What is PHP4 ext/java? PHP4 ext/java provides a simple and effective means for creating and invoking methods on Java objects from PHP. The JVM is created using JNI, and everthing runs in-process. Two examples are provided, jver and jawt, to illustrate usage of this extension. A few things to note: 1) new Java() will create an instance of a class if a suitable constructor is available. If no parameters are passed and the default constructor is useful as it provides access to classes like "java.lang.System" which expose most of their functionallity through static methods. 2) Accessing a member of an instance will first look for bean properties then public fields. In other words, "print $date.time" will first attempt to be resolved as "$date.getTime()", then as "$date.time"; 3) Both static and instance members can be accessed on an object with the same syntax. Furthermore, if the java object is of type "java.lang.Class", then static members 4) Exceptions raised result in PHP warnings, and null results. 5) Overload resolution is in general a hard problem given the differences in types between the two languages. The PHP Java extension employs a simple, but fairly effective, metric for determining which overload is the best match. Additionally, method names in PHP are not case sensitive, potentially increasing the number of overloads to select from. Once a method is selected, the parameters are cooerced if necessary, possibly with a loss of data (example: double precision floating point numbers will be converted to boolean). Build and execution instructions: Given the number of platforms and providers of JVMs, no single set of instructions will be able to cover all cases. So in place of hard and fast instructions, below are a working examples for a number of free and commercial implementations and platforms. Please adjust the paths to suit your installation. Also, if you happen to get this to work on another JVM/platform combination, please let me know, particularly if a unique build or execution setup was required. This function has been tested in both CGI and Apache (apxs) modes. As the current design requires shared libraries, this support can not be linked statically into Apache. With ext/java, no Java Virtual Machines are created until the first Java call is made. This not only eliminates unnecessary overhead if the extension is never used, it also provides error messages directly back to the user instead of being burried in a log some place. For people interested in robustness, performance, and more complete integration with Java, consider using the sapi/servlet interface which is built upon the Java extension. Running PHP as a servlet enables PHP to utilize the existing JVM and threads from the servlet engine, and provides direct access to the servlet request and response objects. ======================================================================== === JVM=Kaffe 1.0.4 (as delivered with OS), OS=Redhat Linux 6.1 === ======================================================================== build instructions: ./configure --with-java php.ini: [java] java.library.path=/usr/lib/kaffe:/home/rubys/php4/modules java.class.path=/usr/share/kaffe/Klasses.jar:/home/rubys/php4/modules/php_java.jar extension_dir=/home/rubys/php4/modules extension=libphp_java.so ======================================================================== === JVM=Kaffe 1.0.5 (built from source), OS=Redhat Linux 6.1 === ======================================================================== build instructions: ./configure --with-java php.ini: [java] java.library.path=/usr/local/lib/kaffe:/home/rubys/php4/modules java.class.path=/usr/local/share/kaffe/Klasses.jar:/home/rubys/php4/modules/php_java.jar extension_dir=/home/rubys/php4/modules extension=libphp_java.so ======================================================================== === JVM=IBM 1.1.8, OS=Redhat Linux 6.1 === ======================================================================== build instructions: ./configure --with-java php.ini: [java] java.class.path=/home/jdk118/lib/classes.zip:/home/rubys/php4/modules/php_java.jar extension_dir=/home/rubys/php4/modules extension=libphp_java.so ======================================================================== === JVM=Blackdown 1.2.2 RC4, OS=Redhat Linux 6.1 === ======================================================================== build instructions: ./configure --with-java php.ini: [java] java.class.path=/home/rubys/php4/lib/php_java.jar extension_dir=/home/rubys/php4/modules extension=libphp_java.so ======================================================================== === JVM=Sun JDK 1.2.2, OS=Linux === ======================================================================== This compiler is not supported at this time. At the moment, only green threads are supported, requiring system calls to be wrapped, which is incompatible with the JNI Invocation API. Once native threads are supported, It is expected that the configuration will be identical to the Blackdown JDK. ======================================================================== === JVM=Sun JDK 1.1.8, OS=Windows NT 4 === ======================================================================== build instructions: SET JAVA_HOME=D:\jdk1.1.8 msdev ext\java\java.dsp /MAKE "java - Win32 Debug_TS" php.ini: [java] java.class.path="D:\jdk1.1.8\lib\classes.zip;F:\PHP4\Debug_TS\php_java.jar" extension=php_java.dll ======================================================================== === JVM=Sun JDK 1.2.2, OS=Windows NT 4 === ======================================================================== build instructions: SET JAVA_HOME=D:\jdk1.2.2 msdev ext\java\java.dsp /MAKE "java - Win32 Debug_TS" php.ini: [java] java.class.path=F:\PHP4\Debug_TS\php_java.jar extension=php_java.dll