core/YumListParser.java

   1 package org.argeo.slc.rpmfactory.core;
   2
   3 import java.io.IOException;
   4 import java.io.InputStream;
   5 import java.util.Set;
   6 import java.util.StringTokenizer;
   7 import java.util.TreeSet;
   8
   9 import org.apache.commons.io.IOUtils;
  10 import org.apache.commons.io.LineIterator;
  11 import org.apache.commons.logging.Log;
  12 import org.apache.commons.logging.LogFactory;
  13 import org.argeo.slc.SlcException;
  14 import org.springframework.core.io.Resource;
  15
  16 /**
  17  * Reads the output of a 'yum list all' command and interpret the list of
  18  * packages.
  19  */
  20 public class YumListParser implements RpmPackageSet {
  21         private final static Log log = LogFactory.getLog(YumListParser.class);
  22
  23         private Set<String> installed = new TreeSet<String>();
  24         /** Not installed but available */
  25         private Set<String> installable = new TreeSet<String>();
  26
  27         private Resource yumListOutput;
  28
  29         public void init() {
  30                 try {
  31                         if (yumListOutput != null) {
  32                                 load(yumListOutput.getInputStream());
  33                                 if (log.isDebugEnabled())
  34                                         log.debug(installed.size() + " installed, "
  35                                                         + installable.size() + " installable, from "
  36                                                         + yumListOutput);
  37                         }
  38                 } catch (IOException e) {
  39                         throw new SlcException("Cannot initialize yum list parser", e);
  40                 }
  41         }
  42
  43         public Boolean contains(String packageName) {
  44                 if (installed.contains(packageName))
  45                         return true;
  46                 else
  47                         return installable.contains(packageName);
  48         }
  49
  50         protected void load(InputStream in) {
  51                 try {
  52                         Boolean readingInstalled = false;
  53                         Boolean readingAvailable = false;
  54                         LineIterator it = IOUtils.lineIterator(in, "UTF-8");
  55                         while (it.hasNext()) {
  56                                 String line = it.nextLine();
  57                                 if (line.trim().equals("Installed Packages")) {
  58                                         readingInstalled = true;
  59                                 } else if (line.trim().equals("Available Packages")) {
  60                                         readingAvailable = true;
  61                                         readingInstalled = false;
  62                                 } else if (readingAvailable) {
  63                                         if (Character.isLetterOrDigit(line.charAt(0))) {
  64                                                 installable.add(extractRpmName(line));
  65                                         }
  66                                 } else if (readingInstalled) {
  67                                         if (Character.isLetterOrDigit(line.charAt(0))) {
  68                                                 installed.add(extractRpmName(line));
  69                                         }
  70                                 }
  71                         }
  72                 } catch (IOException e) {
  73                         throw new SlcException("Cannot load yum list output", e);
  74                 } finally {
  75                         IOUtils.closeQuietly(in);
  76                 }
  77         }
  78
  79         protected String extractRpmName(String line) {
  80                 StringTokenizer st = new StringTokenizer(line, " \t");
  81                 String packageName = st.nextToken();
  82                 return packageName.split("\\.")[0];
  83         }
  84
  85         public Set<String> getInstalled() {
  86                 return installed;
  87         }
  88
  89         public Set<String> getInstallable() {
  90                 return installable;
  91         }
  92
  93         public void setYumListOutput(Resource yumListOutput) {
  94                 this.yumListOutput = yumListOutput;
  95         }
  96
  97 }