Improve error handling in web server

lesson6/client_post.go

@@ -22,6 +22,7 @@ func main() {
 	if err != nil {
 		log.Fatal(err)
 	}
+	defer httpResp.Body.Close()
 	log.Printf("Status: %s", httpResp.Status)
 	io.Copy(os.Stdout, httpResp.Body)
 }

lesson6/proxy.go

@@ -15,4 +15,7 @@ func main() {
 	http.Handle("/", httputil.NewSingleHostReverseProxy(&target))
 	log.Printf("Proxy started")
 	http.ListenAndServe("localhost:8081", nil)
+	if err := http.ListenAndServe("localhost:8081", nil); err != nil {
+		log.Fatal(err)
+	}
 }

lesson6/web_server_body.go

@@ -3,14 +3,19 @@ package main
 import (
 	"fmt"
 	"io"
+	"log"
 	"net/http"
 	"os"
 )
 
 func main() {
 	http.HandleFunc("/hello", func(w http.ResponseWriter, req *http.Request) {
+		defer req.Body.Close()
 		fmt.Println("The body is:")
 		io.Copy(os.Stdout, req.Body)
 	})
 	http.ListenAndServe("localhost:8080", nil)
+	if err := http.ListenAndServe("localhost:8080", nil); err != nil {
+		log.Fatal(err)
+	}
 }

lesson6/web_server_json.go

@@ -3,18 +3,24 @@ package main
 import (
 	"encoding/json"
 	"fmt"
+	"log"
 	"net/http"
 )
 
 func main() {
 	http.HandleFunc("/hello", func(w http.ResponseWriter, req *http.Request) {
+		defer req.Body.Close()
 		var params map[string]interface{}
 		err := json.NewDecoder(req.Body).Decode(&params)
 		if err != nil {
 			fmt.Printf("Error parsing body: %s", err)
+			http.Error(w, fmt.Sprintf("Error parsing body: %s", err), http.StatusBadRequest)
 			return
 		}
 		fmt.Printf("The body is: %#v", params)
 	})
 	http.ListenAndServe("localhost:8080", nil)
+	if err := http.ListenAndServe("localhost:8080", nil); err != nil {
+		log.Fatal(err)
+	}
 }

lesson6/web_server_json_2.go

@@ -3,6 +3,7 @@ package main
 import (
 	"encoding/json"
 	"fmt"
+	"log"
 	"net/http"
 )
 
@@ -14,6 +15,7 @@ type Params struct {
 func main() {
 	http.HandleFunc("/hello", func(w http.ResponseWriter, req *http.Request) {
 		var params Params
+		defer req.Body.Close()
 		err := json.NewDecoder(req.Body).Decode(&params)
 		if err != nil {
 			http.Error(w, fmt.Sprintf("Error parsing body: %s", err), http.StatusBadRequest)
@@ -22,4 +24,7 @@ func main() {
 		fmt.Fprintf(w, "Hello %s", params.Hello)
 	})
 	http.ListenAndServe("localhost:8080", nil)
+	if err := http.ListenAndServe("localhost:8080", nil); err != nil {
+		log.Fatal(err)
+	}
 }