Overview

# NetBeans Architecture Answers for projects/projectapi module

- Author: jglick@netbeans.org
- Answers as of: Dec 7, 2006
- Answers for questions version: 1.24
- Latest available version of questions: 1.26

WARNING: answering questions version 1.24 rather than the current 1.26.

## Interfaces table

##### Group of java interfaces

Interface Name | In/Out | Stability | Specified in What Document?
ProjectAPI | Exported | Official | The Project API defines abstract projects, i.e. groupings of files built and manipulated as units. It is used for Ant-based projects but could support other scenarios such as makefiles. Modules can plug in project types which can recognize certain folders as being projects, and define their behaviors.
Lookup | Imported | Official | For finding project factories. Exported through API of `Project`.
Filesystems | Imported | Official | Project directory and many other uses.
GeneralQueriesAPI | Imported | Under Development | Project-specific multiplexers for queries.
org.netbeans.modules.queries | Imported | Private | .../overview-summary.html The module is needed for compilation. The module is used during runtime.
org.openide.filesystems | Imported | Private | .../overview-summary.html The module is needed for compilation. The module is used during runtime. Specification version 6.2 is required.
org.openide.util | Imported | Private | ../org-openide-util/overview-summary.html The module is needed for compilation. The module is used during runtime. Specification version 6.2 is required.

## General Information

Question (arch-what): What is this project good for?

Answer:

Provides a generic infrastructure for modelling projects. Documentation available in the Javadoc. The build system design overview describes the basic purpose of modelling projects.

Question (arch-overall): Describe the overall architecture.

Answer: ProjectAPI - The Project API defines abstract projects, i.e. groupings of files built and manipulated as units. It is used for Ant-based projects but could support other scenarios such as makefiles. Modules can plug in project types which can recognize certain folders as being projects, and define their behaviors.

Question (arch-usecases): Describe the main use cases 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?

Answer:

The SPI should be used by modules defining particular project types, e.g. the J2SE project type. The API is to be used primarily by GUI infrastructure and some queries, though other module code may on occasion need to refer to the API.

Question (arch-time): What are the time estimates of the work?

Answer:

Basic code already written. No major remaining work anticipated.

Question (arch-quality): How will the quality of your code be tested and how are future regressions going to be prevented?

Answer:

All Javadoc-specified functionality should be covered by unit tests.

Question (arch-where): Where one can find sources for your module?

WARNING: Question with id="arch-where" has not been answered!

## Project and platform dependencies

Question (dep-nb): What other NetBeans projects and modules does this one depend on?

Answer:

- Lookup -

  For finding project factories. Exported through API of `Project`.

- Filesystems -

  Project directory and many other uses.

- GeneralQueriesAPI -

  Project-specific multiplexers for queries.

Default answer to this question is:

These modules are required in project.xml file:

- org.netbeans.modules.queries - The module is needed for compilation. The module is used during runtime.
- org.openide.filesystems - The module is needed for compilation. The module is used during runtime. Specification version 6.2 is required.
- org.openide.util - The module is needed for compilation. The module is used during runtime. Specification version 6.2 is required.

Question (dep-non-nb): What other projects outside NetBeans does this one depend on?

Answer:

None.

Question (dep-platform): On which platforms does your module run? Does it run in the same way on each?

Answer:

No known platform dependencies.

Question (dep-jre): Which version of JRE do you need (1.2, 1.3, 1.4, etc.)?

Answer:

1.4+.

Question (dep-jrejdk): Do you require the JDK or is the JRE enough?

Answer:

JRE only.

## Deployment

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

Answer:

JAR only.

Question (deploy-nbm): Can you deploy an NBM via the Update Center?

Answer:

Yes.

Question (deploy-shared): Do you need to be installed in the shared location only, or in the user directory only, or can your module be installed anywhere?

Answer:

Anywhere.

Question (deploy-packages): Are packages of your module made inaccessible by not declaring them public?

Answer:

Only official API and SPI packages are exported.

Question (deploy-dependencies): What do other modules need to do to declare a dependency on this one?

Answer:

       OpenIDE-Module-Module-Dependencies: org.netbeans.modules.projectapi/1 > 1.9.22

## Compatibility with environment

Question (compat-i18n): Is your module correctly internationalized?

