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<!DOCTYPE api-answers PUBLIC "-//NetBeans//DTD Arch Answers//EN" "../../nbbuild/antsrc/org/netbeans/nbbuild/Arch.dtd" [

<!ENTITY api-questions SYSTEM "../../nbbuild/antsrc/org/netbeans/nbbuild/Arch-api-questions.xml">

]>

<api-answers

question-version="1.29"

author="tball@netbeans.org"

>

&api-questions;

<!--

<question id="arch-overall" when="init">

Describe the overall architecture.

<hint>

What will be API for

<a href="http://openide.netbeans.org/tutorial/api-design.html#design.apiandspi">

clients and what support API</a>?

What parts will be pluggable?

How will plug-ins be registered? Please use <code>&lt;api type="export"/&gt;</code>

to describe your general APIs.

If possible please provide

simple diagrams.

</hint>

</question>

-->

<answer id="arch-overall">

<p>

<api name="classfile"

group="java"

type="export"

category="stable">

</api>

The ClassFile library is an API to read Java classfiles, as described by

<a href="https://docs.oracle.com/javase/specs/jvms/se8/html/index.html">

The Java Virtual Machine Specification</a>. Given a file or stream reference to a Java

classfile, the API provides read-only access to all of its class attributes, including

type information, methods and fields, generics support (if any), etc.

<br/>

NOTE: this library is not really a NetBeans module, in that it doesn't have any NetBeans references.

It therefore has nothing pluggable, no NetBeans Lookups, and is not extensible.

</p>

</answer>

<!--

<question id="arch-quality" when="init">

How will the <a href="http://www.netbeans.org/community/guidelines/q-evangelism.html">quality</a>

of your code be tested and

how are future regressions going to be prevented?

<hint>

What kind of testing do

you want to use? How much functionality, in which areas,

should be covered by the tests?

</hint>

</question>

-->

<answer id="arch-quality">

<p>

The ClassFile API is heavily used by the clazz and javacore modules, so that any

new bugs are normally reflected in those modules' test suites. There currently (as

of the 4.0 freeze date) are no outstanding bugs.

</p>

</answer>

<!--

<question id="arch-time" when="init">

What are the time estimates of the work?

<hint>

Please express your estimates of how long the design, implementation,

stabilization are likely to last. How many people will be needed to

implement this and what is the expected milestone by which the work should be

ready?

</hint>

</question>

-->

<answer id="arch-time">

<p>

N/A; already implemented.

</p>

</answer>

<!--

<question id="arch-usecases" when="init">

<hint>

Content of this answer will be displayed as part of page at

http://www.netbeans.org/download/dev/javadoc/usecases.html

You can use tags &lt;usecase name="name&gt; regular html description &lt;/usecase&gt;

and if you want to use an URL you can prefix if with @TOP@ to begin

at the root of your javadoc

</hint>

Describe the main <a href="http://openide.netbeans.org/tutorial/api-design.html#usecase">

use cases</a> of the new API. Who will use it under

what circumstances? What kind of code would typically need to be written

to use the module?

</question>

-->

<answer id="arch-usecases">

<p>

The normal usecase is for a client wanting to inspect a classfile. A <code>ClassFile</code>

instance is created with either a <code>String</code> path, <code>File</code> or

<code>InputStream</code> instance. All attributes of the classfile are available as properties,

such as <code>getSourceFileName</code> or <code>getMethods</code>.

</p>

</answer>

<!--

<question id="arch-what" when="init">

What is this project good for?

<hint>

Please provide here a few lines describing the project,

what problem it should solve, provide links to documentation,

specifications, etc.

</hint>

</question>

-->

<answer id="arch-what">

<p>

The ClassFile API is designed as a fast, low memory-cost way to access classfile

information. It is useful for tools and modules that directly read classfiles,

such as the clazz and javacore modules.

</p>

</answer>

<!--

<question id="compat-i18n" when="impl">

Is your module correctly internationalized?

<hint>

Correct internationalization means that it obeys instructions

at <a href="http://www.netbeans.org/download/dev/javadoc/org-openide-modules/org/openide/modules/doc-files/i18n-branding.html">

NetBeans I18N pages</a>.

</hint>

</question>

-->

<answer id="compat-i18n">

<p>

The Module names have been internationalized. The only hard-coded strings in the library are either

Java language keywords, JVM attribute names, toString fragments, and exception descriptions. All of

these are marked with "//NOI18N" comments.

</p>

</answer>

<!--

<question id="compat-standards" when="init">

Does the module implement or define any standards? Is the

implementation exact or does it deviate somehow?

