Better Java with JDeveloper 10g

1
Better Java with JDeveloper 10g

• Presented by
• Dustin Marx

2
Symbols Used in These Presentation Slides
Changes since slides were printed
Because the slides are submitted for printing
over one week in advance and in attempt to reduce
paper used to print out the handouts, some
changes and additions were made to the slides
between printing and the presentation. Some
slides were taken out for printing and added back
in for this presentation. Latest version will be
made available at RMOUG site and at
http//www.geocities.com/dustinmarx/.
3
Two Versions of the Same Story

• JDeveloper 10g is label for several versions of
  the JDeveloper IDE
• Some versions start with 9
• g is for Grid
• This presentation primarily presumes JDeveloper
  10g as JDeveloper 9.0.5.x
• Some related changes and enhancements of
  JDeveloper 10g Release 2 (10.1.x) are mentioned
  in this presentation
• The associated paper exclusively treats
  JDeveloper 10g as JDeveloper 9.0.5.x

4
Recent JDeveloper Versions
Version Numbers Name
10.1.3 JDeveloper 10g Release 2
9.0.5.1, 9.0.5.2, 10.1.2 JDeveloper 10g
9.0.4.1, 9.0.4.0 JDeveloper 9i
9.0.3.3, 9.0.3.2, 9.0.3.1, 9.0.3 JDeveloper 9i
9.0.2 JDeveloper 9i
Developer Preview
5
Better Java with JDeveloper 10g Agenda

• JDeveloper 10g Analysis Tools Overview
• JDeveloper 10g Profilers
• Memory Profiler
• Execution Profiler
• Event Profiler
• JDeveloper 10g CodeCoach
• JDeveloper 10g Code Audit
• JDeveloper 10g Code Metrics
• Better Java with the JDeveloper 10g Tools
• Optimization and Code Improvement Best Practices
• Conclusion

6
JDeveloper 10g The J is for Java

• JDeveloper 10g provides tools for the Java
  Development Lifecycle (SDLC)
• Modeling/Design
• JDeveloper models as activity, class, or use case
• Implementation
• Code Insight, color syntax, automatic code
  generation, much more
• Debugging and Testing
• Built-in debugger, JUnit Extension
• Optimization / Performance Tuning
• Analysis Tools covered in this presentation

7
JDeveloper 10g Code Analysis Tools

• JDeveloper 10g provides suite of tools for
  comprehensive code analysis and optimization
• Some tools are static
• Examine code without executing it
• Identify common coding standards problems and
  complexity problems
• Some tools are dynamic
• Execute code to identify potential problems and
  areas for improvement
• Require Oracle Java Compiler (ojc) and execution
  in the Oracle Java Virtual Machine (ojvm)

8
More on JDeveloper 10g Code Analysis Tools

• JDeveloper Analysis Tools Share Many Traits
• Can be run easily within JDeveloper IDE
• Output can be viewed in Log Window or in
  standalone output file (text, HTML, .opr, etc.
  different among tools)
• Can be run from the command line (all but
  Profilers)
• Output displayed on screen or redirected to
  external file
• Can be customized to best fit your development
  environment
• Provide guidance to potential problems and issues
• Knowledgeable human review should often be
  included in process and before making suggested
  changes
• Multiple output/report formats
• IDE log window, HTML, XML, and more

9
Graphical Survey of JDeveloper 10g Tools
Increased Maintainability
Increased Performance
10
JDeveloper 10g Code Analysis Tools IDE or
Command-line?

• Advantages of IDE
• Easier to use in many cases
• Automatic code highlighting for problem areas
• Availability of Profiler tools
• Advantages of Command-line
• Can use as part of batch / nightly builds
• Easy integration with ANT, FOP, other scripted
  tools
• Expanded non-IDE output options
• Can be used with IDEs other than JDeveloper

11
JDeveloper 10g Tools IDE and Command-line
JDeveloper 10g Analysis Tool IDE Command-line
Memory Profiler Run?Memory Profile N/A
Execution Profiler Run?Execution Profile N/A
Event Profiler Run?Event Profile N/A
CodeCoach Run?CodeCoach ojc -g and then java ojvm Xcodecoach
Code Audit Run?Audit ojaudit.exe
Code Metrics Run?Measure ojmetrics.exe
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Command-line Oracle Java Compiler (OJC) Example
ojc -sourcepath ltltjdev_homegt\jdev\mywork\BetterJav
a\Project\src -classpath CLASSPATHltltjdev_homegtgt
\jdev\mywork\BetterJava\Project\classes -d
ltltjdev_homegtgt\jdev\mywork\BetterJava\Project\class
es -verbose -noquiet -g ltltjdev_homegtgt\jdev\mywork\
BetterJava\Project\src\org\rmoug\marx\betterjava\
.java
An even easier way to perform the above is to
place all the options in a text file known as a
Response File (see later slide)
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OJC Command-line Response Files

