com.cloudera.flume.conf.RuntimeRecognitionException.java Source code

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Here is the source code for com.cloudera.flume.conf.RuntimeRecognitionException.java

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/**
 * Licensed to Cloudera, Inc. under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  Cloudera, Inc. licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.cloudera.flume.conf;

import org.antlr.runtime.MismatchedTokenException;
import org.antlr.runtime.NoViableAltException;
import org.antlr.runtime.RecognitionException;
import org.apache.commons.lang.StringEscapeUtils;

import com.google.common.base.Preconditions;

/**
 * This exception is thrown by the antlr parser in its parse error function.
 * antlr requires us to throw a runtime exception, so we wrap the normal
 * exception inside a runtime one. This gives us fail fast behavior (which is
 * reasonable for the small configurations we have).
 */
public class RuntimeRecognitionException extends RuntimeException {

    private static final long serialVersionUID = 1L;
    RecognitionException re;

    public RuntimeRecognitionException(RecognitionException re) {
        Preconditions.checkArgument(re != null);
        this.re = re;
    }

    public RecognitionException getExn() {
        return re;
    }

    /**
     * Translate antlr internal exceptions to sane flume data flow configuration
     * specific messages.
     */
    @Override
    public String getMessage() {
        if (re instanceof NoViableAltException) {
            NoViableAltException nvae = (NoViableAltException) re;
            if (nvae.token == null) {
                String c = StringEscapeUtils.escapeJava("" + (char) nvae.c);
                return "Lexer error at char '" + c + "' at line " + nvae.line + " char " + nvae.charPositionInLine;
            }

            String c = StringEscapeUtils.escapeJava(nvae.token.getText());
            return "Lexer error at token '" + c + "' at line " + nvae.line + " char " + nvae.charPositionInLine;
        }

        if (re instanceof MismatchedTokenException) {
            MismatchedTokenException mte = (MismatchedTokenException) re;
            String token = (mte.token == null) ? "\"\"" : mte.token.getText();

            return "Parser error: unexpected '" + token + "' at position " + mte.charPositionInLine + " line "
                    + mte.line + ": '" + mte.input + "'";
        }

        return "Unknown RecognitionException: " + re.getMessage();
    }
}