Send document to printer

Author: jreznot

src/main/java/demo/AppUI.java

@@ -7,6 +7,15 @@
 import com.vaadin.ui.*;
 import com.vaadin.ui.themes.ValoTheme;
 
+import javax.print.*;
+import javax.print.attribute.HashPrintRequestAttributeSet;
+import javax.print.attribute.PrintRequestAttributeSet;
+import javax.swing.*;
+import java.io.StringReader;
+
+import static com.vaadin.ui.Notification.Type.HUMANIZED_MESSAGE;
+import static com.vaadin.ui.Notification.Type.WARNING_MESSAGE;
+
 @Push(transport = Transport.WEBSOCKET)
 @Theme(ValoTheme.THEME_NAME)
 public class AppUI extends UI {
@@ -15,12 +24,68 @@ protected void init(VaadinRequest request) {
         TextField nameField = new TextField();
         nameField.setCaption("Your name");
 
-        Button button = new Button("Hello", event ->
-                new Notification("Hello " + nameField.getValue()).show(getPage())
-        );
+        Button button = new Button("Print Hello", event -> {
+            Runtime runtime = Runtime.getRuntime();
+
+            printHelloDocument(String.format(
+                    "Hello %s!\n" +
+                            "Your PC is so powerful:\n" +
+                            "%s processors\n" +
+                            "%s free memory\n" +
+                            "%s max memory",
+                    nameField.getValue(),
+                    runtime.availableProcessors(),
+                    runtime.freeMemory(),
+                    runtime.maxMemory()));
+        });
 
         VerticalLayout content = new VerticalLayout();
         content.addComponents(nameField, button);
         setContent(content);
     }
+
+    private void printHelloDocument(String value) {
+        PrintRequestAttributeSet aset = new HashPrintRequestAttributeSet();
+
+        DocFlavor flavor = DocFlavor.READER.TEXT_PLAIN;
+        Doc doc = new SimpleDoc(new StringReader(value), flavor, null);
+
+        PrintService[] services = PrintServiceLookup.lookupPrintServices(flavor, aset);
+        PrintService defaultService = PrintServiceLookup.lookupDefaultPrintService();
+
+        if (services.length == 0) {
+            if (defaultService == null) {
+                new Notification("No printer found", WARNING_MESSAGE).show(getPage());
+            } else {
+                DocPrintJob job = defaultService.createPrintJob();
+                printDocument(doc, aset, job);
+            }
+        } else {
+            SwingUtilities.invokeLater(() -> {
+                PrintService service = ServiceUI.printDialog(null, 200, 200,
+                        services, defaultService, flavor, aset);
+                if (service != null) {
+                    DocPrintJob job = service.createPrintJob();
+                    printDocument(doc, aset, job);
+                }
+            });
+        }
+    }
+
+    private void printDocument(Doc doc, PrintRequestAttributeSet aset, DocPrintJob job) {
+        try {
+            job.print(doc, aset);
+
+            getUI().access(() ->
+                    new Notification("See the result!", HUMANIZED_MESSAGE)
+                            .show(getPage())
+            );
+        } catch (PrintException e) {
+            // may be called from Swing thread
+            getUI().access(() -> {
+                new Notification("Unable to print file, please check settings",
+                        WARNING_MESSAGE).show(getPage());
+            });
+        }
+    }
 }