java/src/main/com/google/apphosting/utils/config/DosXml.java

   1 // Copyright 2010 Google Inc. All Rights Reserved.
   2
   3 package com.google.apphosting.utils.config;
   4
   5 import com.google.net.base.CidrAddressBlock;
   6
   7 import java.util.ArrayList;
   8 import java.util.List;
   9
  10 /**
  11  * Parsed dos.xml file.
  12  *
  13  * Any additions to this class should also be made to the YAML
  14  * version in DosYamlReader.java.
  15  *
  16  */
  17 public class DosXml {
  18
  19   /**
  20    * Describes a single blacklist entry.
  21    */
  22   public static class BlacklistEntry {
  23
  24     String subnet;
  25     String desc;
  26
  27     /** Create an empty blacklist entry. */
  28     public BlacklistEntry() {
  29       desc = "";
  30       subnet = null;
  31     }
  32
  33     /** Records the human-readable description of this blacklist entry. */
  34     public void setDescription(String description) {
  35       this.desc = description.replace('\n', ' ');
  36     }
  37
  38     /** Records the subnet of this blacklist entry. */
  39     public void setSubnet(String subnet) {
  40       try {
  41         CidrAddressBlock parsedSubnet = CidrAddressBlock.create(subnet);
  42         this.subnet = subnet;
  43       } catch (IllegalArgumentException iae) {
  44         this.subnet = null;
  45         throw new AppEngineConfigException("subnet " + subnet + " failed to parse",
  46                                            iae.getCause());
  47       }
  48     }
  49
  50     public String getSubnet() {
  51       return subnet;
  52     }
  53
  54     public String getDescription() {
  55       return desc;
  56     }
  57   }
  58
  59   private List<BlacklistEntry> blacklistEntries;
  60
  61   /** Create an empty configuration object. */
  62   public DosXml() {
  63     blacklistEntries = new ArrayList<BlacklistEntry>();
  64   }
  65
  66   /**
  67    * Puts a new blacklist entry into the list defined by the config file.
  68    *
  69    * @throws AppEngineConfigException if the previously-last blacklist entry is
  70    *    still incomplete.
  71    * @return the new entry
  72    */
  73   public BlacklistEntry addNewBlacklistEntry() {
  74     validateLastEntry();
  75     BlacklistEntry entry = new BlacklistEntry();
  76     blacklistEntries.add(entry);
  77     return entry;
  78   }
  79
  80   public void addBlacklistEntry(BlacklistEntry entry) {
  81     validateLastEntry();
  82     blacklistEntries.add(entry);
  83     validateLastEntry();
  84   }
  85
  86   /**
  87    * Check that the last blacklist entry defined is complete.
  88    * @throws AppEngineConfigException if it is not.
  89    */
  90   public void validateLastEntry() {
  91     if (blacklistEntries.size() == 0) {
  92       return;
  93     }
  94     BlacklistEntry last = blacklistEntries.get(blacklistEntries.size() - 1);
  95     if (last.getSubnet() == null) {
  96       throw new AppEngineConfigException("no subnet for blacklist");
  97     }
  98   }
  99
 100   /**
 101    * Get the YAML equivalent of this dos.xml file.
 102    *
 103    * @return contents of an equivalent {@code dos.yaml} file.
 104    */
 105   public String toYaml() {
 106     StringBuilder builder = new StringBuilder("blacklist:\n");
 107     for (BlacklistEntry ent : blacklistEntries) {
 108       builder.append("- subnet: " + ent.getSubnet() + "\n");
 109       if (!ent.getDescription().equals("")) {
 110         builder.append("  description: " + ent.getDescription() + "\n");
 111       }
 112     }
 113     return builder.toString();
 114   }
 115 }