/* The contents of this file are subject to the license and copyright terms
* detailed in the license directory at the root of the source tree (also
* available online at http://fedora-commons.org/license/).
*/
package org.fcrepo.server.storage.types;
import java.io.IOException;
import java.io.InputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Date;
import org.fcrepo.common.Constants;
import org.fcrepo.server.Context;
import org.fcrepo.server.MultiValueMap;
import org.fcrepo.server.ReadOnlyContext;
import org.fcrepo.server.errors.GeneralException;
import org.fcrepo.server.errors.StreamIOException;
import org.fcrepo.server.utilities.StringUtility;
import org.fcrepo.utilities.DateUtility;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A Fedora datastream.
*
* @author Sandy Payette
*/
public class Datastream {
private static final Logger logger =
LoggerFactory.getLogger(Datastream.class);
public final static String CHECKSUMTYPE_DISABLED = "DISABLED";
public final static String CHECKSUM_NONE = "none";
public final static String CHECKSUM_IOEXCEPTION = "ExceptionReadingStream";
public static final String DS_LOCATION_TYPE_INTERNAL = "INTERNAL_ID";
public static final String DS_LOCATION_TYPE_URL = "URL";
public boolean isNew = false;
public String DatastreamID;
public String[] DatastreamAltIDs = new String[0];
public String DSFormatURI;
public String DSMIME;
/**
* Datastream Control Group: This indicates the nature of the repository's
* control over the datastream content. Values are:
* <p>
* R = Redirected. The datastream resides on an external server and is
* referenced by a URL. When a dissemination request for the *datastream*
* comes through, Fedora sends an HTTP redirect to the client, thereby
* causing the client to directly access the datastream from its external
* location. This is useful in cases where the datastream is really some
* sort of streaming media that cannot be piped through Fedora, or the
* datastream is an HTML document with relative hyperlinks to the server on
* which is is normally hosted. E = External Referenced. The datastream
* content is external to the repository and referenced by URL. The content
* is not under the direct custodianship of the repository. The URL is
* considered public so the repository does not worry about whether it
* exposes the datastream location to collaborating services. M = Managed
* Content. The datastream content is stored and managed by the repository.
* The content is considered under the direct custodianship of the
* repository. The repository does not expose the underlying storage
* location to collaborating services and it mediates all access to the
* content by collaborating services. X = Inline XML Metadata. The
* datastream content is user-defined XML metadata that is stored within the
* digital object XML file itself. As such, it is intrinsically bound to the
* digital object, and by implication, it is stored and managed by the
* repository. The content considered under the custodianship of the
* repository.
*/
public String DSControlGrp;
/** Info Type: DATA or one of the METS MDType values */
/** Used to maintain backwards compatibility with METS-Fedora */
public String DSInfoType;
public String DSState;
public boolean DSVersionable;
// Version-level attributes:
public String DSVersionID;
public String DSLabel;
public Date DSCreateDT;
public long DSSize;
public String DSLocation;
public String DSLocationType;
public String DSChecksumType;
public String DSChecksum;
public static boolean autoChecksum = false;
public static String defaultChecksumType = "DISABLED";
public Datastream() {
}
public InputStream getContentStream() throws StreamIOException {
Context context = null;
try {
context = ReadOnlyContext.getContext(null, null, "", false);
}
catch (Throwable t){
context = null;
}
return getContentStream(context);
}
public InputStream getContentStream(Context context) throws StreamIOException {
return null;
}
public InputStream getContentStreamForChecksum() throws StreamIOException {
/**
* What should the context be here?
*/
MultiValueMap environmentAttributes = beginEnvironmentMap("");
try {
environmentAttributes.set(Constants.HTTP_REQUEST.CLIENT_IP_ADDRESS.uri, "127.0.0.1");
} catch (Exception e) {
logger.warn("Could not set client IP for checksum context!");
}
ReadOnlyContext context;
try {
context = ReadOnlyContext.getContext(null, null, "fcrepo-checksum", false);
} catch (Exception e) {
throw new StreamIOException(e.getMessage(),e);
}
context.setEnvironmentValues(environmentAttributes);
return getContentStream(context);
}
public static String getDefaultChecksumType() {
return defaultChecksumType;
}
public String getChecksumType() {
if (DSChecksumType == null || DSChecksumType.equals("")
|| DSChecksumType.equals(CHECKSUM_NONE)) {
DSChecksumType = getDefaultChecksumType();
if (DSChecksumType == null) {
