Node.js process.setUncaughtExceptionCaptureCallback()用法及代碼示例

process.setUncaughtExceptionCaptureCallback()方法是處理模塊的內置應用程序編程接口，用於設置回調函數，當發生未捕獲的異常時將調用該回調函數。回調函數將接收異常值作為其第一個參數。

用法:

process.setUncaughtExceptionCaptureCallback( callback_function )

參數：該方法接受上麵提到和下麵描述的單個參數。

callback_function:這是一個必需的參數。它可以是函數或空值。如果將其設置為null，則該函數將取消設置回調函數。

返回：它不返回任何值。

以下示例說明了Node.js中process.setUncaughtExceptionCaptureCallback()方法的使用：

範例1：

// Allocating process module 
const process = require('process'); 
  
// Function to be set as call back 
function to_be_called(ex){ 
    console.log(ex); 
} 
  
// Checking whether any callback has been set before calling  
// process.setUncaughtExceptionCaptureCallback(to_be_called); 
console.log(process.hasUncaughtExceptionCaptureCallback()); 
  
// Setting callback  
process.setUncaughtExceptionCaptureCallback(to_be_called); 
  
// Checking whether any callback has been set before calling  
// process.setUncaughtExceptionCaptureCallback(to_be_called); 
console.log(process.hasUncaughtExceptionCaptureCallback());

輸出：

false
true

範例2：

// Allocating process module 
const process = require('process'); 
  
// Function to be set as call back 
function to_be_called(ex) { 
    console.log(ex); 
} 
  
// Checking whether any callback has been set before calling  
// process.setUncaughtExceptionCaptureCallback(to_be_called); 
// Printing whether a callack is set or not 
if (process.hasUncaughtExceptionCaptureCallback()) { 
    console.log("a callback has been set using " + 
        "process.setUncaughtExceptionCaptureCallback() method"); 
} else { 
    console.log("no callback has been set using " + 
        "process.setUncaughtExceptionCaptureCallback() method"); 
} 
  
  
// Setting callback  
if (process.setUncaughtExceptionCaptureCallback) { 
    process.setUncaughtExceptionCaptureCallback(to_be_called); 
} else { 
    console.log("process.setUncaughtExceptionCaptureCallback() "
        + "method is not defied!"); 
} 
  
// Checking whether any callback has been set before calling  
// process.setUncaughtExceptionCaptureCallback(to_be_called); 
if (process.hasUncaughtExceptionCaptureCallback()) { 
    console.log("a callback has been set using " + 
        "process.setUncaughtExceptionCaptureCallback() method"); 
} else { 
    console.log("no callback has been set using " + 
        "process.setUncaughtExceptionCaptureCallback() method"); 
} 
  
  
// Resetting callback  
if (process.setUncaughtExceptionCaptureCallback) { 
    process.setUncaughtExceptionCaptureCallback(null); 
} else { 
    console.log("process.setUncaughtExceptionCaptureCallback() "
        + " method is not defied!"); 
} 
  
// Checking whether any callback has been set after resetting 
if (process.hasUncaughtExceptionCaptureCallback()) { 
    console.log("a callback has been set using " + 
        "process.setUncaughtExceptionCaptureCallback() method"); 
} else { 
    console.log("no callback has been set using " + 
        "process.setUncaughtExceptionCaptureCallback() method"); 
}

輸出：

no callback has been set using process.setUncaughtExceptionCaptureCallback() method
a callback has been set using process.setUncaughtExceptionCaptureCallback() method
no callback has been set using process.setUncaughtExceptionCaptureCallback() method

注意：僅在POSIX平台上，以上程序將使用node filename.js命令編譯並運行。

參考： https://nodejs.org/api/process.html#process_process_setuncaughtexceptioncapturecallback_fn

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注：本文由純淨天空篩選整理自gekcho大神的英文原創作品 Node.js | process.setUncaughtExceptionCaptureCallback() Method。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。