Original Java source code for equals() method. (http://grepcode.com/file/repository.grepcode.com/java/root/jdk/openjdk/6-b14/java/lang/String.java#String.equals%28java.lang.Object%29)

String.java

/**
 * Compares this string to the specified object. The result is true if and only if the argument is not null and is a String object that represents the same sequence of characters as this object.
 * Parameters:
 * anObject The object to compare this String against
 * Returns:
 * true if the given object represents a String equivalent to this string, false otherwise
 * See also:
 * compareTo(java.lang.String)
 * equalsIgnoreCase(java.lang.String)
 */
public boolean equals(Object anObject) {
    if (this == anObject) {
        return true;
    }
    if (anObject instanceof String) {
        String anotherString = (String)anObject;
        int n = count;
        if (n == anotherString.count) {
            char v1[] = value;
            char v2[] = anotherString.value;
            int i = offset;
            int j = anotherString.offset;
            while (n-- != 0) {
                if (v1[i++] != v2[j++])
                    return false;
            }
            return true;
        }
    }
    return false;
}