Introduction to OpenJDK

OpenJDK is an open-source implementation of Oracle's Java Standard Edition platform. OpenJDK is useful for developing Java programs, and provides a complete runtime environment to run Java programs.

This package is known to build and work properly using an LFS-8.1 platform.



A browser plugin and webstart implementation is provided by the Icedtea project. To provide a complete implementation, you will need to later install IcedTea-Web-1.7.

OpenJDK is GPL'd code, with a special exception made for non-free projects to use these classes in their proprietary products. In similar fashion to the LGPL, which allows non-free programs to link to libraries provided by free software, the GNU General Public License, version 2, with the Classpath Exception allows third party programs to use classes provided by free software without the requirement that the third party software also be free. As with the LGPL, any modifications made to the free software portions of a third party application, must also be made freely available.



The OpenJDK source includes a very thorough, open source test suite using the JTreg test harness. The testing instructions below allow to test the just built JDK for reasonable compatibility with the proprietary Oracle JDK. However, in order for an independent implementation to claim compatibility, it must pass a proprietary JCK/TCK test suite. No claims of compatibility, even partial compatibility, may be made without passing an approved test suite.

Oracle does provide free community access, on a case by case basis, to a closed toolkit to ensure 100% compatibility with its proprietary JDK. Neither the binary version provided on the Java- page nor the JVM built with the instructions below have been tested against the TCK. Any version that is built using the instructions given, cannot claim to be compatible with the proprietary JDK, without the user applying for, and completing the compatibility tests themselves.

With that in mind, the binaries produced using this build method are regularly tested against the TCK by the members listed on the site above. In addition to the community license above, an educational, non-commercial license for the TCK can be obtained from here.

Source Package Information

  • OpenJDK Root Package
    Download MD5 sum: df3504e95d6e88924babb3821d4210a6
    Download Size: 498 KB

  • In addition to the root package, the instructions below first download seven subproject tarballs, whose total size is 63 MB.

  • Estimated disk space required: 3.5 GB (additional 529 MB for tests)

  • Estimated build time: 4.3 SBU with 8 jobs in parallel (up to 120 SBU for tests, see below)

Additional Downloads

OpenJDK Dependencies

Required Dependencies

An existing binary (Java- or an earlier built version of this package. The instructions below assume that you are using Configuring the JAVA environment), alsa-lib-, cpio-2.12, Cups-2.2.4, UnZip-6.0, Which-2.21, Xorg Libraries, and Zip-3.0



Mercurial-4.3.1 and an X Window manager such as twm-1.0.9 (for the tests)

User Notes:

Installation of OpenJDK

Unlike other packages in BLFS, the OpenJDK source packages are distributed in multiple tarballs. You need to first extract the source root from jdk8u141-b15.tar.bz2, change into the extracted directory, then proceed with the following instructions:

cat > subprojects.md5 << EOF &&
4061c0f2dc553cf92847e4a39a03ea4e  corba.tar.bz2
269a0fde90b9ab5ca19fa82bdb3d6485  hotspot.tar.bz2
a1dfcd15119dd10db6e91dc2019f14e7  jaxp.tar.bz2
16f904d990cb6a3c84ebb81bd6bea1e7  jaxws.tar.bz2
4fb652cdd6fee5f2873b00404e9a01f3  langtools.tar.bz2
c4a99c9c5293bb5c174366664843c8ce  jdk.tar.bz2
c2f06cd8d6e90f3dcc57bec53f419afe  nashorn.tar.bz2

for subproject in corba hotspot jaxp jaxws langtools jdk nashorn; do
  wget -c${subproject}/archive/jdk8u141-b15.tar.bz2 \
       -O ${subproject}.tar.bz2
done &&

md5sum -c subprojects.md5 &&

for subproject in corba hotspot jaxp jaxws langtools jdk nashorn; do
  mkdir -pv ${subproject} &&
  tar -xf ${subproject}.tar.bz2 --strip-components=1 -C ${subproject}

If you have downloaded the optional test harness, unpack it too:

tar -xf ../jtreg-4.2-b08-891.tar.gz


Before proceeding, you should ensure that your environment PATH variable contains the location of the Java compiler used for bootstrapping OpenJDK. This is the only requirement for the environment. Modern Java installations do not need JAVA_HOME and CLASSPATH is not used here. Furthermore, OpenJDK developers recommend to unset JAVA_HOME.

