CSV Lexer 找不到词法分析器类

Question

我在使用 Netbeans 并在制作 ANTLR Lexer 时遇到以下错误：

C:\Users\Atahualpa\Documents\NetBeansProjects\antlr4CSV\src\antlr4csv\Antlr4CSV.java:26：错误：找不到符号 CSVLexer 词法分析器 = new CSVLexer(new ANTLRStringStream(source)); 符号：CSVLexer 类 位置：Antlr4CSV 类

CSVLexer.java 存在。见下图。

http://gyazo.com/084b85175c0cf8b6029bbd255e39d379

检查编译和保存会出现另一个错误。

我正在关注的教程：http://bkiers.blogspot.nl/2011/03/2-introduction-to-antlr.html

AntlrCSV.java：

package antlr4csv;

import org.antlr.runtime.*;

public class Antlr4CSV {
  public static void main(String[] args) throws Exception {
    // the input source
    String source = 
        "value1,value2,\"value3.1,\"\",value3.2\"" + "\n" + 
        "\"line\nbreak\",Bbb,end";

    // create an instance of the lexer
    CSVLexer lexer = new CSVLexer(new ANTLRStringStream(source));

    // wrap a token-stream around the lexer
    CommonTokenStream tokens = new CommonTokenStream(lexer);

    // when using ANTLR v3.3 or v3.4, un-comment the next line:
    //tokens.fill();

    // traverse the tokens and print them to see if the correct tokens are created
    int n = 1;
    for(Object o : tokens.getTokens()) {
      CommonToken token = (CommonToken)o;
      System.out.println("token(" + n + ") = " + token.getText().replace("\n", "\\n"));
      n++;
    }

CSVLexer.java：

// Generated from CSVLexer.g4 by ANTLR 4.4
import org.antlr.v4.runtime.Lexer;
import org.antlr.v4.runtime.CharStream;
import org.antlr.v4.runtime.Token;
import org.antlr.v4.runtime.TokenStream;
import org.antlr.v4.runtime.*;
import org.antlr.v4.runtime.atn.*;
import org.antlr.v4.runtime.dfa.DFA;
import org.antlr.v4.runtime.misc.*;
import antlr4csv.Antlr4CSV;

@SuppressWarnings({"all", "warnings", "unchecked", "unused", "cast"})
public class CSVLexer extends Lexer {
    static { RuntimeMetaData.checkVersion("4.4", RuntimeMetaData.VERSION); }

    protected static final DFA[] _decisionToDFA;
    protected static final PredictionContextCache _sharedContextCache =
        new PredictionContextCache();
    public static final int
        Comma=1, LineBreak=2, SimpleValue=3, QuotedValue=4;
    public static String[] modeNames = {
        "DEFAULT_MODE"
    };

    public static final String[] tokenNames = {
        "'\\u0000'", "'\\u0001'", "'\\u0002'", "'\\u0003'", "'\\u0004'"
    };
    public static final String[] ruleNames = {
        "Comma", "LineBreak", "SimpleValue", "QuotedValue"
    };


    public CSVLexer(CharStream input) {
        super(input);
        _interp = new LexerATNSimulator(this,_ATN,_decisionToDFA,_sharedContextCache);
    }

    @Override
    public String getGrammarFileName() { return "CSVLexer.g4"; }

    @Override
    public String[] getTokenNames() { return tokenNames; }

    @Override
    public String[] getRuleNames() { return ruleNames; }

    @Override
    public String getSerializedATN() { return _serializedATN; }

    @Override
    public String[] getModeNames() { return modeNames; }

    @Override
    public ATN getATN() { return _ATN; }

    public static final String _serializedATN =
        "\3\u0430\ud6d1\u8206\uad2d\u4417\uaef1\u8d80\uaadd\2\6\"\b\1\4\2\t\2\4"+
        "\3\t\3\4\4\t\4\4\5\t\5\3\2\3\2\3\3\5\3\17\n\3\3\3\3\3\3\4\6\4\24\n\4\r"+
        "\4\16\4\25\3\5\3\5\3\5\3\5\7\5\34\n\5\f\5\16\5\37\13\5\3\5\3\5\2\2\6\3"+
        "\3\5\4\7\5\t\6\3\2\4\6\2\f\f\17\17$$..\3\2$$%\2\3\3\2\2\2\2\5\3\2\2\2"+
        "\2\7\3\2\2\2\2\t\3\2\2\2\3\13\3\2\2\2\5\16\3\2\2\2\7\23\3\2\2\2\t\27\3"+
        "\2\2\2\13\f\7.\2\2\f\4\3\2\2\2\r\17\7\17\2\2\16\r\3\2\2\2\16\17\3\2\2"+
        "\2\17\20\3\2\2\2\20\21\7\f\2\2\21\6\3\2\2\2\22\24\n\2\2\2\23\22\3\2\2"+
        "\2\24\25\3\2\2\2\25\23\3\2\2\2\25\26\3\2\2\2\26\b\3\2\2\2\27\35\7$\2\2"+
        "\30\31\7$\2\2\31\34\7$\2\2\32\34\n\3\2\2\33\30\3\2\2\2\33\32\3\2\2\2\34"+
        "\37\3\2\2\2\35\33\3\2\2\2\35\36\3\2\2\2\36 \3\2\2\2\37\35\3\2\2\2 !\7"+
        "$\2\2!\n\3\2\2\2\7\2\16\25\33\35\2";
    public static final ATN _ATN =
        new ATNDeserializer().deserialize(_serializedATN.toCharArray());
    static {
        _decisionToDFA = new DFA[_ATN.getNumberOfDecisions()];
        for (int i = 0; i < _ATN.getNumberOfDecisions(); i++) {
            _decisionToDFA[i] = new DFA(_ATN.getDecisionState(i), i);
        }
    }
}

Answer 1

该教程适用于 v3，而您使用的是 v4。 ANTLRStringStream 在 v4 中不再可用。

试试这个：

CSVLexer lexer = new CSVLexer(new ANTLRInputStream("a,b,\"c\"\"c\""));
CommonTokenStream tokens = new CommonTokenStream(lexer);
tokens.fill();

for (Token token : tokens.getTokens()) {
    if (token.getType() == Token.EOF) {
        break;
    }
    System.out.printf("%-12s --> %s\n", CSVLexer.ruleNames[token.getType() - 1], token.getText());
}

将打印：

SimpleValue --> 一个
逗号 --> ,
简单值 --> b
逗号 --> ,
QuotedValue --> "c""c"