How to use

DatasetUrl

in

ucar.nc2.dataset

List<String> allprotocols = DatasetUrl.getProtocols(location);
 svctype = searchFragment(fragment);
 svctype = decodeLeadProtocol(leadprotocol);
 svctype = searchPath(trueurl);
  svctype = decodePathExtension(trueurl); // look at the path extension
  if(svctype == null && checkIfNcml(new File(location))) {
   svctype = ServiceType.NCML;
  svctype = disambiguateHttp(trueurl);
   if (checkIfRemoteNcml(trueurl)) {
    svctype = ServiceType.NCML;
return new DatasetUrl(svctype, trueurl);

/**
 * Factory method for opening a NetcdfFile through the netCDF API.
 *
 * @param location   location of dataset.
 * @param cancelTask use to allow task to be cancelled; may be null.
 * @return NetcdfFile object
 * @throws java.io.IOException on read error
 */
public static NetcdfFile openFile(String location, ucar.nc2.util.CancelTask cancelTask) throws IOException {
 DatasetUrl durl = DatasetUrl.findDatasetUrl(location);
 return openOrAcquireFile(null, null, null, durl, -1, cancelTask, null);
}

ServiceType result = checkIfCdmr(location);
if (result != null) return result;
checkCdmr = true;
ServiceType result = checkIfDods(location);
if (result != null) return result;
checkDap2 = true;
ServiceType result = checkIfDap4(location);
if (result != null) return result;
checkDap4 = true;
ServiceType result = checkIfDods(location);
if (result != null)
 return result;
ServiceType result = checkIfDap4(location);
if (result != null)
 return result;
ServiceType result = checkIfCdmr(location);
if (result != null)
 return result;

static private boolean checkIfRemoteNcml(String location) throws IOException {
 if (decodePathExtension(location)==ServiceType.NCML) {
  // just because location ends with ncml does not mean it's ncml
  // if the ncml file is being served up via http by a remote server,
  // we should be able to read the first bit of it and see if it even
  // looks like an ncml file.
  try (HTTPMethod method = HTTPFactory.Get(location)) {
   method.setRange(0, NUM_BYTES_TO_DETERMINE_NCML);
   method.setRequestHeader("accept-encoding", "identity");
   int statusCode = method.execute();
   if (statusCode >= 300) {
    if (statusCode == 401) {
     throw new IOException("Unauthorized to open dataset " + location);
    } else if (statusCode == 406) {
     String msg = location + " - this server does not support returning content without any encoding.";
     msg = msg + " Please download the file locally. Return status=" + statusCode;
     throw new IOException(msg);
    } else {
     throw new IOException(location + " is not a valid URL, return status=" + statusCode);
    }
   }
   return checkIfNcml(method.getResponseAsString());
  }
 }
 return false;
}

public TestDatasetWrapP(String filename) {
 durl = new DatasetUrl(null, filename);
}

protected void protocheck(String path, String expected) {
 if (expected == null)
  expected = "";
 List<String> protocols = DatasetUrl.getProtocols(path);
 StringBuilder buf = new StringBuilder();
 for (String s : protocols) {
  buf.append(s);
  buf.append(":");
 }
 String result = buf.toString();
 boolean ok = expected.equals(result);
 if (show || !ok) System.out.printf(" path=%s; result=%s; pass=%s\n", path, result, ok);
 Assert.assertEquals(path, expected, result);
}

static private boolean checkIfNcml(File file) throws IOException {
 if (!file.exists()) {
  return false;
 }
 try (BufferedInputStream in = new BufferedInputStream(new FileInputStream(file), NUM_BYTES_TO_DETERMINE_NCML)) {
  byte[] bytes = new byte[NUM_BYTES_TO_DETERMINE_NCML];
  int bytesRead = in.read(bytes);
  if (bytesRead <= 0) {
   return false;
  } else {
   return checkIfNcml(new String(bytes, 0, bytesRead));
  }
 }
}

