package tap.resource;
/*
* This file is part of TAPLibrary.
*
* TAPLibrary is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* TAPLibrary is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with TAPLibrary. If not, see <http://www.gnu.org/licenses/>.
*
* Copyright 2012,2014 - UDS/Centre de Données astronomiques de Strasbourg (CDS),
* Astronomisches Rechen Institut (ARI)
*/
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import tap.ServiceConnection;
import tap.ServiceConnection.LimitUnit;
import tap.TAPException;
import tap.error.DefaultTAPErrorWriter;
import tap.formatter.OutputFormat;
import tap.log.TAPLog;
import tap.metadata.TAPMetadata;
import uk.ac.starlink.votable.VOSerializer;
import uws.UWSException;
import uws.job.user.JobOwner;
import uws.service.UWS;
import uws.service.UWSService;
import uws.service.UWSUrl;
import uws.service.error.ServiceErrorWriter;
import uws.service.log.UWSLog.LogLevel;
import adql.db.FunctionDef;
/**
* <p>Root/Home of the TAP service. It is also the resource (HOME) which gathers all the others of the same TAP service.</p>
*
* <p>At its creation it is creating and configuring the other resources in function of the given description of the TAP service.</p>
*
* @author Grégory Mantelet (CDS;ARI)
* @version 2.0 (12/2014)
*/
public class TAP implements VOSIResource {
/** Description of the TAP service owning this resource. */
protected final ServiceConnection service;
/** List of all the other TAP resources of the service. */
protected final Map<String,TAPResource> resources;
/** Base URL of the TAP service. It is also the URL of this resource (HOME). */
protected String tapBaseURL = null;
/** URI of the page or path of the file to display when this resource is requested. */
protected String homePageURI = null;
/** MIME type of the custom home page. By default, it is "text/html". */
protected String homePageMimeType = "text/html";
/** Object to use when an error occurs or comes until this resource from the others.
* This object fills the HTTP response in the most appropriate way in function of the error. */
protected ServiceErrorWriter errorWriter;
/** Last generated request ID. If the next generated request ID is equivalent to this one,
* a new one will generate in order to ensure the uniqueness.
* @since 2.0 */
protected static String lastRequestID = null;
/**
* Build a HOME resource of a TAP service whose the description is given in parameter.
* All the other TAP resources will be created and configured here thanks to the given {@link ServiceConnection}.
*
* @param serviceConnection Description of the TAP service.
*
* @throws UWSException If an error occurs while creating the /async resource.
* @throws TAPException If any other error occurs.
*/
public TAP(final ServiceConnection serviceConnection) throws UWSException, TAPException{
service = serviceConnection;
resources = new HashMap<String,TAPResource>();
// Get the error writer to use, or create a default instance if none are provided by the factory:
errorWriter = serviceConnection.getFactory().getErrorWriter();
if (errorWriter == null)
errorWriter = new DefaultTAPErrorWriter(service);
TAPResource res = new Availability(service);
resources.put(res.getName(), res);
res = new Capabilities(this);
resources.put(res.getName(), res);
res = new Sync(service, (Capabilities)res);
resources.put(res.getName(), res);
res = new ASync(service);
resources.put(res.getName(), res);
TAPMetadata metadata = service.getTAPMetadata();
resources.put(metadata.getName(), metadata);
}
/**
* Get the logger used by this resource and all the other resources managed by it.
*
* @return The used logger.
*/
public final TAPLog getLogger(){
return service.getLogger();
}
/**
* <p>Let initialize this resource and all the other managed resources.</p>
*
* <p>This function is called by the library just once: when the servlet is initialized.</p>
*
* @param config Configuration of the servlet.
*
* @throws ServletException If any error occurs while reading the given configuration.
*
* @see TAPResource#init(ServletConfig)
*/
public void init(final ServletConfig config) throws ServletException{
for(TAPResource res : resources.values())
res.init(config);
}
/**
* <p>Free all the resources used by this resource and the other managed resources.</p>
*
* <p>This function is called by the library just once: when the servlet is destroyed.</p>
*
* @see TAPResource#destroy()
*/
public void destroy(){
for(TAPResource res : resources.values())
res.destroy();
}
/**
* <p>Set the base URL of this TAP service.</p>
*
* <p>
* This URL must be the same as the one of this resource ; it corresponds to the
* URL of the root (or home) of the TAP service.
* </p>
*
* <p>The given URL will be propagated to the other TAP resources automatically.</p>
*
* @param baseURL URL of this resource.
