我需要读取 Java 包中包含的类。这些类在类路径中。我需要直接从 Java 程序执行此任务。你知道一个简单的方法吗?
List<Class> classes = readClassesFrom("my.package")
最佳答案
如果您有 Spring在你的类路径中,那么以下将做到这一点。
查找包中所有使用 XmlRootElement 注解的类:
private List<Class> findMyTypes(String basePackage) throws IOException, ClassNotFoundException
{
ResourcePatternResolver resourcePatternResolver = new PathMatchingResourcePatternResolver();
MetadataReaderFactory metadataReaderFactory = new CachingMetadataReaderFactory(resourcePatternResolver);
List<Class> candidates = new ArrayList<Class>();
String packageSearchPath = ResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX +
resolveBasePackage(basePackage) + "/" + "**/*.class";
Resource[] resources = resourcePatternResolver.getResources(packageSearchPath);
for (Resource resource : resources) {
if (resource.isReadable()) {
MetadataReader metadataReader = metadataReaderFactory.getMetadataReader(resource);
if (isCandidate(metadataReader)) {
candidates.add(Class.forName(metadataReader.getClassMetadata().getClassName()));
}
}
}
return candidates;
}
private String resolveBasePackage(String basePackage) {
return ClassUtils.convertClassNameToResourcePath(SystemPropertyUtils.resolvePlaceholders(basePackage));
}
private boolean isCandidate(MetadataReader metadataReader) throws ClassNotFoundException
{
try {
Class c = Class.forName(metadataReader.getClassMetadata().getClassName());
if (c.getAnnotation(XmlRootElement.class) != null) {
return true;
}
}
catch(Throwable e){
}
return false;
}
关于java - 如何从类路径中的 Java 包中读取所有类?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/1456930/