A collection of tools for running and sharing small experiments with the Java™ language.

Compile

Compile Java code.

Binary and disassembled bytecode are presented with JVM instruction documentation.

Benchmark

Run JMH benchmark.

Display disassembled bytecode and compiled native assembly code, analyze results using OpenAI/o4-mini model.

Supports x86_64 and ARM64 architectures and JDK versions 17 and 21.

Detect Style

Detect code formatting style.

Bracket positioning, indentation, whitespaces, import ordering and more...

Generate Eclipse and IntelliJ IDEA formatter and Checkstyle rule configuration from the detected code style.

Format

Reformat code.

Eclipse formatter or Checkstyle rule configuration can be used as style definition.

Eclipse formatter configuration file can be generated from Checkstyle rule configuration.

Check Style

Verify code formatting.

Verification against a provided Checkstyle rule configuration.

Compile

Compiles a single Java file and displays the disassembled bytecode. The binary bytecode is also displayed.

InputOutput
Java code (single file) Disassembled bytecode
Binary bytecode

Benchmark

Executes a JMH benchmark contained by a single Java file.

Execution is performed using the AWS Lambda infrastructure.
For each run various CPU types (Intel, AMD, clock speed etc.) might be assigned by AWS Lambda so be careful when comparing the results of different executions.

Information about the execution environment (cpuinfo, meminfo) is provided under the Environment tab.

The JDK version, CPU architecture and allocated memory can be configured.

Increasing the amount of memory will also affect the computing power.
Check this StackOverflow question and AWS Lambda documentation for more details.

Disassembled bytecode and compiled native assembly code can be inspected under the Bytecode and Compiled tabs.

Results can be analyzed using the OpenAI/o4-mini model.

InputOutput
Java code (single file) Benchmark output
Benchmark result in JSON format
Disassembled bytecode
Compiled native assembly code
Execution environment information
Result analysis

Detect Style

Detects the code formatting style of Java code.

A single Java file, a Git repository or a Zip file can be provided for detection.

Checkstyle configuration XML will be generated as a result.
Also formatter configuration is generated for IntelliJ IDEA and Eclipse IDEs.

InputOutput
Java code
 - Single file or
 - Git repository (URL)* or
 - Zip file* 		Checkstyle configuration XML
Eclipse code formatter configuration XML
IntelliJ IDEA code formatter configuration XML

*Requires access token
Supported Checks
The following Checkstyle Checks and Properties are recognized during the detection process:

CheckProperty
AnnotationLocation allowSamelineMultipleAnnotations
allowSamelineParameterizedAnnotation
allowSamelineSingleParameterlessAnnotation
tokens
AnnotationOnSameLine tokens
AnnotationUseStyle closingParens
elementStyle
trailingArrayComma
ArrayTypeStyle javaStyle
AvoidStarImport allowClassImports
allowStaticMemberImports
EmptyForInitializerPad option
EmptyForIteratorPad option
EmptyLineSeparator allowMultipleEmptyLines
allowMultipleEmptyLinesInsideClassMembers
allowNoEmptyLineBetweenFields
tokens
FileTabCharacter -
FinalParameters ignorePrimitiveTypes
tokens
ImportOrder option
groups
ordered
separated
staticGroups
sortStaticImportsAlphabetically
separatedStaticGroups
Indentation arrayInitIndent
basicOffset
braceAdjustment
caseIndent
lineWrappingIndentation
throwsIndent
LeftCurly ignoreEnums
option
tokens
MethodParamPad allowLineBreaks
option
tokens
NeedBraces allowEmptyLoopBody
allowSingleLineStatement
tokens
NoWhitespaceAfter allowLineBreaks
tokens
NoWhitespaceBefore allowLineBreaks
tokens
NoWhitespaceBeforeCaseDefaultColon -
OneStatementPerLine -
OperatorWrap option
tokens
ParenPad option
tokens
RequireThis checkFields
checkMethods
RightCurly option
tokens
SeparatorWrap option
tokens
TypecastParenPad option
UpperEll -
WhitespaceAfter tokens
WhitespaceAround allowEmptyCatches
allowEmptyConstructors
allowEmptyLambdas
allowEmptyLoops
allowEmptyMethods
allowEmptyTypes
ignoreEnhancedForColon
tokens

Format

Applies code formatting style to a single Java file.

The code style used for formatting can be specified by an Eclipse code formatter or a Checkstyle configuration file.

If Checkstyle configuration is provided, the Eclipse formatter configuration will be generated.

InputOutput
Java code (single file) Formatted Java file
Style configuration
 - Checkstyle configuration XML or
 - Eclipse code formatter configuration XML
 		Eclipse code formatter configuration XML

Check Style

Executes a Checkstyle analysis against a single Java file.

InputOutput
Java code (single file) Checkstyle result XML
Checkstyle configuration XML

Attribution

Detection is done by abusing a slightly modified fork of Checkstyle version 10.21.2.

Benchmark is performed using JMH version 1.37.

Oracle and Java are registered trademarks of Oracle and/or its affiliates.
Other names may be trademarks of their respective owners.

Privacy

All processing is done on backend side.

All data is stored for an indefinite period of time for debugging purposes.

The service is not intended to be used with confidential data at this moment.

Plans

Free Pro
Access token required
Compile
Decompiled bytecode
Binary bytecode
Benchmark
x86 architecture
ARM architecture
Memory 1024 MB 4096 MB
JDK 17
JDK 21
Analyze results
Timeout 2 minutes 15 minutes
Detect Style
Single Java file
Zip file
Git repository
Format
Using Checkstyle config
Using Eclipse formatter config
Generate Eclipse config
Check Style
Single Java file
Git Repository URL
E.g. https://github.com/apache/commons-io.git

Zip File
Warning!
Content will be sent to and analyzed by a backend service and may be stored for debugging purposes.
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