Fix some issues with Binder serialization (#8660)

Partial fix for #8640

server/src/main/java/com/vaadin/data/BeanPropertySet.java

@@ -134,13 +134,18 @@ public class BeanPropertySet<T> implements PropertySet<T> {
 
         @Override
         public Optional<Setter<T, V>> getSetter() {
-            Method setter = descriptor.getWriteMethod();
-            if (setter == null) {
+            if (descriptor.getWriteMethod() == null) {
                 return Optional.empty();
             }
 
-            return Optional.of(
-                    (bean, value) -> invokeWrapExceptions(setter, bean, value));
+            Setter<T, V> setter = (bean, value) -> {
+                // Do not "optimize" this getter call,
+                // if its done outside the code block, that will produce
+                // NotSerializableException because of some lambda compilation magic
+                Method innerSetter = descriptor.getWriteMethod();
+                invokeWrapExceptions(innerSetter, bean, value);
+            };
+            return Optional.of(setter);
         }
 
         @SuppressWarnings("unchecked")

server/src/test/java/com/vaadin/data/BeanBinderTest.java

@@ -3,6 +3,7 @@ package com.vaadin.data;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertSame;
 
+import java.io.Serializable;
 import java.util.List;
 import java.util.Set;
 
@@ -32,7 +33,7 @@ public class BeanBinderTest
         private TextField number = new TextField();
     }
 
-    private class TestBean {
+    private static class TestBean implements Serializable{
         private Set<TestEnum> enums;
         private int number;
 
@@ -53,7 +54,7 @@ public class BeanBinderTest
         }
     }
 
-    public class RequiredConstraints {
+    public static class RequiredConstraints implements Serializable{
         @NotNull
         @Max(10)
         private String firstname;
@@ -107,6 +108,7 @@ public class BeanBinderTest
 
         // Should correctly bind the enum field without throwing
         otherBinder.bindInstanceFields(testClass);
+        testSerialization(otherBinder);
     }
 
     @Test
@@ -122,6 +124,7 @@ public class BeanBinderTest
         otherBinder.setBean(bean);
         testClass.number.setValue("50");
         assertEquals(50, bean.number);
+        testSerialization(otherBinder);
     }
 
     @Test(expected = IllegalStateException.class)
@@ -304,6 +307,7 @@ public class BeanBinderTest
         binder.setBean(bean);
 
         Assert.assertTrue(field.isRequiredIndicatorVisible());
+        testSerialization(binder);
     }
 
     @Test
@@ -317,6 +321,7 @@ public class BeanBinderTest
         binder.setBean(bean);
 
         Assert.assertTrue(field.isRequiredIndicatorVisible());
+        testSerialization(binder);
     }
 
     @Test
@@ -330,6 +335,7 @@ public class BeanBinderTest
         binder.setBean(bean);
 
         Assert.assertTrue(field.isRequiredIndicatorVisible());
+        testSerialization(binder);
     }
 
     private void assertInvalid(HasValue<?> field, String message) {

server/src/test/java/com/vaadin/data/BinderConverterValidatorTest.java

@@ -21,6 +21,7 @@ import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 
+import java.io.Serializable;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicBoolean;
 
@@ -43,7 +44,7 @@ import com.vaadin.ui.TextField;
 public class BinderConverterValidatorTest
         extends BinderTestBase<Binder<Person>, Person> {
 
-    private static class StatusBean {
+    private static class StatusBean implements Serializable {
         private String status;
 
         public String getStatus() {

server/src/test/java/com/vaadin/data/BinderMultiSelectTest.java

@@ -34,7 +34,7 @@ import com.vaadin.ui.CheckBoxGroup;
 
 public class BinderMultiSelectTest
         extends BinderTestBase<Binder<BeanWithEnums>, BeanWithEnums> {
-    public class TestEnumSetToStringConverter
+    public static class TestEnumSetToStringConverter
             implements Converter<Set<TestEnum>, String> {
         @Override
         public Result<String> convertToModel(Set<TestEnum> value,

server/src/test/java/com/vaadin/data/BinderTestBase.java

@@ -15,8 +15,12 @@
  */
 package com.vaadin.data;
 
+import java.io.ByteArrayOutputStream;
+import java.io.ObjectOutputStream;
+import java.io.Serializable;
 import java.util.Locale;
 
+import org.junit.After;
 import org.junit.Before;
 
 import com.vaadin.ui.TextField;
@@ -28,7 +32,7 @@ import com.vaadin.ui.TextField;
  *
  * @since 8.0
  */
-public abstract class BinderTestBase<BINDER extends Binder<ITEM>, ITEM> {
+public abstract class BinderTestBase<BINDER extends Binder<ITEM>, ITEM> implements Serializable {
 
     protected static final String NEGATIVE_ERROR_MESSAGE = "Value must be non-negative";
 
@@ -50,6 +54,14 @@ public abstract class BinderTestBase<BINDER extends Binder<ITEM>, ITEM> {
     protected Validator<Integer> notNegative = Validator.from(x -> x >= 0,
             NEGATIVE_ERROR_MESSAGE);
 
+    public static void testSerialization(Object toSerialize) {
+        try (ObjectOutputStream objectOutputStream = new ObjectOutputStream(new ByteArrayOutputStream())) {
+            objectOutputStream.writeObject(toSerialize);
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+
     @Before
     public void setUpBase() {
         nameField = new TextField();
@@ -57,4 +69,9 @@ public abstract class BinderTestBase<BINDER extends Binder<ITEM>, ITEM> {
         ageField = new TextField();
         ageField.setLocale(Locale.US);
     }
+
+    @After
+    public void testBinderSerialization() {
+        testSerialization(binder);
+    }
 }

server/src/test/java/com/vaadin/tests/data/bean/BeanToValidate.java

@@ -1,5 +1,6 @@
 package com.vaadin.tests.data.bean;
 
+import java.io.Serializable;
 import java.util.Calendar;
 
 import javax.validation.Valid;
@@ -11,7 +12,7 @@ import javax.validation.constraints.Past;
 import javax.validation.constraints.Pattern;
 import javax.validation.constraints.Size;
 
-public class BeanToValidate {
+public class BeanToValidate implements Serializable {
 
     @NotNull
     @Size(min = 3, max = 16)

server/src/test/java/com/vaadin/tests/data/bean/BeanWithEnums.java

@@ -15,10 +15,11 @@
  */
 package com.vaadin.tests.data.bean;
 
+import java.io.Serializable;
 import java.util.HashSet;
 import java.util.Set;
 
-public class BeanWithEnums {
+public class BeanWithEnums implements Serializable{
     private Set<TestEnum> enums = new HashSet<>();
 
     public Set<TestEnum> getEnums() {

server/src/test/java/com/vaadin/tests/data/bean/Person.java

@@ -1,9 +1,10 @@
 package com.vaadin.tests.data.bean;
 
+import java.io.Serializable;
 import java.math.BigDecimal;
 import java.time.LocalDate;
 
-public class Person {
+public class Person implements Serializable {
     private String firstName;
     private String lastName;
     private String email;