Mercurial > dive4elements > river
comparison flys-artifacts/src/main/java/de/intevation/flys/exports/AbstractExporter.java @ 391:5d6988836f01
Added an exporter to export the computed data of a duration curve.
flys-artifacts/trunk@1814 c6561f87-3c4e-4783-a992-168aeb5c3f6f
| author | Ingo Weinzierl <ingo.weinzierl@intevation.de> |
|---|---|
| date | Tue, 03 May 2011 17:37:56 +0000 |
| parents | |
| children | 046bd86ae41d |
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| 390:a67748ad4d61 | 391:5d6988836f01 |
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| 1 package de.intevation.flys.exports; | |
| 2 | |
| 3 import java.io.IOException; | |
| 4 import java.io.OutputStream; | |
| 5 import java.io.OutputStreamWriter; | |
| 6 | |
| 7 import org.w3c.dom.Document; | |
| 8 | |
| 9 import org.apache.log4j.Logger; | |
| 10 | |
| 11 import au.com.bytecode.opencsv.CSVWriter; | |
| 12 | |
| 13 import de.intevation.artifacts.Artifact; | |
| 14 import de.intevation.artifacts.CallContext; | |
| 15 | |
| 16 | |
| 17 /** | |
| 18 * An abstract exporter that implements some basic methods for exporting data of | |
| 19 * artifacts. | |
| 20 * | |
| 21 * @author <a href="mailto:ingo.weinzierl@intevation.de">Ingo Weinzierl</a> | |
| 22 */ | |
| 23 public abstract class AbstractExporter implements OutGenerator { | |
| 24 | |
| 25 /** The logger used in this exporter.*/ | |
| 26 private static Logger logger = Logger.getLogger(AbstractExporter.class); | |
| 27 | |
| 28 | |
| 29 /** The name of the CSV facet which triggers the CSV creation.*/ | |
| 30 public static final String FACET_CSV = "csv"; | |
| 31 | |
| 32 /** The default charset for the CSV export.*/ | |
| 33 public static final String DEFAULT_CSV_CHARSET = "UTF-8"; | |
| 34 | |
| 35 /** The default separator for the CSV export.*/ | |
| 36 public static final char DEFAULT_CSV_SEPARATOR = ','; | |
| 37 | |
| 38 | |
| 39 /** The document of the incoming out() request.*/ | |
| 40 protected Document request; | |
| 41 | |
| 42 /** The output stream where the data should be written to.*/ | |
| 43 protected OutputStream out; | |
| 44 | |
| 45 /** The CallContext object.*/ | |
| 46 protected CallContext context; | |
| 47 | |
| 48 /** The selected facet.*/ | |
| 49 protected String facet; | |
| 50 | |
| 51 | |
| 52 /** | |
| 53 * Concrete subclasses need to use this method to write their special data | |
| 54 * objects into the CSV document. | |
| 55 * | |
| 56 * @param writer The CSVWriter. | |
| 57 */ | |
| 58 protected abstract void writeCSVData(CSVWriter writer); | |
| 59 | |
| 60 | |
| 61 /** | |
| 62 * This method enables concrete subclasses to collected its own special | |
| 63 * data. | |
| 64 * | |
| 65 * @param artifacts The artifact that stores the data that has to be | |
| 66 * exported. | |
| 67 */ | |
| 68 protected abstract void addData(Artifact artifact); | |
| 69 | |
| 70 | |
| 71 public void init(Document request, OutputStream out, CallContext context) { | |
| 72 logger.debug("AbstractExporter.init"); | |
| 73 | |
| 74 this.request = request; | |
| 75 this.out = out; | |
| 76 this.context = context; | |
| 77 } | |
| 78 | |
| 79 | |
| 80 /** | |
| 81 * This doOut() just collects the data of multiple artifacts. Therefore, it | |
| 82 * makes use of the addData() method which enables concrete subclasses to | |
| 83 * store its data on its own. The real output creation takes place in the | |
| 84 * concrete generate() methods. | |
| 85 * | |
| 86 * @param artifact The artifact. | |
| 87 * @param facet The facet to add - NOTE: the facet needs to fit to the first | |
| 88 * facet inserted into this exporter. Otherwise this artifact/facet is | |
| 89 * skipped. | |
| 90 * @param attr The attr document. | |
| 91 */ | |
| 92 public void doOut(Artifact artifact, String facet, Document attr) { | |
| 93 logger.debug("AbstractExporter.doOut: " + facet); | |
| 94 | |
| 95 if (!isFacetValid(facet)) { | |
| 96 logger.warn("Facet '" + facet + "' not valid. No output created!"); | |
| 97 return; | |
| 98 } | |
| 99 | |
| 100 addData(artifact); | |
| 101 } | |
| 102 | |
| 103 | |
| 104 /** | |
| 105 * Generates an export based on a specified facet. | |
| 106 */ | |
| 107 public void generate() | |
| 108 throws IOException | |
| 109 { | |
| 110 logger.debug("AbstractExporter.generate"); | |
| 111 | |
| 112 if (facet != null && facet.equals(FACET_CSV)) { | |
| 113 generateCSV(); | |
| 114 } | |
| 115 else { | |
| 116 throw new IOException("invalid facet for exporter."); | |
| 117 } | |
| 118 } | |
| 119 | |
| 120 | |
| 121 /** | |
| 122 * Determines if the desired facet is valid for this exporter. If no facet | |
| 123 * is currently set, <i>facet</i> is set. | |
| 124 * | |
| 125 * @param facet The desired facet. | |
| 126 * | |
| 127 * @return true, if <i>facet</i> is valid, otherwise false. | |
| 128 */ | |
| 129 protected boolean isFacetValid(String facet) { | |
| 130 logger.debug("AbstractExporter.isFacetValid"); | |
| 131 | |
| 132 if (facet == null || facet.length() == 0) { | |
| 133 return false; | |
| 134 } | |
| 135 else if (this.facet == null || this.facet.length() == 0) { | |
| 136 logger.debug("Set the facet of this export: " + facet); | |
| 137 this.facet = facet; | |
| 138 | |
| 139 return true; | |
| 140 } | |
| 141 else { | |
| 142 return this.facet.equals(facet); | |
| 143 } | |
| 144 } | |
| 145 | |
| 146 | |
| 147 /** | |
| 148 * This method starts CSV creation. It makes use of writeCSVData() which has | |
| 149 * to be implemented by concrete subclasses. | |
| 150 */ | |
| 151 protected void generateCSV() | |
| 152 throws IOException | |
| 153 { | |
| 154 logger.info("AbstractExporter.generateCSV"); | |
| 155 | |
| 156 CSVWriter writer = new CSVWriter( | |
| 157 new OutputStreamWriter( | |
| 158 out, | |
| 159 DEFAULT_CSV_CHARSET), | |
| 160 DEFAULT_CSV_SEPARATOR); | |
| 161 | |
| 162 writeCSVData(writer); | |
| 163 | |
| 164 writer.close(); | |
| 165 } | |
| 166 } | |
| 167 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 : |