Java tutorial
/* Copyright (c) 2001 - 2013 OpenPlans - www.openplans.org. All rights reserved. * This code is licensed under the GPL 2.0 license, available at the root * application directory. */ package org.geoserver.wps.executor; import java.io.InputStream; import java.net.URL; import java.net.URLConnection; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Map; import net.opengis.wcs11.GetCoverageType; import net.opengis.wfs.GetFeatureType; import net.opengis.wps10.ComplexDataType; import net.opengis.wps10.DataType; import net.opengis.wps10.ExecuteType; import net.opengis.wps10.HeaderType; import net.opengis.wps10.InputReferenceType; import net.opengis.wps10.InputType; import net.opengis.wps10.LiteralDataType; import net.opengis.wps10.MethodType; import org.apache.commons.httpclient.HttpClient; import org.apache.commons.httpclient.HttpConnectionManager; import org.apache.commons.httpclient.HttpMethod; import org.apache.commons.httpclient.SimpleHttpConnectionManager; import org.apache.commons.httpclient.methods.GetMethod; import org.apache.commons.httpclient.methods.InputStreamRequestEntity; import org.apache.commons.httpclient.methods.PostMethod; import org.apache.commons.httpclient.methods.StringRequestEntity; import org.apache.commons.httpclient.params.HttpConnectionManagerParams; import org.geoserver.ows.Dispatcher; import org.geoserver.ows.KvpRequestReader; import org.geoserver.ows.Request; import org.geoserver.ows.util.CaseInsensitiveMap; import org.geoserver.ows.util.KvpMap; import org.geoserver.ows.util.KvpUtils; import org.geoserver.wcs.CoverageCleanerCallback; import org.geoserver.wcs.WebCoverageService100; import org.geoserver.wcs.WebCoverageService111; import org.geoserver.wfs.WebFeatureService; import org.geoserver.wfs.kvp.GetFeatureKvpRequestReader; import org.geoserver.wfs.request.FeatureCollectionResponse; import org.geoserver.wps.WPSException; import org.geoserver.wps.kvp.ExecuteKvpRequestReader; import org.geoserver.wps.ppio.BoundingBoxPPIO; import org.geoserver.wps.ppio.ComplexPPIO; import org.geoserver.wps.ppio.LiteralPPIO; import org.geoserver.wps.ppio.ProcessParameterIO; import org.geoserver.wps.resource.GridCoverageResource; import org.opengis.coverage.Coverage; import org.opengis.coverage.grid.GridCoverage; import org.springframework.context.ApplicationContext; /** * Performs lazy parsing of a specific input * * @author Andrea Aime - GeoSolutions * */ class SimpleInputProvider implements InputProvider { InputType input; ProcessParameterIO ppio; Object value; ApplicationContext context; WPSExecutionManager executor; String inputId; public SimpleInputProvider(InputType input, ProcessParameterIO ppio, WPSExecutionManager executor, ApplicationContext context) { this.input = input; this.ppio = ppio; this.context = context; this.executor = executor; this.inputId = input.getIdentifier().getValue(); } public String getInputId() { return inputId; } public boolean longParse() { if (input.getReference() == null) { return false; } else { InputReferenceType ref = input.getReference(); // grab the location and method String href = ref.getHref(); if (href.startsWith("http://geoserver/wfs")) { // we get a collection almost instantly return false; } else if (href.startsWith("http://geoserver/wcs")) { // same here, most of the time we get a coverage reference almost instantly return false; } else { return true; } } } public Object getValue() throws Exception { if (value == null) { if (input.getReference() != null) { // this is a reference InputReferenceType ref = input.getReference(); // grab the location and method String href = ref.getHref(); if (href.startsWith("http://geoserver/wfs")) { value = handleAsInternalWFS(ppio, ref); } else if (href.startsWith("http://geoserver/wcs")) { value = handleAsInternalWCS(ppio, ref); } else if (href.startsWith("http://geoserver/wps")) { value = handleAsInternalWPS(ppio, ref); } else { value = executeRemoteRequest(ref, (ComplexPPIO) ppio, inputId); } } else { // actual data, figure out which type DataType data = input.getData(); if (data.getLiteralData() != null) { LiteralDataType literal = data.getLiteralData(); value = ((LiteralPPIO) ppio).decode(literal.getValue()); } else if (data.getComplexData() != null) { ComplexDataType complex = data.getComplexData(); value = ((ComplexPPIO) ppio).decode(complex.getData().get(0)); } else if (data.getBoundingBoxData() != null) { value = ((BoundingBoxPPIO) ppio).decode(data.getBoundingBoxData()); } } if (value instanceof GridCoverage) { executor.getResourceManager().addResource(new GridCoverageResource((GridCoverage) value)); } // release the input, it's not needed anymore input = null; } return value; } /** * Process the request as an internal one, without going through GML encoding/decoding * * @param ppio * @param ref * @param method * @return * @throws Exception */ Object handleAsInternalWFS(ProcessParameterIO ppio, InputReferenceType ref) throws Exception { WebFeatureService wfs = (WebFeatureService) context.getBean("wfsServiceTarget"); GetFeatureType gft = null; if (ref.getMethod() == MethodType.POST_LITERAL) { gft = (GetFeatureType) ref.getBody(); } else { GetFeatureKvpRequestReader reader = (GetFeatureKvpRequestReader) context.getBean("getFeatureKvpReader"); gft = (GetFeatureType) kvpParse(ref.getHref(), reader); } FeatureCollectionResponse featureCollectionType = wfs.getFeature(gft); // this will also deal with axis order issues return ((ComplexPPIO) ppio).decode(featureCollectionType.getAdaptee()); } /** * Process the request as an internal one, without going through GML encoding/decoding * * @param ppio * @param ref * @param method * @return * @throws Exception */ Object handleAsInternalWPS(ProcessParameterIO ppio, InputReferenceType ref) throws Exception { ExecuteType request = null; if (ref.getMethod() == MethodType.POST_LITERAL) { request = (ExecuteType) ref.getBody(); } else { ExecuteKvpRequestReader reader = (ExecuteKvpRequestReader) context.getBean("executeKvpRequestReader"); request = (ExecuteType) kvpParse(ref.getHref(), reader); } Map<String, Object> results = executor.submitChained(new ExecuteRequest(request)); Object obj = results.values().iterator().next(); if (obj != null && !ppio.getType().isInstance(obj)) { throw new WPSException("The process output is incompatible with the input target type, was expecting " + ppio.getType().getName() + " and got " + obj.getClass().getName()); } return obj; } /** * Process the request as an internal one, without going through GML encoding/decoding * * @param ppio * @param ref * @param method * @return * @throws Exception */ Object handleAsInternalWCS(ProcessParameterIO ppio, InputReferenceType ref) throws Exception { // first parse the request, it might be a WCS 1.0 or a WCS 1.1 one Object getCoverage = null; if (ref.getMethod() == MethodType.POST_LITERAL) { getCoverage = ref.getBody(); } else { // what WCS version? String version = getVersion(ref.getHref()); KvpRequestReader reader; if (version.equals("1.0.0") || version.equals("1.0")) { reader = (KvpRequestReader) context.getBean("wcs100GetCoverageRequestReader"); } else { reader = (KvpRequestReader) context.getBean("wcs111GetCoverageRequestReader"); } getCoverage = kvpParse(ref.getHref(), reader); } // perform GetCoverage if (getCoverage instanceof GetCoverageType) { WebCoverageService111 wcs = (WebCoverageService111) context.getBean("wcs111ServiceTarget"); return wcs.getCoverage((net.opengis.wcs11.GetCoverageType) getCoverage)[0]; } else if (getCoverage instanceof net.opengis.wcs10.GetCoverageType) { WebCoverageService100 wcs = (WebCoverageService100) context.getBean("wcs100ServiceTarget"); return wcs.getCoverage((net.opengis.wcs10.GetCoverageType) getCoverage)[0]; } else { throw new WPSException("Unrecognized request type " + getCoverage); } } /** * Executes * * @param ref * @return */ Object executeRemoteRequest(InputReferenceType ref, ComplexPPIO ppio, String inputId) throws Exception { URL destination = new URL(ref.getHref()); HttpMethod method = null; GetMethod refMethod = null; InputStream input = null; InputStream refInput = null; // execute the request try { if ("http".equalsIgnoreCase(destination.getProtocol())) { // setup the client HttpClient client = new HttpClient(); // setting timeouts (30 seconds, TODO: make