use LRU map for certain strings

core/src/main/java/hudson/tasks/Fingerprinter.java

@@ -34,7 +34,6 @@ import hudson.matrix.MatrixConfiguration;
 import hudson.model.AbstractBuild;
 import hudson.model.AbstractProject;
 import hudson.model.Action;
-import hudson.model.Build;
 import hudson.model.BuildListener;
 import hudson.model.DependecyDeclarer;
 import hudson.model.DependencyGraph;
@@ -65,7 +64,6 @@ import java.io.IOException;
 import java.io.Serializable;
 import java.lang.ref.WeakReference;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -294,6 +292,7 @@ public class Fingerprinter extends Recorder implements Serializable, DependecyDe
      * Action for displaying fingerprints.
      */
     public static final class FingerprintAction implements RunAction {
+        
         private final AbstractBuild build;
 
         /**

core/src/main/java/hudson/tasks/MailMessageIdAction.java

@@ -24,6 +24,7 @@
 package hudson.tasks;
 
 import hudson.model.Action;
+import hudson.model.Run;
 
 /**
  * Remembers the message ID of the e-mail that was sent for the build.
@@ -34,6 +35,11 @@ import hudson.model.Action;
  * @author Kohsuke Kawaguchi
  */
 public class MailMessageIdAction implements Action {
+
+    static {
+        Run.XSTREAM.processAnnotations(MailMessageIdAction.class);
+    }
+
     /**
      * Message ID of the e-mail sent for the build.
      */

maven-plugin/src/main/java/hudson/maven/reporters/MavenArtifact.java

@@ -30,6 +30,8 @@ import hudson.maven.MavenBuildProxy;
 import hudson.model.Api;
 import hudson.model.BuildListener;
 import hudson.model.FingerprintMap;
+import hudson.model.Run;
+import hudson.util.LRUStringConverter;
 import jenkins.model.Jenkins;
 
 import hudson.util.HttpResponses;
@@ -68,6 +70,11 @@ import java.util.logging.Logger;
  */
 @ExportedBean
 public final class MavenArtifact implements Serializable {
+
+    static {
+        Run.XSTREAM.registerLocalConverter(MavenArtifact.class, "md5sum", new LRUStringConverter(5000));
+    }
+
     /**
      * Basic parameters of a Maven artifact.
      */