diff --git a/tools/preload2/src/com/android/preload/Main.java b/tools/preload2/src/com/android/preload/Main.java
index ca5b0e005a1d2..cc54a8d9c7157 100644
--- a/tools/preload2/src/com/android/preload/Main.java
+++ b/tools/preload2/src/com/android/preload/Main.java
@@ -32,7 +32,8 @@ import com.android.preload.actions.ShowDataAction;
 import com.android.preload.classdataretrieval.ClassDataRetriever;
 import com.android.preload.classdataretrieval.hprof.Hprof;
 import com.android.preload.classdataretrieval.jdwp.JDWPClassDataRetriever;
-import com.android.preload.ui.UI;
+import com.android.preload.ui.IUI;
+import com.android.preload.ui.SwingUI;
 
 import java.util.ArrayList;
 import java.util.Collection;
@@ -66,7 +67,7 @@ public class Main {
     private DumpTableModel dataTableModel;
     private DefaultListModel<Client> clientListModel;
 
-    private UI ui;
+    private IUI ui;
 
     // Actions that need to be updated once a device is selected.
     private Collection<DeviceSpecific> deviceSpecificActions;
@@ -89,13 +90,15 @@ public class Main {
      * @param args
      */
     public static void main(String[] args) {
-        Main m = new Main();
+        Main m = new Main(new SwingUI());
         top = m;
 
         m.startUp();
     }
 
-    public Main() {
+    public Main(IUI ui) {
+        this.ui = ui;
+
         clientListModel = new DefaultListModel<Client>();
         dataTableModel = new DumpTableModel();
 
@@ -124,11 +127,10 @@ public class Main {
             }
         }
 
-        ui = new UI(clientListModel, dataTableModel, actions);
-        ui.setVisible(true);
+        ui.prepare(clientListModel, dataTableModel, actions);
     }
 
-    public static UI getUI() {
+    public static IUI getUI() {
         return top.ui;
     }
 
@@ -176,6 +178,7 @@ public class Main {
         new ReloadListAction(clientUtils, getDevice(), clientListModel).run();
 
         getUI().hideWaitDialog();
+        getUI().ready();
     }
 
     private void initDevice() {
diff --git a/tools/preload2/src/com/android/preload/actions/ComputeThresholdAction.java b/tools/preload2/src/com/android/preload/actions/ComputeThresholdAction.java
index b524716fc2cb2..5d052ccc70723 100644
--- a/tools/preload2/src/com/android/preload/actions/ComputeThresholdAction.java
+++ b/tools/preload2/src/com/android/preload/actions/ComputeThresholdAction.java
@@ -32,7 +32,6 @@ import java.util.TreeSet;
 import java.util.regex.Pattern;
 
 import javax.swing.AbstractAction;
-import javax.swing.JFileChooser;
 
 /**
  * Compute an intersection of classes from the given data. A class is in the intersection if it
@@ -92,10 +91,8 @@ public class ComputeThresholdAction extends AbstractAction implements Runnable {
         boolean ret = Main.getUI().showConfirmDialog("Computed a set with " + result.size()
                 + " classes, would you like to save to disk?", "Save?");
         if (ret) {
-            JFileChooser jfc = new JFileChooser();
-            int ret2 = jfc.showSaveDialog(Main.getUI());
-            if (ret2 == JFileChooser.APPROVE_OPTION) {
-                File f = jfc.getSelectedFile();
+            File f = Main.getUI().showSaveDialog();
+            if (f != null) {
                 saveSet(result, f);
             }
         }
diff --git a/tools/preload2/src/com/android/preload/ui/IUI.java b/tools/preload2/src/com/android/preload/ui/IUI.java
new file mode 100644
index 0000000000000..3c151d90ab0af
--- /dev/null
+++ b/tools/preload2/src/com/android/preload/ui/IUI.java
@@ -0,0 +1,43 @@
+package com.android.preload.ui;
+
+import com.android.ddmlib.Client;
+import java.io.File;
+import java.util.List;
+import javax.swing.Action;
+import javax.swing.ListModel;
+import javax.swing.table.TableModel;
+
+/**
+ * UI abstraction for the tool. This allows a graphical mode, command line mode,
+ * or silent mode.
+ */
+public interface IUI {
+
+    void prepare(ListModel<Client> clientListModel, TableModel dataTableModel,
+            List<Action> actions);
+
+    void ready();
+
+    Client getSelectedClient();
+
+    int getSelectedDataTableRow();
+
+    void showWaitDialog();
+
+    void updateWaitDialog(String s);
+
+    void hideWaitDialog();
+
+    void showMessageDialog(String s);
+
+    boolean showConfirmDialog(String title, String message);
+
+    String showInputDialog(String message);
+
+    <T> T showChoiceDialog(String title, String message, T[] choices);
+
+    File showSaveDialog();
+
+    File[] showOpenDialog(boolean multi);
+
+}
diff --git a/tools/preload2/src/com/android/preload/ui/UI.java b/tools/preload2/src/com/android/preload/ui/SwingUI.java
similarity index 94%
rename from tools/preload2/src/com/android/preload/ui/UI.java
rename to tools/preload2/src/com/android/preload/ui/SwingUI.java
index 47174ddd0e075..1245f2c23d7e3 100644
--- a/tools/preload2/src/com/android/preload/ui/UI.java
+++ b/tools/preload2/src/com/android/preload/ui/SwingUI.java
@@ -41,7 +41,7 @@ import javax.swing.ListModel;
 import javax.swing.SwingUtilities;
 import javax.swing.table.TableModel;
 
