Home

Awesome

web3j-maven-plugin

build status codecov License

web3j maven plugin is used to create java classes based on the solidity contract files.

Usage

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>4.12.1</version>
            <configuration>
                <soliditySourceFiles/>
            </configuration>
        </plugin>
    </plugins>
</build>

to run the plugin execute the goal generate-sources

mvn web3j:generate-sources

Configuration

The are several variable to select the solidity source files, define a source destination path or change the package name.

NameFormatDefault value
<packageName/>valid java package nameorg.web3j.model
<outputDirectory><java/></outputDirectory>relative or absolute path of the generated for 'Java filesvalue in <sourceDestination/>
<outputDirectory><bin/></outputDirectory>relative or absolute path of the generated for 'Bin' filesvalue in <sourceDestination/>
<outputDirectory><abi/></outputDirectory>relative or absolute path of the generated for 'ABI' filesvalue 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 codeorg.web3j.tx.Contract
<soliditySourceFiles>Standard maven fileset<soliditySourceFiles><br> <directory>src/main/resources</directory><br> <includes><br> <include>**/*.sol</include><br> </includes><br></soliditySourceFiles>
<abiSourceFiles>Standard maven fileset<abiSourceFiles><br> <directory>src/main/resources</directory><br> <includes><br> <include>**/*.json</include><br> </includes><br></abiSourceFiles>
<contract>Filter (<include> or <exclude>) contracts based on the name.<contract><br> <includes><br> <include>greeter</include><br> </includes><br> <excludes><br> <exclude>mortal</exclude><br> <excludes><br></contracts>
<pathPrefixes>A list (<pathPrefixe>) of replacements of dependency replacements inside Solidity contract.

Configuration of outputDirectory has priority over sourceDestination

Getting Started

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>4.11.1</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.