fabric-gateway-java 调用虚拟机上的fabric链码，以fabcar为例

作为学习的记录。我是在虚拟机上搭建了fabric网络和通道，并部署了官方示例fabcar链码，现在想在windows上通过fabric-gateway-java 实现对fabric上链码的调用。

fabric的版本是2.4.0，编译器是IDEA，代码基于springboot框架。

fanric环境的搭建、test-network及通道的创建、链码的部署这里不再赘述。

首先导入如下依赖：

1.  
   <dependency>
2.  
   <groupId>org.hyperledger.fabric-sdk-java</groupId>
3.  
   <artifactId>fabric-sdk-java</artifactId>
4.  
   <version>1.4.7</version>
5.  
   </dependency>
6.  
    
7.  
   <dependency>
8.  
   <groupId>org.hyperledger.fabric</groupId>
9.  
   <artifactId>fabric-gateway-java</artifactId>
10.  
    <version>2.2.0</version>
11.  
    </dependency>

代码的结构，我的结构是这样的：

 首先，我们需要将test-network建立好之后，文件夹test-neteork/organizations下的orderorganizations和peerorganizations文件从虚拟机中复制到代码中，我是放在了resources/crypto-config目录下。

随后写的是链接建立文件，connection.json。

1.  
   {
2.  
   "name": "basic-network",
3.  
   "version": "1.0.0",
4.  
   "dependencies": {
5.  
   },
6.  
   "client": {
7.  
   "organization": "Org1",
8.  
   "connection": {
9.  
   "timeout": {
10.  
    "peer": {
11.  
    "endorser": "300"
12.  
    },
13.  
    "orderer": "300"
14.  
    }
15.  
    }
16.  
    },
17.  
    "channels": {
18.  
    "mychannel": {
19.  
    "orderers": [
20.  
    "orderer.example.com"
21.  
    ],
22.  
    "peers": {
23.  
    "peer0.org1.example.com": {
24.  
    "endorsingPeer": true,
25.  
    "chaincodeQuery": true,
26.  
    "ledgerQuery": true,
27.  
    "eventSource": true
28.  
    },
29.  
    "peer0.org2.example.com": {
30.  
    "endorsingPeer": true,
31.  
    "chaincodeQuery": true,
32.  
    "ledgerQuery": true,
33.  
    "eventSource": true
34.  
    }
35.  
    }
36.  
    }
37.  
    },
38.  
    "organizations": {
39.  
    "Org1": {
40.  
    "mspid": "Org1MSP",
41.  
    "peers": [
42.  
    "peer0.org1.example.com"
43.  
    ],
44.  
    "certificateAuthorities": [
45.  
    "ca-org1"
46.  
    ],
47.  
    "adminPrivateKeyPEM": {
48.  
    "path": "src/main/resources/crypto-config/peerOrganizations/org1.example.com/users/Admin@org1.example.com/msp/keystore/priv_sk"
49.  
    },
50.  
    "signedCertPEM": {
51.  
    "path": "src/main/resources/crypto-config/peerOrganizations/org1.example.com/users/Admin@org1.example.com/msp/signcerts/Admin@org1.example.com-cert.pem"
52.  
    }
53.  
    },
54.  
    "Org2": {
55.  
    "mspid": "Org2MSP",
56.  
    "peers": [
57.  
    "peer0.org2.example.com"
58.  
    ],
59.  
    "certificateAuthorities": [
60.  
    "ca-org2"
61.  
    ],
62.  
    "adminPrivateKeyPEM": {
63.  
    "path": "src/main/resources/crypto-config/peerOrganizations/org2.example.com/users/Admin@org2.example.com/msp/keystore/priv_sk"
64.  
    },
65.  
    "signedCertPEM": {
66.  
    "path": "src/main/resources/crypto-config/peerOrganizations/org2.example.com/users/Admin@org2.example.com/msp/signcerts/Admin@org2.example.com-cert.pem"
67.  
    }
68.  
    }
69.  
    },
70.  
    "orderers": {
71.  
    "orderer.example.com": {
72.  
    "url": "grpcs://192.168.16.129:7050",
73.  
    "mspid": "OrdererMSP",
74.  
    "grpcOptions": {
75.  
    "ssl-target-name-override": "orderer.example.com",
76.  
    "hostnameOverride": "orderer.example.com"
77.  
    },
78.  
    "tlsCACerts": {
79.  
    "path": "src/main/resources/crypto-config/ordererOrganizations/example.com/orderers/orderer.example.com/tls/ca.crt"
80.  
    },
81.  
    "adminPrivateKeyPEM": {
82.  
    "path": "src/main/resources/crypto-config/ordererOrganizations/example.com/users/Admin@example.com/msp/keystore/priv_sk"
83.  
    },
84.  
    "signedCertPEM": {
85.  
    "path": "src/main/resources/crypto-config/ordererOrganizations/example.com/users/Admin@example.com/msp/signcerts/Admin@example.com-cert.pem"
86.  
    }
87.  
    }
88.  
    },
89.  
    "peers": {
90.  
    "peer0.org1.example.com": {
91.  
    "url": "grpcs://192.168.16.129:7051",
92.  
    "grpcOptions": {
93.  
    "ssl-target-name-override": "peer0.org1.example.com",
94.  
    "hostnameOverride": "peer0.org1.example.com",
95.  
    "request-timeout": 120001
96.  
    },
97.  
    "tlsCACerts": {
98.  
    "path": "src/main/resources/crypto-config/peerOrganizations/org1.example.com/peers/peer0.org1.example.com/tls/ca.crt"
99.  
    }
100.  
     },
101.  
     "peer0.org2.example.com": {
102.  
     "url": "grpcs://192.168.16.129:9051",
103.  
     "grpcOptions": {
104.  
     "ssl-target-name-override": "peer0.org2.example.com",
105.  
     "hostnameOverride": "peer0.org2.example.com",
106.  
     "request-timeout": 120001
107.  
     },
108.  
     "tlsCACerts": {
109.  
     "path": "src/main/resources/crypto-config/peerOrganizations/org2.example.com/peers/peer0.org2.example.com/tls/ca.crt"
110.  
     }
111.  
     }
112.  
     },
113.  
     "certificateAuthorities": {
114.  
     "ca-org1": {
115.  
     "url": "https://192.168.16.129:7054",
116.  
     "grpcOptions": {
117.  
     "verify": true
118.  
     },
119.  
     "tlsCACerts": {
120.  
     "path": "src/main/resources/crypto-config/peerOrganizations/org1.example.com/ca/ca.org1.example.com-cert.pem"
121.  
     },
122.  
     "registrar": [
123.  
     {
124.  
     "enrollId": "admin",
125.  
     "enrollSecret": "adminpw"
126.  
     }
127.  
     ]
128.  
     },
129.  
     "ca-org2": {
130.  
     "url": "https://192.168.16.129:8054",
131.  
     "grpcOptions": {
132.  
     "verify": true
133.  
     },
134.  
     "tlsCACerts": {
135.  
     "path": "src/main/resources/crypto-config/peerOrganizations/org2.example.com/ca/ca.org2.example.com-cert.pem"
136.  
     },
137.  
     "registrar": [
138.  
     {
139.  
     "enrollId": "admin",
140.  
     "enrollSecret": "adminpw"
141.  
     }
142.  
     ]
143.  
     }
144.  
     }
145.  
     }
146.  
      