The build system does not support the -j switch in MAKEFLAGS.

Configure and build the package with the following commands (--with-milestone value can be modified to fit user preferences):

unset JAVA_HOME               &&
sh ./configure                \
   --with-update-version=141  \
   --with-build-number=b15    \
   --with-milestone=BLFS      \
   --enable-unlimited-crypto  \
   --with-zlib=system         \
   --with-giflib=system       \
   --with-extra-cflags="-std=c++98 -Wno-error -fno-delete-null-pointer-checks -fno-lifetime-dse" \
   --with-extra-cxxflags="-std=c++98 -fno-delete-null-pointer-checks -fno-lifetime-dse" &&
find build/*/images/j2sdk-image -iname \*.diz -delete



Testing will involve the interplay of pairs of JVMs using the networking interface, so networking must be started. If it isn't, not only will these tests fail, but the test cleanup will leave orphaned JVMs running. There will be many of them. Rebooting may be the easiest recovery.

Testing the newly built JVM involves several steps. First, it is better to run the test suite in a frame buffer on a different display, using Xvfb:

if [ -n "$DISPLAY" ]; then
export DISPLAY=:20
nohup Xvfb $DISPLAY                              \
           -fbdir $(pwd)                         \
           -pixdepths 8 16 24 32 > Xvfb.out 2>&1 &
echo $! >
echo Waiting for Xvfb to initialize; sleep 1
nohup twm -display $DISPLAY \
          -f /dev/null > twm.out 2>&1            &
echo $! >
echo Waiting for twm to initialize; sleep 1
xhost +

Then, it is necessary to modify some files:

echo -e "
jdk_all = :jdk_core           \\
          :jdk_svc            \\
          :jdk_beans          \\
          :jdk_imageio        \\
          :jdk_sound          \\
          :jdk_sctp           \\
          com/sun/awt         \\
          javax/accessibility \\
          javax/print         \\
          sun/pisces          \\
          com/sun/java/swing" >> jdk/test/TEST.groups &&
sed -e 's/all:.*jck.*/all: jtreg/'      \
    -e '/^JTREG /s@\$(JT_PLATFORM)/@@'  \
    -i langtools/test/Makefile

Some variables have to be set:

JT_JAVA=$(type -p javac | sed 's@/bin.*@@') &&
JT_HOME=$(pwd)/jtreg                        &&
PRODUCT_HOME=$(echo $(pwd)/build/*/images/j2sdk-image)

The tests are run as follows:

LANG=C make -k -C test                       \
            JT_HOME=${JT_HOME}               \
            JT_JAVA=${JT_JAVA}               \
            PRODUCT_HOME=${PRODUCT_HOME} all || true
LANG=C ${JT_HOME}/bin/jtreg -a -v:fail,error \
                -dir:$(pwd)/hotspot/test     \
                -k:\!ignore                  \
                -jdk:${PRODUCT_HOME}         \
                :jdk || true

Tests duration depends on various factors such as the network speed and the number of concurrent VM, which is computed from the number of cores and threads, and the amount of RAM installed. A maximum of 120 SBU has been observed, but it may be as “low” as 80 SBU.

The test results can be compared to these results, although they usually are run on a newer version. About 30 tests are known to fail, but the exact number depends on various conditions, like whether the computer is connected to network, or to a printer, and on the options given to configure (--enable-unlimited-crypto is known to trigger failures, but those come from the code in the tests, not from the installation). Also, some tests may timeout if the machine is under load.

