nestjs,监听区块链数据代码,websocket ,写代码
时间: 2024-06-10 08:10:10 浏览: 8
下面是一个使用NestJS和WebSocket来监听区块链数据的示例代码:
1. 首先,安装必要的依赖:
```bash
npm install --save @nestjs/websockets
npm install --save ws
```
2. 创建一个WebSocket Gateway
```typescript
// blockchain.gateway.ts
import { WebSocketGateway, OnGatewayInit, OnGatewayConnection, OnGatewayDisconnect, WebSocketServer } from '@nestjs/websockets';
import { Server } from 'ws';
@WebSocketGateway()
export class BlockchainGateway implements OnGatewayInit, OnGatewayConnection, OnGatewayDisconnect {
@WebSocketServer() server: Server;
afterInit(server: Server) {
console.log('WebSocket server initialized');
}
handleConnection(client: any, ...args: any[]) {
console.log('WebSocket client connected');
}
handleDisconnect(client: any) {
console.log('WebSocket client disconnected');
}
}
```
3. 在Module中引入WebSocket Gateway
```typescript
// app.module.ts
import { Module } from '@nestjs/common';
import { WebSocketModule } from '@nestjs/websockets';
import { BlockchainGateway } from './blockchain.gateway';
@Module({
imports: [
WebSocketModule
],
providers: [
BlockchainGateway
],
})
export class AppModule {}
```
4. 在WebSocket Gateway中监听区块链数据
```typescript
// blockchain.gateway.ts
import { WebSocketGateway, OnGatewayInit, OnGatewayConnection, OnGatewayDisconnect, WebSocketServer } from '@nestjs/websockets';
import { Server } from 'ws';
const WebSocket = require('ws');
@WebSocketGateway()
export class BlockchainGateway implements OnGatewayInit, OnGatewayConnection, OnGatewayDisconnect {
@WebSocketServer() server: Server;
private ws: any;
afterInit(server: Server) {
console.log('WebSocket server initialized');
this.connectToBlockchain();
}
handleConnection(client: any, ...args: any[]) {
console.log('WebSocket client connected');
}
handleDisconnect(client: any) {
console.log('WebSocket client disconnected');
}
private connectToBlockchain() {
this.ws = new WebSocket('ws://localhost:8546');
this.ws.on('open', () => {
console.log('Connected to Ethereum node');
// Subscribe to new block headers
this.ws.send(JSON.stringify({
id: 1,
method: 'eth_subscribe',
params: ['newHeads']
}));
});
this.ws.on('message', (data: any) => {
const message = JSON.parse(data);
if (message.method === 'eth_subscription') {
const blockNumber = message.params.result.number;
console.log(`New block mined: ${blockNumber}`);
// Send block number to connected clients
this.server.emit('newBlock', blockNumber);
}
});
this.ws.on('error', (error: any) => {
console.error('WebSocket error: ', error);
});
this.ws.on('close', () => {
console.log('WebSocket connection closed');
setTimeout(() => {
this.connectToBlockchain();
}, 5000);
});
}
}
```
在这个示例中,我们连接到本地的以太坊节点,并订阅新的区块头。当新的区块被挖出时,我们会将区块号发送到连接的所有客户端。客户端可以使用WebSocket客户端连接到这个Gateway来接收这些消息。
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