package org.fcrepo.server.rest;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PipedInputStream;
import java.io.PipedOutputStream;
import javax.servlet.ServletException;
import javax.ws.rs.DefaultValue;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.QueryParam;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.StreamingOutput;
import javax.xml.transform.Templates;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;
import org.fcrepo.common.Constants;
import org.fcrepo.server.Context;
import org.fcrepo.server.Server;
import org.fcrepo.server.access.RepositoryInfo;
import org.fcrepo.server.errors.GeneralException;
import org.fcrepo.server.errors.ServerException;
import org.fcrepo.server.errors.authorization.AuthzException;
import org.fcrepo.utilities.XmlTransformUtility;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
/**
* Implements the "describeRepository" functionality of the Fedora Access LITE
* (API-A-LITE) interface using a java servlet front end. The syntax defined by
* API-A-LITE has for getting a description of the repository has the following
* binding:
* <ol>
* <li>describeRepository URL syntax:
* protocol://hostname:port/fedora/describe[?xml=BOOLEAN] This syntax requests
* information about the repository. The xml parameter determines the type of
* output returned. If the parameter is omitted or has a value of "false", a
* MIME-typed stream consisting of an html table is returned providing a
* browser-savvy means of viewing the object profile. If the value specified is
* "true", then a MIME-typed stream consisting of XML is returned.</li>
* <ul>
* <li>protocol - either http or https.</li>
* <li>hostname - required hostname of the Fedora server.</li>
* <li>port - required port number on which the Fedora server is running.</li>
* <li>fedora - required name of the Fedora access service.</li>
* <li>describe - required verb of the Fedora service.</li>
* <li>xml - an optional parameter indicating the requested output format. A
* value of "true" indicates a return type of text/xml; the absence of the xml
* parameter or a value of "false" indicates format is to be text/html.</li>
* </ul>
*
* @author Ross Wayland
* @author Benjamin Armintor armintor@gmail.com
* @version $Id$
*/
@Path("/")
@Component
public class DescribeRepositoryResource
extends BaseRestResource
implements Constants {
private static final Logger logger =
LoggerFactory.getLogger(DescribeRepositoryResource.class);
private static final long serialVersionUID = 1L;
/** Content type for html. */
private static final String CONTENT_TYPE_HTML = "text/html; charset=UTF-8";
/** Content type for xml. */
private static final String CONTENT_TYPE_XML = "text/xml; charset=UTF-8";
public DescribeRepositoryResource(Server server) {
super(server);
}
/**
* <p>
* Process Fedora Access Request. Parse and validate the servlet input
* parameters and then execute the specified request.
* </p>
*
* @param request
* The servlet request.
* @param response
* servlet The servlet response.
* @throws ServletException
* If an error occurs that effects the servlet's basic operation.
* @throws IOException
* If an error occurs with an input or output operation.
*/
@Path("/")
@GET
public Response describe(@QueryParam("xml")
@DefaultValue("false")
boolean xml)
throws ServletException, IOException {
Context context = getContext();
try {
return describeRepository(context, xml);
} catch (Exception ae) {
return handleException(ae, false);
}
}
@Path("/")
@POST
public Response postDescribe(@QueryParam("xml") @DefaultValue("false") boolean xml)
throws ServletException, IOException {
return describe(xml);
}
public Response describeRepository(Context context,
boolean xml)
throws ServerException {
RepositoryInfo repositoryInfo = null;
try {
repositoryInfo = m_access.describeRepository(context);
if (repositoryInfo != null) {
// Repository info obtained.
// Serialize the RepositoryInfo object into XML
ReposInfoSerializer result = new ReposInfoSerializer(context, repositoryInfo);
if (xml) {
// Return results as raw XML
return Response.ok(result,CONTENT_TYPE_XML).build();
} else {
// Transform results into an html table
return Response.ok(new HtmlTransformation(context, result),CONTENT_TYPE_HTML).build();
}
} else {
// Describe request returned nothing.
logger.error("No repository info returned");
return Response.noContent().build();
}
} catch (AuthzException ae) {
throw ae;
} catch (Throwable th) {
String msg = "Error describing repository";
logger.error(msg, th);
throw new GeneralException(msg, th);
}
}
/**
* <p>
* Serializes RepositoryInfo object into XML.
