Java Runtime getRuntime()用法及代碼示例

在 Java 中，Runtime 類允許您與應用程序的運行時環境進行交互。該類提供的基本方法之一是getRuntime()。此方法返回與當前 Java 應用程序關聯的運行時對象。通過此對象，您可以訪問有關運行時環境的信息、執行係統命令、管理進程等。

Java 運行時 getRuntime() 方法

Runtime.getRuntime() 方法是一個靜態方法，用於檢索當前 Java 應用程序的運行時對象。該對象允許您訪問應用程序運行時環境的各個方麵，例如執行係統命令、管理進程和查詢內存使用情況。

用法:

public static Runtime getRuntime()

Java 運行時示例getRuntime()

現在，讓我們探討一些使用運行時對象的實際示例：

Java


// Java Program to implement 
// Java Runtime getRuntime() 
import java.io.IOException; 
  
// Driver Class 
public class GfgRuntimeExample { 
    // main function 
    public static void main(String[] args) 
    { 
        // Getting the runtime object 
        Runtime runtime = Runtime.getRuntime(); 
  
        // Example 1: Executing System Command 
        try { 
            // Executing a system command to open a web page 
            // (https://www.gfg.com) 
            Process process = runtime.exec( 
                "xdg-open https://www.gfg.com"); 
  
            // Waiting for the process to complete and 
            // retrieving the exit code 
            int exitCode = process.waitFor(); 
  
            // Printing the exit code 
            System.out.println( 
                "Example 1: Executing System Command"); 
            System.out.println("Exit Code: " + exitCode); 
        } 
        catch (IOException | InterruptedException e) { 
            e.printStackTrace(); 
        } 
  
        // Example 2: Retrieving Available Processors 
        int processors = runtime.availableProcessors(); 
        System.out.println( 
            "\nExample 2: Retrieving Available Processors"); 
        System.out.println("Available Processors: "
                           + processors); 
  
        // Example 3: Querying Total and Free Memory 
        long totalMemory = runtime.totalMemory(); 
        long freeMemory = runtime.freeMemory(); 
  
        // Converting memory values to megabytes (MB) 
        long totalMemoryMB = totalMemory / (1024 * 1024); 
        long freeMemoryMB = freeMemory / (1024 * 1024); 
  
        System.out.println( 
            "\nExample 3: Querying Total and Free Memory"); 
        System.out.println("Total Memory (MB): "
                           + totalMemoryMB); 
        System.out.println("Free Memory (MB): "
                           + freeMemoryMB); 
    } 
}

輸出：

Example 1: Executing System Command
Exit Code: 0
Example 2: Retrieving Available Processors
Available Processors: 4
Example 3: Querying Total and Free Memory
Total Memory (MB): 123
Free Memory (MB): 78

結論

Runtime.getRuntime() 方法提供對 Java 應用程序的運行時環境的訪問。您可以使用它來執行係統命令、管理進程以及檢索有關係統資源(例如可用處理器和內存使用情況)的信息。

相關用法

注：本文由純淨天空篩選整理自bishaldubey大神的英文原創作品 Java Runtime getRuntime() Method with Examples。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。