test&doc: add example and update doc for netutil package

netutil/net_example_test.go

@@ -0,0 +1,91 @@
+package netutil
+
+import (
+	"fmt"
+	"net"
+	"net/http"
+)
+
+func ExampleGetInternalIp() {
+	internalIp := GetInternalIp()
+
+	result := IsInternalIP(net.ParseIP(internalIp))
+	fmt.Println(result)
+
+	// Output:
+	// true
+}
+
+func ExampleGetPublicIpInfo() {
+	ipInfo, err := GetPublicIpInfo()
+	if err != nil {
+		return
+	}
+
+	result := IsPublicIP(net.ParseIP(ipInfo.Ip))
+	fmt.Println(result)
+
+	// Output:
+	// true
+}
+
+func ExampleGetRequestPublicIp() {
+	ip := "36.112.24.10"
+
+	request := http.Request{
+		Method: "GET",
+		Header: http.Header{
+			"X-Forwarded-For": {ip},
+		},
+	}
+	publicIp := GetRequestPublicIp(&request)
+
+	fmt.Println(publicIp)
+
+	// Output:
+	// 36.112.24.10
+}
+
+func ExampleIsInternalIP() {
+	ip1 := IsInternalIP(net.ParseIP("127.0.0.1"))
+	ip2 := IsInternalIP(net.ParseIP("192.168.0.1"))
+	ip3 := IsInternalIP(net.ParseIP("36.112.24.10"))
+
+	fmt.Println(ip1)
+	fmt.Println(ip2)
+	fmt.Println(ip3)
+
+	// Output:
+	// true
+	// true
+	// false
+}
+
+func ExampleIsPublicIP() {
+	ip1 := IsPublicIP(net.ParseIP("127.0.0.1"))
+	ip2 := IsPublicIP(net.ParseIP("192.168.0.1"))
+	ip3 := IsPublicIP(net.ParseIP("36.112.24.10"))
+
+	fmt.Println(ip1)
+	fmt.Println(ip2)
+	fmt.Println(ip3)
+
+	// Output:
+	// false
+	// false
+	// true
+}
+
+func ExampleEncodeUrl() {
+	urlAddr := "http://www.lancet.com?a=1&b=[2]"
+
+	encodedUrl, err := EncodeUrl(urlAddr)
+	if err != nil {
+		return
+	}
+
+	fmt.Println(encodedUrl)
+
+	// Output:
+	// http://www.lancet.com?a=1&b=%5B2%5D
+}