$sudo apt-get install sun-java6-bin sun-java6-jre sun-java6-jdk
[sudo] password for bobpete:
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package sun-java6-bin is not available,but is referred to by another package.
This may mean that the package is missing,has been obsoleted,or
is only available from another source
However the following packages replace it:
  sun-java6-jre
E: Package sun-java6-bin has no installation candidate

我检查过/etc/apt/sources.list并运行apt-get更新多次,但没有运气：

# 
# deb cdrom:[Ubuntu-Server 6.06 _Dapper Drake_ - Release amd64 (20060531)]/ dapper main restricted


# deb cdrom:[Ubuntu-Server 6.06 _Dapper Drake_ - Release amd64 (20060531)]/ dapper main restricted

deb http://us.archive.ubuntu.com/ubuntu/ hardy main restricted
deb-src http://us.archive.ubuntu.com/ubuntu/ hardy main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://us.archive.ubuntu.com/ubuntu/ hardy-updates main restricted
deb-src http://us.archive.ubuntu.com/ubuntu/ hardy-updates main restricted

## Uncomment the following two lines to add software from the 'universe'
## repository.
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team,and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also,please note that software in
## universe WILL NOT receive any review or updates from the Ubuntu security
## team.
deb http://us.archive.ubuntu.com/ubuntu/ hardy universe
deb-src http://us.archive.ubuntu.com/ubuntu/ hardy universe

## Uncomment the following two lines to add software from the 'backports'
## repository.
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release,although it includes
## newer versions of some applications which may provide useful features.
## Also,please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://us.archive.ubuntu.com/ubuntu/ hardy-backports main restricted universe multiverse
# deb-src http://us.archive.ubuntu.com/ubuntu/ dapper-backports main restricted universe multiverse


deb http://security.ubuntu.com/ubuntu hardy-security main restricted
deb-src http://security.ubuntu.com/ubuntu hardy-security main restricted
# deb http://security.ubuntu.com/ubuntu dapper-security universe
# deb-src http://security.ubuntu.com/ubuntu dapper-security universe

更新：
@ tux21b你的建议结果如下：

$sudo apt-get install sun-java6-jre sun-java6-jdk
[sudo] password for bobpete:
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package sun-java6-jre is not available,or
is only available from another source
E: Package sun-java6-jre has no installation candidate