其中的ip换成自己虚拟机的ip，文件路径根据自己存放的orderorganizations和peerorganizations的目录进行调整。

之后配置properties文件：

1.  
   fabric.networkConnectionConfigPath = src/main/resources/connection.json
2.  
    
3.  
   fabric.certificatePath = src/main/resources/crypto-config/peerOrganizations/org1.example.com/users/User1@org1.example.com/msp/signcerts/User1@org1.example.com-cert.pem
4.  
    
5.  
   fabric.privateKeyPath = src/main/resources/crypto-config/peerOrganizations/org1.example.com/users/User1@org1.example.com/msp/keystore/priv_sk

指定了，connection,json文件的位置，和后续链接用到的私钥和证书目录。

之后就可以开始写代码了hh。

首先是配置类的代码，主要功能是从properties文件中读取需要的参数值

1.  
   import lombok.Data;
2.  
   import org.springframework.boot.context.properties.ConfigurationProperties;
3.  
   import org.springframework.context.annotation.Configuration;
4.  
    
5.  
   @Configuration
6.  
   @ConfigurationProperties(prefix = "fabric")
7.  
   @Data
8.  
    
9.  
   public class HyperLedgerFabricProperties {
10.  
     
11.  
     
12.  
    String networkConnectionConfigPath;
13.  
    String certificatePath;
14.  
    String privateKeyPath;
15.  
     
16.  
     
17.  
    }

之后还是一个配置类，用来获取gateway.

1.  
   import lombok.AllArgsConstructor;
2.  
   import lombok.extern.slf4j.Slf4j;
3.  
   import org.hyperledger.fabric.gateway.Gateway;
4.  
   import org.hyperledger.fabric.gateway.Identities;
5.  
   import org.hyperledger.fabric.gateway.Wallet;
6.  
   import org.hyperledger.fabric.gateway.Wallets;
7.  
   import org.springframework.context.annotation.Bean;
8.  
   import org.springframework.context.annotation.Configuration;
9.  
    
10.  
    import java.io.BufferedReader;
11.  
    import java.nio.charset.StandardCharsets;
12.  
    import java.nio.file.Files;
13.  
    import java.nio.file.Paths;
14.  
    import java.security.PrivateKey;
15.  
    import java.security.cert.X509Certificate;
16.  
    import java.util.concurrent.TimeUnit;
17.  
     
18.  
    @Configuration
19.  
    @AllArgsConstructor
20.  
    @Slf4j
21.  
    public class HyperLedgerConfig {
22.  
     
