(char moveInput){
switch (moveInput){
case 'u':
currentState.playerMove(0, 1);
break;
case 'd':
currentState.playerMove(0, -1);
break;
case 'l':
currentState.playerMove(-1, 0);
break;
case 'r':
currentState.playerMove(1, 0);
break;
}
}
}
答案 0 :(得分：1)
提示：其中一个
index++;
是多余的。
确定哪一个留作读者的练习。