If a console doesn't exist, read password from stdin.

When signapk.jar is invoked by scripts like
sign_target_files_apks.py, there is no console as signapk is
invoked using popen(). To support signing of APKs using
software keys with passwords, we need to read
the password from stdin if there is no console.

Change-Id: Icf69ba1e58bf1f91979eaf1d3b91cb202782e8fd
Signed-off-by: adattatr <anisha.dattatraya.kulkarni@intel.com>
Signed-off-by: Brad Geltz <brad.geltz@intel.com>
diff --git a/tools/signapk/SignApk.java b/tools/signapk/SignApk.java
index 88f486a..3ddab11 100644
--- a/tools/signapk/SignApk.java
+++ b/tools/signapk/SignApk.java
@@ -167,18 +167,29 @@
     }
 
     /**
-     * Reads the password from console and returns it as a string.
+     * If a console doesn't exist, reads the password from stdin
+     * If a console exists, reads the password from console and returns it as a string.
      *
      * @param keyFile The file containing the private key.  Used to prompt the user.
      */
     private static String readPassword(File keyFile) {
         Console console;
         char[] pwd;
-        if((console = System.console()) != null &&
-           (pwd = console.readPassword("[%s]", "Enter password for " + keyFile)) != null){
-            return String.valueOf(pwd);
+        if ((console = System.console()) == null) {
+            System.out.print("Enter password for " + keyFile + " (password will not be hidden): ");
+            System.out.flush();
+            BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));
+            try {
+                return stdin.readLine();
+            } catch (IOException ex) {
+                return null;
+            }
         } else {
-            return null;
+            if ((pwd = console.readPassword("[%s]", "Enter password for " + keyFile)) != null) {
+                return String.valueOf(pwd);
+            } else {
+                return null;
+            }
         }
     }