增加文档说明，主要说明实现合约来实现充提的方式

README.md

@@ -160,3 +160,112 @@ sendTransaction(string, string, *big.Int) (string, error)
 # 一个简单的示例
 
 github地址： [golang 实现加密货币的充值/提现/归集服务](https://github.com/lmxdawn/wallet)
+
+# 特别说明
+
+> 创建钱包的方式可以用 create2 创建合约，这样可以实现不用批量管理私钥，防止私钥丢失或者被盗。
+
+- solidity
+
+```solidity
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.0;
+
+import "./ERC20.sol";
+
+contract Wallet {
+    address internal token = 0xDA0bab807633f07f013f94DD0E6A4F96F8742B53;
+    address internal hotWallet = 0xAb8483F64d9C6d1EcF9b849Ae677dD3315835cb2;
+
+    constructor() {
+        // send all tokens from this contract to hotwallet
+        IERC20(token).transfer(
+            hotWallet,
+            IERC20(token).balanceOf(address(this))
+        );
+        // selfdestruct to receive gas refund and reset nonce to 0
+        selfdestruct(payable(hotWallet));
+    }
+}
+
+contract Fabric {
+    function createContract(uint256 salt) public returns (address newAddr){
+        // get wallet init_code
+        bytes memory bytecode = type(Wallet).creationCode;
+        assembly {
+            let codeSize := mload(bytecode) // get size of init_bytecode
+            newAddr := create2(
+                0, // 0 wei
+                add(bytecode, 32), // the bytecode itself starts at the second slot. The first slot contains array length
+                codeSize, // size of init_code
+                salt // salt from function arguments
+            )
+        }
+    }
+    function getAddress(uint _salt)
+        public
+        view
+        returns (address)
+    {
+        bytes memory bytecode = type(Wallet).creationCode;
+        bytes32 hash = keccak256(
+            abi.encodePacked(bytes1(0xff), address(this), _salt, keccak256(bytecode))
+        );
+
+        // NOTE: cast last 20 bytes of hash to address
+        return address(uint160(uint(hash)));
+    }
+
+    function getBytecode() public pure returns (bytes memory) {
+        bytes memory bytecode = type(Wallet).creationCode;
+
+        return bytecode;
+    }
+
+    
+    function getBytecode1() public pure returns (bytes1) {
+        
+        return bytes1(0xff);
+    }
+
+    
+    function getBytecode3(uint256 s) public pure returns (bytes memory) {
+        
+        return abi.encodePacked(s);
+    }
+    
+    
+    function getBytecode2() public pure returns (bytes32) {
+        bytes memory bytecode = type(Wallet).creationCode;
+
+        return keccak256(bytecode);
+    }
+}
+```
+
+- go
+
+```go
+code := "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"
+codeB := common.Hex2Bytes(code)
+codeHash := crypto.Keccak256Hash(codeB)
+fmt.Println(codeHash)
+
+address := common.HexToAddress("0x7EF2e0048f5bAeDe046f6BF797943daF4ED8CB47")
+fmt.Println(address)
+
+fmt.Println(common.LeftPadBytes(big.NewInt(1).Bytes(), 32))
+var buffer bytes.Buffer
+buffer.Write(common.FromHex("0xff"))
+buffer.Write(address.Bytes())
+buffer.Write(common.Hex2Bytes("0x30"))
+buffer.Write(codeHash.Bytes())
+
+hash := crypto.Keccak256Hash([]byte{0xff}, address.Bytes(), common.LeftPadBytes(big.NewInt(1).Bytes(), 32), codeHash.Bytes())
+
+//salt := common.LeftPadBytes(big.NewInt(1).Bytes(), 32)
+//crypto.CreateAddress2(address, salt, codeHash.Bytes())
+
+fmt.Println(common.BytesToAddress(hash[12:]))
+```