Java AntlErrorListener获取错误消息

我试图从ANTLR获取错误消息，但我感到困惑

我像这样替换了标准的ErrorListener

这是运行后我的控制台中的文本：

run:
line 2:16 mismatched input 'as' expecting '.'
line 2:19 no viable alternative at input 'date'
line 5:38 mismatched input 'where' expecting {EXCEPT, INTERSECT, UNION, ')'}
BUILD SUCCESSFUL (total time: 5 seconds)

添加

antlErrorListener

run:
org.antlr.v4.runtime.BaseErrorListener@4507ed
BUILD SUCCESSFUL (total time: 4 seconds)

---

我是否实现了

antlErrorListener

正确

它正在工作，下面是我的解决方案：

首先是MyantlErrorListener的实现：

public static MyAntlrErrorListener INSTANCE = new MyAntlrErrorListener();

//When the value is false, the syntaxError method returns without displaying errors.
private static final boolean REPORT_SYNTAX_ERRORS = true;

private String errorMsg = "";

@Override
public void syntaxError(Recognizer<?, ?> recognizer, 
                        Object offendingSymbol, 
                        int line, 
                        int charPositionInLine, 
                        String msg, 
                        RecognitionException re) {

    if (!REPORT_SYNTAX_ERRORS) {
        return;
    }

    String sourceName = recognizer.getInputStream().getSourceName();
    if (!sourceName.isEmpty()) {
        sourceName = String.format("%s:%d:%d: ", sourceName, line, charPositionInLine);
    }

    System.err.println(sourceName+"line "+line+":"+charPositionInLine+" "+msg);
    errorMsg = errorMsg + "\n" + sourceName+"line "+line+":"+charPositionInLine+" "+msg;
}

@Override
public String toString() {
    return errorMsg;
}    

---

错误。toString（）

不起作用。您是否实现了它？error只是BaseErrorListener的一个实例，如果调用正确，它是由antlr使用空方法生成的？我实现了接口

AntlErrorListener

，从

parser

和

lexer

中删除

ErrorListener

并添加新的，然后请粘贴已实现的BaseErrorListener类的代码好吗？否则很难说什么是错的…我没有实现

BaseErrorListener

，它是来自

public static MyAntlrErrorListener INSTANCE = new MyAntlrErrorListener();

//When the value is false, the syntaxError method returns without displaying errors.
private static final boolean REPORT_SYNTAX_ERRORS = true;

private String errorMsg = "";

@Override
public void syntaxError(Recognizer<?, ?> recognizer, 
                        Object offendingSymbol, 
                        int line, 
                        int charPositionInLine, 
                        String msg, 
                        RecognitionException re) {

    if (!REPORT_SYNTAX_ERRORS) {
        return;
    }

    String sourceName = recognizer.getInputStream().getSourceName();
    if (!sourceName.isEmpty()) {
        sourceName = String.format("%s:%d:%d: ", sourceName, line, charPositionInLine);
    }

    System.err.println(sourceName+"line "+line+":"+charPositionInLine+" "+msg);
    errorMsg = errorMsg + "\n" + sourceName+"line "+line+":"+charPositionInLine+" "+msg;
}

@Override
public String toString() {
    return errorMsg;
}    

...
lexer.removeErrorListeners();
lexer.addErrorListener(MyAntlrErrorListener.INSTANCE);
parser.removeErrorListeners();
parser.addErrorListener(MyAntlrErrorListener.INSTANCE);

...

return MyAntlrErrorListener.INSTANCE.toString();