• Place all command-line tool options in a text
  file (named something like cc_args.txt)
• Can have each ojc option on a different line
• Can include comments in file with delimiter
• Compile with Oracle Java Compiler
• ojc _at_cc_args.txt
• Compare to verbosity on previous slide

14
OJC Response File Example
ocj_args.txt
-sourcepath ltltjdev_homegtgt\jdev\mywork\BetterJava\P
roject\src -classpath CLASSPATHltltjdev_homegtgt\jd
ev\mywork\BetterJava\Project\classes -d
ltltjdev_homegtgt\jdev\mywork\BetterJava\Project\class
es -verbose -noquiet -g ltltjdev_homegtgt\jdev\BetterJ
ava\Project\src\org\rmoug\marx\betterjava\.java
To use the above file, one would run the
following command ojc _at_ojc_args.txt
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Oracle Java Compiler Command-line and ANT

• The easiest way to repeatedly use Oracle Java
  Compiler (OJC) from the Command-line may be to
  employ ANT
• JDeveloper 10g automatically generates ANT
  build.xml file with OJC compilation
• JDeveloper 10g can read and incorporate existing
  ANT build.xml files
• See next slide for example of building with OJC
  in ANT

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Compiling with OJC and ANT An Example
lt!--Configure Oracle Java Compiler--gt ltproperty
name"build.compiler value"oracle.jdeveloper
.compiler.ant.taskdefs.OjcAdapter"/gt ltproperty
name"ojc.assertions.enabled" value"true"/gt
ltproperty name"ojc.update.imports"
value"none"/gt lt!--Compile Java source
files--gt ltjavac destdir"compile.outdir"
debug"on" encoding"Cp1252"gt ltclasspath
refid"classpath"/gt ltsrc refid"srcpath"/gt
ltinclude name"org/rmoug/marx/betterjava/TestBadEx
ample.java"/gt ltinclude name"org/rmoug/marx/bett
erjava/SimpleLogger.java"/gt ltinclude
name"org/rmoug/marx/betterjava/SimpleDataClass.ja
va"/gt ltinclude name"org/rmoug/marx/betterjava/P
rofilerExample.java"/gt ltinclude
name"org/rmoug/marx/betterjava/ParentItem.java"/gt
ltinclude name"org/rmoug/marx/betterjava/ChildI
tem.java"/gt ltinclude name"org/rmoug/marx/better
java/BadExampleParent.java"/gt ltinclude
name"org/rmoug/marx/betterjava/BadExample.java"/gt
lt/javacgt
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setvars.bat (Windows Only)

• Sets up PATH, CLASSPATH, and other significant
  environmental variables for JDeveloper
  command-line tool use
• Set path to directory with ojc, java,
  ojmetrics.exe, ojaudit.exe, and JDeveloper IDEs
  executable
• Use setvars go to use default environmental
  variable settings
• Use setvars show to see most significant
  environmental variables settings
• Use setvars show all to see all related
  environmental variables settings
• Use setvars without options to see usage (help)

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JDeveloper 10g Profilers

• JDeveloper 10g Features Three Profilers
• Memory Profiler
• Execution Profiler
• Event Profiler
• All Three Profilers are Dynamic
• Must compile code with Oracle Java Compiler (ojc)
• Must execute code in Oracle Java Virtual Machine
  (ojvm)
• Must execute all code for which profiling is
  sought
• Not running pieces of code impacts profile results

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Memory Profiler

• Java does have memory leaks!
• Long-lived references
• JDeveloper Memory Profiler identifies memory
  leaks
• Monitors memory usage on Java heap at periodic
  intervals
• Watch for Diff Sz column in Memory Profiler
  output
• Easily locate where Java objects are instantiated
• Pause Memory Profiler ? Get Allocation Details
• Can also use JDevelopers Debugger to identify
  memory leaks!
• Heap Window is especially useful

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Example of Memory Profiler Output
Notes
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Another Example of Memory Profiler Output
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Still Another Example of Memory Profiler Output
Notes
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Memory Profiler Customization

