这是一个自定义构建的解析器，因为我真的不喜欢默认 java.util.Scanner 的工作方式。
我的问题是，当我使用 new Parser("Parsed phrase here") 或函数 reloadBuffer("Parsed phrase here") 创建解析器时，它会丢失输入的最后一个单词。我试图使这段代码尽可能地可读，但它仍然非常密集，对此感到抱歉。哦，如果这得到修复，请随意使用它。
import java.util.*;
public class Parser
{
public static char letters[] = new char[]{'q','w','e','r','t','y','u','i','o','p','a','s','d','f','g','h','j','k','l','z','x','c','v','b','n','m','Q','W','E','R','T','Y','U','I','O','P','A','S','D','F','G','H','J','K','L','Z','X','C','V','B','N','M'};
public static char numbers[] = new char[]{'0','1','2','3','4','5','6','7','8','9'};
public ArrayList<String> words;
public String buffer;
public int wordIndex;
/**
* Assembles an empty parser.
*/
public Parser()
{
words = new ArrayList<String>();
buffer = "";
wordIndex = 0;
}
/**
* Assembles the Parser with given String as input. Uses reloadBuffer();
* @see reloadBuffer
*/
public Parser(String input)
{
words = new ArrayList<String>();
reloadBuffer(input);
}
/**
* Parses each word/set of chars into the array. Must be called before any retreiving of words can be done.
* This is basically the core function of the class. Be very careful if you edit this part.
*/
public void parseBuffer(){
String input = buffer;
while(input.length()>=1)
{
input = trimToSelectedChars(input);
words.add(removeFirstSet(input)[0]);
input = removeFirstSet(input)[1];
}
}
/**
* Resets the array with given String as input. Used in the primary constructor. Uses parseBuffer();
* @see parseBuffer()
*/
public void reloadBuffer(String input){
buffer = input;
wordIndex = 0;
parseBuffer();
}
/**
* @return the next word parsed from the string, based upon the value of wordIndex.
*/
public String next(){
wordIndex++;
if (wordIndex<= words.size()+1){
try {return words.get(wordIndex-1);
} catch(Exception ex) {
System.err.println("Error: reached end of list. Resetting index to 0.");
resetIndex();
}
}
return "";
}
//Notice that when using wordAt(), it leaves the index where you selected, and it does not revert to where it was before.
/**
* @return the word at indicated index, much like the charAt() function, using the next() function. Also sets wordIndex to input index.
* @see String
* @see next()
*/
public String wordAt(int index){
wordIndex = index;
return next();
}
/**
* @return the first word parsed from the input.
* @see String
*/
public String firstWord()
{
return wordAt(0);
}
/**
*Be careful in using lastWord() as it sets the wordIndex to the last value which will return a String
*@return the last parsed word from the input.
*/
public String lastWord(){
return wordAt(words.size()-1);
}
/**
* Resets the wordIndex to 0, the beginning.
*/
public void resetIndex(){wordIndex = 0;}
/**
* return whether or not there is another word in the parser list.
*/
public boolean hasNext(){
return (wordIndex<words.size());
}
//internal methods here.
private String[] removeFirstSet(String input)
//removes the first set of adjecent letters from a string, and returns it.
{
String[] words = new String[2];
int index = 0;
if(input.length()<1) words[0] = "";
while(index<input.length()){
//this loop to retrieve the first word.
if(isLetter(input.charAt(index))||isNumber(input.charAt(index))){
index++; //if the first char is a letter, move on to the next one.
}
else{
words[0]=input.substring(0,index);
words[1]=input.substring(index);
return words;
}
}
return new String[]{"",""};
}
private String trimToSelectedChars(String input)
//trims anything that is not a letter from the front of a String.
{
input = input.trim();
while(input.length()>0){
//this loop to clear up junk before the input.
if(isLetter(input.charAt(0))||isNumber(input.charAt(0))){
break; //if the first char is a letter or a number, break the loop
}
else input=input.substring(1);// else cut the first char off the string.
}
return input;
}
private boolean isLetter(char c)
//returns whether or not the indicated char is an alphabetical letter.
{
for(int i = 0; i<letters.length; i++){
if(letters[i]==c)return true;
}
return(false);
}
private boolean isNumber(char c)
//returns whether or not the indicated char is a number.
{
for(int i = 0; i<numbers.length; i++){
if(numbers[i]==c)return true;
}
return(false);
}
}