从私有区块链搭建到部署智能合约再到java调用操作步骤godloveayuan的博客-搭建私有链部署智能合约java调用

一、搭建私有链

1. 创世json文件: genesis.json

{     "config":{         "chainId":15,         "homesteadBlock":0,         "eip155Block":0,         "eip158Block":0     },     "difficulty":"4",     "gasLimit":"2100000",     "alloc":{ } } 

2. 创建区块链节点: dataChain

geth init genesis.json --datadir dataChain 

2.1 错误与常见问题

<1>错误1：pcscd服务错误

如果初始化节点过程中报以下错误：

INFO [11-09|17:23:10.229] Smartcard socket not found, disabling    err="stat /run/pcscd/pcscd.comm: no such file or directory" 

则后面会挖不出来矿，需要安装pscd服务

sudo apt-get -y install libusb-dev sudo apt-get -y install pcscd 

<2>错误2：创世文件block

如果初始化节点过程中报以下错误：

Fatal: Failed to write genesis block: unsupported fork ordering: eip150Block not enabled, but eip155Block enabled at 0 

则修改创世文件block号150和155：

"eip150Block": 0, "eip155Block": 0 

3. 启动服务端: dataChainServer

# geth --networkid 123 --datadir dataChain --rpc --rpcaddr 127.0.0.1 --rpcport 8545 --port 3000 --allow-insecure-unlock 

备注:

• rpcaddr 可以写本机地址，也可以写127.0.0.1
• 如果这里的rpcaddr 和 rpcport 修改为其他值了，则需要修改程序里web3j连接的url
• 加上 –allow-insecure-unlock 防止解锁账户过程中出错；

4. 启动客户端: dataChainClient

# cd dataChain # geth attach ipc:geth.ipc  

5. 客户端设置挖矿账户

# geth attach ipc:geth.ipc > personal.listAccounts [] > personal.newAccount("123456") "0x0f6740d209db6ed6b12c70daf667340cd06c5611" > personal.listAccounts ["0x0f6740d209db6ed6b12c70daf667340cd06c5611"] > eth.getBalance(personal.listAccounts[0]) 0 > miner.setEtherbase(personal.listAccounts[0]) true > miner.start() null > miner.stop() null > eth.getBalance(personal.listAccounts[0]) 35000000000000000000 

说明：

• 创建账户过程中newAccount()方法传递的参数即是该账户的密码(如:“123456”)

5.1 常见问题

<1> 首次挖矿需要等待较长时间

• 一台计算机创建完节点首次挖矿时需要等待较长时间，Generating DAG in progress需要从0%到100%

二、部署智能合约

1. 合约代码

pragma solidity ^0.4.4; contract CheckContract {          function check(string attributeA, string attributeB) pure public returns(bool){   if(bytes(attributeA).length != bytes(attributeB).length){    return false;   }else{    return keccak256(bytes(attributeA)) == keccak256(bytes(attributeA));   }     } } 

2. 编译合约

# 编译合约，生成bin文件 solc --bin CheckContract.sol -o ./  # 编译合约，生成abi文件 solc --abi CheckContract.sol -o ./  // web3j 根据bin文件和abi文件生成Java合约类 web3j solidity generate --javaTypes --binFile=CheckContract.bin --abiFile=CheckContract.abi -o ./ --package='myContract'  

3. 部署合约

#! dataChainClient  # 合约bin赋值，拷贝.bin文件里的值 # 记得在.bin文件的值之前加 0x >var publicBinCode="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"  # 合约 abi赋值  >var publicAbiCode=[{"constant":true,"inputs":[{"name":"attributeA","type":"string"},{"name":"attributeB","type":"string"}],"name":"check","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"pure","type":"function"}]    # 解锁挖矿账户  > personal.unlockAccount(personal.listAccounts[0]) Passphrase: // 输入创建账户时，括号里的参数，即账户的密码，"123456" Unlock account 0x449f09d90a4726db78b86972528fc99ea00777d8  # 预估gas > eth.estimateGas({data:publicBinCode}) 199867  > var publicAbiContract=eth.contract(publicAbiCode) undefined > var publicContract=publicAbiContract.new({from:personal.listAccounts[0],data:publicBinCode,gas:200000}) undefined  # 开始挖矿 > miner.start() > miner.stop()  # 查看合约 > publicContract {   abi: [{       constant: true,       inputs: [{...}, {...}],       name: "check",       outputs: [{...}],       payable: false,       stateMutability: "pure",       type: "function"   }],   address: "0x291f3347f9cb6d58ca9c24b61f87bf2348b15d2f",   transactionHash: "0xf9cbfcf8027a085106855eb31b1e10368b63bca177c2b9fffe9131d179bf061b",   allEvents: function(),   check: function() }  > publicContract.address "0x291f3347f9cb6d58ca9c24b61f87bf2348b15d2f"  

3.1 常见问题

<1>错误：无法解锁挖矿账户

如果解锁账户过程中报以下错误：

account unlock with HTTP access is forbidden 

因为新版本geth，出于安全考虑，默认禁止了HTTP通道解锁账户,解决办法是在启动服务端时加上参数

--allow-insecure-unlock # 完整的启动命令 geth --networkid 123 --datadir dataChain --rpc --rpcaddr 127.0.0.1 --rpcport 8545 --port 3000 --allow-insecure-unlock 

