REST_Quads_RW.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.jena.fuseki.servlets ;

import org.apache.jena.fuseki.FusekiLib ;
import org.apache.jena.riot.RiotException ;
import org.apache.jena.riot.system.StreamRDF ;
import org.apache.jena.riot.system.StreamRDFLib ;
import org.apache.jena.riot.web.HttpNames ;
import org.apache.jena.sparql.core.DatasetGraph ;
import org.apache.jena.sparql.core.DatasetGraphFactory ;

/**
 * Servlet for operations directly on a dataset - REST(ish) behaviour on the
 * dataset URI.
 */

public class REST_Quads_RW extends REST_Quads_R {

    private static final long serialVersionUID = 4752486333862676195L;

    public REST_Quads_RW() {
        super() ;
    }

    @Override
    protected void validate(HttpAction action) { 
    }
    
    @Override
    protected void doOptions(HttpAction action) {
        setCommonHeadersForOptions(action.response) ;
        action.response.setHeader(HttpNames.hAllow, "GET,HEAD,OPTIONS,PUT,POST");
        action.response.setHeader(HttpNames.hContentLengh, "0") ;
        ServletOps.success(action) ;
    }
    
    @Override
    protected void doPost(HttpAction action) {
        if ( !action.getDataService().allowUpdate() )
            ServletOps.errorMethodNotAllowed("POST") ;

        if ( action.isTransactional() )
            doPutPostTxn(action, false) ;
        else
            doPutPostNonTxn(action, false) ;
    }

    @Override
    protected void doPut(HttpAction action) {
        if ( !action.getDataService().allowUpdate() )
            ServletOps.errorMethodNotAllowed("POST") ;

        if ( action.isTransactional() )
            doPutPostTxn(action, true) ;
        else
            doPutPostNonTxn(action, true) ;
    }

    // These are very similar to SPARQL_REST_RW.addDataIntoTxn/nonTxn
    // Maybe can be usually DRYed.

    @Override
    protected void doDelete(HttpAction action) {
        ServletOps.errorMethodNotAllowed("DELETE") ;
    }

    @Override
    protected void doPatch(HttpAction action) {
        ServletOps.errorMethodNotAllowed("PATCH") ;
    }

    private void doPutPostTxn(HttpAction action, boolean clearFirst) {
        UploadDetails details = null ;
        action.beginWrite() ;
        try {
            DatasetGraph dsg = action.getActiveDSG() ;
            if ( clearFirst )
                dsg.clear() ;
            StreamRDF dest = StreamRDFLib.dataset(dsg) ;
            details = Upload.incomingData(action, dest) ;
            action.commit() ;
            ServletOps.success(action) ;
        } catch (RiotException ex) {
            // Parse error
            action.abort() ;
            ServletOps.errorBadRequest(ex.getMessage()) ;
        } catch (ActionErrorException ex) {
            action.abort() ;
            throw ex ;
        } catch (Exception ex) {
            // Something else went wrong. Backout.
            action.abort() ;
            ServletOps.errorOccurred(ex.getMessage()) ;
        } finally {
            action.endWrite() ;
        }
        ServletOps.uploadResponse(action, details) ;
    }
    
    private void doPutPostNonTxn(HttpAction action, boolean clearFirst) {
        DatasetGraph dsgTmp = DatasetGraphFactory.create() ;
        StreamRDF dest = StreamRDFLib.dataset(dsgTmp) ;

        UploadDetails details ;
        try {
            details = Upload.incomingData(action, dest) ;
        } catch (RiotException ex) {
            ServletOps.errorBadRequest(ex.getMessage()) ;
            return ;
        }
        // Now insert into dataset
        action.beginWrite() ;
        try {
            DatasetGraph dsg = action.getActiveDSG() ;
            if ( clearFirst )
                dsg.clear() ;
            FusekiLib.addDataInto(dsgTmp, dsg) ;
            action.commit() ;
            ServletOps.success(action) ;
        } catch (Exception ex) {
            // We're in the non-transactional branch, this probably will not
            // work
            // but it might and there is no harm safely trying.
            try {
                action.abort() ;
            } catch (Exception ex2) {}
            ServletOps.errorOccurred(ex.getMessage()) ;
        } finally {
            action.endWrite() ;
        }
        ServletOps.uploadResponse(action, details) ;
    }
}