-public class UI extends JFrame {
+public class SwingUI extends JFrame implements IUI {
 
     private JList<Client> clientList;
     private JTable dataTable;
@@ -49,11 +49,13 @@ public class UI extends JFrame {
     // Shared file chooser, means the directory is retained.
     private JFileChooser jfc;
 
-    public UI(ListModel<Client> clientListModel,
-              TableModel dataTableModel,
-              List<Action> actions) {
+    public SwingUI() {
         super("Preloaded-classes computation");
+    }
 
+    @Override
+    public void prepare(ListModel<Client> clientListModel, TableModel dataTableModel,
+            List<Action> actions) {
         getContentPane().add(new JScrollPane(clientList = new JList<Client>(clientListModel)),
                 BorderLayout.WEST);
         clientList.setCellRenderer(new ClientListCellRenderer());
@@ -74,18 +76,27 @@ public class UI extends JFrame {
 
         setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         setBounds(100, 100, 800, 600);
+
+        setVisible(true);
     }
 
+    @Override
+    public void ready() {
+    }
+
+    @Override
     public Client getSelectedClient() {
         return clientList.getSelectedValue();
     }
 
+    @Override
     public int getSelectedDataTableRow() {
         return dataTable.getSelectedRow();
     }
 
     private JDialog currentWaitDialog = null;
 
+    @Override
     public void showWaitDialog() {
         if (currentWaitDialog == null) {
             currentWaitDialog = new JDialog(this, "Please wait...", true);
@@ -111,6 +122,7 @@ public class UI extends JFrame {
         });
     }
 
+    @Override
     public void updateWaitDialog(String s) {
         if (currentWaitDialog != null) {
             ((JLabel) currentWaitDialog.getContentPane().getComponent(0)).setText(s);
@@ -124,6 +136,7 @@ public class UI extends JFrame {
         }
     }
 
+    @Override
     public void hideWaitDialog() {
         if (currentWaitDialog != null) {
             currentWaitDialog.setVisible(false);
@@ -131,6 +144,7 @@ public class UI extends JFrame {
         }
     }
 
+    @Override
     public void showMessageDialog(String s) {
         // Hide the wait dialog...
         if (currentWaitDialog != null) {
@@ -147,6 +161,7 @@ public class UI extends JFrame {
         }
     }
 
+    @Override
     public boolean showConfirmDialog(String title, String message) {
         // Hide the wait dialog...
         if (currentWaitDialog != null) {
@@ -164,6 +179,7 @@ public class UI extends JFrame {
         }
     }
 
+    @Override
     public String showInputDialog(String message) {
         // Hide the wait dialog...
         if (currentWaitDialog != null) {
@@ -180,6 +196,7 @@ public class UI extends JFrame {
         }
     }
 
+    @Override
     @SuppressWarnings("unchecked")
     public <T> T showChoiceDialog(String title, String message, T[] choices) {
         // Hide the wait dialog...
@@ -203,6 +220,7 @@ public class UI extends JFrame {
         }
     }
 
+    @Override
     public File showSaveDialog() {
         // Hide the wait dialog...
         if (currentWaitDialog != null) {
@@ -228,6 +246,7 @@ public class UI extends JFrame {
         }
     }
 
+    @Override
     public File[] showOpenDialog(boolean multi) {
         // Hide the wait dialog...
         if (currentWaitDialog != null) {