| commit | author | age | ||
| b379f5 | 1 | /* |
| 5f70da | 2 | Mediazentrale - Personal Media Center |
| U | 3 | Copyright (C) 2021 Ulrich Hilger |
| 4 | ||
| 5 | This program is free software: you can redistribute it and/or modify | |
| 6 | it under the terms of the GNU Affero General Public License as | |
| 7 | published by the Free Software Foundation, either version 3 of the | |
| 8 | License, or (at your option) any later version. | |
| 9 | ||
| 10 | This program is distributed in the hope that it will be useful, | |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 13 | GNU Affero General Public License for more details. | |
| 14 | ||
| 15 | You should have received a copy of the GNU Affero General Public License | |
| 16 | along with this program. If not, see <https://www.gnu.org/licenses/>. | |
| b379f5 | 17 | */ |
| U | 18 | package de.uhilger.mediaz.api; |
| 19 | ||
| 20 | import com.google.gson.Gson; | |
| a43e1a | 21 | import com.google.gson.GsonBuilder; |
| b379f5 | 22 | import com.sun.net.httpserver.HttpExchange; |
| U | 23 | import com.sun.net.httpserver.HttpHandler; |
| 24 | import de.uhilger.mediaz.App; | |
| 25 | import de.uhilger.mediaz.Server; | |
| 2b5c60 | 26 | import static de.uhilger.mediaz.Server.RB_SLASH; |
| 081606 | 27 | import de.uhilger.mediaz.store.FileStorage; |
| b1bf96 | 28 | import de.uhilger.mediaz.entity.Entity; |
| b379f5 | 29 | import java.io.BufferedReader; |
| 081606 | 30 | import java.io.File; |
| b379f5 | 31 | import java.io.IOException; |
| U | 32 | import java.io.InputStream; |
| 33 | import java.io.InputStreamReader; | |
| 34 | import java.io.OutputStream; | |
| 2b5c60 | 35 | import java.util.List; |
| 081606 | 36 | import java.util.logging.Level; |
| b379f5 | 37 | import java.util.logging.Logger; |
| U | 38 | |
| 39 | /** | |
| 5f70da | 40 | * HttpHandler fuer die Ablage von Entitaeten der Mediazentrale |
| U | 41 | * |
| 42 | * @author Ulrich Hilger | |
| 43 | * @version 1, 5.4.2021 | |
| b379f5 | 44 | */ |
| 081606 | 45 | public class StorageHandler implements HttpHandler { |
| b379f5 | 46 | |
| 081606 | 47 | private static final Logger logger = Logger.getLogger(StorageHandler.class.getName()); |
| b379f5 | 48 | |
| U | 49 | |
| 50 | /* | |
| 2b5c60 | 51 | Das REST-Muster sieht je Entitaet fuenf Faelle vor (Beispiel Ablageort): |
| U | 52 | |
| 53 | 1. HTTP GET Ablageort/[Name]: Liefere den Ablageort als JSON | |
| 54 | 2. HTTP GET Ablageort/: Liefere einer Liste von Ablageorten als JSON | |
| 55 | 3. HTTP PUT: schreibe einen neuen Ablageort auf die Platte | |
| 56 | 4. HTTP POST: schreibe Aenderungen auf die Platte | |
| 57 | 5. HTTP DELETE: loesche den Ablageort | |
| b379f5 | 58 | |
| U | 59 | Beispiele: |
| 2b5c60 | 60 | |
| U | 61 | HTTP GET an /mz/api/store/Ablageort/ |
| 62 | liefert eine Liste der Namen vorhandener Ablageorte | |
| b379f5 | 63 | |
| U | 64 | HTTP GET an /mz/api/store/Ablageort/Katalog |
| 65 | liest den Ablageort namens "Katalog" | |
| 66 | ||
| 67 | HTTP POST an /mz/api/store/Ablageort | |
| 081606 | 68 | schreibt den neuen Ablageort im Body der Anfrage (Neu) |
| b379f5 | 69 | |
| U | 70 | HTTP PUT an /mz/api/store/Ablageort |
| 71 | sucht den Ablageort mit dem Namen laut Body der Anfrage | |
| 081606 | 72 | und schreibt den Inhalt aus der Anfrage in die Datei (Aenderung) |
| b379f5 | 73 | |
| U | 74 | HTTP DELETE an /mz/api/store/Ablageort/Katalog |
| 75 | löscht den Ablageort namens "Katalog" | |
| 76 | ||
| 77 | */ | |
| 78 | ||
| 2b5c60 | 79 | /** Name der HTTP Methode GET */ |
| b379f5 | 80 | public static final String HTTP_GET = "GET"; |
| 2b5c60 | 81 | |
| U | 82 | /** Name der HTTP Methode PUT */ |
| b379f5 | 83 | public static final String HTTP_PUT = "PUT"; |
| 2b5c60 | 84 | |
| U | 85 | /** Name der HTTP Methode POST */ |
| b379f5 | 86 | public static final String HTTP_POST = "POST"; |
| 2b5c60 | 87 | |
| U | 88 | /** Name der HTTP Methode DELETE */ |
| b379f5 | 89 | public static final String HTTP_DELETE = "DELETE"; |
| U | 90 | |
| 91 | @Override | |
| 92 | public void handle(HttpExchange e) throws IOException { | |
| 93 | String method = e.getRequestMethod(); | |
| 5f70da | 94 | String response = ""; |
| U | 95 | int code = 200; |
| b379f5 | 96 | switch(method) { |
| U | 97 | case HTTP_GET: |
| 5f70da | 98 | String json = lesen(e); |
| U | 99 | if(json != null) { |
| 100 | response = json; | |
