JavaInspect - Utility to visualize java software
+Table of Contents
+1 General
+-
+
- This program is free software: you can redistribute it and/or modify +it under the terms of the GNU Lesser General Public License as +published by the Free Software Foundation, either version 3 of the +License, or (at your option) any later version. + +
- Program authors:
+
-
+
- Svjatoslav Agejenko + + +
- Tony Bargnesi
+
-
+
- GitHub fork for the project: +https://github.com/abargnesi/javainspect +
+
+
1.1 Source code
+-
+
- Download latest snapshot in TAR GZ format + +
- Browse Git repository online + +
+Clone Git repository using command: +
++git clone https://www2.svjatoslav.eu/git/javainspect.git +
+
2 Goal and operating principle
++Goal: simplify/speed up understanding the computer program code by +automatically visualizing its structure. +
+ ++See example produced graphs for Sixth 3D - 3D engine project. +
+ ++JavaInspect can be used as a standalone commandline utility as well as +java library. JavaInspect uses primarily Java built-in reflection to +discover and visualize any part of Java program. +
+ ++JavaInspect currently has no graphical user interface, configuration +files, embedded scripting support, direct Maven, Gradle or Ant +integration. See usage to learn how to instuct Javainspect what to do. +
+ ++After discovering application structure and optionally filtering out +unimportant parts, JavaInspect produces GraphViz dot file that +describes data to be visualized. Then launches GraphViz to generate +bitmap graph in PNG or SVG format. +
+ ++Notes: +
+-
+
- JavaInspect is developed and tested so far only on GNU/Linux. +
3 Example graphs
+-
+
+A very simple example: +
+ + +++ +
+
++Graph legend: +
+ + ++
+
+
+
4 Installation
++GraphViz - shall be installed on the computer. +
+ ++On Ubuntu/Debian GraphViz can be installed using: +
+sudo apt-get install graphviz ++
+To use JavaInspect via Java API, no further installation is +needed. JavaInspect will be embedded into your project as dependency. +This is described in usage via Java API. It will expect GraphViz to be +available in the system. +
+ ++To use JavaInspect as a commandline tool, JavaInspect source +repository has to be cloned locally: See Source code. +
+ ++Then study and execute installation script: +
++commandline launcher/install ++ + +
+After installation, new commandline tool should be available +
++javainspect ++ + +
+Quick commandline usage help can be viewed by issuing +
++javainspect --help ++
5 Usage
++JavaInspect can be controlled in 2 different ways: +
+ +5.1 Usage as commandline utility
+5.1.1 Available commandline arguments
+
+-j (existing files)…
+ JAR file(s) to render.
+
+-c (existing directories)…
+ Classpath directories
+
+-n (string)
+ Graph name. (default: "graph")
+
+–debug
+ Show debug info.
+
+-h, –help
+ Show commandline usage help.
+
+-k
+ Keep dot file.
+
+-ho
+ Hide orphaned classes.
+
+-w (one to many strings)…
+ Whitelist glob(s).
+
+-b (one to many strings)…
+ Blacklist glob(s).
+
+-r (one to many strings)…
+ root class(es).
+
+-d (existing directory)
+ Target directory. Default is current directory.
+
+-t (options: png, svg)
+ Target image type. Default is: svg.
+
5.1.2 Specifying classes to render
++Normal Java application has immense complexity. In addition to code +that was directly written by particular project developers, lots of +functionality is typically added as frameworks or libraries to the +project. In addition there is significant Java standard library. +
+ ++Because JavaInspect uses reflection, it does not easily distinguish +between those. In normal situation you would rather want to visualize +only code that was developed specifically for your project and leave +frameworks like Spring etc. out. If you visualize all classes that are +possibly reachable from you project, you will easily get huge and +incomprehensible graph. +
+ ++JavaInspect can digest compiled Java classes in 2 modes: +
+-
+
- Provide list of Jar files. Use -j option. +
- Provide list of filesystem directories that can be used as +classpath root. Use -c option. +
+Currently JavaInspect uses following algorithm to add classes to +rendered graph: +
+ +-
+
- All classes that were found in Jar files are added to graph by default. +
- None of the classes that were found in filesystem directories are +added to the graph by default (unless explicitly referenced). (TODO: +for consistency it would be better to add them too by default) +
- If whitelist is specified (-w option) everything that is not +matched by whitelist pattern(s) will be removed from the graph. +
- If blacklist is specified (-b option) everything that is matched +by blacklist pattern(s) will be removed from the graph. +
- Root classes can be specified using -r option. Root classes will +be added to the graph. JavaInspect will then try to recursively +discover all classes that were referenced by root class and add +those also to the graph. +
5.2 Usage via Java API
++Requires that classes to be visualised are available in the classpath. +
+ ++To get JavaInspect into same classpath with your projecs I so far came +up with 2 solutions: +
+ +-
+
- Add JavaInspect library in your project as a dependency. + +
- Create new Java project for the purpose visualizing your other +projects and include JavaInspect and your projecs binary artifacts +(Jar's) into new project classpath. Built binary Jar's (with no +source code) are sufficient because JavaInspect operates via +reflection. +