• Type of Sampling Automatic (time) vs. Manual
• Sampling frequency for automatic sampling
• Slider depth Number of samples available for
  review
• Include/Exclude instances (objects) or different
  classes
• Columns displayed in Memory Profiler output
• Use Profiler API (oracle.jdeveloper.profiler) to
  customize profiling from within source code
• ProfilerAPI.startSampling()
• ProfilerAPI.stopSampling()

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Memory Profiler Configuration Window
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Execution Profiler

• Perform statistical analysis of application
  performance
• Identify methods that top the call stack

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Example of Execution Profiler Output
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Execution Profiler Customization

• Sample Interval
• More samples means better statistical results
• Columns displayed in Execution Profiler output
• ProfilerAPI

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Execution Profiler Configuration Window
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Event Profiler

• Identify time spent on different events
• Focus on events that involve interaction between
  the application and the Java Virtual Machine
• Garbage Collection
• Wait
• Prepare, Load, and Resolve Class
• Synchronization Blocks
• Can monitor BC4J events
• Most importantly can monitor own custom events

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Example of Event Profiler
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Event Profiler Customization

• Types/Groups of events to be monitored
• Including custom Discovered Events
• Columns displayed in Event Profiler output
• ProfilerAPI

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Event Profiler Customization Window
Notes
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Event Profiler Events Monitoring

• Real power is ability to create and monitor own
  events
• Suns HotSpot Java 5.0 (AKA 1.5) JVM provides
  jvmstat and other JVM monitoring tools
• See Backup slide for additional details

34
CodeCoach

• Your own Java code guru
• Help improve code by flagging omissions and
  problems common to routine Java code
• Dynamic Analysis Tool
• Code must be compiled with Oracle Java Compiler
  (OJC)
• Code must be executed in Oracle Java Virtual
  Machine (OJVM)
• All relevant threads of controlled code should be
  exercised (executed) to improve result accuracy

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What CodeCoach Tells You Results

• CodeCoach results include the following
• Textual description of recommended change to code
• This is referred to as advice
• As with any advice you might hear, consider it
  carefully before implementing recommendations
• Line number of source code that is subject of
  advice
• Advice Type (four letter uppercase keyword)
• See next slide for example of CodeCoach results
  in the IDE

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CodeCoach Results (IDE Example)
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CodeCoach Results Options

• Hide Messages of This Type
• Hides all messages with matching advice type
• Show Hidden Messages brings them all back
• Ignore Message
• Adds CodeCoach pragma to source code to prevent
  that particular message (not all with same advice
  type) from appearing again
• Apply Fix to Source
• If available, fixes source code according to
  recommendation
• Go to Source
• Highlights line of source code that CodeCoach has
  flagged
• Save to HTML
• Saves CodeCoach results to HTML page

38
CodeCoach Results Options (IDE Example)
39
Properly Using CodeCoach Advice

• Quality of CodeCoach advice depends on how you
  run CodeCoach!
• Should run CodeCoach through all significant
  threads of code
• Any code not executed during a CodeCoach run is
  unknown to CodeCoach
• CodeCoach results can be correct for the code it
  saw, but incorrect when the larger picture is
  taken into account
• Generally, choose to Go to Source and analyze
  recommendation manually rather than choosing
  Apply Fix to Source
• Always unit and regression test your code after
  making CodeCoach-recommended changes

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CodeCoach Customization

• Customize CodeCoach Advice Types, Covered
  Packages, and Level of Advice
• Project-level settings
• Via command-line or IDE
• Customize which advice types to identify
• Specific advice types individually or via setting
  of level
• Customize which classes/packages to analyze
• For classes, all analyzed same or not at all
• File, Class, or Method Level settings
• Via in-code (comments) pragmas for more granular
  scope
• Can more specifically tailor each classs
  CodeCoach analysis

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CodeCoach Customization Advice Types

• Choose advice types to focus on or ignore
• Advice types allow associated with major pieces
  of CodeCoach advice
• Representative keywords are typically four
  uppercase letters
• ALL is only exception (three uppercase letters)
• Groups of advice types can be selected or ignored
• ALL displays CodeCoach advice for all advice
  types
• Can use Level to select one of ten
  predetermined advice types mixes
• Increasing level indicates increased advice