*
* @see TAPResource#setTAPBaseURL(String)
*/
public void setTAPBaseURL(final String baseURL){
tapBaseURL = baseURL;
for(TAPResource res : resources.values())
res.setTAPBaseURL(tapBaseURL);
}
/**
* <p>Build the base URL from the given HTTP request, and use it to set the base URL of this TAP service.</p>
*
* <p>The given URL will be propagated to the other TAP resources automatically.</p>
*
* @param request HTTP request from which a TAP service's base URL will be extracted.
*
* @see #setTAPBaseURL(String)
*/
public void setTAPBaseURL(final HttpServletRequest request){
setTAPBaseURL(request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + request.getContextPath() + request.getServletPath());
}
/* ******************** */
/* RESOURCES MANAGEMENT */
/* ******************** */
/**
* Get the /availability resource of this TAP service.
*
* @return The /availability resource.
*/
public final Availability getAvailability(){
return (Availability)resources.get(Availability.RESOURCE_NAME);
}
/**
* Get the /capabilities resource of this TAP service.
*
* @return The /capabilities resource.
*/
public final Capabilities getCapabilities(){
return (Capabilities)resources.get(Capabilities.RESOURCE_NAME);
}
/**
* Get the /sync resource of this TAP service.
*
* @return The /sync resource.
*/
public final Sync getSync(){
return (Sync)resources.get(Sync.RESOURCE_NAME);
}
/**
* Get the /async resource of this TAP service.
*
* @return The /async resource.
*/
public final ASync getASync(){
return (ASync)resources.get(ASync.RESOURCE_NAME);
}
/**
* Get the UWS service used for the /async service.
*
* @return The used UWS service.
*/
public final UWSService getUWS(){
TAPResource res = getASync();
if (res != null)
return ((ASync)res).getUWS();
else
return null;
}
/**
* <p>Get the object managing all the metadata (information about the published columns and tables)
* of this TAP service.</p>
*
* <p>This object is also to the /tables resource.</p>
*
* @return List of all metadata of this TAP service.
*/
public final TAPMetadata getTAPMetadata(){
return (TAPMetadata)resources.get(TAPMetadata.RESOURCE_NAME);
}
/**
* <p>Add the given resource in this TAP service.</p>
*
* <p>The ID of this resource (which is also its URI) will be its name (given by {@link TAPResource#getName()}).</p>
*
* <p><b>WARNING:
* If another resource with an ID strictly identical (case sensitively) to the name of the given resource, it will be overwritten!
* You should check (thanks to {@link #hasResource(String)}) before calling this function that no resource is associated with the same URI.
* If it is the case, you should then use the function {@link #addResource(String, TAPResource)} with a different ID/URI.
* </b></p>
*
* <p><i>Note:
* This function is equivalent to {@link #addResource(String, TAPResource)} with {@link TAPResource#getName()} in first parameter.
* </i></p>
*
* @param newResource Resource to add in the service.
*
* @return <i>true</i> if the given resource has been successfully added,
* <i>false</i> otherwise (and particularly if the given resource is NULL).
*
* @see #addResource(String, TAPResource)
*/
public final boolean addResource(final TAPResource newResource){
return addResource(newResource.getName(), newResource);
}
/**
* <p>Add the given resource in this TAP service with the given ID (which will be also the URI to access this resource).</p>
*
* <p><b>WARNING:
* If another resource with an ID strictly identical (case sensitively) to the name of the given resource, it will be overwritten!
* You should check (thanks to {@link #hasResource(String)}) before calling this function that no resource is associated with the same URI.
* If it is the case, you should then use the function {@link #addResource(String, TAPResource)} with a different ID/URI.
* </b></p>
*
* <p><i>Note:
* If the given ID is NULL, the name of the resource will be used.
* </i></p>
*
* @param resourceId ID/URI of the resource to add.
* @param newResource Resource to add.
*
* @return <i>true</i> if the given resource has been successfully added to this service with the given ID/URI,
* <i>false</I> otherwise (and particularly if the given resource is NULL).
*/
public final boolean addResource(final String resourceId, final TAPResource newResource){
if (newResource == null)
return false;
resources.put((resourceId == null) ? newResource.getName() : resourceId, newResource);
return true;
}
/**
* Get the number of all resources managed by this TAP service (this resource - HOME - excluded).
*
* @return Number of managed resources.
*/
public final int getNbResources(){
return resources.size();
}
/**
* <p>Get the specified resource.</p>
*
* <p><i>Note:
* The research is case sensitive.
