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/corba/se/impl/orbutil/ObjectUtility.java

/*
 * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
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 *
 *
 *
 *
 *
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 *
 *
 *
 *
 *
 *
 *
 *
 */

package com.sun.corba.se.impl.orbutil;

import java.security.PrivilegedAction;
import java.security.AccessController;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Map;
import java.util.List;
import java.util.ListIterator;
import java.util.Set;
import java.util.Map.Entry;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.Enumeration;
import java.util.Properties;
import java.util.IdentityHashMap;
import java.lang.reflect.Array;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.math.BigInteger ;
import java.math.BigDecimal ;

public final class ObjectUtility {
    private ObjectUtility() {}


    /** If arr1 and arr2 are both arrays of the same component type,
     * return an array of that component type that consists of the
     * elements of arr1 followed by the elements of arr2.
     * Throws IllegalArgumentException otherwise.
     */
    public static Object concatenateArrays( Object arr1, Object arr2 )
    {
        Class comp1 = arr1.getClass().getComponentType() ;
        Class comp2 = arr2.getClass().getComponentType() ;
        int len1 = Array.getLength( arr1 ) ;
        int len2 = Array.getLength( arr2 ) ;

        if ((comp1 == null) || (comp2 == null))
            throw new IllegalStateException( "Arguments must be arrays" ) ;
        if (!comp1.equals( comp2 ))
            throw new IllegalStateException(
                "Arguments must be arrays with the same component type" ) ;

        Object result = Array.newInstance( comp1, len1 + len2 ) ;

        int index = 0 ;

        for (int ctr=0; ctr<len1; ctr++)
            Array.set( result, index++, Array.get( arr1, ctr ) ) ;

        for (int ctr=0; ctr<len2; ctr++)
            Array.set( result, index++, Array.get( arr2, ctr ) ) ;

        return result ;
    }

}

⏎ com/sun/corba/se/impl/orbutil/ObjectUtility.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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