42
CodeCoach Customization Advice Type Groupings

• Class Advice Types (CALL)
• CFIN, CSTAT
• Method Advice Types (MALL)
• MFIN, MSTAT, MPRI
• Field Advice Types (FALL)
• FFIN, FSTA, FPRI, FUNU, FLOC
• Local Variable Advice Types (LALL)
• LFIN, LUNU
• Memory Improvement Advice Types (NALL)
• NALS, NBST, NHTB, NHMP, NSBU, NVCT, NWHT
• Miscellaneous Advice Types (OALL)
• CDEA, ACST, INST

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CodeCoach Customization IDE

• Check boxes for advice types (or groups of advice
  types) you want CodeCoach to report by checking
  on them under Advice to Report
• Use Level bar to select integer between 1 and
  10 to specify rough percentages of advice types
  to be monitored and flagged
• Specifically include and/or exclude packages and
  classes from CodeCoach analysis
• Refer to next slide (CodeCoach Customization
  Window) for example of IDE customization

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CodeCoach Customization Window
Notes
45
CodeCoach Customization Command-line

• Instruct CodeCoach via command-line using Xcc
  flags and options
• -Xcclevelltltygtgt where y is integer 0 through 9
• Corresponds to IDEs Level bar (1 through 10)
• -Xccenableltlttypegtgt and -Xccdisableltlttypegtgt
• where type is ALL or one of the more specific
  four-letter advice types to be specifically
  identified (enable) or specifically not
  identified (disable) in CodeCoach run
• -Xccinclltltclassesgtgt and -Xccexclltltclassesgtgt
• where classes is semicolon-separated list of
  classes and/or packages to analyze (incl) or
  ignore (excl) during CodeCoach analysis
• Dont forget the ojvm option to run CodeCoach on
  source code in the Oracle Java Virtual Machine
• Application must be have been built with OJC and
  g option to have CodeCoach analyze it

46
CodeCoach Command-line Customization
ExampleRunning CodeCoach with OJVM
java ojvm Xcodecoach Xcclevel9
XccenableALL Xccinclorg.rmoug.marx.bet
terjava -Xccexclcomjavajavaxsunsunwora
cle classpath CLASSPATH
MyBadClassTest
The above assumes that MyBadClassTest was built
with Oracle Java Compiler and the g debugger
option.
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For More on CodeCoach

• See my article on CodeCoach in the next edition
  of the Rocky Mountain Oracle Users Group (RMOUG)
  newsletter
• Expected late February/early March
• Effective Java by Joshua Block
• Much of CodeCoach advice is espoused in this book
• Other tools also make use of principles outlined
  in this book
• Opinion Must-read for the serious Java developer

48
Code Audit

• Static tool analyzes static code
• No OJC compiling or OJVM execution required
• Can be run on code that doesnt compile!
• JDeveloper 10g Code Audit audits code for
  compliance with coding standards
• Can have JDeveloper automatically fix flagged
  coding standards (audit) violations
• Typically less risky to code execution than
  automatic fixes done for dynamic tools

49
Code Audit Results/Output Options IDE

• Each identified violation listed in IDE with
  descriptive text and a priority
• Some violations allow for automatic fix (Apply
  ) with right-click
• Violations of same type can be hidden or
  described with right-click
• Go to Source (after right-click) highlights
  line of code associated with identified violation
• Export to HTML (or text)
• Can select default (HTML or simple text) or
  customized Cascading Style Sheet
• Default HTML Cascading Style Sheet
• Associates violation with severity rather than
  priority (see later slide)
• Adds line number to output to enable quick lookup
  of associated line in source code

50
Code Audit Results/Output Options (IDE Example)
51
Code Audit Priorities / Severities
Notes
IDE (Priority) HTML (Severity)
Low Convention
Low Suggestion
Medium Violation
High Warning
Critical Error
The IDE associates a priority with Code Audit
identified violations while the HTML output lists
a severity for each identified violation.
52
Code Audit Customization

• Code Audit reports can be customized to not
  display certain categories/groups of violations
• Cannot suppress individual violation types
• Use Audit Profile to specify which audit rules to
  use (or not use) in analysis
• Code Audit can be extended and customized with
  oracle.jdeveloper.audit package
• Also used for Code Metrics

53
Code Audit Customization Example
Notes
54
Command-Line Code Audit

• ojaudit.exe (Windows)
• Generates XML output containing same data
  available in IDE/HTML output
• Including line number of relevant source code
• Use quiet option to remove most non-XML output
  normally included (Oracle header and summary
  footer information)
• Use style to specify XSLT style sheet that could
  be applied to Code Audit resultant HTML to
  produce own HTML similar to IDEs HTML Export
• Use ojaudit (without parameters) or ojaudit help
  to display usage
• Use fix to have Code Audit address violations

