Improve PolicyTool launch method in PolicyPanel

http://mail.openjdk.java.net/pipermail/distro-pkg-dev/2014-January/025971.html
* netx/net/sourceforge/jnlp/controlpanel/PolicyPanel.java: added license
header and javadocs. Launch PolicyTool by ProcessBuilder rather than
calling PolicyTool.main directly, with reflective launch fallback method.
* netx/net/sourceforge/jnlp/resources/Messages.properties: added message
(CPPolicyEditorNotFound)

2 files changed, 144 insertions, 18 deletions

diff --git a/netx/net/sourceforge/jnlp/controlpanel/PolicyPanel.java b/netx/net/sourceforge/jnlp/controlpanel/PolicyPanel.java
index c75611d..ac3c672 100644
--- a/netx/net/sourceforge/jnlp/controlpanel/PolicyPanel.java
+++ b/netx/net/sourceforge/jnlp/controlpanel/PolicyPanel.java
@@ -1,3 +1,39 @@
+/* Copyright (C) 2014 Red Hat, Inc.
+
+This file is part of IcedTea.
+
+IcedTea is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License as published by
+the Free Software Foundation, version 2.
+
+IcedTea is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with IcedTea; see the file COPYING.  If not, write to
+the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version.
+ */
+
 package net.sourceforge.jnlp.controlpanel;
 
 import static net.sourceforge.jnlp.runtime.Translator.R;
@@ -10,6 +46,7 @@ import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
 import java.io.File;
 import java.io.IOException;
+import java.lang.reflect.Method;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.ArrayList;
@@ -28,12 +65,24 @@ import net.sourceforge.jnlp.config.DirectoryValidator;
 import net.sourceforge.jnlp.config.DirectoryValidator.DirectoryCheckResults;
 import net.sourceforge.jnlp.util.FileUtils;
 import net.sourceforge.jnlp.util.logging.OutputController;
-import sun.security.tools.policytool.PolicyTool;
 
 public class PolicyPanel extends NamedBorderPanel {
 
+    /**
+     * Indicates whether a file was successfully opened. If not, provides specific reasons
+     * along with a general failure case
+     */
     private enum OpenFileResult {
-        SUCCESS, FAILURE, CANT_CREATE, CANT_WRITE, NOT_FILE
+        /** The file was successfully opened */
+        SUCCESS,
+        /** The file could not be opened, for non-specified reasons */
+        FAILURE,
+        /** The file could not be opened because it did not exist and could not be created */
+        CANT_CREATE,
+        /** The file can be opened but in read-only */
+        CANT_WRITE,
+        /** The specified path pointed to a non-file filesystem object, ie a directory */
+        NOT_FILE
     }
 
     public PolicyPanel(final JFrame frame, final DeploymentConfiguration config) {
@@ -70,7 +119,10 @@ public class PolicyPanel extends NamedBorderPanel {
         c.gridx++;
         add(showUserPolicyButton, c);
 
-        /* Keep all the elements at the top of the panel (Extra padding) */
+        /* Keep all the elements at the top of the panel (Extra padding)
+         * Keep View/Edit button next to location field, with padding between
+         * the right edge of the frame and the button
+         */
         c.fill = GridBagConstraints.BOTH;
         Component filler1 = Box.createRigidArea(new Dimension(240, 1));
         Component filler2 = Box.createRigidArea(new Dimension(1, 1));
@@ -84,17 +136,18 @@ public class PolicyPanel extends NamedBorderPanel {
 
     /**
      * Launch the policytool for a specified file path
-     * @param filePath the policy file path to be opened with policytool
+     * @param frame a {@link JFrame} to act as parent to warning dialogs which may appear
+     * @param filePath a {@link String} representing the path to the file to be opened
      */
     private static void launchPolicyTool(final JFrame frame, final String filePath) {
         try {
             final File policyFile = new File(filePath).getCanonicalFile();
             OpenFileResult result = canOpenPolicyFile(policyFile);
             if (result == OpenFileResult.SUCCESS) {
-                PolicyTool.main(new String[] { "-file", policyFile.getPath() });
+                policyToolLaunchHelper(frame, filePath);
             } else if (result == OpenFileResult.CANT_WRITE) {
                 showReadOnlyDialog(frame);
-                PolicyTool.main(new String[] { "-file", policyFile.getPath() });
+                policyToolLaunchHelper(frame, filePath);
             } else {
                 showCouldNotOpenFileDialog(frame, policyFile.getPath(), result);
             }
@@ -105,10 +158,61 @@ public class PolicyPanel extends NamedBorderPanel {
     }
 