23.  
    final HyperLedgerFabricProperties hyperLedgerFabricProperties;
24.  
     
25.  
    @Bean
26.  
    public Gateway gateway() throws Exception {
27.  
     
28.  
     
29.  
    BufferedReader certificateReader = Files.newBufferedReader(Paths.get(hyperLedgerFabricProperties.getCertificatePath()), StandardCharsets.UTF_8);
30.  
     
31.  
    X509Certificate certificate = Identities.readX509Certificate(certificateReader);
32.  
     
33.  
    BufferedReader privateKeyReader = Files.newBufferedReader(Paths.get(hyperLedgerFabricProperties.getPrivateKeyPath()), StandardCharsets.UTF_8);
34.  
     
35.  
    PrivateKey privateKey = Identities.readPrivateKey(privateKeyReader);
36.  
     
37.  
    Wallet wallet = Wallets.newInMemoryWallet();
38.  
    wallet.put("user1" , Identities.newX509Identity("Org1MSP", certificate , privateKey));
39.  
     
40.  
     
41.  
    Gateway.Builder builder = Gateway.createBuilder()
42.  
    .identity(wallet , "user1")
43.  
    .networkConfig(Paths.get("src/main/resources/connection.json"));
44.  
     
45.  
    Gateway gateway = builder.connect();
46.  
     
47.  
     
48.  
    log.info("=========================================== connected fabric gateway {} " , gateway);
49.  
     
50.  
    return gateway;
51.  
    }
52.  
    }

没有问题以后，就是controller的代码，这里就以queryAllCars命令为例。

1.  
   import com.谷歌.common.collect.Maps;
2.  
   import lombok.AllArgsConstructor;
3.  
   import lombok.extern.slf4j.Slf4j;
4.  
   import org.apache.commons.codec.binary.StringUtils;
5.  
   import org.hyperledger.fabric.gateway.*;
6.  
   import org.springframework.context.annotation.Bean;
7.  
   import org.springframework.context.annotation.Configuration;
8.  
   import org.springframework.web.bind.annotation.GetMapping;
9.  
   import org.springframework.web.bind.annotation.PathVariable;
10.  
    import org.springframework.web.bind.annotation.RequestMapping;
11.  
    import org.springframework.web.bind.annotation.RestController;
12.  
     
13.  
    import javax.servlet.http.HttpServletRequest;
14.  
    import java.io.BufferedReader;
15.  
    import java.nio.charset.StandardCharsets;
16.  
    import java.nio.file.Files;
17.  
    import java.nio.file.Paths;
18.  
    import java.security.PrivateKey;
19.  
    import java.security.cert.X509Certificate;
20.  
    import java.util.Map;
21.  
    import java.util.concurrent.TimeoutException;
22.  
     
23.  
     
24.  
    @RestController
25.  
    @RequestMapping("/car")
26.  
    @Slf4j
27.  
    @AllArgsConstructor
28.  
    public class Fabriccontroller {
29.  
    final Gateway gateway;
30.  
     
31.  
     
32.  
     
33.  
    @GetMapping("/queryall")
34.  
    public Map<String, Object> queryall() throws ContractException {
35.  
     
36.  
    Map<String, Object> result = Maps.newConcurrentMap();
37.  
    Contract contract = getContract();
38.  
    byte[] car = contract.evaluateTransaction("queryAllCars");
39.  
     
40.  
    result.put("result", StringUtils.newStringUtf8(car));
41.  
     
42.  
     
43.  
    return result;
44.  
    }
45.  
     
46.  
    private Network getNetwork(){
47.  
    return gateway.getNetwork("mychannel");
48.  
    }
49.  
     
50.  
    private Contract getContract(){
51.  
    return getNetwork().getContract("fabcar");
52.  
    }
53.  
     
54.  
     
55.  
    }

最后getnetwork()和getcontract()的参数分别是通道的名称和链码的名称，根据自己的情况做调整。

最后，运行主启动类。

1.  
   import org.springframework.boot.SpringApplication;
2.  
   import org.springframework.boot.autoconfigure.SpringBootApplication;
3.  
   import org.springframework.boot.context.properties.EnableConfigurationProperties;
4.  
    
5.  
   @SpringBootApplication
6.  
   @EnableConfigurationProperties
7.  
   public class FabricJdkApplication {
8.  
    
9.  
   public static void main(String[] args) {
10.  
    SpringApplication.run(FabricJdkApplication.class, args);
11.  
    }
12.  
     
13.  
    }

注意：一定要在linux中先运行起来测试网络并安装好链码后才能够连接成功。

浏览器测试一下，返回查询数据

还有一点注意的是，当我们这一次工作结束，关闭了区块链网络。下一次在重启网络，要更新代码中的 orderorganizations和peerorganizations，替换成新网络的属性文件，否则自然是链接不上的。

学习中参考了B站“老哥没有饿意”的视频。作为初学者，如有问题和错误，欢迎大家的讨论和指正。

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