CJRE: Custom (J2SE) Java Runtime Environment

CJRE

Custom JavaTM Runtime Environment

Each CJRE is comprised of RTOS/processor ports of:
  1. J9VM equipped with a JIT compiler (if the JRE is not RTSJ compliant);
  2. RTSJCL if the JRE is RTSJ compliant;
  3. GNU classpath library; and
  4. any of the following components needed by Java applications that will be running on this CJRE:
    1. Components that would be included in the RTOS/processor-targeted EJRE, for example Javax.comm class library, unless all the APIs of each such package are included in the port of GNU classpath.
    2. Client-side runtimes that need the J2SE-compatible Java API packages, for example, the runtimes supporting the access to/from certain server-resident databases, which need the java.beans and javax.sql J2SE-compatible packages. Each needed J2SE-compatible package is obtained from the GNU classpath library, ported to the customer requested RTOS/processor platform, and the port is made to work with the relevant components of CJRE and customer's Java applications.
    3. Application-level packages obtained from various providers of the open-source Java software, each of which needs at least one J2SE-compatible API package, for example: the Tomcat servlet container from Apache.org; or the JavaMAIL package from Sun's open-source Java software website. Each needed J2SE-compatible package is obtained from the GNU classpath library, ported to the customer requested RTOS/processor platform, and the port is made to work with the relevant components of CJRE and customer's Java applications.

    5. Note that GNU classpath presently includes the following API packages compatible with J2SE 1.5 (about 90% of them) or J2SE 1.4 (remaining ones):

    • java.applet, java.awt, java.beans, java.io, java.lang, java.math, java.net, java.nio, java.rmi, java.security, java.sql, java.text, and java.util.
    • javax.accessibility, javax.crypto, javax.imageio, javax.management, javax.naming, javax.net, javax.print, javax.rmi, javax.security, javax.sound, javax.sql, javax.swing, javax.transaction, and javax.xml.
    • org.omg.

    CJREs are not compatible with Sun's CDC J2ME platform. However, each CJRE can still pass a large majority (over 95%) of tests in relevant Sun's J2ME TCK test suites.