好的，对于这个项目，我有一个文本文件，格式如下：
4 4
boba
cduf
engt
tach
aunt
bob
cat
第一行指定为单词搜索拼图的尺寸。我创建了一个这个大小的二维char数组来控制拼图。然后，我需要从接下来的4行读取每个char，在本例中，读入我的数组。在那之后，我必须通过搜索我创建的拼图之下的任何单词来解决这个难题，在这种情况下将是阿姨，鲍勃和猫。
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.LinkedList;
public class WordPuzzleSolver {
private char[][] puzzle;
private String word;
private LinkedList<String> words;
private int index = 0;
public void readFile(File inFile) {
try{
FileReader read = new FileReader(inFile);
BufferedReader reader = new BufferedReader(read);
String[] dimensions = reader.readLine().split(" ");
puzzle = new char[Integer.parseInt(dimensions[0])][Integer.parseInt(dimensions[1])];
for(int i = 0; i < puzzle[0].length; i++){
String val = reader.readLine();
puzzle[i] = val.toCharArray();
}
words = new LinkedList<String>();
word = reader.readLine();
while(word != null){
words.add(word);
word = reader.readLine();
}
while(index < words.size()){
solvePuzzle();
index++;
}
reader.close();
}catch(IOException e){
e.printStackTrace();
}
}
public void solvePuzzle() {
char firstLetter = words.get(index).charAt(0);
for(int i = 0; i < puzzle.length; i++){
for(int j = 0; j < puzzle[i].length; j++){
if(puzzle[i][j] == firstLetter){
if(checkUp(i, j, words.get(index))){
print(words.get(index), i, j, "U");
//System.out.println("the word found:"+word);
}
}
}
}
}
private boolean checkUp(int i, int j, String word){
int index = j;
for(char letter : word.toCharArray()){
if(index >= puzzle[i].length){
return false;
}
if(puzzle[i][index] != letter){
return false;
}
index++;
}
return true;
}
我在阅读我的文件时做错了，但我无法弄清楚是什么。因为现在当我尝试使用char firstLetter = word.charAt(0);方法拨打solvePuzzle()时，我收到了NullPointerException。这是我的主要问题，但在我开始工作后，我不确定我的checkUp方法是否写得正确。我仍然需要为其他7个可能的方向编写辅助方法，但我想首先在文本文件中使用这个方法，其中唯一要解决的词就是这个方向。
这是我得到的当前堆栈跟踪：
Exception in thread "AWT-EventQueue-0" java.lang.IndexOutOfBoundsException: Index: 1, Size: 1
at java.util.LinkedList.checkElementIndex(Unknown Source)
at java.util.LinkedList.get(Unknown Source)
at WordPuzzleSolver.solvePuzzle(WordPuzzleSolver.java:43)
at WordPuzzle.solve(WordPuzzle.java:77)
at WordPuzzle.actionPerformed(WordPuzzle.java:95)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$500(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
在抛出错误之前调用的最后一行是当我调用char firstLetter = words.get（index）.charAt（0）;
答案 0 :(得分：1)
我已经处理了你的代码。 以下是工作代码
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
public class WordPuzzleSolver {
private static char[][] puzzle;
public static String word;
public static void readFile(File inFile) {
try{
FileReader read = new FileReader(inFile);
BufferedReader reader = new BufferedReader(read);
String[] dimensions = reader.readLine().split(" ");
puzzle = new char[Integer.parseInt(dimensions[0])][Integer.parseInt(dimensions[1])];
for(int i = 0; i < puzzle[0].length; i++){
String val = reader.readLine();
puzzle[i] = val.toCharArray();
}
word = reader.readLine();
while(word != null){
solvePuzzle();
word = reader.readLine();
}
reader.close();
}catch(IOException e){
e.printStackTrace();
}
}
public static void solvePuzzle() {
char firstLetter = word.charAt(0);
for(int i = 0; i < puzzle.length; i++){
for(int j = 0; j < puzzle[i].length; j++){
if(puzzle[i][j] == firstLetter){
if(checkUp(i, j, word)){
print(word, i, j, "U");
//System.out.println("the word found:"+word);
}
}
}
}
}
private static boolean checkUp(int i, int j, String word){
int index = j;
for(char letter : word.toCharArray()){
if(index >= puzzle[i].length){
return false;
}
if(puzzle[i][index] != letter){
return false;
}
index++;
}
return true;
}