public GribCollectionImmutable getGribCollection() throws IOException {
 String path = getIndexFilenameInCache();
 if (path == null) {
  if (Grib.debugIndexOnly) {  // we are running in debug mode where we only have the indices, not the data files
   // tricky: substitute the current root
   File orgParentDir = new File(directory);
   File currentFile = new File(PartitionCollectionMutable.this.indexFilename);
   File currentParent = currentFile.getParentFile();
   File currentParentWithDir = new File(currentParent, orgParentDir.getName());
   File nestedIndex = isPartitionOfPartitions ? new File(currentParentWithDir, filename) : new File(currentParent, filename); // JMJ
   path = nestedIndex.getPath();
  } else {
   throw new FileNotFoundException("No index filename for partition= "+this.toString());
  }
 }
 // LOOK not cached
 return (GribCollectionImmutable) PartitionCollectionImmutable.partitionCollectionFactory.open(new DatasetUrl(null, path), -1, null, this);
}

protected boolean protocheck(String path, String expected)
{
  if(expected == null)
    expected = "";
  List<String> protocols = DatasetUrl.getProtocols(path);
  StringBuilder buf = new StringBuilder();
  for(String s : protocols) {
    buf.append(s);
    buf.append(":");
  }
  String result = buf.toString();
  boolean ok = expected.equals(result);
  System.err.printf("path=|%s| result=|%s| pass=%s\n",
      path, result, (ok ? "true" : "false"));
  System.err.flush();
  return ok;
}

public TestNcmlWriteAndCompareShared(String location, boolean compareData) throws IOException {
 this.durl = DatasetUrl.findDatasetUrl(location);
 this.compareData = compareData;
}

static public GribCollectionImmutable acquireGribCollection(FileFactory factory, Object hashKey, String location, int buffer_size, CancelTask cancelTask, Object spiObject) throws IOException {
 FileCacheable result;
 DatasetUrl durl = new DatasetUrl(null, location);
 if (gribCollectionCache != null) {
  // FileFactory factory, Object hashKey, String location, int buffer_size, CancelTask cancelTask, Object spiObject
  result = GribCdmIndex.gribCollectionCache.acquire(factory, hashKey, durl, buffer_size, cancelTask, spiObject);
 } else {
  // String location, int buffer_size, ucar.nc2.util.CancelTask cancelTask, Object iospMessage
  result = factory.open(durl, buffer_size, cancelTask, spiObject);
 }
 return (GribCollectionImmutable) result;
}

/**
 * Factory method for opening a dataset through the netCDF API, and identifying its coordinate variables.
 *
 * @param location    location of file
 * @param enhance     if true, use defaultEnhanceMode, else no enhancements
 * @param buffer_size RandomAccessFile buffer size, if <= 0, use default size
 * @param cancelTask  allow task to be cancelled; may be null.
 * @param spiObject   sent to iosp.setSpecial() if not null
 * @return NetcdfDataset object
 * @throws java.io.IOException on read error
 */
static public NetcdfDataset openDataset(String location, boolean enhance, int buffer_size, ucar.nc2.util.CancelTask cancelTask, Object spiObject) throws IOException {
 DatasetUrl durl = DatasetUrl.findDatasetUrl(location);
 return openDataset(durl, enhance ? defaultEnhanceMode : null, buffer_size, cancelTask, spiObject);
}

static public RandomAccessFile acquire(String location) throws IOException {
 if (cache == null)
  return new RandomAccessFile(location, "r");
 else
  return (RandomAccessFile) cache.acquire(factory, new DatasetUrl(null, location));
}

/**
 * Open a netcdf dataset, using NetcdfDataset.defaultEnhanceMode plus CoordSystems
 * and turn into a DtCoverageDataset.
 *
 * @param location netcdf dataset to open, using NetcdfDataset.acquireDataset().
 * @return GridDataset
 * @throws java.io.IOException on read error
 * @see ucar.nc2.dataset.NetcdfDataset#acquireDataset
 */
static public DtCoverageDataset open(String location) throws java.io.IOException {
 DatasetUrl durl = DatasetUrl.findDatasetUrl(location);
 return open(durl, NetcdfDataset.getDefaultEnhanceMode());
}

static public RandomAccessFile acquire(String location, int buffer_size) throws IOException {
 if (cache == null)
  return new RandomAccessFile(location, "r", buffer_size);
 else
  return (RandomAccessFile) cache.acquire(factory, location, new DatasetUrl(null, location), buffer_size, null, null);
}