</question>

-->

<answer id="compat-standards">

<p>

The module depends upon the <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/index.html">

The Java Virtual Machine Specification</a>. It does not implement or define any standards, however.

</p>

</answer>

<!--

<question id="compat-version" when="impl">

Can your module coexist with earlier and future

versions of itself? Can you correctly read all old settings? Will future

versions be able to read your current settings? Can you read

or politely ignore settings stored by a future version?

<hint>

Very helpful for reading settings is to store version number

there, so future versions can decide whether how to read/convert

the settings and older versions can ignore the new ones.

</hint>

</question>

-->

<answer id="compat-version">

<p>

N/A; the classfile module has no settings or other persistent data.

</p>

</answer>

<!--

<question id="dep-jre" when="final">

Which version of JRE do you need (1.2, 1.3, 1.4, etc.)?

<hint>

It is expected that if your module runs on 1.x that it will run

on 1.x+1 if no, state that please. Also describe here cases where

you run different code on different versions of JRE and why.

</hint>

</question>

-->

<answer id="dep-jre">

<p>

The classfile module now depends on the 1.4 JRE, since it uses assert statements.

Although this library can read 1.5 classfiles, it does not use any API from that

JRE.

</p>

</answer>

<!--

<question id="dep-jrejdk" when="final">

Do you require the JDK or is the JRE enough?

</question>

-->

<answer id="dep-jrejdk">

<p>

The JDK is not required; the JRE is enough.

</p>

</answer>

<!--

<question id="dep-nb" when="init">

What other NetBeans projects and modules does this one depend on?

<hint>

If you want, describe such projects as imported APIs using

the <code>&lt;api name="identification" type="import or export" category="stable" url="where is the description" /&gt;</code>

</hint>

</question>

-->

<answer id="dep-nb">

<p>

The classfile module has no dependencies on any NetBeans module or API.

</p>

</answer>

<!--

<question id="dep-non-nb" when="init">

What other projects outside NetBeans does this one depend on?

<hint>

Some non-NetBeans projects are packaged as NetBeans modules

(see <a href="http://libs.netbeans.org/">libraries</a>) and

it is preferred to use this approach when more modules may

depend on such third-party library.

</hint>

</question>

-->

<answer id="dep-non-nb">

<p>

The classfile module has no dependencies on any other project.

</p>

</answer>

<!--

<question id="dep-platform" when="init">

On which platforms does your module run? Does it run in the same

way on each?

<hint>

If your module is using JNI or deals with special differences of

OSes like filesystems, etc. please describe here what they are.

</hint>

</question>

-->

<answer id="dep-platform">

<p>

The classfile module is platform-independent.

</p>

</answer>

<answer id="deploy-dependencies">

<p>

Nothing.

</p>

</answer>

<!--

<question id="deploy-jar" when="impl">

Do you deploy just module JAR file(s) or other files as well?

<hint>

Usually a module consist of one JAR file (perhaps with Class-Path

extensions) and also a configuration file that enables it. If you

have any other files, use

&lt;api group="java.io.File" name="yourname" type="export" category="friend"&gt;...&lt;/api&gt;

to define the location, name and stability of your files (of course

changing "yourname" and "friend" to suit your needs).

If it uses more than one JAR, describe where they are located, how

they refer to each other.

If it consist of module JAR(s) and other files, please describe

what is their purpose, why other files are necessary. Please

make sure that installation/uninstallation leaves the system

in state as it was before installation.

</hint>

</question>

-->

<answer id="deploy-jar">

<p>

Just the module jar is deployed.

</p>

</answer>

<!--

<question id="deploy-nbm" when="impl">

Can you deploy an NBM via the Update Center?

<hint>

If not why?

</hint>

</question>

-->

<answer id="deploy-nbm">

<p>

Yes.

</p>

</answer>

<!--

<question id="deploy-packages" when="init">

Are packages of your module made inaccessible by not declaring them

public?

<hint>

NetBeans module system allows restriction of access rights to

public classes of your module from other modules. This prevents

unwanted dependencies of others on your code and should be used

whenever possible (<a href="http://www.netbeans.org/download/javadoc/OpenAPIs/org/openide/doc-files/upgrade.html#3.4-public-packages">

public packages

</a>). If you do not restrict access to your classes you are

making it too easy for other people to misuse your implementation

details, that is why you should have good reason for not

restricting package access.

</hint>

</question>

-->

<answer id="deploy-packages">

<p>

No.

