查看MetaMask发起的节点请求

背景

    在调研一个defi项目时，经常需要抓取eth节点上请求的数据。节点请求数据和restful的http请求数据不一样，完全看不懂。本文主要教大家如何看懂区块链节点请求

请求举例

前提：有eth MetaMask钱包操作经验
举例项目：借贷项目compound
看如下请求：

入参和返回值

入参说明：

1. “to” 表示需要请求的合约地址：0xa1bd4a10185f30932c78185f86641f11902e873f 可以到区块链浏览器查询合约源码：https://etherscan.io/address/0xa1bd4a10185f30932c78185f86641f11902e873f#code
2. “data” 按字符串长度拆分 8/64/64/64/64/64/64/64/64
   第一个8位是方法签名，详见：ETH(以太坊)交易日志解读
   后面每64位是一个16进制参数，截取后如下：
   
   后面都是32位的地址，这里将前面的数字解析一下：
   

入参：
{
 "to":"0xa1bd4a10185f30932c78185f86641f11902e873f",
 "data":"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"
}

返回值说明：
返回值就比较纯粹了，去掉0x，都是64位16进制字符串，截取后如图：

16进制20表示：32

返回值
{
    "jsonrpc":"2.0",
    "id":14,
    "result":"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"
}