| 101 | } else { | |
| 102 | response = "nicht gefunden"; | |
| 103 | code = 404; | |
| 104 | } | |
| b379f5 | 105 | break; |
| U | 106 | |
| 107 | case HTTP_PUT: | |
| 2b5c60 | 108 | response = aendern(e); |
| b379f5 | 109 | break; |
| U | 110 | |
| 111 | case HTTP_POST: | |
| 5f70da | 112 | response = neu(e); |
| b379f5 | 113 | break; |
| U | 114 | |
| 115 | case HTTP_DELETE: | |
| 2b5c60 | 116 | boolean geloescht = loeschen(e); |
| U | 117 | if(geloescht) { |
| 118 | response = "geloescht"; | |
| 119 | } else { | |
| 120 | response = "nicht geloescht"; | |
| 121 | } | |
| b379f5 | 122 | break; |
| U | 123 | } |
| 124 | logger.info(response); | |
| 5f70da | 125 | e.sendResponseHeaders(code, response.length()); |
| b379f5 | 126 | OutputStream os = e.getResponseBody(); |
| U | 127 | os.write(response.getBytes()); |
| 128 | os.close(); | |
| b1bf96 | 129 | } |
| U | 130 | |
| 5f70da | 131 | private String neu(HttpExchange e) throws IOException { |
| b1bf96 | 132 | String path = e.getRequestURI().toString(); |
| U | 133 | String[] elems = path.split(App.getRs(Server.RB_SLASH)); |
| 134 | String type = elems[elems.length - 1]; | |
| 135 | String body = bodyLesen(e); | |
| 5f70da | 136 | String filename = ""; |
| b1bf96 | 137 | FileStorage fs = new FileStorage(App.getInitParameter(App.getRs(App.RB_AP_CONF))); |
| U | 138 | Gson gson = new Gson(); |
| 139 | logger.log(Level.INFO, "type: {0}", type); | |
| 140 | Object o = gson.fromJson(body, fs.typeFromName(type).getType()); | |
| 141 | if(o instanceof Entity) { | |
| 142 | Object antwortObjekt = fs.write((Entity) o); | |
| 143 | if(antwortObjekt instanceof File) { | |
| 144 | File file = (File) antwortObjekt; | |
| 145 | logger.log(Level.INFO, "Datei {0} geschrieben.", file.getAbsolutePath()); | |
| 5f70da | 146 | filename = file.getName(); |
| b1bf96 | 147 | } |
| U | 148 | } |
| 5f70da | 149 | return type + FileHandler.STR_BLANK + filename; |
| b1bf96 | 150 | } |
| U | 151 | |
| 2b5c60 | 152 | private String aendern(HttpExchange e) throws IOException { |
| U | 153 | return neu(e); // einstweilen wird einfach ueberschrieben |
| b1bf96 | 154 | } |
| U | 155 | |
| 2b5c60 | 156 | private boolean loeschen(HttpExchange e) { |
| 5f70da | 157 | String path = e.getRequestURI().toString(); |
| U | 158 | String[] elems = path.split(App.getRs(Server.RB_SLASH)); |
| 159 | String type = elems[elems.length - 2]; | |
| 160 | String elemName = elems[elems.length - 1]; | |
| 161 | FileStorage fs = new FileStorage(App.getInitParameter(App.getRs(App.RB_AP_CONF))); | |
| 2b5c60 | 162 | return fs.delete(type, elemName); |
| U | 163 | } |
| 164 | ||
| 165 | private String lesen(HttpExchange e) { | |
| 166 | String path = e.getRequestURI().toString(); | |
| 167 | String[] elems = path.split(App.getRs(Server.RB_SLASH)); | |
| 168 | FileStorage fs = new FileStorage(App.getInitParameter(App.getRs(App.RB_AP_CONF))); | |
| 169 | if(path.endsWith(App.getRs(RB_SLASH))) { | |
| 170 | String type = elems[elems.length - 1]; | |
| 171 | logger.info(type); | |
| 172 | List list = fs.list(type); | |
| a43e1a | 173 | return jsonWithEnclosingType(list); |
| 2b5c60 | 174 | } else { |
| U | 175 | String type = elems[elems.length - 2]; |
| 176 | String elemName = elems[elems.length - 1]; | |
| 177 | return fs.readJson(type, elemName); | |
| 178 | } | |
| b379f5 | 179 | } |
| U | 180 | |
| a43e1a | 181 | private String jsonWithEnclosingType(Object o) { |
| U | 182 | StringBuilder sb = new StringBuilder(); |
| 183 | sb.append("{\""); | |
| 184 | sb.append(o.getClass().getSimpleName()); | |
| 185 | sb.append("\": "); | |
| 186 | Gson gson = new Gson(); | |
| 187 | sb.append(gson.toJson(o)); | |
| 188 | sb.append("}"); | |
| 189 | return sb.toString(); | |
| 190 | } | |
| 191 | ||
| b379f5 | 192 | |
| U | 193 | private String bodyLesen(HttpExchange e) throws IOException { |
| 194 | InputStream is = e.getRequestBody(); | |
| 195 | BufferedReader r = new BufferedReader(new InputStreamReader(is)); | |
| 196 | StringBuilder sb = new StringBuilder(); | |
| 197 | String line = r.readLine(); | |
| 198 | while(line != null) { | |
| 199 | sb.append(line); | |
| 200 | line = r.readLine(); | |
| 201 | } | |
| 202 | r.close(); | |
| 203 | String json = sb.toString(); | |
| b1bf96 | 204 | logger.log(Level.INFO, "json: {0}", json); |
| b379f5 | 205 | return json; |
| U | 206 | } |
| 207 | } | |