/**
 * Open a netcdf dataset, using NetcdfDataset.defaultEnhanceMode plus CoordSystems
 * and turn into a GridDataset.
 *
 * @param location netcdf dataset to open, using NetcdfDataset.acquireDataset().
 * @param enhanceMode open netcdf dataset with this enhanceMode
 * @return GridDataset
 * @throws java.io.IOException on read error
 * @see ucar.nc2.dataset.NetcdfDataset#acquireDataset
 */
static public GridDataset open(String location, Set<NetcdfDataset.Enhance> enhanceMode) throws java.io.IOException {
 NetcdfDataset ds = ucar.nc2.dataset.NetcdfDataset.acquireDataset(null, DatasetUrl.findDatasetUrl(location), enhanceMode, -1, null, null);
 return new GridDataset(ds, null);
}

/**
 * Open a file, keep track of open files
 * @param location open this location
 * @param openFiles keep track of open files
 * @return file or null if not found
 */
private NetcdfDataset open(String location, Map<String, NetcdfDataset> openFiles)  throws IOException {
 NetcdfDataset ncd;
 if (openFiles != null) {
  ncd = openFiles.get(location);
  if (ncd != null) return ncd;
 }
 if (config.innerNcml == null) {
  ncd = NetcdfDataset.acquireDataset(new DatasetUrl(null, location), true, null);  // default enhance
 } else {
  NetcdfFile nc = NetcdfDataset.acquireFile(new DatasetUrl(null, location), null);
  ncd = NcMLReader.mergeNcML(nc, config.innerNcml); // create new dataset
  ncd.enhance(); // now that the ncml is added, enhance "in place", ie modify the NetcdfDataset
 }
 if (openFiles != null && ncd != null) {
  openFiles.put(location, ncd);
 }
 return ncd;
}

/**
 * Open a dataset as a TypedDataset.
 *
 * @param datatype open this kind of Typed Dataset; may be null, which means search all factories.
 *   If datatype is not null, only return correct TypedDataset (eg PointObsDataset for DataType.POINT).
 * @param location URL or file location of the dataset
 * @param task user may cancel
 * @param errlog place errors here, may not be null
 * @return a subclass of TypedDataset
 * @throws java.io.IOException on io error
 */
static public TypedDataset open( FeatureType datatype, String location, ucar.nc2.util.CancelTask task, StringBuilder errlog) throws IOException {
 DatasetUrl durl = DatasetUrl.findDatasetUrl(location);
 NetcdfDataset ncd = NetcdfDataset.acquireDataset(durl, true, task);
 return open( datatype, ncd, task, errlog);
}

static private NetcdfFile acquireDODS(FileCache cache, FileFactory factory, Object hashKey,
                   String location, int buffer_size, ucar.nc2.util.CancelTask cancelTask, Object spiObject) throws IOException {
 if (cache == null) {
  return openDodsByReflection(location, cancelTask);
 }
 if (factory == null) factory = new DodsFactory();
 return (NetcdfFile) cache.acquire(factory, hashKey, new DatasetUrl(ServiceType.OPENDAP, location), buffer_size, cancelTask, spiObject);
}

public NetcdfFile acquireFile(CancelTask cancelTask) throws IOException {
 if (debugOpenFile) System.out.println(" try to acquire " + cacheLocation);
 long start = System.currentTimeMillis();
 if (durl == null)
  durl = DatasetUrl.findDatasetUrl(cacheLocation); // cache the ServiceType so we dont have to keep figuring it out
 NetcdfFile ncfile = NetcdfDataset.acquireFile(reader, null, durl, -1, cancelTask, spiObject);
 // must merge NcML before enhancing
 if (mergeNcml != null)
  ncfile = NcMLReader.mergeNcML(ncfile, mergeNcml); // create new dataset
 if (enhance == null || enhance.isEmpty()) {
  if (debugOpenFile) System.out.println(" acquire (no enhance) " + cacheLocation + " took " + (System.currentTimeMillis() - start));
  return ncfile;
 }
 // must enhance
 NetcdfDataset ds;
 if (ncfile instanceof NetcdfDataset) {
  ds = (NetcdfDataset) ncfile;
  ds.enhance(enhance); // enhance "in place", ie modify the NetcdfDataset
 } else {
  ds = new NetcdfDataset(ncfile, enhance); // enhance when wrapping
 }
 if (debugOpenFile) System.out.println(" acquire (enhance) " + cacheLocation + " took " + (System.currentTimeMillis() - start));
 return ds;
}