logger.warn("checksumType is null");
}
}
return DSChecksumType;
}
public String getChecksum() {
if (DSChecksum == null || DSChecksum.equals(CHECKSUM_NONE)) {
DSChecksum = computeChecksum(getChecksumType());
}
logger.debug("Checksum = " + DSChecksum);
return DSChecksum;
}
public String setChecksum(String csType) {
if (csType != null) {
DSChecksumType = csType;
}
logger.debug("setting checksum using type: " + DSChecksumType);
DSChecksum = computeChecksum(DSChecksumType);
return DSChecksum;
}
public boolean compareChecksum() {
if (DSChecksumType == null || DSChecksumType.equals("")
|| DSChecksumType.equals(CHECKSUM_NONE)) {
return false;
}
if (DSChecksum == null) {
return false;
}
if (DSChecksumType.equals(CHECKSUMTYPE_DISABLED)) {
return true;
}
String curChecksum = computeChecksum(DSChecksumType);
if (curChecksum.equals(DSChecksum)) {
return true;
}
return false;
}
private String computeChecksum(String csType) {
logger.debug("checksumType is {}", csType);
String checksum = CHECKSUM_NONE;
if (csType == null) {
logger.warn("checksumType is null");
}
if (csType.equals(CHECKSUMTYPE_DISABLED)) {
checksum = CHECKSUM_NONE;
return checksum;
}
InputStream is = null;
try {
MessageDigest md = MessageDigest.getInstance(csType);
logger.debug("Classname = {}", this.getClass().getName());
logger.debug("location = {}", DSLocation);
is = getContentStreamForChecksum();
if (is != null) {
byte buffer[] = new byte[5000];
int numread;
logger.debug("Reading content...");
while ((numread = is.read(buffer, 0, 5000)) > 0) {
md.update(buffer, 0, numread);
}
is.close();
logger.debug("...Done reading content");
checksum = StringUtility.byteArraytoHexString(md.digest());
}
} catch (NoSuchAlgorithmException e) {
checksum = CHECKSUM_NONE;
} catch (StreamIOException e) {
checksum = CHECKSUM_IOEXCEPTION;
logger.warn("IOException reading datastream to generate checksum");
} catch (IOException e) {
checksum = CHECKSUM_IOEXCEPTION;
logger.warn("IOException reading datastream to generate checksum");
} finally {
if (is != null) {
try {
is.close();
} catch (IOException e) {
logger.warn("IOException closing stream (computeChecksum) in finally");
}
}
}
return checksum;
}
public static String validateChecksumType(String checksumType)
throws GeneralException {
String csType = null;
if (checksumType == null || checksumType.equalsIgnoreCase("DEFAULT")) {
return Datastream.getDefaultChecksumType();
}
if (checksumType.equalsIgnoreCase("DISABLED")) {
return "DISABLED";
}
if (checksumType.equalsIgnoreCase("MD5")) {
csType = "MD5";
}
if (checksumType.equalsIgnoreCase("SHA-1")) {
csType = "SHA-1";
}
if (checksumType.equalsIgnoreCase("SHA-256")) {
csType = "SHA-256";
}
if (checksumType.equalsIgnoreCase("SHA-384")) {
csType = "SHA-384";
}
if (checksumType.equalsIgnoreCase("SHA-512")) {
csType = "SHA-512";
}
if (checksumType.equalsIgnoreCase("HAVAL")) {
csType = "HAVAL";
}
if (checksumType.equalsIgnoreCase("TIGER")) {
csType = "TIGER";
}
if (checksumType.equalsIgnoreCase("WHIRLPOOL")) {
csType = "WHIRLPOOL";
}
if (csType == null) {
throw new GeneralException("Unknown checksum algorithm specified: "
+ checksumType);
}
try {
MessageDigest.getInstance(csType);
} catch (NoSuchAlgorithmException e) {
throw new GeneralException("Checksum algorithm not yet implemented: "
+ csType);
}
return csType;
}
// Get a complete copy of this datastream
public Datastream copy() {
Datastream ds = new Datastream();
copy(ds);
return ds;
}
// Copy this instance into target
public void copy(Datastream target) {
target.isNew = isNew;
target.DatastreamID = DatastreamID;
if (DatastreamAltIDs != null) {
target.DatastreamAltIDs = new String[DatastreamAltIDs.length];
for (int i = 0; i < DatastreamAltIDs.length; i++) {
target.DatastreamAltIDs[i] = DatastreamAltIDs[i];
}
}
target.DSFormatURI = DSFormatURI;
target.DSMIME = DSMIME;
target.DSControlGrp = DSControlGrp;
target.DSInfoType = DSInfoType;
target.DSState = DSState;
target.DSVersionable = DSVersionable;
target.DSVersionID = DSVersionID;
target.DSLabel = DSLabel;
target.DSCreateDT = DSCreateDT;
target.DSSize = DSSize;
target.DSLocation = DSLocation;
target.DSLocationType = DSLocationType;
target.DSChecksumType = DSChecksumType;
target.DSChecksum = DSChecksum;
}
private static final MultiValueMap beginEnvironmentMap(String messageProtocol) {
MultiValueMap environmentMap = new MultiValueMap();
try {
environmentMap.set(Constants.HTTP_REQUEST.MESSAGE_PROTOCOL.uri,
messageProtocol);
Date now = new Date();
environmentMap.set(Constants.ENVIRONMENT.CURRENT_DATE_TIME.uri,
DateUtility.convertDateToString(now));
environmentMap.set(Constants.ENVIRONMENT.CURRENT_DATE.uri, DateUtility
.convertDateToDateString(now));
environmentMap.set(Constants.ENVIRONMENT.CURRENT_TIME.uri, DateUtility
.convertDateToTimeString(now));
} catch (Exception e) {
logger.warn("Datastream could not set envAttributes for checksum context");
}
return environmentMap;
}
}