Java中如何判断一个字符串是Java代码还是英文呢？

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();
}
}

import java.io.IOException;
import java.sql.SQLException;
public class EnglishOrCode {
private static Tokenizer tokenizer = null;
private static String keyStr="";
public static void initializeTokenizer() {
tokenizer = new Tokenizer();
tokenizer.add(keyStr, 1);
tokenizer.add("\(|\)|\{|\}|\[|\]|;|,|\.|=|>|<|!|~|" + "\?|:|==|<=|>=|!=|&&|\|\||\+
+|--|"
+ "\+|-|\*|/|&|\||\^|%|'|"| | |\$|\#", 2);
tokenizer.add("[0-9]+", 3);
tokenizer.add("[a-zA-Z][a-zA-Z0-9_]*", 4);
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("英文");
} else {
System.out.println("Java代码");
}
}
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;
}
}
}