55
Code Metrics

• Static tool analyzes static code
• No OJC compiling or OJVM execution required
• JDeveloper 10g Code Metrics measures three
  metrics
• Depth of Inheritance Tree DIT
• Your classes will have DIT gt 2
• Number of Statements NOS
• Number of Java statements in code block
• Cyclomatic Complexity V(G)
• Branching complexity of code
• Generally strive for V(G) lt 10
• Rough rule of thumb

56
Code Metrics Results/Output Options

• Go to Source highlights class or method
  right-clicked on
• Export saves Code Metrics results as HTML
• Same information as in IDE Code Metrics output
  window
• Can use default Cascading Style Sheets (to HTML
  or to very basic text) or select own CSS to apply
  in creation of HTML output
• Show Over Threshold Only only displays Code
  Metrics findings that have a metric exceeding
  Threshold set in Metrics Preferences

57
Code Metrics Output Example (IDE)
58
Code Metrics Customization

• Code Metrics reports can be customized to focus
  on problem level results
• Use Metrics Profile to specify which metrics to
  evaluate
• Threshold can be set for each metric type to
  control which measurements or metrics are
  displayed
• Code Metrics can be customized and extended with
  oracle.jdeveloper.audit package
• Same as used with Code Audit

59
Code Metrics Customization Example
60
Command-line Code Metrics

• ojmetrics.exe (Windows)
• Generates XML output containing same data
  available in IDE/HTML output
• Adds line numbers for easier tracing of output to
  source code
• Adds nice descriptions of meanings of metrics
  NOS, V(G), DIT at top of produced output file
• XML results file has audit as root tag and other
  tag names matching the Code Audit output
• Use quiet option to remove most non-XML output
  normally included (Oracle header and summary
  footer information)
• Use style to specify XSLT style sheet that could
  be applied to Code Audit resultant HTML to
  produce own HTML similar to IDEs HTML Export
• Use ojmetrics (without parameters) or ojmetrics
  help to display usage

61
New Features / Changes for JDeveloper 10g Release
2
Notes

• Combining of similar Code Audit and Code Metrics
  tool into single Code Audit tool
• Code Audit Rules similar to Code Audit of
  9.0.5.x
• Code Audit Metrics similar to Code Metrics of
  9.0.5.x
• These tools shared many traits even in 9.0.5.x
• Introduction of Code Assist
• Can be executed from Run Audit option
• Automatically displays light bulb icon when
  affected line is highlighted
• Versus explicit execution of other Code Audit
  family of tools
• See following slide on Code Assist

62
The Multi-Function Code Audit in Release 2

• Code Audit (R2) contains many audit options
  (profiles)
• All Metrics
• Java source errors (rules)
• Metrics from 9.0.5
• All Rules
• All Rules but no Metrics or Code Assists
• Code Assist Rules
• Most Rules, All Code Assists, No Metrics
• Default Rules
• No Code Assists
• No Metrics
• Most Rules
• Javadoc Rules
• Only Javadoc Comments rules
• Your Own Auditing Profile
• Custom selected rules

63
A Quick Peek at Code Assist

• New Feature of JDeveloper 10g R2 (10.1.3)
• Similar functionality to CodeCoach
• But do not need to explicitly run tool separately
• Light bulb icon highlights available advice
• Use CtrlAltEnter to manually display Code
  Assist advice
• Change/disable Code Assist settings via
  Tools?Preferences (Audit)
• Click on light bulb icon to view advice
• Click on advice to implement advice
• Potential side effects displayed
• Opportunity to cancel recommendation rather than
  accepting it

64
A Code Assist Example IDE
Notes
65
Current Limitations of CodeAssist

• Spacing of accepted CodeAssist recommendations
  does not always match well with source code
  indentation
• CodeAssist recommendations are currently limited
• Not a whole lot of recommendations yet
• Add Javadoc Comment
• Separate Declaration and Assignment
• Remove Unused Local Variable
• Invert If Statement
• Negate Expression
• Others?
• May disagree with some of the recommendations
• Some recommendations made regardless of context

