如何判斷一個字符串是英文還是Java代碼？

考慮以下兩個字符串：

1. ?for (int i = 0; i < b.size(); i++) {?

2.?do something in English (not necessary to be a sentence).?

第一個是Java代碼，第二個是英文。如何檢測第一個是代碼，第二個是英文？

Java 代碼可能無法解析，因?yàn)樗皇峭暾姆椒?語句/表達(dá)式。下面為這個問題提供了一個解決方案。由于有時代碼和英文之間沒有明確的界限，準(zhǔn)確度不可能是 100%。但是，使用下面的解決方案，你可以輕松調(diào)整程序以滿足你的需求。

基本思想是將字符串轉(zhuǎn)換為一組標(biāo)記。例如，上面的代碼行可能會變成“?KEY,SEPARATOR,ID,ASSIGN,NUMBER,SEPARATOR,...?”。然后我們可以使用簡單的規(guī)則將代碼與英文分開。

標(biāo)記器類將字符串轉(zhuǎn)換為標(biāo)記列表。

package lexical;
 
import java.util.LinkedList;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
 
public class Tokenizer {
	private class TokenInfo {
		public final Pattern regex;
		public final int token;
 
		public TokenInfo(Pattern regex, int token) {
			super();
			this.regex = regex;
			this.token = token;
		}
	}
 
	public class Token {
		public final int token;
		public final String sequence;
 
		public Token(int token, String sequence) {
			super();
			this.token = token;
			this.sequence = sequence;
		}
 
	}
 
	private LinkedList<TokenInfo> tokenInfos;
	private LinkedList<Token> tokens;
 
	public Tokenizer() {
		tokenInfos = new LinkedList<TokenInfo>();
		tokens = new LinkedList<Token>();
	}
 
	public void add(String regex, int token) {
		tokenInfos
				.add(new TokenInfo(Pattern.compile("^(" + regex + ")"), token));
	}
 
	public void tokenize(String str) {
		String s = str.trim();
		tokens.clear();
		while (!s.equals("")) {
			//System.out.println(s);
			boolean match = false;
			for (TokenInfo info : tokenInfos) {
				Matcher m = info.regex.matcher(s);
				if (m.find()) {
					match = true;
					String tok = m.group().trim();
					s = m.replaceFirst("").trim();
					tokens.add(new Token(info.token, tok));
					break;
				}
			}
			if (!match){
				//throw new ParserException("Unexpected character in input: " + s);
				tokens.clear();
				System.out.println("Unexpected character in input: " + s);
				return;
			}
 
		}
	}
 
	public LinkedList<Token> getTokens() {
		return tokens;
	}
 
	public String getTokensString() {
		StringBuilder sb = new StringBuilder();
		for (Tokenizer.Token tok : tokens) {
			sb.append(tok.token);
		}
 
		return sb.toString();
	}
}

我們可以得到Java的關(guān)鍵字、分隔符、運(yùn)算符、標(biāo)識符等，如果我們給token分配一個映射值，就可以將一個英文字符串轉(zhuǎn)換為一個token字符串。

package lexical;
 
import greenblocks.javaapiexamples.DB;
import java.io.IOException;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
 
import org.apache.commons.lang.StringUtils;
 
import NLP.POSTagger;
 
public class EnglishOrCode {
 
	private static Tokenizer tokenizer = null;
 
	public static void initializeTokenizer() {
		tokenizer = new Tokenizer();
 
		//key words
		String keyString = "abstract assert boolean break byte case catch "
				+ "char class const continue default do double else enum"
				+ " extends false final finally float for goto if implements "
				+ "import instanceof int interface long native new null "
				+ "package private protected public return short static "
				+ "strictfp super switch synchronized this throw throws true "
				+ "transient try void volatile while todo";
		String[] keys = keyString.split(" ");
		String keyStr = StringUtils.join(keys, "|");
 
		tokenizer.add(keyStr, 1);
		tokenizer.add("\\(|\\)|\\{|\\}|\\[|\\]|;|,|\\.|=|>|<|!|~|"
						+ "\\?|:|==|<=|>=|!=|&&|\\|\\||\\+\\+|--|"
						+ "\\+|-|\\*|/|&|\\||\\^|%|\'|\"|\n|\r|\\$|\\#",
						2);//separators, operators, etc
 
		tokenizer.add("[0-9]+", 3); //number
		tokenizer.add("[a-zA-Z][a-zA-Z0-9_]*", 4);//identifier
		tokenizer.add("@", 4);
	}
 
	public static void main(String[] args) throws SQLException, ClassNotFoundException, IOException {
		initializeTokenizer();
		String s = "do something in English";
		if(isEnglish(s)){
			System.out.println("English");
		}else{
			System.out.println("Java Code");
		}
 
		s = "for (int i = 0; i < b.size(); i++) {";
		if(isEnglish(s)){
			System.out.println("English");
		}else{
			System.out.println("Java Code");
		}
 
	}
 
	private static boolean isEnglish(String replaced) {
		tokenizer.tokenize(replaced);
		String patternString = tokenizer.getTokensString();
 
		if(patternString.matches(".*444.*") || patternString.matches("4+")){
			return true;
		}else{
			return false;
		}
	}
}

輸出：

English
Java Code

本篇關(guān)于如何判斷一個字符串是英文還是 Java 代碼的內(nèi)容就到此結(jié)束了，感謝各位讀者的閱讀。