     /**
+     * This executes a new process for policytool using ProcessBuilder, with the new process'
+     * working directory set to the user's home directory. policytool then attempts to
+     * open the provided policy file path, if policytool can be run. ProcessBuilder does
+     * some verification to ensure that the built command can be executed - if not, it
+     * throws an IOException. In this event, we try our reflective fallback launch.
+     * We do this in a new {@link Thread} to ensure that the fallback launch does not
+     * block the AWT thread, and neither does ProcessBuilder#start() in case it happens
+     * to be synchronous on the current system.
+     * @param frame a {@link JFrame} to act as parent to warning dialogs which may appear
+     * @param filePath a {@link String} representing the path to the file to be opened
+     */
+    private static void policyToolLaunchHelper(final JFrame frame, final String filePath) {
+        new Thread(new Runnable() {
+            @Override
+            public void run() {
+                ProcessBuilder pb = new ProcessBuilder("policytool", "-file", filePath)
+                        .directory(new File(System.getProperty("user.home")));
+                try {
+                    pb.start();
+                } catch (IOException ioe) {
+                    OutputController.getLogger().log(ioe);
+                    try {
+                        reflectivePolicyToolLaunch(filePath);
+                    } catch (Exception e) {
+                        OutputController.getLogger().log(e);
+                        showCouldNotOpenFileDialog(frame, filePath, R("CPPolicyEditorNotFound"));
+                    }
+                }
+            }
+        }).start();
+    }
+
+    /**
+     * This is used as a fallback in case launching the policytool by executing a new process
+     * fails. This probably happens because we are running on a system where the policytool
+     * executable is not on the PATH, or because we are running on a non-POSIX compliant system.
+     * We do this reflectively to avoid needing to add PolicyTool as build dependency simply for
+     * this small edge case.
+     * @param filePath a {@link String} representing the path of the file to attempt to open
+     * @throws Exception if any sort of exception occurs during reflective launch of policytool
+     */
+    private static void reflectivePolicyToolLaunch(final String filePath) throws Exception {
+        Class<?> policyTool = Class.forName("sun.security.tools.policytool.PolicyTool");
+        Class<?>[] signature = new Class<?>[] { String[].class };
+        Method main = policyTool.getDeclaredMethod("main", signature);
+        Object args = new String[] { "-file", filePath };
+        main.invoke(null, args);
+    }
+
+    /**
      * Verify that a given file object points to a real, accessible plain file.
      * As a side effect, if the file is accessible but does not yet exist, it will be created
      * as an empty plain file.
-     * @param policyFile the file to verify
+     * @param policyFile the {@link File} to verify
+     * @return an {@link OpenFileResult} representing the accessibility level of the file
      * @throws IOException if the file is not accessible
      */
     private static OpenFileResult canOpenPolicyFile(final File policyFile) {
@@ -137,8 +241,8 @@ public class PolicyPanel extends NamedBorderPanel {
     /**
      * Ensure that the parent directory of the Policy File exists and that we are
      * able to create and access files within this directory
-     * @param policyFile the location of the policy file
-     * @return an object representing the results of the test
+     * @param policyFile the {@link File} representing a Java Policy file to test
+     * @return a {@link DirectoryCheckResults} object representing the results of the test
      */
     private static DirectoryCheckResults testPolicyFileDirectory(final File policyFile) {
         List<File> policyDirectory = new ArrayList<File>();
@@ -149,10 +253,21 @@ public class PolicyPanel extends NamedBorderPanel {
         return result;
     }
 
+    /**
+     * Show a generic error dialog indicating the policy file could not be opened
+     * @param frame a {@link JFrame} to act as parent to this dialog
+     * @param filePath a {@link String} representing the path to the file we failed to open
+     */
     private static void showCouldNotOpenFileDialog(final JFrame frame, final String filePath) {
         showCouldNotOpenFileDialog(frame, filePath, OpenFileResult.FAILURE);
     }
 