+Simple Java based control/configuration code needs to be written for +each project. I usually put such code into directories devoted for +JUnit tests. Because it needs not to be compiled/embedded into final +product or project artifact I'm just willing to visualize. +
+ ++Control code in general does the following: +
+-
+
- Create graph object. +
- Java reflection/classloaders does not provide mechanism for +discovering all classes under given package. Therefore you need to +declare at least some classes to be added to the graph by manually +adding individual classes to the graph. For every class added to +the graph, GraphViz will recursively inspect it and add all +referecned classes to the graph as well. +
- Graphs easilly get very big and complex so optionally we filter +important code using classname glob patterns based blacklist and/or +whitelist. +
- Optionally we can tune some rendering parameters like:
+
-
+
- Possibility to remove orphaned classes (classes with no +references) from the graph. +
- Specify target directory for generated visualization +files. (Default is current directory) +
- Keep intermediate GraphViz dot file for later inspection. +
+ - Render graph. +
5.2.1 Example 1: individually picked objects
++This example demonstrates generating of class graph from hand picked +classes and visualizing GraphViz itself. +
+ ++// Create graph +final ClassGraph graph = new ClassGraph(); + +// Add some random object to the graph. GraphViz will detect Class from +// the object. +graph.add(graph); + +// Also add some random class to the graph. +graph.add(Utils.class); + +// Keep intermediary GraphViz DOT file for reference. +graph.setKeepDotFile(true); + +// Produce bitmap image titled "JavaInspect.png" to the user Desktop +// directory +graph.generateGraph("JavaInspect"); + ++
+Note: if desired, more compact version of the above: +
+new ClassGraph().add(randomObject, RandomClass.class) + .setKeepDotFile(true).generateGraph("JavaInspect"); ++
+Result: +
+-
+
- Generated DOT file: JavaInspect.dot +
- Generated PNG image: JavaInspect.png +
5.2.2 Example 2: GraphViz embedded in another project
+-
+
- Download project Sixth code snapshot. +
- Inspect and run DataGraph.java. +
5.2.3 Embedding JavaInspect in your Maven project
++Declare JavaInspect as dependency: +
+<dependencies> + ... + <dependency> + <groupId>eu.svjatoslav</groupId> + <artifactId>javainspect</artifactId> + <version>1.7</version> + </dependency> + ... +</dependencies> ++
+Add Maven repository to retrieve artifact from: +
+<repositories> + ... + <repository> + <id>svjatoslav.eu</id> + <name>Svjatoslav repository</name> + <url>http://www2.svjatoslav.eu/maven/</url> + </repository> + ... +</repositories> ++
6 TO DO
++Note: Because this is side project (and I have many of them) I can +only contribute few hours per year at average. Any help is welcome. A +LOT of cool ideas could be implemented. For intstance: +
+ +-
+
- BUG: Should not hide references if there are too many of them to +classes if referring classes are not visible anyway because of +blacklist/whitelist rules. Basically reference counting should +exclude not visible classes. + +
- BUG: Orphaned class removal does not work always. There are many +bugs and corner cases to find and fix still. + +
- BUG: Code is not very readable. Document and refactor for better +maintainability. + +
- FEATURE: Create installable DEB package.
+
-
+
- Submit it to some Debian developer for integration or become +Debian package maintainer. +
+
+ - FEATURE: Make it modular. That is: central part, an application
+model could be standalone and serializable.
+
+
-
+
- There could be multiple ways to acquire model:
+
-
+
- By introspecting application via Java reflections (current mode +of operation). +
- By parsing java source. (unfinished) +
+
+ - There could be ways to manipulate model:
+
-
+
- Store/load/compare. +
- Trim uninteresting parts. +
- Highlight important parts. +
+
+ - There could be multiple ways to render model:
+
-
+
- PNG/SVG (currently implemented) +
- PlantUML (TODO) +
- Interactive 3D visualization (TODO) +
+
+
+ - There could be multiple ways to acquire model:
+
- FEATURE: Implement (or integrate existing java parser +https://javaparser.org/) to be able to produce code visualizations +based on source code (in addition to current reflection based +approach). + +
- FEATURE: Integarte with PlantUML. + +
- FEATURE: Add dark theme for generated graphs. + +
- FEATURE: Sort Class fields by alphabet. + +
- FEATURE: Visualize also concrete field values so it could be used as +ultra cool runtime logging/debugging framework. + +
- FEATURE: Possibility to visualize structure and data from JVM +snapshot. + +
- FEATURE: Possibility to attach to remote process to visualize +data/structure using JVM debug port and mechanism. + +
- FEATURE: Possibility to attach to JVM using JVM agent. + +
- FEATURE: Possibility to inspect graphs in 3D using Sixth 3D engine. + +
- FEATURE: Possibility to select classes/fields/values to be +visualized in some graph query language. For greater flexibility in +comparison to currently supported glob syntax. + +
- FEATURE: Add option to control JavaInspect via JSON or XML config +file. For example different graphs for given project could be +defined once in plain text config, possibly with the aid of some +interactive utility. Then defined graphs could be updated as part of +project build or release process. + +
- FEATURE: Configurable maven plugin to generate graphs as part of the +project build/release process. +
7 See also
++Similar or alternative solutions: +
+ +