golang 实现程序运行时函数动态替换，举例说明动态注入和替换本地方法、系统库方法、第三方库方法，附完整源码实现

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文章标签 golang 动态注入动态替换函数替换 hook 文章分类 代码人生

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golang 实现程序运行时函数动态替换，举例说明动态注入和替换本地方法、系统库方法、第三方库方法，附完整源码实现。

1、先创建一个go文件，把包名设置为main，并写一个main方法；

golang 实现程序运行时函数动态替换，举例说明动态注入和替换本地方法、系统库方法、第三方库方法，附完整源码实现_hook

2、测试本地方法动态替换

func originFunc() {
  str := "this is origin func"
  fmt.Println(str)
}

func replaceFunc() {
  str := "this is replace func"
  fmt.Println(str)
}

func testLocalMethod() {
  originFunc()
  hook.Hook(originFunc, replaceFunc, nil)
  originFunc()
  fmt.Println("====================")
}

测试结果：

golang 实现程序运行时函数动态替换，举例说明动态注入和替换本地方法、系统库方法、第三方库方法，附完整源码实现_hook_02

3、测试系统方法动态替换，以time下的方法为例

func nowTime() time.Time {
  return time.Date(2022, 1, 1, 0, 0, 0, 0, &time.Location{})
}

func Local3(t time.Time) time.Time {
  return time.Date(2022, 1, 1, 0, 0, 0, 0, &time.Location{})
}

func Local4() time.Time {
  return time.Date(2022, 1, 1, 0, 0, 0, 0, &time.Location{})
}

func testSystemLib() {

  fmt.Println(time.Now())
  hook.Hook(time.Now, nowTime, nil)
  fmt.Println(time.Now())
  fmt.Println("====================")

  t1 := time.Time{}
  fmt.Println(t1.Local())
  hook.HookMethod(t1, "Local", Local3, nil)
  fmt.Println(t1.Local())
  hook.Hook(t1.Local, Local4, nil)
  fmt.Println(t1.Local())
  fmt.Println("====================")
}

测试结果：

golang 实现程序运行时函数动态替换，举例说明动态注入和替换本地方法、系统库方法、第三方库方法，附完整源码实现_golang_03

4、测试第三方库方法，动态注入和替换，以net/http包下http请求方法为例：

func do1(req *http.Request) (*http.Response, error) {
  return nil, fmt.Errorf("replace request success")
}

func do2(*http.Client, *http.Request) (*http.Response, error) {
  return nil, fmt.Errorf("replace request success")
}

func ThirdRequest(url, method, token string, data map[string]interface{}) (error, map[string]interface{}) {
  //Method: "OPTIONS" | "GET" | "HEAD" | "POST" | "PUT" | "DELETE" | "TRACE" | "CONNECT"
  client := &http.Client{
    Transport: &http.Transport{TLSClientConfig: &tls.Config{InsecureSkipVerify: true}},
  }
  jsonBytes, err := json.Marshal(data)
  if err != nil {
    fmt.Println("11", err)
    return err, nil
  }
  request, err := http.NewRequest(method, url, bytes.NewReader(jsonBytes))
  if err != nil {
    fmt.Println("22", err)
    return err, nil
  }
  // 设置请求头
  request.Header.Add("Content-Type", "application/json;charset=utf-8")
  if len(token) > 0 {
    request.Header.Add("token", token)
  }
  // 设置5秒的超时时间
  client.Timeout = 5 * time.Second

  // 发起请求
  resp, err := client.Do(request)
  if err != nil {
    return err, nil
  }

  defer resp.Body.Close()
  body, err := ioutil.ReadAll(resp.Body)
  if err != nil {
    return err, nil
  }

  res := map[string]interface{}{}
  err = json.Unmarshal(body, &res)
  if err != nil {
    return err, nil
  }
  return nil, res
}

func testThirdLib() {
  params := map[string]interface{}{
    "query": "test",
  }
  err, result := ThirdRequest("http://www.baidu.com", "GET", "", params)
  fmt.Println(err, result)
  client := &http.Client{}
  hook.HookMethod(client, "Do", do2, nil)
  err, result = ThirdRequest("http://www.baidu.com", "GET", "", params)
  fmt.Println(err, result)

