debarm:~# apt-get install default-jre
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following extra packages will be installed:
  default-jre-headless fastjar gcj-4.3-base gij-4.3 hicolor-icon-theme java-common
  java-gcj-compat java-gcj-compat-headless libatk1.0-0 libatk1.0-data libbcel-java
  libcairo2 libdatrie0 libdirectfb-1.0-0 libfontenc1 libgcj-bc libgcj-common libgcj9-0
  libgcj9-0-awt libgcj9-jar libgtk2.0-0 libgtk2.0-bin libgtk2.0-common liblog4j1.2-java
  liblog4j1.2-java-gcj libmx4j-java libpango1.0-0 libpango1.0-common libpixman-1-0
  libregexp-java libsysfs2 libthai-data libthai0 libtiff4 libts-0.0-0
  libxcb-render-util0 libxcb-render0 libxcomposite1 libxfont1 libxtst6 x-ttcidfont-conf
  xfonts-encodings xfonts-utils
Suggested packages:
  gcj-4.3 equivs libgcj9-src libgcj9-dbg libbcel-java-doc librsvg2-common
  libgnumail-java libservlet2.4-java jython ttf-kochi-gothic ttf-kochi-mincho
  ttf-thryomanes ttf-baekmuk ttf-arphic-gbsn00lp ttf-arphic-bsmi00lp ttf-arphic-gkai00mp
  ttf-arphic-bkai00mp
The following NEW packages will be installed:
  default-jre default-jre-headless fastjar gcj-4.3-base gij-4.3 hicolor-icon-theme
  java-common java-gcj-compat java-gcj-compat-headless libatk1.0-0 libatk1.0-data
  libbcel-java libcairo2 libdatrie0 libdirectfb-1.0-0 libfontenc1 libgcj-bc
  libgcj-common libgcj9-0 libgcj9-0-awt libgcj9-jar libgtk2.0-0 libgtk2.0-bin
  libgtk2.0-common liblog4j1.2-java liblog4j1.2-java-gcj libmx4j-java libpango1.0-0
  libpango1.0-common libpixman-1-0 libregexp-java libsysfs2 libthai-data libthai0
  libtiff4 libts-0.0-0 libxcb-render-util0 libxcb-render0 libxcomposite1 libxfont1
  libxtst6 x-ttcidfont-conf xfonts-encodings xfonts-utils
0 upgraded, 44 newly installed, 0 to remove and 41 not upgraded.
Need to get 28.7MB/34.2MB of archives.
After this operation, 82.5MB of additional disk space will be used.
Do you want to continue [Y/n]? Y
WARNING: The following packages cannot be authenticated!
  java-common gcj-4.3-base libgcj-common libgcj9-0 gij-4.3 fastjar libgcj-bc libgcj9-jar
  libatk1.0-0 libsysfs2 libts-0.0-0 libdirectfb-1.0-0 libpixman-1-0 libxcb-render0
  libxcb-render-util0 libcairo2 libgtk2.0-common libpango1.0-common libdatrie0
  libpango1.0-0 libxcomposite1 libgtk2.0-0 libxtst6 libgcj9-0-awt java-gcj-compat
  liblog4j1.2-java libregexp-java libbcel-java libmx4j-java java-gcj-compat-headless
  default-jre-headless default-jre hicolor-icon-theme libatk1.0-data libfontenc1
  libgtk2.0-bin liblog4j1.2-java-gcj xfonts-encodings xfonts-utils x-ttcidfont-conf
Install these packages without verification [y/N]? y
Get:1 http://ftp.it.debian.org lenny/main libgcj9-0 4.3.2-2 [10.2MB]
Get:2 http://ftp.it.debian.org lenny/main libgcj9-jar 4.3.2-2 [10.1MB]
Get:3 http://ftp.it.debian.org lenny/main libgtk2.0-common 2.12.12-1~lenny2 [5494kB]
Get:4 http://ftp.it.debian.org lenny/main libgtk2.0-0 2.12.12-1~lenny2 [2094kB]
Get:5 http://ftp.it.debian.org lenny/main libmx4j-java 3.0.2-4 [905kB]
Fetched 28.7MB in 27s (1030kB/s)
Failed to fetch http://ftp.it.debian.org/debian/pool/main/g/gcj-4.3/libgcj9-0_4.3.2-2_armel.deb  Hash Sum mismatch
Failed to fetch http://ftp.it.debian.org/debian/pool/main/g/gcj-4.3/libgcj9-jar_4.3.2-2_all.deb  Hash Sum mismatch
Failed to fetch http://ftp.it.debian.org/debian/pool/main/g/gtk+2.0/libgtk2.0-common_2.12.12-1~lenny2_all.deb  Hash Sum mismatch
Failed to fetch http://ftp.it.debian.org/debian/pool/main/g/gtk+2.0/libgtk2.0-0_2.12.12-1~lenny2_armel.deb  Hash Sum mismatch
Failed to fetch http://ftp.it.debian.org/debian/pool/main/libm/libmx4j-java/libmx4j-java_3.0.2-4_all.deb  Hash Sum mismatch
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?