我假设您已经知道如何创建包(否则,请检查此)。
经过对Reflections API的调试和探索之后,我意识到问题是Reflections根本无法读取OSGi URL(bundleresource:// …),从而导致异常:
org.reflections.ReflectionsException: Could not create Vfs.Dir from url,
no matching UrlType was found [bundleresource://1009.fwk651584550/]
和这个建议:
either use fromURL(final URL url, final List<UrlType> urlTypes)
or use the static setDefaultURLTypes(final List<UrlType> urlTypes)
or addDefaultURLTypes(UrlType urlType) with your specialized UrlType.
因此,我相信为OSGi实现UrlType(例如class BundleUrlType implements UrlType {...}
)并像这样注册它:
Vfs.addDefaultURLTypes(new BundleUrlType());
应该从捆绑包内部使Reflections API可用。描述思考的依赖应该被添加到Eclipse插件项目在这里 。
这是添加所需罐子后的示例MANIFEST.MF的样子:
Manifest-Version: 1.0
Bundle-ManifestVersion: 2
Bundle-Name: ReflectivePlugin
Bundle-SymbolicName: ReflectivePlugin
Bundle-Version: 1.0.0.qualifier
Bundle-Activator: reflectiveplugin.Activator
Bundle-ActivationPolicy: lazy
Bundle-requiredExecutionEnvironment: JavaSE-1.6
Import-Package: javax.annotation;version="1.0.0",
org.osgi.framework;version="1.3.0",
org.osgi.service.log;version="1.3",
org.osgi.util.tracker;version="1.3.1"
Bundle-ClassPath: .,
lib/dom4j-1.6.1.jar,
lib/guava-r08.jar,
lib/javassist-3.12.1.GA.jar,
lib/reflections-0.9.5.jar,
lib/slf4j-api-1.6.1.jar,
lib/xml-apis-1.0.b2.jar
Export-Package: reflectiveplugin,
reflectiveplugin.data
注意:Used Reflections v。0.9.5
这是一个示例UrlType实现:
package reflectiveplugin;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.Enumeration;
import java.util.Iterator;
import org.osgi.framework.Bundle;
import org.reflections.vfs.Vfs;
import org.reflections.vfs.Vfs.Dir;
import org.reflections.vfs.Vfs.File;
import org.reflections.vfs.Vfs.UrlType;
import com.google.common.collect.AbstractIterator;
public class BundleUrlType implements UrlType {
public static final String BUNDLE_PROTOCOL = "bundleresource";
private final Bundle bundle;
public BundleUrlType(Bundle bundle) {
this.bundle = bundle;
}
@Override
public boolean matches(URL url) {
return BUNDLE_PROTOCOL.equals(url.getProtocol());
}
@Override
public Dir createDir(URL url) {
return new BundleDir(bundle, url);
}
public class BundleDir implements Dir {
private String path;
private final Bundle bundle;
public BundleDir(Bundle bundle, URL url) {
this(bundle, url.getPath());
}
public BundleDir(Bundle bundle, String p) {
this.bundle = bundle;
this.path = p;
if (path.startsWith(BUNDLE_PROTOCOL + ":")) {
path = path.substring((BUNDLE_PROTOCOL + ":").length());
}
}
@Override
public String getPath() {
return path;
}
@Override
public Iterable<File> getFiles() {
return new Iterable<Vfs.File>() {
public Iterator<Vfs.File> iterator() {
return new AbstractIterator<Vfs.File>() {
final Enumeration<URL> entries = bundle.findEntries(path, "*.class", true);
protected Vfs.File computeNext() {
return entries.hasMoreElements() ? new BundleFile(BundleDir.this, entries.nextElement()) : endOfData();
}
};
}
};
}
@Override
public void close() { }
}
public class BundleFile implements File {
private final BundleDir dir;
private final String name;
private final URL url;
public BundleFile(BundleDir dir, URL url) {
this.dir = dir;
this.url = url;
String path = url.getFile();
this.name = path.substring(path.lastIndexOf("/") + 1);
}
@Override
public String getName() {
return name;
}
@Override
public String getRelativePath() {
return getFullPath().substring(dir.getPath().length());
}
@Override
public String getFullPath() {
return url.getFile();
}
@Override
public InputStream openInputStream() throws IOException {
return url.openStream();
}
}
}
这就是我在Activator类中创建反射的方法:
private Reflections createReflections(Bundle bundle) {
Vfs.addDefaultURLTypes(new BundleUrlType(bundle));
Reflections reflections = new Reflections(new Object[] { "reflectiveplugin.data" });
return reflections;
}
最后一点非常令人困惑,但仍然很重要:如果您在Eclipse(运行方式为/ OSGi Framework)中运行插件,则还必须将类输出目录添加到Reflections路径模式(即“ bin”或“ target / classes”) ”)。但是,对于已发布的插件,不需要(要构建插件/捆绑,请执行“导出”->“可部署的插件和片段”)。