从外部检查 Java 对象层次结构 [英] Check Java Object Hierarchy Externally

问题描述

假设我有字符串Bar"，我想知道 Bar 是否是有效对象，以及Bar"是否扩展了Foo".我会使用 Java 反射还是有更好的方法，比如数据库?我该怎么做?

Say I have the string "Bar" and I want to know whether or not Bar is a valid object, and further, whether "Bar" extends "Foo". Would I be using Java reflection or is there a better way, like a database? and how would I do it?

干杯

推荐答案

如果你不知道包——只知道类名，你可以试试这个，使用 spring 框架:

In case you don't know the package - only the class name, you could try this, using spring framework:

List<Class> classes = new LinkedList<Class>();
PathMatchingResourcePatternResolver scanner = new 
    PathMatchingResourcePatternResolver();
// this should match the package and the class name. for example "*.Bar"
Resource[] resources = scanner.getResources(matchPattern); 

for (Resource resource : resources) {
    Class<?> clazz = getClassFromFileSystemResource(resource);
    classes.add(clazz);
}


public static Class getClassFromFileSystemResource(Resource resource) throws Exception {
    String resourceUri = resource.getURI().toString();
    // finding the fully qualified name of the class
    String classpathToResource = resourceUri.substring(resourceUri
            .indexOf("com"), resourceUri.indexOf(".class"));
    classpathToResource = classpathToResource.replace("/", ".");
    return Class.forName(classpathToResource);
}

上述两个方法为您提供了名为Bar"的类列表(它们可能不止一个！).

The two above methods give you the list of classes that are named "Bar" (they may be more than one!).

那就更简单了

expectedSuperclass.isAssignableFrom(yourClass);

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