</p>

</answer>

<!--

<question id="deploy-shared" when="final">

Do you need to be installed in the shared location only, or in the user directory only,

or can your module be installed anywhere?

<hint>

Installation location shall not matter, if it does explain why.

Consider also whether <code>InstalledFileLocator</code> can help.

</hint>

</question>

-->

<answer id="deploy-shared">

<p>

Installation location does not matter.

</p>

</answer>

<!--

<question id="exec-classloader" when="impl">

Does your code create its own class loader(s)?

<hint>

A bit unusual. Please explain why and what for.

</hint>

</question>

-->

<answer id="exec-classloader">

<p>

No.

</p>

</answer>

<!--

<question id="exec-component" when="impl">

Is execution of your code influenced by any (string) property

of any of your components?

<hint>

Often <code>JComponent.getClientProperty</code>, <code>Action.getValue</code>

or <code>PropertyDescriptor.getValue</code>, etc. are used to influence

a behavior of some code. This of course forms an interface that should

be documented. Also if one depends on some interface that an object

implements (<code>component instanceof Runnable</code>) that forms an

API as well.

</hint>

</question>

-->

<answer id="exec-component">

<p>

No.

</p>

</answer>

<!--

<question id="exec-introspection" when="impl">

Does your module use any kind of runtime type information (<code>instanceof</code>,

work with <code>java.lang.Class</code>, etc.)?

<hint>

Check for cases when you have an object of type A and you also

expect it to (possibly) be of type B and do some special action. That

should be documented. The same applies on operations in meta-level

(Class.isInstance(...), Class.isAssignableFrom(...), etc.).

</hint>

</question>

-->

<answer id="exec-introspection">

<p>

No.

</p>

</answer>

<!--

<question id="exec-privateaccess" when="final">

Are you aware of any other parts of the system calling some of

your methods by reflection?

<hint>

If so, describe the "contract" as an API. Likely private or friend one, but

still API and consider rewrite of it.

</hint>

</question>

-->

<answer id="exec-privateaccess">

<p>

No.

</p>

</answer>

<!--

<question id="exec-process" when="impl">

Do you execute an external process from your module? How do you ensure

that the result is the same on different platforms? Do you parse output?

Do you depend on result code?

<hint>

If you feed an input, parse the output please declare that as an API.

</hint>

</question>

-->

<answer id="exec-process">

<p>

No.

</p>

</answer>

<!--

<question id="exec-property" when="impl">

Is execution of your code influenced by any environment or

Java system (<code>System.getProperty</code>) property?

<hint>

If there is a property that can change the behavior of your

code, somebody will likely use it. You should describe what it does

and the <a href="http://openide.netbeans.org/tutorial/api-design.html#life">stability category</a>

of this API. You may use

<pre>

&lt;api type="export" group="property" name="id" category="private" url="http://..."&gt;

description of the property, where it is used, what it influence, etc.

&lt;/api&gt;

</pre>

</hint>

</question>

-->

<answer id="exec-property">

<p>

No.

</p>

</answer>

<!--

<question id="exec-reflection" when="impl">

Does your code use Java Reflection to execute other code?

<hint>

This usually indicates a missing or insufficient API in the other

part of the system. If the other side is not aware of your dependency

this contract can be easily broken.

</hint>

</question>

-->

<answer id="exec-reflection">

<p>

No.

</p>

</answer>

<!--

<question id="exec-threading" when="impl">

What threading models, if any, does your module adhere to?

<hint>

If your module calls foreign APIs which have a specific threading model,

indicate how you comply with the requirements for multithreaded access

(synchronization, mutexes, etc.) applicable to those APIs.

If your module defines any APIs, or has complex internal structures

that might be used from multiple threads, declare how you protect

data against concurrent access, race conditions, deadlocks, etc.,

and whether such rules are enforced by runtime warnings, errors, assertions, etc.

Examples: a class might be non-thread-safe (like Java Collections); might

be fully thread-safe (internal locking); might require access through a mutex

(and may or may not automatically acquire that mutex on behalf of a client method);

might be able to run only in the event queue; etc.

Also describe when any events are fired: synchronously, asynchronously, etc.

Ideas: <a href="http://core.netbeans.org/proposals/threading/index.html#recommendations">Threading Recommendations</a> (in progress)

</hint>

</question>

-->

<answer id="exec-threading">

<p>

The ClassFile API creates invariant objects, which should be safe in any threading model.