}

测试结果：

golang 实现程序运行时函数动态替换，举例说明动态注入和替换本地方法、系统库方法、第三方库方法，附完整源码实现_动态替换_04

完整源码：

package main

import (
  "bytes"
  "crypto/tls"
  "encoding/json"
  "fmt"
  "github.com/YouAreOnlyOne/goutils/hook"
  "io/ioutil"
  "net/http"
  "time"
)

func originFunc() {
  str := "this is origin func"
  fmt.Println(str)
}

func replaceFunc() {
  str := "this is replace func"
  fmt.Println(str)
}

func do1(req *http.Request) (*http.Response, error) {
  return nil, fmt.Errorf("replace request success")
}

func do2(*http.Client, *http.Request) (*http.Response, error) {
  return nil, fmt.Errorf("replace request success")
}

func nowTime() time.Time {
  return time.Date(2022, 1, 1, 0, 0, 0, 0, &time.Location{})
}

func Local3(t time.Time) time.Time {
  return time.Date(2022, 1, 1, 0, 0, 0, 0, &time.Location{})
}

func Local4() time.Time {
  return time.Date(2022, 1, 1, 0, 0, 0, 0, &time.Location{})
}

func testThirdLib() {
  params := map[string]interface{}{
    "query": "test",
  }
  err, result := ThirdRequest("http://www.baidu.com", "GET", "", params)
  fmt.Println(err, result)
  client := &http.Client{}
  hook.HookMethod(client, "Do", do2, nil)
  err, result = ThirdRequest("http://www.baidu.com", "GET", "", params)
  fmt.Println(err, result)

}

func ThirdRequest(url, method, token string, data map[string]interface{}) (error, map[string]interface{}) {
  //Method: "OPTIONS" | "GET" | "HEAD" | "POST" | "PUT" | "DELETE" | "TRACE" | "CONNECT"
  client := &http.Client{
    Transport: &http.Transport{TLSClientConfig: &tls.Config{InsecureSkipVerify: true}},
  }
  jsonBytes, err := json.Marshal(data)
  if err != nil {
    fmt.Println("11", err)
    return err, nil
  }
  request, err := http.NewRequest(method, url, bytes.NewReader(jsonBytes))
  if err != nil {
    fmt.Println("22", err)
    return err, nil
  }
  // 设置请求头
  request.Header.Add("Content-Type", "application/json;charset=utf-8")
  if len(token) > 0 {
    request.Header.Add("token", token)
  }
  // 设置5秒的超时时间
  client.Timeout = 5 * time.Second

  // 发起请求
  resp, err := client.Do(request)
  if err != nil {
    return err, nil
  }

  defer resp.Body.Close()
  body, err := ioutil.ReadAll(resp.Body)
  if err != nil {
    return err, nil
  }

  res := map[string]interface{}{}
  err = json.Unmarshal(body, &res)
  if err != nil {
    return err, nil
  }
  return nil, res
}

func testLocalMethod() {
  originFunc()
  hook.Hook(originFunc, replaceFunc, nil)
  originFunc()
  fmt.Println("====================")
}

func testSystemLib() {

  fmt.Println(time.Now())
  hook.Hook(time.Now, nowTime, nil)
  fmt.Println(time.Now())
  fmt.Println("====================")

  t1 := time.Time{}
  fmt.Println(t1.Local())
  hook.HookMethod(t1, "Local", Local3, nil)
  fmt.Println(t1.Local())
  hook.Hook(t1.Local, Local4, nil)
  fmt.Println(t1.Local())
  fmt.Println("====================")
}

func main() {
  testLocalMethod()
  testSystemLib()
  testThirdLib()

}