注意事项：

• bin赋值时需要在数字前加’0x’,然后将一串数字放入引号内(单双引号均可)
• abi赋值时不需要加内容，也不需要加引号！

三、Java 通过web3j 调用智能合约

1. 将web3j编译生成的java合约文件拷贝到工程中

package access.contract;  import java.math.BigInteger; import java.util.Arrays; import org.web3j.abi.TypeReference; import org.web3j.abi.datatypes.Bool; import org.web3j.abi.datatypes.Function; import org.web3j.abi.datatypes.Type; import org.web3j.crypto.Credentials; import org.web3j.protocol.Web3j; import org.web3j.protocol.core.RemoteCall; import org.web3j.tx.Contract; import org.web3j.tx.TransactionManager; import org.web3j.tx.gas.ContractGasProvider;  /**  * <p>Auto generated code.  * <p><strong>Do not modify!</strong>  * <p>Please use the <a href="https://docs.web3j.io/command_line.html">web3j command line tools</a>,  * or the org.web3j.codegen.SolidityFunctionWrapperGenerator in the   * <a href="https://github.com/web3j/web3j/tree/master/codegen">codegen module</a> to update.  *  * <p>Generated with web3j version 4.3.0.  */ public class CheckContract extends Contract {     private static final String BINARY = "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";      public static final String FUNC_CHECK = "check";      @Deprecated     protected CheckContract(String contractAddress, Web3j web3j, Credentials credentials, BigInteger gasPrice, BigInteger gasLimit) {         super(BINARY, contractAddress, web3j, credentials, gasPrice, gasLimit);     }      protected CheckContract(String contractAddress, Web3j web3j, Credentials credentials, ContractGasProvider contractGasProvider) {         super(BINARY, contractAddress, web3j, credentials, contractGasProvider);     }      @Deprecated     protected CheckContract(String contractAddress, Web3j web3j, TransactionManager transactionManager, BigInteger gasPrice, BigInteger gasLimit) {         super(BINARY, contractAddress, web3j, transactionManager, gasPrice, gasLimit);     }      protected CheckContract(String contractAddress, Web3j web3j, TransactionManager transactionManager, ContractGasProvider contractGasProvider) {         super(BINARY, contractAddress, web3j, transactionManager, contractGasProvider);     }      public RemoteCall<Boolean> check(String attributeA, String attributeB) {         final Function function = new Function(FUNC_CHECK,                  Arrays.<Type>asList(new org.web3j.abi.datatypes.Utf8String(attributeA),                  new org.web3j.abi.datatypes.Utf8String(attributeB)),                  Arrays.<TypeReference<?>>asList(new TypeReference<Bool>() {}));         return executeRemoteCallSingleValueReturn(function, Boolean.class);     }      @Deprecated     public static CheckContract load(String contractAddress, Web3j web3j, Credentials credentials, BigInteger gasPrice, BigInteger gasLimit) {         return new CheckContract(contractAddress, web3j, credentials, gasPrice, gasLimit);     }      @Deprecated     public static CheckContract load(String contractAddress, Web3j web3j, TransactionManager transactionManager, BigInteger gasPrice, BigInteger gasLimit) {         return new CheckContract(contractAddress, web3j, transactionManager, gasPrice, gasLimit);     }      public static CheckContract load(String contractAddress, Web3j web3j, Credentials credentials, ContractGasProvider contractGasProvider) {         return new CheckContract(contractAddress, web3j, credentials, contractGasProvider);     }      public static CheckContract load(String contractAddress, Web3j web3j, TransactionManager transactionManager, ContractGasProvider contractGasProvider) {         return new CheckContract(contractAddress, web3j, transactionManager, contractGasProvider);     }      public static RemoteCall<CheckContract> deploy(Web3j web3j, Credentials credentials, ContractGasProvider contractGasProvider) {         return deployRemoteCall(CheckContract.class, web3j, credentials, contractGasProvider, BINARY, "");     }      @Deprecated     public static RemoteCall<CheckContract> deploy(Web3j web3j, Credentials credentials, BigInteger gasPrice, BigInteger gasLimit) {         return deployRemoteCall(CheckContract.class, web3j, credentials, gasPrice, gasLimit, BINARY, "");     }      public static RemoteCall<CheckContract> deploy(Web3j web3j, TransactionManager transactionManager, ContractGasProvider contractGasProvider) {         return deployRemoteCall(CheckContract.class, web3j, transactionManager, contractGasProvider, BINARY, "");     }      @Deprecated     public static RemoteCall<CheckContract> deploy(Web3j web3j, TransactionManager transactionManager, BigInteger gasPrice, BigInteger gasLimit) {         return deployRemoteCall(CheckContract.class, web3j, transactionManager, gasPrice, gasLimit, BINARY, "");     } }  

2. web3j 工具类连接区块链

public class Web3JClient {      // 启动区块链服务端时的 rpcaddr 和 rpcport 参数，如果没有使用了其他参数，则需要在这里修改     private static String url = "https://127.0.0.1:8545/";      private Web3JClient() {     }      private volatile static Web3j web3j;      public static Web3j getClient() {         if (web3j == null) {             synchronized (Web3JClient.class) {                 if (web3j == null) {                     web3j = Web3j.build(new HttpService(url));                 }             }         }         return web3j;     } } 

3. 调用智能合约里的方法

public class ContractService {     private static Web3j web3j = Web3JClient.getClient();      /**      * 调用合约的方法      */     public static Boolean publicCheck(String contractAddress, String subAttribute, String objAttribute) {         try {             // 获取第一个账户             String minerBaseAccount = web3j.ethAccounts().send().getAccounts().get(0);              Credentials credentials = Credentials.create(minerBaseAccount);              // 合约对象             CheckContract checkContract = CheckContract.load(contractAddress, web3j, credentials, Contract.GAS_PRICE, Contract.GAS_PRICE);             return checkContract.check(subAttribute, objAttribute).send();         } catch (Exception e) {             System.out.println("exception");             return null;         }     } }