Next some cleanup has to be done. The instructions below only stop the frame buffer, but it has been reported that some java VM may be left running after the tests, so it is necessary to check orphaned processes:

kill -9 `cat`  &&
kill -9 `cat` &&
rm -f Xvfb.out twm.out &&
rm -f &&
if [ -n "$OLD_DISP" ]; then

Install the package with the following commands as the root user:

cp -RT build/*/images/j2sdk-image /opt/OpenJDK- &&
chown -R root:root /opt/OpenJDK-

There are now two OpenJDK SDKs installed in /opt. You should decide on which one you would like to use as the default. Normally, you would opt for the just installed OpenJDK. If so, do the following as the root user:

ln -v -nsf OpenJDK- /opt/jdk

If desired, you may install a .desktop file corresponding to an entry in a desktop menu for policytool. First, you need to obtain an icon from IcedTea-Web-1.7:

tar -xf ../icedtea-web-1.7.tar.gz  \
        icedtea-web-1.7/javaws.png \

Now, as root user:

mkdir -pv /usr/share/applications &&

cat > /usr/share/applications/openjdk-8-policytool.desktop << "EOF" &&
[Desktop Entry]
Name=OpenJDK Java Policy Tool
Name[pt_BR]=OpenJDK Java - Ferramenta de Política
Comment=OpenJDK Java Policy Tool
Comment[pt_BR]=OpenJDK Java - Ferramenta de Política

install -v -Dm0644 javaws.png /usr/share/pixmaps/javaws.png

The choice of pt_BR is just an example. You can add any translation by adding lines corresponding to your locale, e.g. for fr_FR, “Name[fr_FR]=” and “Comment[fr_FR]=” with the appropriate text as values.

Command Explanations

sh configure...: the top level configure is a wrapper around the autotools one. It is not executable and must be run through sh.

--with-boot-jdk: This switch provides the location of the temporary JDK. It is normally not needed if java is found in the PATH.

--with-update-version: Currently, the build system does not include the update number in the version string. It has to be specified here.

--with-build-number: Again, the build system does not include the build number in the version string. It has to be specified here too.

--with-milestone: Used to customize the version string.

--enable-unlimited-crypto: Because of limitations on the usage of cryptography in some countries, there is the possibility to limit the size of encryption keys and the use of some algorithms in a policy file. This switch allows to ship a policy file with no restriction. It is the responsibility of the user to ensure proper adherence to the law.

--with-zlib=system, --with-giflib=system: Allows to use the system libraries instead of the bundled ones.

--with-extra-cflags=... --with-extra-cxxflags=...: Works around some defects in the code brought to light by the GCC 6 more rigorous checking of the C/C++ constructs. Remove those switches if compiling with GCC 5.

--with-jobs=N: Allows setting the number of jobs for make equal to N. The default is the result of a calculation involving the available memory and the number of processors. Note that even if you specify N=1, some parallelization may be used during the build. The SBU given above are with N=4, on a single processor, 4-core, virtual machine, with 4 GB of memory.

--with-cacerts-file=...: Specifies where to find a cacerts file, /etc/ssl/java/cacerts on a BLFS system. Otherwise, an empty one is created. You can use the --force command to generate it, once you have installed the Java binaries.

make DEBUG_BINARIES=true SCTP_WERROR= all: The build fails on 32 bit machines if DEBUG_BINARIES is not set to true. Unsetting SCTP_WERROR is part of the workarounds needed to use GCC 6. You may omit that part of the command if using GCC 5.

find ... -iname '*.diz' -delete: This command removes redundant files.

Configuring OpenJDK

Configuration Information

Normally, the JAVA environment has been configured after installing the binary version, and can be used with the just built package as well. Review Configuring the JAVA environment in case you want to modify something.

To test if the man pages are correctly installed, issue source /etc/profile and man java to display the respective man page.

