Java中的类 getResourceAsStream() 方法和示例

Java.lang.Class类的getResourceAsStream()方法用于获取该类指定资源的资源。该方法以 InputStream 对象的形式返回该类的指定资源。

句法：

public InputStream getResourceAsStream(String resourceName)

参数：此方法接受参数resourceName ，即要获取的资源。

返回值：该方法以InputStream对象的形式返回该类的指定资源。

异常此方法抛出：

• 如果名称为空，则出现NullPointerException

下面的程序演示了 getResourceAsStream() 方法。

示例 1：

// Java program to demonstrate
// getResourceAsStream() method
  
import java.util.*;
  
public class Test {
  
    public Object obj;
  
    public static void main(String[] args)
        throws ClassNotFoundException
    {
  
        // returns the Class object for this class
        Class myClass = Class.forName("Test");
  
        System.out.println("Class represented by myClass: "
                           + myClass.toString());
  
        String resourceName = "obj";
  
        // Get the resource of myClass
        // using getResourceAsStream() method
        System.out.println(
            resourceName + " resource of myClass: "
            + myClass.getResourceAsStream(resourceName));
    }
}

输出：

Class represented by myClass: class Test
obj resource of myClass: null

示例 2：

// Java program to demonstrate
// getResourceAsStream() method
  
import java.util.*;
  
class Main {
  
    private Object obj;
  
    public static void main(String[] args)
        throws ClassNotFoundException, NoSuchFieldException
    {
  
        // returns the Class object for this class
        Class myClass = Class.forName("Main");
  
        System.out.println("Class represented by myClass: "
                           + myClass.toString());
  
        String resourceName = "obj";
  
        try {
            // Get the resource of myClass
            // using getResourceAsStream() method
            System.out.println(
                resourceName + " resource of myClass: "
                + myClass.getResourceAsStream(resourceName));
        }
        catch (Exception e) {
            System.out.println(e);
        }
    }
}

输出：

Class represented by myClass: class Main
obj resource of myClass: null

参考： https://docs.oracle.com/javase/9/docs/api/ Java/lang/Class.html#getResourceAsStream-java.lang.String-