66
Better Java Code with JDeveloper 10g Tools

• Improve your Java Code with the JDeveloper
  Analysis Tools
• Use tools together for most comprehensive and
  accurate results
• Take advantage of different purposes of tools to
  identify different types of problems
• Use results of individual tools as input for
  other JDeveloper tools
• For example, identify most significant problems
  with Profilers and use other tools to improve
  problem areas

67
JDeveloper 10g Tools Improving Java Code

• CodeCoach
• More efficient classes
• More efficient maintainable methods
• More efficient/maintainable fields
• More efficient local variables
• More efficient Collections memory usage
• Minimizing unnecessary instanceof usage
• Minimizing constant object propagation problems

Memory Profiler Identify potential memory leaks
in code
Execution Profiler Identify performance problems
in application

• Event
• Profiler
• Identify problems or potential problems
  associated with particular events in the
  application.
• Garbage Collection Events
• BC4J Events
• Customized Events

Code Audit Identifies potential coding standard
violations including naming and coding
conventions, unused constructs, source code
errors, Javadoc problems and omissions,
appropriate API usage, and more.
Code Metrics Summarizes complexity and size of
application including number of statements
(NOS), Depth of Inheritance Tree (DIT), and
Cyclomatic/Branching Complexity V(G).
68
Example Better Java Code with CodeCoach
ParentItem item new ChildItem() if ( item
instanceof ChildItem ) name
item.getName()
While instanceof is very useful at times, it is
expensive and should not be used unless truly
needed.
69
Example Better Java Code with Code Audit
String abusedString new String() for ( int
i0 ilt10000 i ) abusedString
abusedString '1'
Strings are immutable and so a new String must be
instantiated each time that 1 character is
added above. This repeated String construction
is expensive and unnecessary.
70
Example Better Java Code with Code Metrics
if () if () if () if () if
() if () else if () else if ()
else if () else if ()
Cyclomatic complexity here is shown with a red
11 because the recommended complexity (10) has
been exceeded.
71
Optimization and Code Improvement Best Practices

• Know When and Where to Optimize
• Prefer architecture and design optimization over
  code optimization
• Biggest bang for the buck
• Perform architecture and design optimization
  early and often
• Prototype risky pieces
• Perform code optimization late and rarely
• Code optimization effort rarely justifies cost

72
Optimization and Code Improvement Best Practices

• Design code for modularity, maintainability, and
  functionality first
• Only optimize and tune code if necessary
• Pareto Principle (80/20 rule)
• Eighty percent of problems in twenty percent of
  code
• Numbers not exact, but real meaning is that a few
  problems often cause most of the negative
  consequences
• Tuning code for one area of improvement may
  negatively impact other areas of code (new bugs)
• Do not allow code optimization to trump good
  design and maintainability unless justified by
  business case

73
Optimization and Code Improvement Best Practices

• Experienced Developer Involved in Process
• JDeveloper tools are very useful for identifying
  potential issues, but use expert review
• No automatic tool is foolproof
• Analysis only as good as configuration of tools
  and executable tests
• Not all recommended results may apply to your
  situation
• Results can be adjusted through various IDE and
  command-line options and via in-code pragmas
• Need to discern which results are valid for
  organization and which do not apply or are not
  really an issue

74
Optimization and Code Improvement Best Practices

• Review Your Code, Only Your Code, and Nothing But
  Your Code
• With JDeveloper 10g dynamic tools, accuracy of
  results depends on thoroughness of code coverage
• Exercise all methods/threads of your own code in
  Profilers and CodeCoach tests
• Do not analyze third-party code with tools
• Typically cannot do anything about this code
  anyway
• Adds significant delay to analysis execution time
• Distracts reviewers from own code issues
• Example dont analyze java, javax, and similar
  packages

75
Optimization and Code Improvement Best Practices

• Train/Educate with JDeveloper Tools
• Ultimately want personnel to learn and follow
  software development best practices
• Developers can examine and discuss JDeveloper
  results and why they do or do not apply
• Java Experts are developed by learning common
  issues with Java code
• JDeveloper Experts are developed by learning
  how to use and customize the JDeveloper tools
• Read Explanations and other JDeveloper
  documentation on rules and metrics to better
  understand why certain practices should be
  followed

76
Optimization and Code Improvement Best Practices

• Use JDeveloper 10g Tools Together
• JDeveloper tools best used together because of
  differing areas of focus
• Favor non-invasive analysis over invasive
  analysis techniques
• For example, in-code changes are more invasive
• Comments (CodeCoach Pragmas) are less troubling
  than executable source code statements
• In-code instrumentation (Profilers) is designed
  to be transparent outside OJVM in Profile Mode
• Aspect-Oriented Programming (AOP) concepts?

