Added Meta#getClass

src/android/ext/PrintManager.java

@@ -166,30 +166,23 @@ public final class PrintManager {
     public void setOnPrintJobStateChangeListener(
             OnPrintJobStateChangeListener listener) {
 
-        if (this.listener == listener) {
+        if (this.listener == listener)
             return;
-        }
 
         if (listener == null) {
             unsetOnPrintJobStateChangeListener();
             return;
         }
 
-        Class<?> interfaceCls = null;
+        Class<?> interfaceCls = Meta.getClass(
-
-        this.listener =
-                new WeakReference<OnPrintJobStateChangeListener>(listener);
-
-        try {
-            interfaceCls = Class.forName(
                 "android.print.PrintManager$PrintJobStateChangeListener");
-        } catch (ClassNotFoundException e) {
-            e.printStackTrace();
-        }
 
         if (interfaceCls == null)
             return;
 
+        this.listener =
+                new WeakReference<OnPrintJobStateChangeListener>(listener);
+
         Method method = Meta.getMethod(getInstance().getClass(),
                 "addPrintJobStateChangeListener", interfaceCls);
 
@@ -208,14 +201,8 @@ public final class PrintManager {
      * Removes the listener from the observing the state of print jobs.
      */
     public void unsetOnPrintJobStateChangeListener() {
-        Class<?> interfaceCls = null;
+        Class<?> interfaceCls = Meta.getClass(
-
-        try {
-            interfaceCls = Class.forName(
                 "android.print.PrintManager$PrintJobStateChangeListener");
-        } catch (ClassNotFoundException e) {
-            // Nothing to do
-        }
 
         if (interfaceCls == null || proxy == null)
             return;
@@ -238,6 +225,7 @@ public final class PrintManager {
         if (listener != null && listener.get() != null) {
             Method method = Meta.getMethod(getInstance().getClass(),
                     "getPrintJob", PrintJobId.class);
+
             PrintJob job  = (PrintJob) Meta.invokeMethod(getInstance(),
                     method, printJobId);
 

src/android/ext/PrinterDiscoverySession.java

@@ -110,21 +110,15 @@ public final class PrinterDiscoverySession {
     public final void setOnPrintersChangeListener(
             OnPrintersChangeListener listener) {
 
-        Class<?> interfaceCls = null;
         Object proxy          = null;
-
+        Class<?> interfaceCls = Meta.getClass(
-        this.listener = listener;
-
-        try {
-            interfaceCls = Class.forName(
                 "android.print.PrinterDiscoverySession$OnPrintersChangeListener");
-        } catch (ClassNotFoundException e) {
-            e.printStackTrace();
-        }
 
         if (interfaceCls == null)
             return;
 
+        this.listener = listener;
+
         Method method = Meta.getMethod(session.getClass(),
                 "setOnPrintersChangeListener", interfaceCls);
 

src/android/reflect/Meta.java

@@ -31,6 +31,24 @@ import java.lang.reflect.Method;
  * This is an activity for selecting a printer.
  */
 public abstract class Meta  {
+
+    /**
+     * Tries to find the class for the given name.
+     *
+     * @param fullName
+     *      The full class name including the package scope.
+     * @return
+     *      The found class or null.
+     */
+    public static Class<?> getClass (String fullName) {
+        try {
+            return Class.forName(fullName);
+        } catch (ClassNotFoundException e) {
+            e.printStackTrace();
+            return null;
+        }
+    }
+
     /**
      * Finds the method with given name and set of arguments.
      *
@@ -48,10 +66,9 @@ public abstract class Meta  {
             return cls.getDeclaredMethod(name, params);
         } catch (NoSuchMethodException e) {
             e.printStackTrace();
-        }
-
             return null;
         }
+    }
 
     /**
      * Invokes the method on the given object with the specified arguments.