</p>

</answer>

<!--

<question id="format-clipboard" when="impl">

Which data flavors (if any) does your code read from or insert to

the clipboard (by access to clipboard on means calling methods on <code>java.awt.datatransfer.Transferable</code>?

<hint>

Often Node's deal with clipboard by usage of <code>Node.clipboardCopy, Node.clipboardCut and Node.pasteTypes</code>.

Check your code for overriding these methods.

</hint>

</question>

-->

<answer id="format-clipboard">

<p>

N/A; the classfile module has no user interface.

</p>

</answer>

<!--

<question id="format-dnd" when="impl">

Which protocols (if any) does your code understand during Drag &amp; Drop?

<hint>

Often Node's deal with clipboard by usage of <code>Node.drag, Node.getDropType</code>.

Check your code for overriding these methods. Btw. if they are not overridden, they

by default delegate to <code>Node.clipboardCopy, Node.clipboardCut and Node.pasteTypes</code>.

</hint>

</question>

-->

<answer id="format-dnd">

<p>

N/A; the classfile module has no user interface.

</p>

</answer>

<!--

<question id="format-types" when="impl">

Which protocols and file formats (if any) does your module read or write on disk,

or transmit or receive over the network?

</question>

-->

<answer id="format-types">

<p>

It reads Java classfiles.

</p>

</answer>

<!--

<question id="lookup-lookup" when="init">

Does your module use <code>org.openide.util.Lookup</code>

or any similar technology to find any components to communicate with? Which ones?

<hint>

Please describe the interfaces you are searching for, where

are defined, whether you are searching for just one or more of them,

if the order is important, etc. Also classify the stability of such

API contract. For that use &lt;api group=&amp;lookup&amp; /&gt; tag.

</hint>

</question>

-->

<answer id="lookup-lookup">

<p>

The classfile module does not use Lookup.

</p>

</answer>

<!--

<question id="lookup-register" when="final">

Do you register anything into lookup for other code to find?

<hint>

Do you register using layer file or using <code>META-INF/services</code>?

Who is supposed to find your component?

</hint>

</question>

-->

<answer id="lookup-register">

<p>

N/A

</p>

</answer>

<!--

<question id="lookup-remove" when="final">

Do you remove entries of other modules from lookup?

<hint>

Why? Of course, that is possible, but it can be dangerous. Is the module

your are masking resource from aware of what you are doing?

</hint>

</question>

-->

<answer id="lookup-remove">

<p>

N/A

</p>

</answer>

<!--

<question id="perf-exit" when="final">

Does your module run any code on exit?

</question>

-->

<answer id="perf-exit">

<p>

No.

</p>

</answer>

<!--

<question id="perf-huge_dialogs" when="final">

Does your module contain any dialogs or wizards with a large number of

GUI controls such as combo boxes, lists, trees, or text areas?

</question>

-->

<answer id="perf-huge_dialogs">

<p>

No.

</p>

</answer>

<!--

<question id="perf-limit" when="init">

Are there any hard-coded or practical limits in the number or size of

elements your code can handle?

</question>

-->

<answer id="perf-limit">

<p>

No, other than the limits defined for classfiles in

<a href="https://docs.oracle.com/javase/specs/jvms/se8/html/index.html">

The Java Virtual Machine Specification</a>.

</p>

</answer>

<!--

<question id="perf-mem" when="final">

How much memory does your component consume? Estimate

with a relation to the number of windows, etc.

</question>

-->

<answer id="perf-mem">

<p>

It depends on the size and complexity of the classfile being represented. ClassFile

representations can be roughly 7-10 times the size of the associated classfile, but

much smaller (2-4x) if the <code>includeCode</code> constructor parameter is false.

</p>

</answer>

<!--

<question id="perf-menus" when="final">

Does your module use dynamically updated context menus, or

context-sensitive actions with complicated enablement logic?

</question>

-->

<answer id="perf-menus">

<p>

No.

</p>

</answer>

<!--

<question id="perf-progress" when="final">

Does your module execute any long-running tasks?

<hint>Long running tasks should never block

AWT thread as it badly hurts the UI

<a href="http://performance.netbeans.org/responsiveness/issues.html">

responsiveness</a>.

Tasks like connecting over

network, computing huge amount of data, compilation

be done asynchronously (for example

using <code>RequestProcessor</code>), definitively it should

not block AWT thread.

</hint>

</question>

-->

<answer id="perf-progress">

<p>

No.

</p>

</answer>

<!--

<question id="perf-scale" when="init">

Which external criteria influence the performance of your

program (size of file in editor, number of files in menu,

in source directory, etc.) and how well your code scales?

