I am completely stumped. The problem is as follows.

user@mycomputer:~$ sudo apt-get -f install

Reading package lists... Done

Building dependency tree       

Reading state information... Done

Correcting dependencies... Done

The following extra packages will be installed:

   openjdk-7-jdk

Suggested packages:

  visualvm

The following packages will be upgraded:

  openjdk-7-jdk

1 upgraded, 0 newly installed, 0 to remove and 322 not upgraded.

85 not fully installed or removed.

Need to get 0 B/16.3 MB of archives.

After this operation, 348 kB of additional disk space will be used.

Do you want to continue? [Y/n] Y

debconf: unable to initialize frontend: Dialog

debconf: (Dialog frontend will not work on a dumb terminal, an emacs shell buffer, or     without a controlling terminal.)

debconf: falling back to frontend: Readline

Selecting previously unselected package openjdk-7-jdk:i386.

(Reading database ... 258923 files and directories currently installed.)

Preparing to unpack .../openjdk-7-jdk_7u71-2.5.3-0ubuntu0.14.04.1_i386.deb ...

Unpacking openjdk-7-jdk:i386 (7u71-2.5.3-0ubuntu0.14.04.1) over (7u55-2.4.7-1ubuntu1) ...

dpkg: error processing archive /var/cache/apt/archives/openjdk-7-jdk_7u71-2.5.3-    0ubuntu0.14.04.1_i386.deb (--unpack):

 trying to overwrite '/usr/lib/jvm/java-7-openjdk-i386/src.zip', which is also in     package openjdk-7-source 7u55-2.4.7-1ubuntu1

Errors were encountered while processing:

 /var/cache/apt/archives/openjdk-7-jdk_7u71-2.5.3-0ubuntu0.14.04.1_i386.deb

E: Sub-process /usr/bin/dpkg returned an error code (1)

I don't know what to delete/remove. Any suggestions? Thanks in advance.

EDIT #1

Adding output from Charles Green's suggestion because it's impossible to read in the comment.

user@mycomputer:~$ sudo apt-get remove --purge openjdk-7-source

[sudo] password for user: 

Reading package lists... Done

Building dependency tree       

Reading state information... Done

You might want to run 'apt-get -f install' to correct these:

The following packages have unmet dependencies:

 openjdk-7-jdk : Depends: openjdk-7-jre (= 7u55-2.4.7-1ubuntu1) but 7u71-2.5.3-0ubuntu0.14.04.1 is to be installed

E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).

EDIT #2

Charles Smith's second suggestion.

user@mycomputer:~$ sudo dpkg -i --force-overwrite /var/cache/apt/archives/openjdk-7-jdk_7u71-2.5.3-0ubuntu0.14.04.1_i386.deb

(Reading database ... 258923 files and directories currently installed.)

Preparing to unpack .../openjdk-7-jdk_7u71-2.5.3-0ubuntu0.14.04.1_i386.deb ...

Unpacking openjdk-7-jdk:i386 (7u71-2.5.3-0ubuntu0.14.04.1) over (7u55-2.4.7-1ubuntu1) ...

dpkg: warning: overriding problem because --force enabled:

dpkg: warning: trying to overwrite '/usr/lib/jvm/java-7-openjdk-i386/src.zip', which is also in package openjdk-7-source 7u55-2.4.7-1ubuntu1

dpkg: dependency problems prevent configuration of openjdk-7-jdk:i386:

 openjdk-7-jdk:i386 depends on openjdk-7-jre (= 7u71-2.5.3-0ubuntu0.14.04.1); however:

  Package openjdk-7-jre:i386 is not configured yet.



dpkg: error processing package openjdk-7-jdk:i386 (--install):

 dependency problems - leaving unconfigured

Errors were encountered while processing:

 openjdk-7-jdk:i386

However, if I try to sudo apt-get -f install, I still get an error.

EDIT 3

user@mycomputer:~$ sudo dpkg -i /var/cache/apt/archives/openjdk-7-jre_7u71-2.5.3-0ubuntu0.14.04.1_i386.deb

dpkg: error processing archive /var/cache/apt/archives/openjdk-7-jre_7u71-2.5.3-0ubuntu0.14.04.1_i386.deb (--install):

 cannot access archive: No such file or directory

Errors were encountered while processing:

 /var/cache/apt/archives/openjdk-7-jre_7u71-2.5.3-0ubuntu0.14.04.1_i386.deb

EDIT 4

user@mycomputer:~/Downloads$ sudo dpkg -i openjdk-7-jre_7u71-2.5.3-0ubuntu0.14.04.1_i386.deb 

(Reading database ... 258922 files and directories currently installed.)

Preparing to unpack openjdk-7-jre_7u71-2.5.3-0ubuntu0.14.04.1_i386.deb ...

Unpacking openjdk-7-jre:i386 (7u71-2.5.3-0ubuntu0.14.04.1) over (7u71-2.5.3-0ubuntu0.14.04.1) ...

dpkg: dependency problems prevent configuration of openjdk-7-jre:i386:

 openjdk-7-jre:i386 depends on openjdk-7-jre-headless (= 7u71-2.5.3-0ubuntu0.14.04.1); however:

  Package openjdk-7-jre-headless:i386 is not configured yet.



dpkg: error processing package openjdk-7-jre:i386 (--install):

 dependency problems - leaving unconfigured

Processing triggers for hicolor-icon-theme (0.13-1) ...

Processing triggers for bamfdaemon (0.5.1+14.04.20140409-0ubuntu1) ...

Rebuilding /usr/share/applications/bamf-2.index...

Processing triggers for desktop-file-utils (0.22-1ubuntu1) ...

Processing triggers for gnome-menus (3.10.1-0ubuntu2) ...

Processing triggers for mime-support (3.54ubuntu1) ...

Errors were encountered while processing:

 openjdk-7-jre:i386