I want to uninstall java 7 and install the version 6 (as some of programs I would like to use are incompatible with 7).

I tried :

$ sudo apt-get remove openjdk-7-jre

[sudo] password for USER: 

Reading package lists... Done

Building dependency tree       

Reading state information... Done

Some packages could not be installed. This may mean that you have

requested an impossible situation or if you are using the unstable

distribution that some required packages have not yet been created

or been moved out of Incoming.

The following information may help to resolve the situation:



The following packages have unmet dependencies:

 libatk-wrapper-java-jni : Depends: libatk-wrapper-java (>= 0.30.4-0ubuntu4) but it is not going to be installed

E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.



$ sudo dpkg -r openjdk-7-jre

dpkg: dependency problems prevent removal of openjdk-7-jre:amd64:

 default-jre depends on openjdk-7-jre (>= 7~u3-2.1).

 icedtea-7-plugin:amd64 depends on openjdk-7-jre.

 icedtea-netx:amd64 depends on openjdk-6-jre (>= 6b23~pre10~) | openjdk-7-jre; however:

  Package openjdk-6-jre is not installed.

  Package openjdk-7-jre:amd64 is to be removed.

 openjdk-7-jdk:amd64 depends on openjdk-7-jre (= 7u15-2.3.7-0ubuntu1~12.10).



dpkg: error processing openjdk-7-jre:amd64 (--remove):

 dependency problems - not removing

Errors were encountered while processing:

 openjdk-7-jre:amd64



$ dpkg -l | grep icedtea

ii  icedtea-7-jre-jamvm:amd64                 7u15-2.3.7-0ubuntu1~12.10                  amd64        Alternative JVM for OpenJDK, using JamVM

ii  icedtea-7-plugin:amd64                    1.3-1ubuntu1.1                             amd64        web browser plugin based on OpenJDK and IcedTea to execute Java applets

ii  icedtea-netx:amd64                        1.3-1ubuntu1.1                             amd64        NetX - implementation of the Java Network Launching Protocol (JNLP)

ii  icedtea-netx-common                       1.3-1ubuntu1.1                             all          NetX - implementation of the Java Network Launching Protocol (JNLP)

monkey@ICANSEEYOU:~$ dpkg -l | grep jre

ii  default-jre                               1:1.7-43ubuntu3                            amd64        Standard Java or Java compatible Runtime

ii  default-jre-headless                      1:1.7-43ubuntu3                            amd64        Standard Java or Java compatible Runtime (headless)

ii  icedtea-7-jre-jamvm:amd64                 7u15-2.3.7-0ubuntu1~12.10                  amd64        Alternative JVM for OpenJDK, using JamVM

ri  openjdk-7-jre:amd64                       7u15-2.3.7-0ubuntu1~12.10                  amd64        OpenJDK Java runtime, using Hotspot JIT

ii  openjdk-7-jre-headless:amd64              7u15-2.3.7-0ubuntu1~12.10                  amd64        OpenJDK Java runtime, using Hotspot JIT (headless)

ii  openjdk-7-jre-lib                         7u15-2.3.7-0ubuntu1~12.10                  all          OpenJDK Java runtime (architecture independent libraries)