JRE 8 rt.jar is the JAR file for JRE 8 RT (Runtime) libraries. JRE (Java Runtime) 8 is the runtime environment included in JDK 8. JRE 8 rt.jar libraries are divided into 6 packages:

com.* - Internal Oracle and Sun Microsystems libraries
java.* - Standard Java API libraries.
javax.* - Extended Java API libraries.
jdk.* -  JDK supporting libraries.
org.* - Third party libraries.
sun.* - Old libraries developed by Sun Microsystems.

JAR File Information:

Directory of C:\fyicenter\jdk-1.8.0_191\jre\lib
      63,596,151 rt.jar

Here is the list of Java classes of the com.* package in JRE 1.8.0_191 rt.jar. Java source codes are also provided.

⏎ com/sun/org/apache/xerces/internal/jaxp/DefaultValidationErrorHandler.java

/*
 * Copyright (c) 2007, 2018, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 2000-2002,2004 The Apache Software Foundation.
 *
 * Licensed 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.sun.org.apache.xerces.internal.jaxp;

import com.sun.org.apache.xerces.internal.util.SAXMessageFormatter;
import java.util.Locale;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
import org.xml.sax.helpers.DefaultHandler;

/**
 */

class DefaultValidationErrorHandler extends DefaultHandler {
    static private int ERROR_COUNT_LIMIT = 10;
    private int errorCount = 0;
    private Locale locale = Locale.getDefault();

    public DefaultValidationErrorHandler(Locale locale) {
        this.locale = locale;
    }

    // XXX Fix message i18n
    public void error(SAXParseException e) throws SAXException {
        if (errorCount >= ERROR_COUNT_LIMIT) {
            // Ignore all errors after reaching the limit
            return;
        } else if (errorCount == 0) {
            // Print a warning before the first error
            System.err.println(SAXMessageFormatter.formatMessage(locale,
                        "errorHandlerNotSet", new Object [] {errorCount}));
        }

        String systemId = e.getSystemId();
        if (systemId == null) {
            systemId = "null";
        }
        String message = "Error: URI=" + systemId +
            " Line=" + e.getLineNumber() +
            ": " + e.getMessage();
        System.err.println(message);
        errorCount++;
    }
}

⏎ com/sun/org/apache/xerces/internal/jaxp/DefaultValidationErrorHandler.java

Or download all of them as a single archive file:

File name: jre-rt-com-1.8.0_191-src.zip
File size: 8099783 bytes
Release date: 2018-10-28
Download 

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