Failed to use SolSample.java

[marlonprudente]

I trying to use SolSample with Ganache, my method is the same:

	private static void deploy() {
		Web3j web3j = Web3j.build(new HttpService(Environment.RPC_URL));
		Credentials credentials = Credentials.create("9797ab180fae3c9fa50c1b713beb5e08e012a303de04760349712dbcf6d497c1");//可以根据私钥生成
                System.out.println("Address: " + credentials.getAddress());
		RemoteCall<TokenERC20> deploy = TokenERC20.deploy(web3j, credentials,
				Convert.toWei("10", Convert.Unit.GWEI).toBigInteger(),
				BigInteger.valueOf(3000000),
				BigInteger.valueOf(5201314),
				"my token", "mt");
		try {
			TokenERC20 tokenERC20 = deploy.send();
			tokenERC20.isValid();
		} catch (Exception e) {
			e.printStackTrace();
		}

	}

but, the error is:

Address: 0xf7e06fc2159da20efa1a5c3bfe3330445259314d java.lang.RuntimeException: java.lang.NoSuchMethodException: com.ethjava.sol.TokenERC20.<init>(java.lang.String, org.web3j.protocol.Web3j, org.web3j.crypto.Credentials, org.web3j.tx.gas.ContractGasProvider) at org.web3j.tx.Contract.deploy(Contract.java:359) at org.web3j.tx.Contract.deploy(Contract.java:396) at org.web3j.tx.Contract.lambda$deployRemoteCall$5(Contract.java:419) at org.web3j.protocol.core.RemoteCall.send(RemoteCall.java:30) at com.ethjava.sol.SolSample.deploy(SolSample.java:29) at com.ethjava.sol.SolSample.main(SolSample.java:15) Caused by: java.lang.NoSuchMethodException: com.ethjava.sol.TokenERC20.<init>(java.lang.String, org.web3j.protocol.Web3j, org.web3j.crypto.Credentials, org.web3j.tx.gas.ContractGasProvider) at java.base/java.lang.Class.getConstructor0(Class.java:3350) at java.base/java.lang.Class.getDeclaredConstructor(Class.java:2554) at org.web3j.tx.Contract.deploy(Contract.java:346) ... 5 more Exception in thread "main" java.lang.NullPointerException at org.web3j.tx.RawTransactionManager.<init>(RawTransactionManager.java:36) at org.web3j.tx.RawTransactionManager.<init>(RawTransactionManager.java:66) at org.web3j.tx.Contract.<init>(Contract.java:94) at com.ethjava.sol.TokenERC20.<init>(TokenERC20.java:75) at com.ethjava.sol.TokenERC20.load(TokenERC20.java:263) at com.ethjava.sol.SolSample.use(SolSample.java:41) at com.ethjava.sol.SolSample.main(SolSample.java:16) Command execution failed. org.apache.commons.exec.ExecuteException: Process exited with an error: 1 (Exit value: 1) at org.apache.commons.exec.DefaultExecutor.executeInternal(DefaultExecutor.java:404) at org.apache.commons.exec.DefaultExecutor.execute(DefaultExecutor.java:166) at org.codehaus.mojo.exec.ExecMojo.executeCommandLine(ExecMojo.java:764) at org.codehaus.mojo.exec.ExecMojo.executeCommandLine(ExecMojo.java:711) at org.codehaus.mojo.exec.ExecMojo.execute(ExecMojo.java:289) at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134) at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:207) at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153) at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145) at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:116) at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80) at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51) at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128) at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:307) at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193) at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106) at org.apache.maven.cli.MavenCli.execute(MavenCli.java:863) at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:288) at org.apache.maven.cli.MavenCli.main(MavenCli.java:199) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:566) at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289) at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229) at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415) at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)

[hadiseShaaban]

Hi! The error you're seeing usually means that the TokenERC20 class generated from your Solidity contract doesn't have the correct constructor that Web3j expects.

This often happens when the contract wrapper (TokenERC20.java) is not generated properly. To fix it, make sure you generate the Java class using the official Web3j CLI or Gradle/Maven plugin with your .sol, .abi, and .bin files. Here's the CLI command:
web3j solidity generate
-b TokenERC20.bin
-a TokenERC20.abi
-o /path/to/java/output
-p com.yourpackage
This will create the correct constructor and method signatures that Web3j can work with.
web3j solidity generate -b TokenERC20.bin -a TokenERC20.abi -o ./src/main/java -p com.ethjava.sol

This constructor must be in your class:
public TokenERC20(String contractAddress, Web3j web3j, Credentials credentials, ContractGasProvider contractGasProvider)

deploy method must be:
TokenERC20.deploy( Web3j web3j, Credentials credentials, ContractGasProvider gasProvider, BigInteger totalSupply, String name, String symbol )

you must create:
ContractGasProvider gasProvider = new StaticGasProvider( Convert.toWei("10", Convert.Unit.GWEI).toBigInteger(), BigInteger.valueOf(3_000_000) );
and then:
RemoteCall<TokenERC20> deploy = TokenERC20.deploy( web3j, credentials, gasProvider, BigInteger.valueOf(5201314), "my token", "mt" );
Good luck :)