Common error analysis and solutions for Go standard library

The Go language standard library provides developers with rich and efficient tools, covering all aspects from network programming to file operations. However, although the standard library is good, it can backfire if it is used improperly. As the saying goes, "If you want to do a good job, you must first sharpen your tools." This article will thoroughly analyze common errors in the use of the Go standard library, help developers avoid these pitfalls and write more robust code.

1. The wrong one was used

Error example:

package main

import (
    "fmt"
    "time"
)

func main() {
    // Error: Pass an integer directly    (1000) // It's actually 1000 nanoseconds, not 1 second    ("Hibernation Completed")
}

Problem analysis:Many developers are prone to making this mistake of "reading text to make sense", thinking that passing 1,000 is 1 second. Little do you knowIn nanoseconds, writing like this actually only sleeps one thousandth of a millisecond, which can be said to be "a slight difference, a thousand miles of mistakes".

Solution:Use clear time units to make the code intention clear at a glance.

func main() {
    (1 * ) // Use clear time units    ("FunTester hibernation completed")
}

2. Memory leak caused

Error example:

package main

import (
    "fmt"
    "time"
)

func main() {
    for i := 0; i < 1000; i++ {
        <-(1 * ) // Create a new timer every loop        ("FunTester Timed Task")
    }
}

Problem analysis: Each call creates a new timer, which is used in a loop like "monkey breaks corn", constantly creating new resources without releasing them, which may eventually lead to a "rise" memory level.

Solution:useAnd actively manage resources to achieve "start and end".

func main() {
    timer := (1 * )
    defer () // Ensure resource release    
    for i := 0; i < 1000; i++ {
        <-
        ("FunTester Timed Task")
        (1 * ) // Multiplexing timer    }
}

3. Common pitfalls in JSON processing

(1) Unexpected behavior caused by type nesting

Error example:

type Event struct {
    Name string
     // Embedding will override the default JSON serialization}

Problem analysis:This way of writing is like "occupying the magpie's nest", embeddedWill take over the JSON serialization behavior of the entire structure, resulting in the output not matching the expected one.

Solution:Clearly specify the field name and serialization method to achieve "legitimate meaning".

type Event struct {
    Name string    `json:"name"`
    Time  `json:"time"`
}

(2) The pit of time comparison

Error example:

t1 := ()
t2 := (1 * )
(t1 == t2) // Error comparison method

Problem analysis:Directly comparing time will compare the wall clock and the monotonic clock at the same time, just like "grab your eyebrows and beards", often not getting the desired result.

Solution:useEqualMethods focus on comparing the wall clocks.

((t2)) // Correct comparison method

(3) Numerical type assertion problem

Error example:

var m map[string]any
([]byte(`{"key":123}`), &m)
(m["key"].(int)) // Type assertion failed

Problem analysis:The default resolution of numeric values ​​in JSON isfloat64, directly asserted asintJust like "cutting your feet to fit your shoes", it will inevitably lead to runtime errors.

Solution:Convert tofloat64Change the target type again, or use a more elegant type assertion method.

if val, ok := m["key"].(float64); ok {
    (int(val)) // Safe conversion}

4. Things to note in SQL operations

(1) Forgot to verify the database connection

Error example:

db, _ := ("mysql", "user:pass@/db")
// Connection test is missing

Problem analysis: It's just "talking on paper" and it won't really establish a connection. It's too late to find the problem when you actually query it.

Solution:usePingMethods verify the connection and achieve "prevent problems before they happen".

if err := (); err != nil {
    ("FunTester database connection failed:", err)
    return
}

(2) Forgot to release the query result

Error example:

rows, _ := ("SELECT * FROM table")
// forget()

Problem analysis:Not closing the query results is like "opening the gate and not releasing water", which will cause the database connection to be unable to be released, and may eventually "break the dam and dam".

Solution:usedeferEnsure the release of resources and achieve "borrow and return".

rows, err := ("SELECT * FROM table")
if err != nil {
    return
}
defer ()

5. Common errors in HTTP processing

(1) Forgot to return after response

Error example:

func handler(w , r *) {
    (w, "mistake", )
    // Forgot to return    (w, "Supplementary content")
}

Problem analysis:This error is like "adding the most" and continues to process it after returning the error, which may lead to confusion in response.

Solution:Return immediately after the error is processed, and the "if it is broken, it is broken".

func handler(w , r *) {
    (w, "FunTester Error", )
    return
}

(2) Use the default HTTP client

Error example:

("") // No timeout setting

Problem analysis:The default client has no timeout setting, like "Horse Without Rein", which may cause the request to hang.

Solution:Customize client parameters and be "prepared for the future".

client := &{
    Timeout: 10 * ,
}
("")

6. Summary

Although the Go standard library is powerful, "details determine success or failure". Through the analysis of this article, we can see that from time processing to resource management, developers need to "be aware of the situation". Only by following the solution can we write efficient and reliable code, making our Go program "as stable as Mount Tai".

This is the article about common error analysis and solutions to Go standard library. For more common error content related to Go standard library, please search for my previous articles or continue browsing the related articles below. I hope you will support me in the future!