Answer:

No I18N messages. Projects may have localized display names if they wish.

Question (compat-standards): Does the module implement or define any standards? Is the implementation exact or does it deviate somehow?

Answer:

None applicable.

Question (compat-version): 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?

Answer:

No settings defined by this module.

## Access to resources

Question (resources-file): Does your module use `java.io.File` directly?

Answer:

Only where needed for queries.

Question (resources-layer): 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?

Answer:

No.

Question (resources-read): Does your module read any resources from layers? For what purpose?

Answer:

No.

Question (resources-mask): Does your module mask/hide/override any resources provided by other modules in their layers?

Answer:

No.

## Lookup of components

Question (lookup-lookup): Does your module use `org.openide.util.Lookup` or any similar technology to find any components to communicate with? Which ones?

Answer:

Project factories are searched for in global lookup. Order is significant; earlier factories take precedence. Similarly for `FileBuiltQuery`.

Question (lookup-register): Do you register anything into lookup for other code to find?

Answer:

Query multiplexers.

Question (lookup-remove): Do you remove entries of other modules from lookup?

Answer:

No.

## Execution Environment

Question (exec-property): Is execution of your code influenced by any environment or Java system (`System.getProperty`) property?

Answer:

No.

Question (exec-component): Is execution of your code influenced by any (string) property of any of your components?

Answer:

No.

Question (exec-ant-tasks): Do you define or register any ant tasks that other can use?

WARNING: Question with id="exec-ant-tasks" has not been answered!

Question (exec-classloader): Does your code create its own class loader(s)?

Answer:

No.

Question (exec-reflection): Does your code use Java Reflection to execute other code?

Answer:

No.

Question (exec-privateaccess): Are you aware of any other parts of the system calling some of your methods by reflection?

Answer:

No.

Question (exec-process): 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?

Answer:

No.

Question (exec-introspection): Does your module use any kind of runtime type information (`instanceof`, work with `java.lang.Class`, etc.)?

Answer:

No.

Question (exec-threading): What threading models, if any, does your module adhere to?

Answer:

There is a single global read-write lock used by all project metadata operations. Additionally, certain read operations use a nested private lock to avoid cache corruption.

Question (security-policy): Does your functionality require modifications to the standard policy file?

Answer:

No.

Question (security-grant): Does your code grant additional rights to some other code?

Answer:

No.

## Format of files and protocols

Question (format-types): Which protocols and file formats (if any) does your module read or write on disk, or transmit or receive over the network? Do you generate an ant build script? Can it be edited and modified?

Answer:

None.

Question (format-dnd): Which protocols (if any) does your code understand during Drag & Drop?

Answer:

None.

Question (format-clipboard): Which data flavors (if any) does your code read from or insert to the clipboard (by access to clipboard on means calling methods on `java.awt.datatransfer.Transferable`?

Answer:

None.

## Performance and Scalability

Question (perf-startup): Does your module run any code on startup?

Answer:

No.

Question (perf-exit): Does your module run any code on exit?

Answer:

No.

Question (perf-scale): 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?

Answer:

Performance scales linearly in number of project type providers registered globally. However typically there is just the singleton Ant-based provider which delegates to others in constant time.

Question (perf-limit): Are there any hard-coded or practical limits in the number or size of elements your code can handle?

Answer:

None known.

Question (perf-mem): How much memory does your component consume? Estimate with a relation to the number of windows, etc.

Answer:

Each loaded project consumes a small amount of memory for object overhead.

Question (perf-wakeup): Does any piece of your code wake up periodically and do something even when the system is otherwise idle (no user interaction)?

Answer:

No.

Question (perf-progress): Does your module execute any long-running tasks?

Answer:

No.

Question (perf-huge_dialogs): Does your module contain any dialogs or wizards with a large number of GUI controls such as combo boxes, lists, trees, or text areas?

Answer:

No.

Question (perf-menus): Does your module use dynamically updated context menus, or context-sensitive actions with complicated and slow enablement logic?

Answer:

No.

Question (perf-spi): How the performance of the plugged in code will be enforced?

Answer:

Project factories are expected to operate quickly.

Built on December 7 2006. | Portions Copyright 1997-2005 Sun Microsystems, Inc. All rights reserved.