<hint>

Please include some estimates, there are other more detailed

questions to answer in later phases of implementation.

</hint>

</question>

-->

<answer id="perf-scale">

<p>

None, other than general filesystem and processor performance.

</p>

</answer>

<!--

<question id="perf-spi" when="init">

How the performance of the plugged in code will be enforced?

<hint>

If you allow foreign code to be plugged into your own module, how

do you enforce that it will behave correctly and quickly and will not

negatively influence the performance of your own module?

</hint>

</question>

-->

<answer id="perf-spi">

<p>

N/A

</p>

</answer>

<!--

<question id="perf-startup" when="final">

Does your module run any code on startup?

</question>

-->

<answer id="perf-startup">

<p>

No.

</p>

</answer>

<!--

<question id="perf-wakeup" when="final">

Does any piece of your code wake up periodically and do something

even when the system is otherwise idle (no user interaction)?

</question>

-->

<answer id="perf-wakeup">

<p>

No.

</p>

</answer>

<!--

<question id="resources-file" when="final">

Does your module use <code>java.io.File</code> directly?

<hint>

NetBeans provide a logical wrapper over plain files called

<code>org.openide.filesystems.FileObject</code> that

provides uniform access to such resources and is the preferred

way that should be used. But of course there can be situations when

this is not suitable.

</hint>

</question>

-->

<answer id="resources-file">

<p>

Yes, because the classfile module has no NetBeans API dependencies.

</p>

</answer>

<!--

<question id="resources-layer" when="final">

Does your module provide own layer? Does it create any files or

folders in it? What it is trying to communicate by that and with which

components?

<hint>

NetBeans allows automatic and declarative installation of resources

by module layers. Module register files into appropriate places

and other components use that information to perform their task

(build menu, toolbar, window layout, list of templates, set of

options, etc.).

</hint>

</question>

-->

<answer id="resources-layer">

<p>

No.

</p>

</answer>

<!--

<question id="resources-mask" when="final">

Does your module mask/hide/override any resources provided by other modules in

their layers?

<hint>

If you mask a file provided by another module, you probably depend

on that and do not want the other module to (for example) change

the file's name. That module shall thus make that file available as an API

of some stability category.

</hint>

</question>

-->

<answer id="resources-mask">

<p>

No.

</p>

</answer>

<!--

<question id="resources-read" when="final">

Does your module read any resources from layers? For what purpose?

<hint>

As this is some kind of intermodule dependency, it is a kind of API.

Please describe it and classify according to

<a href="http://openide.netbeans.org/tutorial/api-design.html#categories">

common stability categories</a>.

</hint>

</question>

-->

<answer id="resources-read">

<p>

No.

</p>

</answer>

<!--

<question id="security-grant" when="final">

Does your code grant additional rights to some other code?

<hint>Avoid using a class loader that adds extra

permissions to loaded code unless really necessary.

Also note that your API implementation

can also expose unneeded permissions to enemy code by

calling AccessController.doPrivileged().</hint>

</question>

-->

<answer id="security-grant">

<p>

No.

</p>

</answer>

<!--

<question id="security-policy" when="final">

Does your functionality require modifications to the standard policy file?

<hint>Your code might pass control to third-party code not

coming from trusted domains. This could be code downloaded over the

network or code coming from libraries that are not bundled

with NetBeans. Which permissions need to be granted to which domains?</hint>

</question>

-->

<answer id="security-policy">

<p>

No policy file modifications needed. All permissions granted.

</p>

</answer>

<!--

<question id="arch-where" when="init">

Where one can find sources for your module?

<hint>

Please provide link to the CVS web client at

http://www.netbeans.org/download/source_browse.html

or just use tag defaultanswer generate='here'

</hint>

</question>

-->

<answer id="arch-where">

<defaultanswer generate='here' />

</answer>

<!--

<question id="exec-ant-tasks" when="impl">

Do you define or register any ant tasks that other can use?

<hint>

If you provide an ant task that users can use, you need to be very

careful about its syntax and behaviour, as it most likely forms an

API for end users and as there is a lot of end users, their reaction

when such API gets broken can be pretty strong.

</hint>

</question>

-->

<answer id="exec-ant-tasks">

<p>

No.

</p>

</answer>

<!--

<question id="compat-deprecation" when="init">

How the introduction of your project influences functionality

provided by previous version of the product?

<hint>

If you are planning to deprecate/remove/change any existing APIs,

list them here accompanied with the reason explaining why you

are doing so.

</hint>

</question>

-->