Go语言中的Panic和Recover,从原理到实践

package main
import "fmt"
func main() {
	fmt.Println("Start")
	panic("Something went wrong!")
	fmt.Println("End") // 不会执行
}

package main
import "fmt"
func level3() {
	panic("Panic at level 3")
}
func level2() {
	level3()
}
func level1() {
	level2()
}
func main() {
	fmt.Println("Start")
	level1()
	fmt.Println("End") // 不会执行
}

package main
import "fmt"
func mayPanic() {
	panic("A problem occurred")
}
func main() {
	defer func() {
		if r := recover(); r != nil {
			fmt.Println("Recovered from:", r)
		}
	}()
	mayPanic()
	fmt.Println("After mayPanic()") // 不会执行
}

package main
import "fmt"
func safeDivide(a, b int) (result int, err error) {
	defer func() {
		if r := recover(); r != nil {
			err = fmt.Errorf("division error: %v", r)
		}
	}()
	if b == 0 {
		panic("division by zero")
	}
	return a / b, nil
}
func main() {
	result, err := safeDivide(10, 0)
	if err != nil {
		fmt.Println("Error:", err)
	} else {
		fmt.Println("Result:", result)
	}
	result, err = safeDivide(10, 2)
	if err != nil {
		fmt.Println("Error:", err)
	} else {
		fmt.Println("Result:", result)
	}
}

package main
import (
	"fmt"
	"net/http"
)
func safeHandler(fn func(http.ResponseWriter, *http.Request)) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		defer func() {
			if err := recover(); err != nil {
				http.Error(w, "Internal Server Error", 500)
				fmt.Println("Recovered from panic:", err)
			}
		}()
		fn(w, r)
	}
}
func riskyHandler(w http.ResponseWriter, r *http.Request) {
	panic("Something went wrong!")
}
func main() {
	http.HandleFunc("/", safeHandler(riskyHandler))
	http.ListenAndServe(":8080", nil)
}

package main
import "fmt"
type Resource struct {
	name string
}
func (r *Resource) Close() {
	fmt.Println("Closing resource:", r.name)
}
func processResource() (err error) {
	resource := &Resource{name: "test"}
	defer resource.Close()
	defer func() {
		if r := recover(); r != nil {
			err = fmt.Errorf("process failed: %v", r)
		}
	}()
	// 模拟处理
	panic("processing error")
}
func main() {
	err := processResource()
	if err != nil {
		fmt.Println("Error:", err)
	}
}