* </i></p>
*
* @param resourceId Exact ID/URI of the resource to get.
*
* @return The corresponding resource,
* or NULL if no match can be found.
*/
public final TAPResource getResource(final String resourceId){
return resources.get(resourceId);
}
/**
* Let iterate over the full list of the TAP resources managed by this TAP service.
*
* @return Iterator over the available TAP resources.
*/
public final Iterator<TAPResource> getTAPResources(){
return resources.values().iterator();
}
/**
* <p>Tell whether a resource is already associated with the given ID/URI.</p>
*
* <p><i>Note:
* The research is case sensitive.
* </i></p>
*
* @param resourceId Exact ID/URI of the resource to find.
*
* @return <i>true</i> if a resource is already associated with the given ID/URI,
* <i>false</i> otherwise.
*/
public final boolean hasResource(final String resourceId){
return resources.containsKey(resourceId);
}
/**
* <p>Remove the resource associated with the given ID/URI.</p>
*
* <p><i>Note:
* The research is case sensitive.
* </i></p>
*
* @param resourceId Exact ID/URI of the resource to remove.
*
* @return The removed resource, if associated with the given ID/URI,
* otherwise, NULL is returned.
*/
public final TAPResource removeResource(final String resourceId){
return resources.remove(resourceId);
}
/* **************** */
/* ERROR MANAGEMENT */
/* **************** */
/**
* Get the object to use in order to report errors to the user in replacement of the expected result.
*
* @return Used error writer.
*/
public final ServiceErrorWriter getErrorWriter(){
return errorWriter;
}
/**
* Set the object to use in order to report errors to the user in replacement of the expected result.
*
* @param errorWriter Error writer to use. (if NULL, nothing will be done)
*/
public final void setErrorWriter(final ServiceErrorWriter errorWriter){
if (errorWriter != null){
this.errorWriter = errorWriter;
getUWS().setErrorWriter(errorWriter);
}
}
@Override
public String getStandardID(){
return "ivo://ivoa.net/std/TAP";
}
@Override
public String getAccessURL(){
return tapBaseURL;
}
@Override
public String getCapability(){
StringBuffer xml = new StringBuffer();
// Header:
xml.append("<capability ").append(VOSerializer.formatAttribute("standardID", getStandardID())).append(" xsi:type=\"tr:TableAccess\">\n");
// TAP access:
xml.append("\t<interface role=\"std\" xsi:type=\"vs:ParamHTTP\">\n");
xml.append("\t\t<accessURL use=\"base\">").append((getAccessURL() == null) ? "" : VOSerializer.formatText(getAccessURL())).append("</accessURL>\n");
xml.append("\t</interface>\n");
// Language description:
xml.append("\t<language>\n");
xml.append("\t\t<name>ADQL</name>\n");
xml.append("\t\t<version ivo-id=\"ivo://ivoa.net/std/ADQL#v2.0\">2.0</version>\n");
xml.append("\t\t<description>ADQL 2.0</description>\n");
// Geometrical functions:
if (service.getGeometries() != null && service.getGeometries().size() > 0){
xml.append("\t\t<languageFeatures type=\"ivo://ivoa.net/std/TAPRegExt#features-adqlgeo\">");
for(String geom : service.getGeometries()){
if (geom != null){
xml.append("\t\t\t<feature>");
xml.append("\t\t\t\t<form>").append(VOSerializer.formatText(geom.toUpperCase())).append("</form>");
xml.append("\t\t\t</feature>");
}
}
xml.append("\t\t</languageFeatures>");
}
// User Defined Functions (UDFs):
if (service.getUDFs() != null && service.getUDFs().size() > 0){
xml.append("\t\t<languageFeatures type=\"ivo://ivoa.net/std/TAPRegExt#features-udf\">");
for(FunctionDef udf : service.getUDFs()){
if (udf != null){
xml.append("\t\t\t<feature>");
xml.append("\t\t\t\t<form>").append(VOSerializer.formatText(udf.toString())).append("</form>");
if (udf.description != null && udf.description.length() > 0)
xml.append("\t\t\t\t<description>").append(VOSerializer.formatText(udf.description)).append("</description>");
xml.append("\t\t\t</feature>");
}
}
xml.append("\t\t</languageFeatures>");
}
xml.append("\t</language>\n");
// Available output formats:
Iterator<OutputFormat> itFormats = service.getOutputFormats();
OutputFormat formatter;
while(itFormats.hasNext()){
formatter = itFormats.next();
xml.append("\t<outputFormat>\n");
xml.append("\t\t<mime>").append(VOSerializer.formatText(formatter.getMimeType())).append("</mime>\n");
if (formatter.getShortMimeType() != null)
xml.append("\t\t<alias>").append(VOSerializer.formatText(formatter.getShortMimeType())).append("</alias>\n");
if (formatter.getDescription() != null)
xml.append("\t\t<description>").append(VOSerializer.formatText(formatter.getDescription())).append("</description>\n");
xml.append("\t</outputFormat>\n");
}
// Write upload methods: INLINE, HTTP, FTP:
if (service.uploadEnabled()){
xml.append("\t<uploadMethod ivo-id=\"ivo://ivoa.net/std/TAPRegExt#upload-inline\" />\n");
xml.append("\t<uploadMethod ivo-id=\"ivo://ivoa.net/std/TAPRegExt#upload-http\" />\n");
xml.append("\t<uploadMethod ivo-id=\"ivo://ivoa.net/std/TAPRegExt#upload-ftp\" />\n");
}
// Retention period (for asynchronous jobs):
int[] retentionPeriod = service.getRetentionPeriod();
if (retentionPeriod != null && retentionPeriod.length >= 2){
if (retentionPeriod[0] > -1 || retentionPeriod[1] > -1){
xml.append("\t<retentionPeriod>\n");
if (retentionPeriod[0] > -1)
xml.append("\t\t<default>").append(retentionPeriod[0]).append("</default>\n");
if (retentionPeriod[1] > -1)
xml.append("\t\t<hard>").append(retentionPeriod[1]).append("</hard>\n");
xml.append("\t</retentionPeriod>\n");
}
}
// Execution duration (still for asynchronous jobs):
int[] executionDuration = service.getExecutionDuration();
if (executionDuration != null && executionDuration.length >= 2){
if (executionDuration[0] > -1 || executionDuration[1] > -1){
xml.append("\t<executionDuration>\n");
if (executionDuration[0] > -1)
xml.append("\t\t<default>").append(executionDuration[0]).append("</default>\n");
if (executionDuration[1] > -1)
xml.append("\t\t<hard>").append(executionDuration[1]).append("</hard>\n");
xml.append("\t</executionDuration>\n");
}
}
// Output/Result limit:
int[] outputLimit = service.getOutputLimit();
LimitUnit[] outputLimitType = service.getOutputLimitType();
if (outputLimit != null && outputLimit.length >= 2 && outputLimitType != null && outputLimitType.length >= 2){
if (outputLimit[0] > -1 || outputLimit[1] > -1){
xml.append("\t<outputLimit>\n");
if (outputLimit[0] > -1)
xml.append("\t\t<default ").append(VOSerializer.formatAttribute("unit", outputLimitType[0].toString())).append(">").append(outputLimit[0]).append("</default>\n");
if (outputLimit[1] > -1)
xml.append("\t\t<hard ").append(VOSerializer.formatAttribute("unit", outputLimitType[1].toString())).append(">").append(outputLimit[1]).append("</hard>\n");
xml.append("\t</outputLimit>\n");
}
}
// Upload limits
if (service.uploadEnabled()){
// Write upload limits:
int[] uploadLimit = service.getUploadLimit();
LimitUnit[] uploadLimitType = service.getUploadLimitType();
if (uploadLimit != null && uploadLimit.length >= 2 && uploadLimitType != null && uploadLimitType.length >= 2){
if (uploadLimit[0] > -1 || uploadLimit[1] > -1){
xml.append("\t<uploadLimit>\n");
if (uploadLimit[0] > -1)
xml.append("\t\t<default ").append(VOSerializer.formatAttribute("unit", uploadLimitType[0].toString())).append(">").append(uploadLimit[0]).append("</default>\n");
if (uploadLimit[1] > -1)
xml.append("\t\t<hard ").append(VOSerializer.formatAttribute("unit", uploadLimitType[1].toString())).append(">").append(uploadLimit[1]).append("</hard>\n");
xml.append("\t</uploadLimit>\n");
}
}
}
// Footer:
xml.append("\t</capability>");
return xml.toString();
}
/* ************************************* */
/* MANAGEMENT OF THIS RESOURCE'S CONTENT */
/* ************************************* */
/**
* <p>Get the URL or the file path of a custom home page.</p>
*
* <p>The home page will be displayed when this resource is directly requested.</p>
*
* @return URL or file path of the file to display as home page,
* or NULL if no custom home page has been specified.