+    /**
+     * Show an error dialog indicating the policy file could not be opened, with a particular reason
+     * @param frame a {@link JFrame} to act as parent to this dialog
+     * @param filePath a {@link String} representing the path to the file we failed to open
+     * @param reason a {@link OpenFileResult} specifying more precisely why we failed to open the file
+     */
     private static void showCouldNotOpenFileDialog(final JFrame frame, final String filePath, final OpenFileResult reason) {
         String message;
         switch (reason) {
@@ -174,30 +289,40 @@ public class PolicyPanel extends NamedBorderPanel {
 
     /**
      * Show a dialog informing the user that the policy file could not be opened
-     * @param frame the parent frame for this dialog
-     * @param filePath the path to the file we tried to open
-     * @param message the specific reason the file could not be opened
+     * @param frame a {@link JFrame} to act as parent to this dialog
+     * @param filePath a {@link String} representing the path to the file we failed to open
+     * @param message a {@link String} giving the specific reason the file could not be opened
      */
     private static void showCouldNotOpenFileDialog(final JFrame frame, final String filePath, final String message) {
         OutputController.getLogger().log(OutputController.Level.ERROR_ALL, "Could not open user JNLP policy");
-        JOptionPane.showMessageDialog(frame, message, R("Error"), JOptionPane.ERROR_MESSAGE);
+        SwingUtilities.invokeLater(new Runnable() {
+            @Override
+            public void run() {
+                JOptionPane.showMessageDialog(frame, message, R("Error"), JOptionPane.ERROR_MESSAGE);
+            }
+        });
     }
 
     /**
      * Show a dialog informing the user that the policy file is currently read-only
-     * @param frame the parent frame for this dialog
+     * @param frame a {@link JFrame} to act as parent to this dialog
      */
     private static void showReadOnlyDialog(final JFrame frame) {
         OutputController.getLogger().log(OutputController.Level.WARNING_ALL, "Opening user JNLP policy read-only");
-        JOptionPane.showMessageDialog(frame, R("RFileReadOnly"), R("Warning"), JOptionPane.WARNING_MESSAGE);
+        SwingUtilities.invokeLater(new Runnable() {
+            @Override
+            public void run() {
+                JOptionPane.showMessageDialog(frame, R("RFileReadOnly"), R("Warning"), JOptionPane.WARNING_MESSAGE);
+            }
+        });
     }
 
     /**
      * Loosely attempt to get the path part of a file URL string. If this fails,
      * simply return back the input. This is only intended to be used for displaying
      * GUI elements such as the CPPolicyTooltip.
-     * @param url the String representing the URL whose path is desired
-     * @return a String representing the local filepath of the given file:/ URL
+     * @param url the {@link String} representing the URL whose path is desired
+     * @return a {@link String} representing the local filepath of the given file:/ URL
      */
     private static String localFilePathFromUrlString(String url) {
         try {
@@ -208,7 +333,7 @@ public class PolicyPanel extends NamedBorderPanel {
         }
     }
 
-    /*
+    /**
      * Implements the action to be performed when the "View Policy" button is clicked
      */
     private class ViewPolicyButtonAction implements ActionListener {
diff --git a/netx/net/sourceforge/jnlp/resources/Messages.properties b/netx/net/sourceforge/jnlp/resources/Messages.properties
index bff5e34..3d22d2c 100644
--- a/netx/net/sourceforge/jnlp/resources/Messages.properties
+++ b/netx/net/sourceforge/jnlp/resources/Messages.properties
@@ -360,6 +360,7 @@ CPJVMconfirmInvalidJdkTitle=Confirm invalid JDK
 CPJVMconfirmReset=Reset to default?
 CPPolicyDetail=View or edit your user-level Java Policy File. This allows you to grant or deny runtime permissions to applets regardless of the standard security sandboxing rules.
 CPPolicyTooltip=Open {0} in policy editor
+CPPolicyEditorNotFound=Could not find a system policy file editor. Check that policytool is on your PATH.
 
 # Control Panel - Buttons
 CPButAbout=About...