web3j maven plugin is used to create java classes based on the solidity contract files.
The base configuration for the plugin will take the solidity files from src/main/resources and generates
the java classes into the folder src/main/java.
<build>
<plugins>
<plugin>
<groupId>org.web3j</groupId>
<artifactId>web3j-maven-plugin</artifactId>
<version>4.11.0</version>
<configuration>
<soliditySourceFiles/>
</configuration>
</plugin>
</plugins>
</build>to run the plugin execute the goal generate-sources
mvn web3j:generate-sourcesThe are several variable to select the solidity source files, define a source destination path or change the package name.
| Name | Format | Default value |
|---|---|---|
<packageName/> |
valid java package name | org.web3j.model |
<outputDirectory><java/></outputDirectory> |
relative or absolute path of the generated for 'Java files | value in <sourceDestination/> |
<outputDirectory><bin/></outputDirectory> |
relative or absolute path of the generated for 'Bin' files | value in <sourceDestination/> |
<outputDirectory><abi/></outputDirectory> |
relative or absolute path of the generated for 'ABI' files | value in <sourceDestination/> |
<sourceDestination/> |
relative or absolute path of the generated files (java, bin, abi) | src/main/java |
<outputFormat/> |
generate Java Classes(java), ABI(abi) and/or BIN (bin) Files (comma separated) |
java |
<nativeJavaType/> |
Creates Java Native Types (instead of Solidity Types) | true |
<outputJavaParentContractClassName/> |
Sets custom(? extends org.web3j.tx.Contract) class as a parent for java generated code | org.web3j.tx.Contract |
<soliditySourceFiles> |
Standard maven fileset | <soliditySourceFiles> <directory>src/main/resources</directory> <includes> <include>**/*.sol</include> </includes></soliditySourceFiles> |
<abiSourceFiles> |
Standard maven fileset | <abiSourceFiles> <directory>src/main/resources</directory> <includes> <include>**/*.json</include> </includes></abiSourceFiles> |
<contract> |
Filter (<include> or <exclude>) contracts based on the name. |
<contract> <includes> <include>greeter</include> </includes> <excludes> <exclude>mortal</exclude> <excludes></contracts> |
<pathPrefixes> |
A list (<pathPrefixe>) of replacements of dependency replacements inside Solidity contract. |
Configuration of outputDirectory has priority over sourceDestination
Create a standard java maven project. Add following <plugin> - configuration into the pom.xml file:
<plugin>
<groupId>org.web3j</groupId>
<artifactId>web3j-maven-plugin</artifactId>
<version>4.11.0</version>
<configuration>
<packageName>com.zuehlke.blockchain.model</packageName>
<sourceDestination>src/main/java/generated</sourceDestination>
<nativeJavaType>true</nativeJavaType>
<outputFormat>java,bin</outputFormat>
<soliditySourceFiles>
<directory>src/main/resources</directory>
<includes>
<include>**/*.sol</include>
</includes>
</soliditySourceFiles>
<abiSourceFiles>
<directory>src/main/resources</directory>
<includes>
<include>**/*.json</include>
</includes>
</abiSourceFiles>
<outputDirectory>
<java>src/java/generated</java>
<bin>src/bin/generated</bin>
<abi>src/abi/generated</abi>
</outputDirectory>
<contract>
<includes>
<include>greeter</include>
</includes>
<excludes>
<exclude>mortal</exclude>
</excludes>
</contract>
<pathPrefixes>
<pathPrefix>dep=../dependencies</pathPrefix>
</pathPrefixes>
</configuration>
</plugin>Add your solidity contract files into the folder src/main/resources. Make sure that the solidity files
ends with .sol.
Start the generating process:
> mvn web3j:generate-sources
[INFO] --- web3j-maven-plugin:0.1.2:generate-sources (default-cli) @ hotel-showcase ---
[INFO] process 'HotelShowCaseProxy.sol'
[INFO] Built Class for contract 'HotelShowCaseProxy'
[INFO] Built Class for contract 'HotelShowCaseV2'
[INFO] Built Class for contract 'Owned'
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 4.681 s
[INFO] Finished at: 2017-06-13T07:07:04+02:00
[INFO] Final Memory: 14M/187M
[INFO] ------------------------------------------------------------------------
Process finished with exit code 0
You find the generated java classes inside the directory src/main/java/generated/.
Next step is to interact with the smart contract. See for that deploying and interacting with smart contracts in the official web3j documentation.
For a multi module project configuration see following post
from @fcorneli. In short: For pick up the generated java source
files, you need the build-helper-maven-plugin configuration. Also, ${basedir} prefix is required
within a multi-module project.
- Update web3j core version to 4.11.0
- Update web3j core version to 4.8.1
- Replace SolC with Sokt (thx to @josh-richardson & @AlexandrouR)
- Update web3j core version to 4.5.11
- Update solcj version to 0.5.7
- Update web3j core version to 4.2.0
- Update web3j core version to 4.1.0
- Revert Java Update
- Bringing all web3j-related projects up to the same build number to reduce confusion
- Update solcj version to 0.4.25
- Update web3j core version to 3.5.0
- Destination Directory for ABI, BIN and Java can be different
- Generate and Store ABI & BIN Files
- Update to 3.5.0 web3j core version
- Update to newest solcj version. Support for Solidity Version 0.4.24
- Update to 3.4.0 web3j core version
- Support of imported Files
import './other.sol';
- Update Core Version
- Update Core Version
- Update Core Version
- Support Java Native Type creation
- Better Contract Handling
- Initial Release