*/
public final String getHomePageURI(){
return homePageURI;
}
/**
* <p>Set the URL or the file path of a custom home page.</p>
*
* <p>The home page will be displayed when this resource is directly requested.</p>
*
* @param uri URL or file path of the file to display as home page, or NULL to display the default home page.
*/
public final void setHomePageURI(final String uri){
homePageURI = (uri != null) ? uri.trim() : uri;
if (homePageURI != null && homePageURI.length() == 0)
homePageURI = null;
}
/**
* <p>Get the MIME type of the custom home page.</p>
*
* <p>
* By default, it is the same as the default home page: "text/html".
* </p>
*
* @return MIME type of the custom home page.
*/
public final String getHomePageMimeType(){
return homePageMimeType;
}
/**
* <p>Set the MIME type of the custom home page.</p>
*
* <p>A NULL value will be considered as "text/html".</p>
*
* @param mime MIME type of the custom home page.
*/
public final void setHomePageMimeType(final String mime){
homePageMimeType = (mime == null || mime.trim().length() == 0) ? "text/html" : mime.trim();
}
/**
* <p>Generate a unique ID for the given request.</p>
*
* <p>By default, a timestamp is returned.</p>
*
* @param request Request whose an ID is asked.
*
* @return The ID of the given request.
*
* @since 2.0
*/
protected synchronized String generateRequestID(final HttpServletRequest request){
String id;
do{
id = System.currentTimeMillis() + "";
}while(lastRequestID != null && lastRequestID.startsWith(id));
lastRequestID = id;
return id;
}
/**
* <p>Execute the given request in the TAP service by forwarding it to the appropriate resource.</p>
*
* <h3>Home page</h3>
* <p>
* If the appropriate resource is the home page, the request is not propagated and
* this class/resource displays directly the home page in the given response by calling {@link #writeHomePage(HttpServletResponse, JobOwner)}.
* The default implementation of this function takes 2 cases into account:
* </p>
* <ol>
* <li><b>A custom home page has been specified</b> using {@link #setHomePageURI(String)}. In this case, the content of the URL or file path will
* be directly copied into the HTTP response. The content type of the response must be specified by
* {@link #setHomePageMimeType(String)} ; by default, it is "text/html".</li>
* <li><b>Default home page.</b> When no custom home page has been specified, a default content is displayed. It is an HTML document which merely
* lists all resources available in this TAP service.</li>
* </ol>
*
* <h3>Error/Exception management</h3>
* <p>
* Only this resource (the root) should write any errors in the response. For that, it catches any {@link Throwable} and
* write an appropriate message in the HTTP response. The format and the content of this message is designed by the {@link ServiceErrorWriter}
* set in this class. By changing it, it is then possible to change, for instance, the format of the error responses.
* </p>
*
* <h3>Request ID & Log</h3>
* <p>
* Each request is identified by a unique identifier (see {@link #generateRequestID(HttpServletRequest)}).
* This ID is used only for logging purpose. Request and jobs/threads can then be associated more easily in the logs.
* Besides, every requests and their response are logged as INFO with this ID.
* </p>
*
* @param request Request of the user to execute in this TAP service.
* @param response Object in which the result of the request must be written.
*
* @throws ServletException If any grave/fatal error occurs.
* @throws IOException If any error occurs while reading or writing from or into a stream (and particularly the given request or response).
