[[Hyperledger Fabric V2]] 提交交易失败：类型错误：无法读取未定义的属性“toString”

Question

我使用节点的 fabcar 逻辑开发了一个 hyperldger 应用程序。
提交交易时一切正常。
我用 express 创建了一个 rest API 服务器来与链代码交互，并使用一个 angular 应用程序来服务 rest api。
虽然 createCertificate 事务运行良好，但有关将证书添加到分类帐的 api 请求会抛出上述错误。
来自智能联系人的addCertificate function

async createCertificate(ctx, certificateNumber, studentFullName, apogee, cin, birthDate, birthPlace, title, honor, graduationDate) {
        console.info('============= START : Create Certificate ===========');

        const certificate = {
            studentFullName,
            docType: 'certificate',
            apogee,
            cin,
            birthDate,
            birthPlace,
            title,
            honor,
            graduationDate
        };

        await ctx.stub.putState(certificateNumber, Buffer.from(JSON.stringify(certificate)));
        console.info('============= END : Create Certificate ===========');
    }

添加证书请求api

app.post('/api/addcertificate/', urlencodedParser, async function (req, res) {
    try {
const ccpPath = path.resolve(__dirname, '..', '..', 'test-network', 'organizations', 'peerOrganizations', 'org1.example.com', 'connection-org1.json');
        const ccp = JSON.parse(fs.readFileSync(ccpPath, 'utf8'));
// Create a new file system based wallet for managing identities.
        const walletPath = path.join(process.cwd(), 'wallet');
        const wallet = await Wallets.newFileSystemWallet(walletPath);
        console.log(`Wallet path: ${walletPath}`);

        // Check to see if we've already enrolled the user.
        const identity = await wallet.get('appUser');
        if (!identity) {
            console.log('An identity for the user "appUser" does not exist in the wallet');
            console.log('Run the registerUser.js application before retrying');
            return;
        }
  // Create a new gateway for connecting to our peer node.
        const gateway = new Gateway();
        await gateway.connect(ccp, { wallet, identity: 'appUser', discovery: { enabled: true, asLocalhost: true } });

        // Get the network (channel) our contract is deployed to.
        const network = await gateway.getNetwork('mychannel');

        // Get the contract from the network.
        const contract = network.getContract('certificate');
// Submit the specified transaction.
        // createCertificate transaction - requires 8 argument, ex: ('createCertificate', 'CERT12', 'Honda', 'Accord', 'Black', 'Tom')
        // changeCarOwner transaction - requires 2 args , ex: ('changeStudentName', 'CERT10', 'HADI')
        await contract.submitTransaction('createCertificate', req.body.certificateNumber, req.body.studentFullName, req.body.apogee, req.body.cin, req.body.birthDate, req.body.birthPlace, 
        req.body.title, req.body.honor, req.body.graduationDate);
        console.log('Transaction has been submitted');
        res.send('Transaction has been submitted');
// Disconnect from the gateway.
        await gateway.disconnect();
} catch (error) {
        console.error(`Failed to submit transaction: ${error}`);
        process.exit(1);
    }
})

错误：

Failed to submit transaction: TypeError: Cannot read property 'toString' of undefined

感谢任何提示、说明和/或如何获取快速日志。

Answer 1

拐弯抹角 1：我发现文件中的另一个 API 抛出了这个问题。

require('crypto').randomBytes(48, function(err, buffer) {
var token = buffer.toString('hex');
});

以上代码片段中的 toString 出现了问题。 删除它后工作。

拐弯抹角2：

req = {"body": {"a":1, "b":2}}
req.a ==> wrong
data = req.body = {"a":1, "b":2}
data.a => correct