this configurable) HttpConnectionManagerParams params = new HttpConnectionManagerParams(); params.setSoTimeout(executor.getConnectionTimeout()); params.setConnectionTimeout(executor.getConnectionTimeout()); // TODO: make the http client a well behaved http client, no more than x connections // per server (x admin configurable maybe), persistent connections and so on HttpConnectionManager manager = new SimpleHttpConnectionManager(); manager.setParams(params); client.setHttpConnectionManager(manager); // prepare either a GET or a POST request if (ref.getMethod() == null || ref.getMethod() == MethodType.GET_LITERAL) { GetMethod get = new GetMethod(ref.getHref()); get.setFollowRedirects(true); method = get; } else { String encoding = ref.getEncoding(); if (encoding == null) { encoding = "UTF-8"; } PostMethod post = new PostMethod(ref.getHref()); Object body = ref.getBody(); if (body == null) { if (ref.getBodyReference() != null) { URL refDestination = new URL(ref.getBodyReference().getHref()); if ("http".equalsIgnoreCase(refDestination.getProtocol())) { // open with commons http client refMethod = new GetMethod(ref.getBodyReference().getHref()); refMethod.setFollowRedirects(true); client.executeMethod(refMethod); refInput = refMethod.getResponseBodyAsStream(); } else { // open with the built-in url management URLConnection conn = refDestination.openConnection(); conn.setConnectTimeout(executor.getConnectionTimeout()); conn.setReadTimeout(executor.getConnectionTimeout()); refInput = conn.getInputStream(); } post.setRequestEntity(new InputStreamRequestEntity(refInput, ppio.getMimeType())); } else { throw new WPSException("A POST request should contain a non empty body"); } } else if (body instanceof String) { post.setRequestEntity(new StringRequestEntity((String) body, ppio.getMimeType(), encoding)); } else { throw new WPSException("The request body should be contained in a CDATA section, " + "otherwise it will get parsed as XML instead of being preserved as is"); } method = post; } // add eventual extra headers if (ref.getHeader() != null) { for (Iterator it = ref.getHeader().iterator(); it.hasNext();) { HeaderType header = (HeaderType) it.next(); method.setRequestHeader(header.getKey(), header.getValue()); } } int code = client.executeMethod(method); if (code == 200) { input = method.getResponseBodyAsStream(); } else { throw new WPSException("Error getting remote resources from " + ref.getHref() + ", http error " + code + ": " + method.getStatusText()); } } else { // use the normal url connection methods then... URLConnection conn = destination.openConnection(); conn.setConnectTimeout(executor.getConnectionTimeout()); conn.setReadTimeout(executor.getConnectionTimeout()); input = conn.getInputStream(); } // actually parse teh data if (input != null) { return ppio.decode(input); } else { throw new WPSException("Could not find a mean to read input " + inputId); } } finally { // make sure to close the connection and streams no matter what if (input != null) { input.close(); } if (method != null) { method.releaseConnection(); } if (refMethod != null) { refMethod.releaseConnection(); } } } /** * Simulates what the Dispatcher is doing when parsing a KVP request * * @param href * @param reader * @return */ Object kvpParse(String href, KvpRequestReader reader) throws Exception { Map original = new KvpMap(KvpUtils.parseQueryString(href)); KvpUtils.normalize(original); Map parsed = new KvpMap(original); List<Throwable> errors = KvpUtils.parse(parsed); if (errors.size() > 0) { throw new WPSException("Failed to parse KVP request", errors.get(0)); } // hack to allow wcs filters to work... we should really upgrade the WCS models instead... Request r = Dispatcher.REQUEST.get(); if (r != null) { Map kvp = new HashMap(r.getKvp()); r.setKvp(new CaseInsensitiveMap(parsed)); } return reader.read(reader.createRequest(), parsed, original); } /** * Returns the version from the kvp request * * @param href * @return */ String getVersion(String href) { return (String) new KvpMap(KvpUtils.parseQueryString(href)).get("VERSION"); } @Override public boolean resolved() { return value != null; } }