77
Summary

• JDeveloper 10g enables better Java code and
  better Java applications
• Identifies memory problems/issues
• Identifies execution/event performance/issues
• Identifies areas for code improvement
• Identifies non-compliance with industry and
  organizational conventions and standards
• Identifies code that may be overly complex
• Provides teaching and training opportunities for
  developers
• Recognize that not all recommendations should be
  followed
• Expert judgment should be used in applying
  recommendations

78
Related RMOUG Training Days 2005 Presentations

• Already completed
• The Leap From PL/SQL to Java More Than Just
  Syntax Session 1
• The Object-Oriented SDLC and JDeveloper
  Session 1
• Visual and Declarative J2EE Development with
  Oracle JDeveloper 10g and Oracle ADF Session 4

79
Related RMOUG Training Days 2005 Presentations

• Still to Come
• Avoiding Land Mines As You Struts Your Stuff
  Through J2EE Development Using JDeveloper
  Session 7
• Introduction to Java PL/SQL Developers Take
  Heart! Session 8
• Applied Testing Architectures to Prove
  Correctness of Enterprise J2EE Applications
  Session 9
• Oracle JDeveloper for Database Developers and
  DBAs Session 10
• Quick Web Development Using JDeveloper 10g
  Session 12
• I Love the Java Jive J2EE Overview for Oracle
  Technologists Session 12

80
Trademarks and Disclaimer

• While significant effort was invested in an
  attempt to ensure accuracy, correctness, and
  completeness of this presentation, no guarantees
  of accuracy, correctness, or completeness are
  made by any individual or organization
• Java and all Java-based marks are trademarks or
  registered trademarks of Sun Microsystems, Inc.
  in the United States and other countries.
• Oracle and Oracle-based marks (including
  JDeveloper) are registered trademarks of Oracle
  Corporation and/or its affiliates.
• Dustin Marx is independent of both Sun
  Microsystems, Inc. and Oracle Corporation.

81
Better Java with JDeveloper 10g

• Backup Slides

82
JDeveloper 10g Release 2 Tools

• CodeCoach
• More efficient and maintainable code.

Memory Profiler Identify potential memory leaks
in code
Execution Profiler Identify performance problems
in application
Event Profiler Identify problems or potential
problems associated with events.
Code Audit
Rules (formerly Code Audit) Identifies potential
coding standard violations including naming and
coding conventions, unused constructs, source
code errors, Javadoc problems and omissions,
appropriate API usage, and more.
Metrics (formerly Code Metrics) Summarizes
complexity and size of application including
number of statements (NOS), Depth of Inheritance
Tree (DIT), and Cyclomatic/Branching Complexity
V(G).
Code Assist
83
Transforming Code Audit and Code Metrics XML
Output
Notes

• Code Code/Code Metrics results are in XML format
• Select XSLT style sheet in IDE to transform to
  HTML, text, or other format
• Specify XSLT style sheet with style option on
  command line for transformed formats
• JDeveloper 10g provides default HTML and text
  style sheets for both Code Metrics and Code Audit
• audit-html.xsl, audit-text.xsl
• metrics-html.xsl, metrics-text.xsl
• Useful for transforming command-line results
  directly
• Useful in IDE as default style sheet selections
• Useful as starting point for adapting own custom
  style sheets

84
jvmstat

• Suite of tools compatible with Java 1.4.2, but
  with more complete support for Java 5 (AKA 1.5)
• Subset of jvmstat tools bundled with Java 5
• jps (Java Virtual Machine Process Status Tool)
• jstat (Java Virtual Machine Statistics Monitoring
  Tool)
• jstatd (Java Virtual Machine jstat Daemon)
• visualgc available, but not bundled with Java 5
• Visual Garbage Collection Monitoring Tool

85
-Xlink javac Option

• Non-standard javac option
• Reports legal but potentially problematic syntax
• -Xlink (all recommended warnings)
• -Xlinknone (display only mandatory warnings)
• -Xlinkunchecked (detailed unchecked conversion
  warnings)
• -Xlinkpath (non-existent path directories)
• -Xlinkfinally (problem with finally clause)
• -Xlinkfallthrough (switch-case without break)
• -Xlinkserial (missing serialVersionUID)
• http//www.javapractices.com/Topic45.cjp

