// return the resource as a stream
private InputStream mapResource(String publicId) {
if (publicId == null || id2resource == null) return null;
String resourceName = (String) id2resource.get(publicId);
ClassLoader loader = null;
if (resourceName == null) return null;
if (id2loader != null) loader = (ClassLoader) id2loader.get(publicId);
if (loader == null) return ClassLoader.getSystemResourceAsStream(resourceName);
return loader.getResourceAsStream(resourceName);
}
// This method is called whenever an external entity is accessed
// for the first time.
public InputSource resolveEntity(String publicId, String systemId) {
// Map the external entity to a local file
if (URL_PROPERTY_LIST.equals(systemId)) {
return new InputSource(ClassLoader.getSystemResourceAsStream(FILENAME_PROPERTY_LIST));
}
// Returning null causes the caller to try accessing the systemid
return null;
}
@SuppressWarnings("unchecked")
public void addDefaultValue(String className, JSONObject oper) throws Exception {
ObjectMapper defaultValueMapper = ObjectMapperFactory.getOperatorValueSerializer();
Class<? extends Operator> clazz = (Class<? extends Operator>) classLoader.loadClass(className);
if (clazz != null) {
Operator operIns = clazz.newInstance();
String s = defaultValueMapper.writeValueAsString(operIns);
oper.put("defaultValue", new JSONObject(s).get(className));
}
}
public OperatorDiscoverer(String[] jars) {
URL[] urls = new URL[jars.length];
for (int i = 0; i < jars.length; i++) {
pathsToScan.add(jars[i]);
try {
urls[i] = new URL("file://" + jars[i]);
} catch (MalformedURLException ex) {
throw new RuntimeException(ex);
}
}
classLoader = new URLClassLoader(urls, ClassLoader.getSystemClassLoader());
}
@SuppressWarnings("unchecked")
public Class<? extends Operator> getOperatorClass(String className)
throws ClassNotFoundException {
if (CollectionUtils.isEmpty(operatorClassNames)) {
loadOperatorClass();
}
Class<?> clazz = classLoader.loadClass(className);
if (!Operator.class.isAssignableFrom(clazz)) {
throw new IllegalArgumentException("Argument must be a subclass of Operator class");
}
return (Class<? extends Operator>) clazz;
}
public OperatorDiscoverer() {
classLoader = ClassLoader.getSystemClassLoader();
}
