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    1   /*
    2    * Created on Aug 12, 2004 by mgreer
    3    */
    4   package org.apache.struts2.sitegraph;
    5
    6   import java.io.ByteArrayOutputStream;
    7   import java.io.FileWriter;
    8   import java.io.IOException;
    9   import java.io.InputStream;
    10  import java.io.Writer;
    11
    12  import org.apache.commons.logging.Log;
    13  import org.apache.commons.logging.LogFactory;
    14  import org.apache.struts2.StrutsException;
    15  import org.apache.struts2.sitegraph.renderers.DOTRenderer;
    16
    17  /***
    18   * // START SNIPPET: javadocs-intro
    19   * SiteGraph is a tool that renders out GraphViz-generated images depicting your
    20   * Struts-powered web application's flow. SiteGraph requires GraphViz be installed
    21   * and that the "dot" executable be in your command path. You can find GraphViz
    22   * at http://www.graphviz.org.
    23   * // END SNIPPET: javadocs-intro
    24   * <p/>
    25   * // START SNIPPET: javadocs-api
    26   * If you wish to use SiteGraph through its API rather than through the command line,
    27   * you can do that as well. All you need to do is create a new SiteGraph instance,
    28   * optionally specify a {@link Writer} to output the dot content to, and then call
    29   * {@link #prepare()}.
    30   * // END SNIPPET: javadocs-api
    31   */
    32  public class SiteGraph {
    33
    34      private static final Log LOG = LogFactory.getLog(SiteGraph.class);
    35
    36      private String configDir;
    37      private String views;
    38      private String output;
    39      private String namespace;
    40      private Writer writer;
    41
    42      public SiteGraph(String configDir, String views, String output, String namespace) {
    43          this.configDir = configDir;
    44          this.views = views;
    45          this.output = output;
    46          this.namespace = namespace;
    47      }
    48
    49      public static void main(String[] args) throws IOException {
    50          LOG.info("SiteGraph starting...");
    51
    52          if (args.length != 8 && args.length != 6) {
    53              InputStream is = SiteGraph.class.getResourceAsStream("sitegraph-usage.txt");
    54              byte[] buffer = new byte[2048];
    55              int length = -1;
    56              ByteArrayOutputStream baos = new ByteArrayOutputStream();
    57              while ((length = is.read(buffer)) != -1) {
    58                  baos.write(buffer, 0, length);
    59              }
    60              is.close();
    61              baos.close();
    62
    63              String usage = baos.toString();
    64              System.out.println(usage.replaceAll("//.*", ""));
    65              return;
    66          }
    67
    68          String configDir = getArg(args, "config");
    69          String views = getArg(args, "views");
    70          String output = getArg(args, "output");
    71          String namespace = getArg(args, "ns");
    72
    73          // START SNIPPET: example-api
    74          SiteGraph siteGraph = new SiteGraph(configDir, views, output, namespace);
    75          siteGraph.prepare();
    76          siteGraph.render();
    77          // END SNIPPET: example-api
    78      }
    79
    80      private static String getArg(String[] args, String arg) {
    81          for (int i = 0; i < args.length; i++) {
    82              if (("-" + arg).equals(args[i]) && ((i + 1) < args.length)) {
    83                  return args[i + 1];
    84              }
    85          }
    86
    87          return "";
    88      }
    89
    90      /***
    91       * Prepares the dot generated content and writes out to the provided writer
    92       * object. If no writer has been given, that a {@link FileWriter} pointing to "out.dot"
    93       * in the specified output directly shall be used.
    94       */
    95      public void prepare() {
    96          if (writer == null) {
    97              try {
    98                  writer = new FileWriter(output + "/out.dot");
    99              } catch (IOException e) {
    100                 throw new StrutsException(e);
    101             }
    102         }
    103
    104         StrutsConfigRetriever.setConfiguration(configDir, views.split("[, ]+"));
    105         DOTRenderer renderer = new DOTRenderer(writer);
    106         renderer.render(namespace);
    107     }
    108
    109     /***
    110      * Invokes the dot command, cause GraphViz to render out.dot in the form of out.gif,
    111      * located in the specified output directory. If an error occurs during this process,
    112      * the error is logged and the method completes without throwing an exception.
    113      */
    114     public void render() {
    115         try {
    116             Runtime.getRuntime().exec("dot -o" + output + "/out.gif -Tgif " + output + "/out.dot");
    117         } catch (IOException e) {
    118             LOG.error("Could not invoke dot", e);
    119         }
    120     }
    121
    122     public void setWriter(Writer writer) {
    123         this.writer = writer;
    124     }
    125 }