Install or update the JRE Certificate Authority Certificates (cacerts) file

OpenJDK uses its own format for the CA certificates. Those certificates are located in a file named /etc/ssl/java/cacerts. That file should be generated using the system PKI trust store. The instructions on the Certificate Authority Certificates page should be used to update the file located in /etc/ssl/java. Setup a symlink in the default location as the root user:

ln -sfv /etc/ssl/java/cacerts /opt/jdk/jre/lib/security/cacerts

Use the following commands to check if the cacerts file has been successfully installed:

cd /opt/jdk
bin/keytool -list -keystore /etc/ssl/java/cacerts

At the prompt "Enter keystore password:", enter "changeit" (the default). If the cacerts file was installed correctly, you will see a list of the certificates with related information for each one. If not, you need to reinstall them.


Installed Programs: appletviewer, extcheck, idlj, jar, jarsigner, java, javac, javadoc, javah, javap, java-rmi.cgi, jcmd, jconsole, jdb, jdeps, jhat, jinfo, jjs, jmap, jps, jrunscript, jsadebugd, jstack, jstat, jstatd, keytool, native2ascii, orbd, pack200, policytool, rmic, rmid, rmiregistry, schemagen, serialver, servertool, tnameserv, unpack200, wsgen, wsimport, and xjc
Installed Libraries: /opt/OpenJDK-*, and /opt/OpenJDK-*
Installed Directory: /opt/OpenJDK-

Short Descriptions


allows to run applets outside of a web browser.


checks a specified jar file for title and version conflicts with any extensions installed in the OpenJDK software.


generates Java bindings from a given IDL file.


combines multiple files into a single jar archive.


signs jar files and verifies the signatures and integrity of a signed jar file.


launches a Java application by starting a Java runtime environment, loading a specified class and invoking its main method.


reads class and interface definitions, written in the Java programming language, and compiles them into bytecode class files.


parses the declarations and documentation comments in a set of Java source files and produces a corresponding set of HTML pages describing the classes, interfaces, constructors, methods, and fields.


generates C header and source files that are needed to implement native methods.


disassembles a Java class file.


is the Java RMI client.


is a utility to send diagnostic command requests to a running Java Virtual Machine.


is a graphical console tool to monitor and manage both local and remote Java applications and virtual machines.


is a simple command-line debugger for Java classes.


shows the package-level or class-level dependencies of Java class files.


parses a java heap dump file and allows viewing it in a web browser.


prints Java configuration information for a given Java process, core file, or a remote debug server.


is a command-line tool used to invoke the Nashorn engine. It can be used to interpret one or several script files, or to run an interactive shell.


prints shared object memory maps or heap memory details of a given process, core file, or a remote debug server.


lists the instrumented JVMs on the target system.


is a command line script shell.


attaches to a Java process or core file and acts as a debug server.


prints Java stack traces of Java threads for a given Java process, core file, or a remote debug server.


displays performance statistics for an instrumented JVM.


is an RMI server application that monitors for the creation and termination of instrumented JVMs.


is a key and certificate management utility.


converts files that contain non-supported character encoding into files containing Latin-1 or Unicode-encoded characters.


is used to enable clients to transparently locate and invoke persistent objects on servers in the CORBA environment.


is a Java application that transforms a jar file into a compressed pack200 file using the Java gzip compressor.


creates and manages a policy file graphically.


generates stub and skeleton class files for remote objects from the names of compiled Java classes that contain remote object implementations.


starts the activation system daemon.


creates and starts a remote object registry on the specified port on the current host.


is a Java XML binding schema generator.


returns the serialVersionUID for one or more classes in a form suitable for copying into an evolving class.


provides an ease-of-use interface for application programmers to register, unregister, startup and shutdown a server.


starts the Java IDL name server.


is a native implementation that transforms a packed file produced by pack200 into a jar file.


generates JAX-WS portable artifacts used in JAX-WS web services.


generates JAX-WS portable artifacts.


is a Java XML binding compiler.

Last updated on 2017-08-30 17:11:31 -0700