Golang catches errors globally

In Go language, error handling is very important. Especially in some large applications, errors may be passed through multiple levels of functions and ultimately affect the overall performance of the application. Therefore, error handling and capturing have become particularly critical. This article will introduce a method of capturing global errors in the Go language.

1. Error principle

In the process of writing Go applications, we usually use the defer statement to ensure that resources are released after the function is executed. When using defer, we can also use the recover function to capture errors generated during the function call. The function of the recover statement is to allow the program to recover from the recent panic and return the error information passed in the panic. Therefore, we can use the recover statement in the function to capture the error and handle it accordingly.

2. Global Error Handling

Go language provides a global error handling mechanism, which captures all unhandled errors while the program is running. Through this mechanism, the program can perform some specific processing when an error occurs, such as logging, sending error emails, etc. The specific implementation method is as follows:

1. Custom error handling function

We can declare a global error handling function to handle unhandled errors in the entire program. The function must meet the following two conditions:

(1) The function name is panicHandler, and the parameter type is interface{}.

(2) The function must be an ordinary function, not a method or closure.

The code is as follows:

func panicHandler(err interface{}) {
    // 处理错误
}

2. Use defer and recover statements

Next, we need to use defer and recover statements to capture errors and call global Error handling function. The specific implementation code is as follows:

func main() {
    defer func() {
        if err := recover(); err != nil {
            panicHandler(err)
        }
    }()

    // 代码逻辑
}

When a panic error occurs during program running, it will immediately jump to the recover statement in the defer statement and pass the error to the panicHandler function for processing.

3. Error handling example

Below we use an example to demonstrate how to use the global error handling mechanism. Suppose we have a function to obtain user information from the database. The code is as follows:

func getUserInfo(id int64) (*User, error) {
    // 数据库查询逻辑
}

Now, we hope to capture all errors generated in this function and record them when the program is running. to the log. To this end, we can add a global error handling function to the program, the code is as follows:

func panicHandler(err interface{}) {
    // 记录错误日志
    log.Printf("[PANIC] %+v
", err)
}

func main() {
    defer func() {
        if err := recover(); err != nil {
            panicHandler(err)
        }
    }()

    // 查询用户信息
    user, err := getUserInfo(123)
    if err != nil {
        panic(err)
    }

    // 处理用户信息
    // ...
}

When the getUserInfo function generates a panic error, it will immediately jump to the recover statement in the defer statement and pass the error to panicHandler function for processing. Through this function, we can record errors to the program's log and find problems in time.

4. Summary

The error handling mechanism of Go language is a very important function and a skill that Go language programmers need to master proficiently. The global error handling mechanism can help us catch all unhandled errors during program running and handle them accordingly. Through the above methods, we can manage errors in the program more effectively and improve the stability and reliability of the application.

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