代码示例：

package com.thb;

import java.io.IOException;
import java.io.InputStream;

public class Demo4 {

    public static void main(String[] args) throws IOException {
        String resource = "com/thb/test.properties";
        // 获得ClassLoader
        ClassLoader classLoader = new Demo4().getClass().getClassLoader();
        System.out.println("ClassLoader: " + classLoader);
        // 通过ClassLoader加载文件，转换为输入流
        InputStream inputStream = classLoader.getResourceAsStream(resource);
        if (inputStream != null) {
            // 判断输入流的可读字节数
            System.out.println("available bytes: " + inputStream.available());
        } else {
            System.out.println("inputStream is null");
        }
    }
}

运行输出：