86
Java Virtual Machine Tool Interface (JVMTI)

• Programming interface native to JVM intended for
  use by tools such as JDeveloper IDE and tools
• Profiling
• Debugging
• Monitoring
• Coverage
• http//java.sun.com/j2se/1.5.0/docs/guide/jvmti/
• Replaces JVMPI and JVMDI
• Java Virtual Machine Profiler Interface (JVMPI)
  is now deprecated
• http//java.sun.com/j2se/1.4.2/docs/guide/jvmpi/jv
  mpi.html
• Java Virtual Machine Debug Interface (JVMDI) is
  now deprecated
• http//java.sun.com/j2se/1.4.2/docs/guide/jpda/jvm
  di-spec.html

87
Java Object Toolkit (JOT)

• Similar to Javas Reflection API
• But does not require loading of classes into JVM
• Interfaces and classes used to parse and generate
  other Java code
• Used in oracle.jdeveloper.audit package for
  customizing and extending Code Audit and Code
  Metrics
• Available with Oracle JDeveloper (and Borland
  JBuilder)

88
Better Java with JDeveloper 10g

• Resources and References

89
Other Papers/Presentations by the Author

• An Introduction to Aspect-Oriented Programming
  (AOP)
• RMOUG TD 2005 Session 11!
• To Oracle XML and Beyond PDF and Pictures
• RMOUG TD 2004
• Beyond the Buzzwords Walking the Talk, III
• RMOUG TD 2003
• JSP Best Practices and More JSP Best
  Practices
• http//www.javaworld.com/javaworld/jw-11-2001/jw-1
  130-jsp.html
• http//www.javaworld.com/javaworld/jw-07-2003/jw-0
  725-morejsp.html

90
References Oracle JDeveloper

• Oracle JDeveloper
• http//www.oracle.com/technology/products/jdev/ind
  ex.html
• Oracle JDeveloper 10g Overview
• http//www.oracle.com/technology/products/jdev/eve
  nts/owsf2004/jdevoverview_oow2004.pdf
• Oracle JDeveloper Tips and Tricks
• http//www.oracle.com/technology/products/jdev/tip
  s/index.html
• Oracle Technology Forum JDeveloper
• http//forums.oracle.com/forums/forum.jsp?forum83

91
References Oracle JDeveloper Tools

• Oracle 9i JDeveloper Performance Tuning J2EE
  Applications
• http//www.oracle.com/technology/products/ids/dail
  y/jun25.html
• How to Build Your Own Audit Rules
• http//www.oracle.com/technology/products/jdev/how
  tos/10g/AuditTutorial/index.html
• Code Auditing as Part of the Build Process
• http//www.oracle.com/technology/products/jdev/tip
  s/lediouris/audit/index.html
• Oracle JDeveloper Extension SDK
• http//www.oracle.com/technology/products/jdev/htd
  ocs/partners/addins/index.html

92
References Java Best Practices

• Java Practices
• http//www.javapractices.com/index.cjp
• JSP Best Practices
• http//www.javaworld.com/javaworld/jw-11-2001/jw-1
  130-jsp.html
• http//www.javaworld.com/javaworld/jw-07-2003/jw-0
  725-morejsp.html
• Effective Java
• http//java.sun.com/developer/Books/effectivejava/
  
• http//www.javaworld.com/javaworld/jw-06-2001/j1-0
  1-sintes2.html
• Effective Java Programming with Tiger
• http//www.developer.com/java/other/article.php/31
  12301

93
References JVM Monitoring Tools and Interfaces

• jvmstat
• http//java.sun.com/performance/jvmstat/
• Java Virtual Machine Tool Interface (JVMTI)
• http//java.sun.com/j2se/1.5.0/docs/guide/jvmti/
• Java Virtual Machine Profiler Interface (JVMPI)
• http//java.sun.com/j2se/1.4.2/docs/guide/jvmpi/jv
  mpi.html
• Java Virtual Machine Debug Interface (JVMDI)
• http//java.sun.com/j2se/1.4.2/docs/guide/jpda/jvm
  di-spec.html

94
References Java Tuning

• Java Performance Tuning
• http//www.javaperformancetuning.com/tips/index.sh
  tml
• Java Performance
• http//java.sun.com/performance/
• Java Performance Documentation
• http//java.sun.com/docs/performance/
• Java Platform Performance Strategies and Tips
• http//java.sun.com/docs/books/performance/