go智能合约具体实现代码

以下是一个简单的go智能合约实现代码，实现了一个简单的存储和读取功能：

package main

import (
	"fmt"
	"github.com/hyperledger/fabric/core/chaincode/shim"
)

type SimpleChaincode struct {
}

func (t *SimpleChaincode) Init(stub shim.ChaincodeStubInterface, function string, args []string) ([]byte, error) {
	fmt.Println("Init Chaincode...")
	return nil, nil
}

func (t *SimpleChaincode) Invoke(stub shim.ChaincodeStubInterface, function string, args []string) ([]byte, error) {
	fmt.Println("Invoke Chaincode...")
	if function == "write" {
		return t.write(stub, args)
	} else if function == "read" {
		return t.read(stub, args)
	}
	return nil, nil
}

func (t *SimpleChaincode) Query(stub shim.ChaincodeStubInterface, function string, args []string) ([]byte, error) {
	fmt.Println("Query Chaincode...")
	if function == "read" {
		return t.read(stub, args)
	}
	return nil, nil
}

func (t *SimpleChaincode) write(stub shim.ChaincodeStubInterface, args []string) ([]byte, error) {
	var key, value string
	var err error
	fmt.Println("Running write()")
	if len(args) != 2 {
		return nil, fmt.Errorf("Incorrect number of arguments. Expecting 2. name of the key and value to set")
	}
	key = args[0]
	value = args[1]
	err = stub.PutState(key, []byte(value))
	if err != nil {
		return nil, err
	}
	return nil, nil
}

func (t *SimpleChaincode) read(stub shim.ChaincodeStubInterface, args []string) ([]byte, error) {
	var key string
	var err error
	fmt.Println("Running read()")
	if len(args) != 1 {
		return nil, fmt.Errorf("Incorrect number of arguments. Expecting 1. name of the key to query")
	}
	key = args[0]
	value, err := stub.GetState(key)
	if err != nil {
		jsonResp := "{\"Error\":\"Failed to get state for " + key + "\"}"
		return nil, fmt.Errorf(jsonResp)
	}
	if value == nil {
		jsonResp := "{\"Error\":\"Nil value for " + key + "\"}"
		return nil, fmt.Errorf(jsonResp)
	}
	jsonResp := "{\"Name\":\"" + key + "\",\"Value\":\"" + string(value) + "\"}"
	fmt.Printf("Query Response:%s\n", jsonResp)
	return value, nil
}

func main() {
	err := shim.Start(new(SimpleChaincode))
	if err != nil {
		fmt.Printf("Error starting Simple chaincode: %s", err)
	}
}

这个合约定义了一个名为SimpleChaincode的结构体，并实现了Init、Invoke和Query三个方法。Init方法在合约初始化时调用，Invoke方法实现了合约的写和读操作，Query方法实现了查询操作。具体实现中，write方法将传入的key-value对存储到区块链上，read方法从区块链上检索并返回指定的key-value对。最后，main函数调用了shim.Start方法启动了该合约