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120 строки
4.0 KiB
Plaintext
120 строки
4.0 KiB
Plaintext
Using the Java DOM API
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----------------------
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A Java component obtains a org.w3c.dom.Document by registering for
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Document load notifications. The Document is passed in along with the
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notifications. The preferred way for a Java component to register for
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Document load notifications is to register via the DOMAccessor
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class. However if OJI is not use to obtain JNIEnv one has to apply
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two patches
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webshell/src/nsWebShell.cpp.patch
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java/dom/jni/DocumentImpl.java.patch
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The first one inits nsJavaDOM component and starts jvm. The second one
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registers a document load listener via DOMAccessor.
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Note:
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any class that implements the DocumentLoadListener interface may
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stand for TestDocLoadListener.
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See the section on Building for instructions on how to apply the patches.
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To enable OJI usage on win nt add -DJAVA_DOM_OJI_ENABLE to the
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DEFINES variable in makefile.win and also set an environment
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variable JAVA_DOM_OJI_ENABLE=true
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Makefiles
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---------
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You may have to set DEPTH to point to the mozilla CVS workspace root
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in Makefile and jni/Makefile. Since this stuff is not part of the
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regular SeaMonkeyBuild, Makefiles are not generated from Makefile.in,
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so just go ahead and hack the Makefile.
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Building
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--------
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After having done a configure at the top level of SeaMonkey, do a make
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in the dom and the dom/jni directories. This will copy over a few
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header files that are needed by the patch to nsWebShell. You can then
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apply the patch to nsWebShell.cpp by executing
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`patch nsWebShell.cpp <nsWebShell.cpp.patch`
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Edit Makefile.in to add -DJAVA_DOM to the list of defines. Then do a
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gmake in this directory.
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Similarly apply the DocumetnImpl.java patch. Then recompile the
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DocumentImpl class. No changes in makefiles are needed.
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Define JDKHOME so that $JDKHOME/bin points to javac.
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You will also need to get the w3c DOM level 2 interfaces from
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http://www.w3.org/TR/WD-DOM-Level-2/java-binding.zip
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and put the class files in your CLASSPATH.
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DOM2 events
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------------
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At the moment all DOM2 event-related interfaces are present
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however they are not fully implemented yet
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because Mozilla's core DOM does not support DOM2 events fully.
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Consequences:
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- some methods throws OperationUnsupportedException()
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The basic implementation architecture is following:
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- NodeImpl is extended to support EventTarget interface
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- for every addEventListener call special NativeDOMProxyListener object is
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created and is registered with Mozilla's DOM
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It's task is to propagate event notifications from Mozilla's DOM
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to target Java EventListener
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- In order to sucessfully unregister EventListeners we need to
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save association between java EventListener and corresponding
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NativeDOMProxyListener object. This is done by storing such
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associations Vector at NodeImpl
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- javaDOMEventsGlobals class is used much like javaDOMGlobals for caching
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(this code may be moved to javaDOMGlobals)
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NSPR Logging
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------------
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The NSPR Log module name is javadom. For instructions on how to enable
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logging, see dist/include/prlog.h
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Debug output
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------------
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The debug build of the Java DOM API creates the JVM with the verbose
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and the verboseGC options turned on, to help in debugging. It also
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creates two files in the current working directory, dom-java.txt and
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dom-cpp.txt, which are simple dumps of the DOM, as printed from C++
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and from Java. The two should be identical. The code to write these
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files is, essentially, my regression test. Feel free to add to it.
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OJI
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---
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Currently the nsJavaDOM component instantiates its own JVM. When an
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OJI-compatible JVM is available, we will move over to using it.
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Dependencies
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------------
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Currently tested on Solaris 7 only with Java 2 SDK 1.2.1. egcs-2.91.66,
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Sun Workshop C++ 4.2 and 5.0 have been know to compile this code
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fine. gcc-2.8.1 does *not* work. I have not used anything
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Java2-specific, and it works with JDK1.1.x too (I have been using JDK
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1.1.6 too).
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References
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----------
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I highly recommend reading Sheng Liang's new JNI book.
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