*/
public void executeRequest(final HttpServletRequest request, final HttpServletResponse response) throws ServletException, IOException{
if (request == null || response == null)
return;
// Generate a unique ID for this request execution (for log purpose only):
final String reqID = generateRequestID(request);
if (request.getAttribute(UWS.REQ_ATTRIBUTE_ID) == null)
request.setAttribute(UWS.REQ_ATTRIBUTE_ID, reqID);
// Extract all parameters:
if (request.getAttribute(UWS.REQ_ATTRIBUTE_PARAMETERS) == null){
try{
request.setAttribute(UWS.REQ_ATTRIBUTE_PARAMETERS, getUWS().getRequestParser().parse(request));
}catch(UWSException ue){
getLogger().log(LogLevel.ERROR, "REQUEST_PARSER", "Can not extract the HTTP request parameters!", ue);
}
}
// Retrieve the resource path parts:
String[] resourcePath = (request.getPathInfo() == null) ? null : request.getPathInfo().split("/");
final String resourceName = (resourcePath == null || resourcePath.length < 1) ? "homePage" : resourcePath[1].trim().toLowerCase();
// Log the reception of the request, only if the asked resource is not UWS (because UWS is already logging the received request):
if (!resourceName.equalsIgnoreCase(ASync.RESOURCE_NAME))
getLogger().logHttp(LogLevel.INFO, request, reqID, null, null);
// Initialize the base URL of this TAP service by guessing it from the received request:
if (tapBaseURL == null){
// initialize the base URL:
setTAPBaseURL(request);
// log the successful initialization:
getLogger().logUWS(LogLevel.INFO, this, "INIT", "TAP successfully initialized.", null);
}
JobOwner owner = null;
try{
// Identify the user:
try{
if (service.getUserIdentifier() != null)
owner = service.getUserIdentifier().extractUserId(new UWSUrl(request), request);
}catch(UWSException ue){
throw new TAPException(ue);
}
// Display the TAP Main Page:
if (resourceName.equals("homePage"))
writeHomePage(response, owner);
// or Display/Execute the selected TAP Resource:
else{
// search for the corresponding resource:
TAPResource res = resources.get(resourceName);
// if one is found, execute it:
if (res != null)
res.executeResource(request, response);
// otherwise, throw an error:
else
throw new TAPException("Unknown TAP resource: \"" + resourceName + "\"!", UWSException.NOT_IMPLEMENTED);
}
response.flushBuffer();
// Log the successful execution of the action, only if the asked resource is not UWS (because UWS is already logging the received request):
if (!resourceName.equalsIgnoreCase(ASync.RESOURCE_NAME))
getLogger().logHttp(LogLevel.INFO, response, reqID, owner, "HTTP " + UWSException.OK + " - Action \"" + resourceName + "\" successfully executed.", null);
}catch(Throwable t){
// Write the error in the response and return the appropriate HTTP status code:
errorWriter.writeError(t, response, request, reqID, owner, resourceName);
// Log the error:
getLogger().logHttp(LogLevel.ERROR, response, reqID, owner, "HTTP " + response.getStatus() + " - Can not complete the execution of the TAP resource \"" + resourceName + "\"!", t);
}finally{
// Notify the queue of the asynchronous jobs that a new connection is available:
if (resourceName.equalsIgnoreCase(Sync.RESOURCE_NAME) && service.getFactory().countFreeConnections() >= 1)
getASync().freeConnectionAvailable();
}
}
/**
* <p>Write the content of the home page in the given writer.</p>
*
* <p>This content can be:</p>
* <ul>
* <li><b>a distance document</b> if a URL has been provided to this class using {@link #setHomePageURI(String)}.
* In this case, the content of the distant document is copied in the given writer.
* No redirection is done.</li>
* <li><b>a local file</b> if a file path has been provided to this class using {@link #setHomePageURI(String)}.
* In this case, the content of the local file is copied in the given writer.</li>
* <li><b>a default content</b> if no custom home page has been specified using {@link #setHomePageURI(String)}.
* This default home page is hard-coded in this function and displays just an HTML list of
* links. There is one link for each resources of this TAP service.</li>
* </ul>
*
* @param response {@link HttpServletResponse} in which the home page must be written.
* @param owner The identified user who asked this home page.
*
* @throws IOException If any error occurs while writing the home page in the given HTTP response.
*/
public void writeHomePage(final HttpServletResponse response, final JobOwner owner) throws IOException{
PrintWriter writer = response.getWriter();
// By default, list all available resources:
if (homePageURI == null){
// Set the content type: HTML document
response.setContentType("text/html");
// Write the home page:
writer.println("<html><head><title>TAP HOME PAGE</title></head><body><h1 style=\"text-align: center\">TAP HOME PAGE</h1><h2>Available resources:</h2><ul>");
for(TAPResource res : resources.values())
writer.println("<li><a href=\"" + tapBaseURL + "/" + res.getName() + "\">" + res.getName() + "</a></li>");
writer.println("</ul></body></html>");
}
// or Display the specified home page:
else{
response.setContentType(homePageMimeType);
// Get an input toward the custom home page:
BufferedInputStream input = null;
try{
// CASE: URL => distant document
input = new BufferedInputStream((new URL(homePageURI)).openStream());
}catch(MalformedURLException mue){
// CASE: file path => local file
input = new BufferedInputStream(new FileInputStream(new File(homePageURI)));
}
// Copy the content of the input into the given writer:
byte[] buffer = new byte[255];
int nbReads = 0;
while((nbReads = input.read(buffer)) > 0)
writer.print(new String(buffer, 0, nbReads));
}
}
}