* </p>
*/
public class ReposInfoSerializer
implements StreamingOutput {
private RepositoryInfo repositoryInfo = null;
/**
* <p>
* Constructor for ReposInfoSerializerThread.
* </p>
*
* @param repositoryInfo
* A repository info data structure.
* @param pw
* A PipedWriter to which the serialization info is written.
*/
public ReposInfoSerializer(Context context,
RepositoryInfo repositoryInfo) {
this.repositoryInfo = repositoryInfo;
}
/**
* <p>
* This method executes the thread.
* </p>
*/
@Override
public void write(OutputStream output)
throws IOException {
OutputStreamWriter pw = new OutputStreamWriter(output,"UTF-8");
pw.write("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
pw.write("<fedoraRepository"
+ " xmlns=\"" + REPO_DESC1_0.namespace.uri + "\""
+ " xmlns:xsd=\"" + XML_XSD.uri + "\""
+ " xmlns:xsi=\"" + XSI.uri + "\""
+ " xsi:schemaLocation=\"" + ACCESS.uri + " "
+ REPO_DESC1_0.xsdLocation + "\">");
// REPOSITORY INFO FIELDS SERIALIZATION
pw.write("<repositoryName>" + repositoryInfo.repositoryName
+ "</repositoryName>");
pw.write("<repositoryBaseURL>"
+ repositoryInfo.repositoryBaseURL
+ "</repositoryBaseURL>");
pw.write("<repositoryVersion>"
+ repositoryInfo.repositoryVersion
+ "</repositoryVersion>");
pw.write("<repositoryPID>");
pw.write(" <PID-namespaceIdentifier>"
+ repositoryInfo.repositoryPIDNamespace
+ "</PID-namespaceIdentifier>");
pw.write(" <PID-delimiter>" + ":" + "</PID-delimiter>");
pw.write(" <PID-sample>" + repositoryInfo.samplePID
+ "</PID-sample>");
String[] retainPIDs = repositoryInfo.retainPIDs;
for (String element : retainPIDs) {
pw.write(" <retainPID>" + element + "</retainPID>");
}
pw.write("</repositoryPID>");
pw.write("<repositoryOAI-identifier>");
pw.write(" <OAI-namespaceIdentifier>"
+ repositoryInfo.OAINamespace
+ "</OAI-namespaceIdentifier>");
pw.write(" <OAI-delimiter>" + ":" + "</OAI-delimiter>");
pw.write(" <OAI-sample>"
+ repositoryInfo.sampleOAIIdentifer
+ "</OAI-sample>");
pw.write("</repositoryOAI-identifier>");
pw.write("<sampleSearch-URL>"
+ repositoryInfo.sampleSearchURL
+ "</sampleSearch-URL>");
pw.write("<sampleAccess-URL>"
+ repositoryInfo.sampleAccessURL
+ "</sampleAccess-URL>");
pw.write("<sampleOAI-URL>" + repositoryInfo.sampleOAIURL
+ "</sampleOAI-URL>");
String[] emails = repositoryInfo.adminEmailList;
for (String element : emails) {
pw.write("<adminEmail>" + element + "</adminEmail>");
}
pw.write("</fedoraRepository>");
pw.flush();
pw.close();
}
}
public class HtmlTransformation implements StreamingOutput {
private final ReposInfoSerializer reposInfo;
private final Context context;
public HtmlTransformation(Context context, ReposInfoSerializer input) {
this.reposInfo = input;
this.context = context;
}
@Override
public void write(OutputStream out) throws IOException {
File xslFile =
new File(m_server.getHomeDir(),
"access/viewRepositoryInfo.xslt");
PipedOutputStream po = new PipedOutputStream();
PipedInputStream pr = new PipedInputStream(po);
this.reposInfo.write(po);
try {
Templates template =
XmlTransformUtility.getTemplates(xslFile);
Transformer transformer = template.newTransformer();
transformer.setParameter("fedora", context
.getEnvironmentValue(FEDORA_APP_CONTEXT_NAME));
transformer.transform(new StreamSource(pr),
new StreamResult(out));
} catch (TransformerException te) {
throw new IOException("Transform error" + te.toString(), te);
}
out.flush();
}
}
}