使用线程上下文类加载器加载class

最新推荐文章于 2021-10-16 13:25:47 发布

原创最新推荐文章于 2021-10-16 13:25:47 发布 · 734 阅读

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文章标签：

#classloader #class #object #application #string #null

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本文介绍了一个实用的Java工具类，该工具类提供了一种从Web应用程序类加载器中加载指定全限定类名的方法。通过这个工具类，可以简化类加载的过程，并提供了详细的实现代码示例。

范例：

public class RequestUtils {

/**
     * <p>Return the <code>Class</code> object for the specified fully
     * qualified class name, from this web application's class loader.</p>
     *
     * @param className Fully qualified class name to be loaded
     * @return Class object
     * @throws ClassNotFoundException if the class cannot be found
     */
    public static Class applicationClass(String className)
        throws ClassNotFoundException {
        return applicationClass(className, null);
    }

    /**
     * <p>Return the <code>Class</code> object for the specified fully
     * qualified class name, from this web application's class loader.</p>
     *
     * @param className   Fully qualified class name to be loaded
     * @param classLoader The desired classloader to use
     * @return Class object
     * @throws ClassNotFoundException if the class cannot be found
     */
    public static Class applicationClass(String className,
        ClassLoader classLoader)
        throws ClassNotFoundException {
        if (classLoader == null) {
            // Look up the class loader to be used
            classLoader = Thread.currentThread().getContextClassLoader();

            if (classLoader == null) {
                classLoader = RequestUtils.class.getClassLoader();
            }
        }

System.out.println(classLoader.loadClass(className).getName());

        // Attempt to load the specified class
        return (classLoader.loadClass(className));
    }

    public static void main(String[] args) {

    try {
   RequestUtils.applicationClass("cn.ehome.blog.util.PropertyMessageResources");
  } catch (ClassNotFoundException e) {
   e.printStackTrace();
  }
    }
}

输出结果：

cn.ehome.blog.util.PropertyMessageResources