001/*
002 * (C) Copyright 2006-2014 Nuxeo SA (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 * Contributors:
017 *     bstefanescu
018 */
019package org.nuxeo.connect.update.task.standalone.commands;
020
021import java.io.File;
022import java.io.IOException;
023import java.util.Map;
024
025import org.apache.commons.logging.Log;
026import org.apache.commons.logging.LogFactory;
027import org.w3c.dom.Element;
028import org.nuxeo.common.utils.FileRef;
029import org.nuxeo.connect.update.PackageException;
030import org.nuxeo.connect.update.ValidationStatus;
031import org.nuxeo.connect.update.task.Command;
032import org.nuxeo.connect.update.task.Task;
033import org.nuxeo.connect.update.util.IOUtils;
034import org.nuxeo.connect.update.xml.XmlWriter;
035
036/**
037 * The delete command. This command takes 2 arguments: the file path to delete and an optional md5. If md5 is set then
038 * the command fails if the target file has not the same md5.
039 * <p>
040 * The inverse of the delete command is a copy command.
041 *
042 * @author <a href="mailto:[email protected]">Bogdan Stefanescu</a>
043 */
044public class Delete extends AbstractCommand {
045
046    protected static final Log log = LogFactory.getLog(Delete.class);
047
048    public static final String ID = "delete";
049
050    protected File file; // the file to restore
051
052    protected String md5;
053
054    protected boolean onExit;
055
056    public Delete() {
057        super(ID);
058    }
059
060    public Delete(File file, String md5) {
061        this(file, md5, false);
062    }
063
064    public Delete(File file, String md5, boolean onExit) {
065        super(ID);
066        this.file = file;
067        this.md5 = md5;
068        this.onExit = onExit;
069    }
070
071    @Override
072    protected void doValidate(Task task, ValidationStatus status) {
073        if (file == null) {
074            status.addError("Invalid delete syntax: No file specified");
075            return;
076        }
077        if (file.isDirectory()) {
078            status.addError("Cannot delete directories: " + file.getName());
079        }
080    }
081
082    @Override
083    protected Command doRun(Task task, Map<String, String> prefs) throws PackageException {
084        try {
085            if (file.isFile()) {
086                if (md5 != null && !md5.equals(IOUtils.createMd5(file))) {
087                    // ignore the command since the md5 doesn't match
088                    return null;
089                }
090                File bak = IOUtils.backup(task.getPackage(), file);
091                if (onExit) {
092                    file.deleteOnExit();
093                } else {
094                    if (!file.delete()) {
095                        throw new PackageException("Cannot delete " + file.getName());
096                    }
097                }
098                return new Copy(bak, file, md5, false, onExit);
099            } else {
100                return null;
101            }
102        } catch (IOException e) {
103            throw new PackageException("Failed to create backup when deleting: " + file.getName(), e);
104        }
105    }
106
107    @Override
108    public void readFrom(Element element) throws PackageException {
109        String v = element.getAttribute("file");
110        if (v.length() > 0) {
111            FileRef ref = FileRef.newFileRef(v);
112            ref.fillPatternVariables(guardVars);
113            file = ref.getFile();
114            guardVars.put("file", file);
115        }
116        v = element.getAttribute("md5");
117        if (v.length() > 0) {
118            md5 = v;
119        }
120        v = element.getAttribute("onExit");
121        if (v.length() > 0) {
122            onExit = Boolean.parseBoolean(v);
123        }
124    }
125
126    @Override
127    public void writeTo(XmlWriter writer) {
128        writer.start(ID);
129        if (file != null) {
130            writer.attr("file", file.getAbsolutePath());
131        }
132        if (md5 != null) {
133            writer.attr("md5", md5);
134        }
135        if (onExit) {
136            writer.attr("onExit", "true");
137        }
138        writer.end();
139    }
140}