echo-server.go 2.8 KB

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  1. //go:build ignore
  2. // +build ignore
  3. package main
  4. import (
  5. "flag"
  6. "html/template"
  7. "log"
  8. "net/http"
  9. "github.com/gorilla/websocket"
  10. )
  11. var addr = flag.String("addr", "127.0.0.1:10808", "http service address")
  12. var upgrader = websocket.Upgrader{} // use default options
  13. func echo(w http.ResponseWriter, r *http.Request) {
  14. c, err := upgrader.Upgrade(w, r, nil)
  15. if err != nil {
  16. log.Print("upgrade:", err)
  17. return
  18. }
  19. defer c.Close()
  20. for {
  21. mt, message, err := c.ReadMessage()
  22. if err != nil {
  23. log.Println("read:", err)
  24. break
  25. }
  26. log.Printf("recv: %s", message)
  27. err = c.WriteMessage(mt, message)
  28. if err != nil {
  29. log.Println("write:", err)
  30. break
  31. }
  32. }
  33. }
  34. func home(w http.ResponseWriter, r *http.Request) {
  35. homeTemplate.Execute(w, "ws://"+r.Host+"/echo")
  36. }
  37. func main() {
  38. flag.Parse()
  39. log.SetFlags(0)
  40. http.HandleFunc("/echo", echo)
  41. http.HandleFunc("/", home)
  42. log.Fatal(http.ListenAndServe(*addr, nil))
  43. }
  44. var homeTemplate = template.Must(template.New("").Parse(`
  45. <!DOCTYPE html>
  46. <html>
  47. <head>
  48. <meta charset="utf-8">
  49. <script>
  50. window.addEventListener("load", function(evt) {
  51. var output = document.getElementById("output");
  52. var input = document.getElementById("input");
  53. var ws;
  54. var print = function(message) {
  55. var d = document.createElement("div");
  56. d.textContent = message;
  57. output.appendChild(d);
  58. output.scroll(0, output.scrollHeight);
  59. };
  60. document.getElementById("open").onclick = function(evt) {
  61. if (ws) {
  62. return false;
  63. }
  64. ws = new WebSocket("{{.}}");
  65. ws.onopen = function(evt) {
  66. print("OPEN");
  67. }
  68. ws.onclose = function(evt) {
  69. print("CLOSE");
  70. ws = null;
  71. }
  72. ws.onmessage = function(evt) {
  73. print("RESPONSE: " + evt.data);
  74. }
  75. ws.onerror = function(evt) {
  76. print("ERROR: " + evt.data);
  77. }
  78. return false;
  79. };
  80. document.getElementById("send").onclick = function(evt) {
  81. if (!ws) {
  82. return false;
  83. }
  84. print("SEND: " + input.value);
  85. ws.send(input.value);
  86. return false;
  87. };
  88. document.getElementById("close").onclick = function(evt) {
  89. if (!ws) {
  90. return false;
  91. }
  92. ws.close();
  93. return false;
  94. };
  95. });
  96. </script>
  97. </head>
  98. <body>
  99. <table>
  100. <tr><td valign="top" width="50%">
  101. <p>Click "Open" to create a connection to the server,
  102. "Send" to send a message to the server and "Close" to close the connection.
  103. You can change the message and send multiple times.
  104. <p>
  105. <form>
  106. <button id="open">Open</button>
  107. <button id="close">Close</button>
  108. <p><input id="input" type="text" value="Hello world!">
  109. <button id="send">Send</button>
  110. </form>
  111. </td><td valign="top" width="50%">
  112. <div id="output" style="max-height: 70vh;overflow-y: scroll;"></div>
  113. </td></tr></table>
  114. </body>
  115. </html>
  116. `))