add missing code example of chapter 15.3 (#678)

example code from: https://sites.google.com/site/thewaytogo2012/Downhome/Topic3/code_examples.zip
2025-08-12 01:21:38 +08:00 · 2019-07-16 10:57:06 +08:00
parent 9865ae64a9
commit 00e4346204
4 changed files with 137 additions and 0 deletions
--- a/eBook/examples/chapter_15/http_fetch.go
+++ b/eBook/examples/chapter_15/http_fetch.go
@@ -0,0 +1,23 @@
+// httpfetch.go
+package main
+
+import (
+	"fmt"
+	"net/http"
+	"io/ioutil"
+	"log"
+)
+
+func main() {
+	res, err := http.Get("http://www.google.com")
+	CheckError(err)
+	data, err := ioutil.ReadAll(res.Body)
+	CheckError(err)
+	fmt.Printf("Got: %q", string(data))
+}
+
+func CheckError(err error) {
+	if err != nil {
+		log.Fatalf("Get: %v", err)
+	}
+}
--- a/eBook/examples/chapter_15/poll_url.go
+++ b/eBook/examples/chapter_15/poll_url.go
@@ -0,0 +1,30 @@
+// poll_url.go
+package main
+
+import (
+	"fmt"
+	"net/http"
+)
+
+var urls = []string{
+	"http://www.google.com/",
+	"http://golang.org/",
+	"http://blog.golang.org/",
+}
+
+func main() {
+	// Execute an HTTP HEAD request for all url's 
+	// and returns the HTTP status string or an error string.
+	for _, url := range urls {
+		resp, err := http.Head(url)
+		if err != nil {
+			fmt.Println("Error", url, err)
+		}
+		fmt.Print(url, ": ", resp.Status)
+	}
+}
+/* Output:
+http://www.google.com/ :  302 Found
+http://golang.org/ :  200 OK
+http://blog.golang.org/ :  200 OK
+*/
--- a/eBook/examples/chapter_15/simple_webserver.go
+++ b/eBook/examples/chapter_15/simple_webserver.go
@@ -0,0 +1,42 @@
+// simple_webserver.go
+package main  
+  
+import (  
+     "net/http"  
+     "io"  
+)  
+
+const form = `<html><body><form action="#" method="post" name="bar">
+		      <input type="text" name="in"/>
+			  <input type="submit" value="Submit"/>
+			  </form></html></body>`
+
+/* handle a simple get request */  
+func SimpleServer(w http.ResponseWriter, request *http.Request) {  
+     io.WriteString(w, "<h1>hello, world</h1>")  
+}  
+  
+/* handle a form, both the GET which displays the form 
+   and the POST which processes it.*/  
+func FormServer(w http.ResponseWriter, request *http.Request) {
+     w.Header().Set("Content-Type", "text/html")  
+     switch request.Method {  
+            case "GET":  
+                 /* display the form to the user */  
+                 io.WriteString(w, form );  
+            case "POST":  
+                 /* handle the form data, note that ParseForm must 
+                    be called before we can extract form data*/  
+                 //request.ParseForm();  
+                 //io.WriteString(w, request.Form["in"][0])
+				io.WriteString(w, request.FormValue("in")) 
+     }  
+}  
+  
+func main() {  
+     http.HandleFunc("/test1", SimpleServer)  
+     http.HandleFunc("/test2", FormServer)  
+     if err := http.ListenAndServe(":8088", nil); err != nil {
+		panic(err)
+     }
+}  
--- a/eBook/examples/chapter_15/twitter_status.go
+++ b/eBook/examples/chapter_15/twitter_status.go
@@ -0,0 +1,42 @@
+// twitter_status.go
+package main
+
+import (
+	"net/http"
+	"fmt"
+	"encoding/xml"
+	"io/ioutil"
+)
+/* these structs will house the unmarshalled response. 
+   they should be hierarchically shaped like the XML 
+   but can omit irrelevant data. */
+type Status struct {
+	Text string
+}
+
+type User struct {
+	XMLName xml.Name
+	Status  Status
+}
+// var user User
+
+func main() {
+	// perform an HTTP request for the twitter status of user: Googland  
+	resp, _ := http.Get("http://twitter.com/users/Googland.xml")
+	// initialize the structure of the XML response  
+	user := User{xml.Name{"", "user"}, Status{""}}
+	// unmarshal the XML into our structures 
+	defer resp.Body.Close()
+	if body, err := ioutil.ReadAll(resp.Body); err != nil {
+			fmt.Printf("error: %s", err.Error())
+	} else {
+			fmt.Printf("%s ---", body)
+			xml.Unmarshal(body, &user)
+	}
+	fmt.Printf("name: %s ", user.XMLName)
+	fmt.Printf("status: %s", user.Status.Text)
+}
+/* Output:
+status: Robot cars invade California, on orders from Google: Google has been testing self-driving cars ... http://bit.ly/cbtpUN http://retwt.me/97p<exit code="0" msg="process exited normally"/>
+After Go1: no output: name: { user} status:
+*/