Handle nulls gracefully

Author: exabrial

form-binding/src/main/java/com/github/exabrial/formbinding/impl/DefaultFormBindingReader.java

@@ -18,22 +18,27 @@ public class DefaultFormBindingReader implements FormBindingReader {
 
 	@Override
 	public <ReturnType> ReturnType read(String input, Class<ReturnType> returnTypeClazz) {
-		try {
-			Set<Field> boundFields = extractBoundFields(returnTypeClazz);
-			ReturnType returnValue = returnTypeClazz.newInstance();
-			Map<String, String> valueMap = splitQuery(input);
-			for (String key : valueMap.keySet()) {
-				Field field = findMatchingField(key, boundFields);
-				if (field != null) {
-					field.setAccessible(true);
-					Class<?> type = field.getType();
-					Object object = CommonCode.cub.convert(valueMap.get(key), type);
-					field.set(returnValue, object);
+		if (returnTypeClazz != null && input != null) {
+			input = input.trim();
+			try {
+				Set<Field> boundFields = extractBoundFields(returnTypeClazz);
+				ReturnType returnValue = returnTypeClazz.newInstance();
+				Map<String, String> valueMap = splitQuery(input);
+				for (String key : valueMap.keySet()) {
+					Field field = findMatchingField(key, boundFields);
+					if (field != null) {
+						field.setAccessible(true);
+						Class<?> type = field.getType();
+						Object object = CommonCode.cub.convert(valueMap.get(key), type);
+						field.set(returnValue, object);
+					}
 				}
+				return returnValue;
+			} catch (InstantiationException | IllegalAccessException e) {
+				throw new RuntimeException(e);
 			}
-			return returnValue;
-		} catch (InstantiationException | IllegalAccessException e) {
-			throw new RuntimeException(e);
+		} else {
+			return null;
 		}
 	}
 

form-binding/src/main/java/com/github/exabrial/formbinding/impl/DefaultFormBindingWriter.java

@@ -15,10 +15,14 @@
 public class DefaultFormBindingWriter implements FormBindingWriter {
 	@Override
 	public String write(Object object) {
-		Set<Field> boundFields = extractBoundFields(object.getClass());
-		Map<String, String> values = convertToMap(object, boundFields);
-		String result = convertMapToString(values);
-		return result;
+		if (object == null) {
+			return null;
+		} else {
+			Set<Field> boundFields = extractBoundFields(object.getClass());
+			Map<String, String> values = convertToMap(object, boundFields);
+			String result = convertMapToString(values);
+			return result;
+		}
 	}
 
 	private Map<String, String> convertToMap(Object object, Set<Field> boundFields) {

form-binding/src/test/java/com/github/exabrial/formbinding/impl/DefaultFormBindingReaderTest.java

@@ -1,6 +1,8 @@
 package com.github.exabrial.formbinding.impl;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
 
 import java.math.BigDecimal;
 
@@ -13,11 +15,14 @@ class DefaultFormBindingReaderTest {
 	private DefaultFormBindingReader reader = new DefaultFormBindingReader();
 
 	@Test
-	void testRead_mixedAnnnotations() {
-		String payload = "ThisIsATest";
-		String input = "differentName=" + payload;
-		MixedAnnotations mixedAnnotations = reader.read(input, MixedAnnotations.class);
-		assertEquals(payload, mixedAnnotations.getHeresAField());
+	void testRead_null() {
+		assertNull(reader.read(null, MixedAnnotations.class));
+		assertNull(reader.read("a=b", null));
+	}
+
+	@Test
+	void testRead_empty() {
+		assertNotNull(reader.read("", MixedAnnotations.class));
 	}
 
 	@Test
@@ -29,8 +34,9 @@ void testRead_VeryComplexObject() {
 		object.testDouble = 4.2;
 		object.stringParam = "testParam";
 		VeryComplexObject readValue = reader.read(
-				"date=Wed+Dec+31+18%3A00%3A00+CST+1969&stringParam=testParam&testInt=-1&wrapperLong=42&bigDecimal=1234&testDouble=4.2",
+				"ignored=true&date=Wed+Dec+31+18%3A00%3A00+CST+1969&stringParam=testParam&testInt=-1&wrapperLong=42&bigDecimal=1234&testDouble=4.2",
 				VeryComplexObject.class);
 		assertEquals(object, readValue);
+		assertNull(readValue.ignored);
 	}
 }

form-binding/src/test/java/com/github/exabrial/formbinding/impl/DefaultFormBindingWriterTest.java

@@ -1,6 +1,7 @@
 package com.github.exabrial.formbinding.impl;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
 
 import java.math.BigDecimal;
 
@@ -15,6 +16,11 @@
 class DefaultFormBindingWriterTest {
 	private DefaultFormBindingWriter writer = new DefaultFormBindingWriter();
 
+	@Test
+	void testRead_null() {
+		assertNull(writer.write(null));
+	}
+
 	@Test
 	void testWrite_MixedAnnotations() {
 		String value = writer.write(new MixedAnnotations());
@@ -48,6 +54,7 @@ void testWrite_VeryComplexObject() {
 		object.bigDecimal = BigDecimal.valueOf(1234L);
 		object.testDouble = 4.2;
 		object.stringParam = "testParam";
+		object.ignored = true;
 		String value = writer.write(object);
 		assertEquals("stringParam=testParam&testInt=-1&wrapperLong=42&bigDecimal=1234&testDouble=4.2", value);
 	}

form-binding/src/test/java/com/github/exabrial/formbinding/test/model/VeryComplexObject.java

@@ -2,18 +2,23 @@
 
 import java.math.BigDecimal;
 
+import com.github.exabrial.formbinding.FormBindingTransient;
+
 public class VeryComplexObject {
 	public int testInt;
 	public Integer wrapperLong;
 	public BigDecimal bigDecimal;
 	public double testDouble;
 	public String stringParam;
+	@FormBindingTransient
+	public Boolean ignored;
 
 	@Override
 	public int hashCode() {
 		final int prime = 31;
 		int result = 1;
 		result = prime * result + ((bigDecimal == null) ? 0 : bigDecimal.hashCode());
+		result = prime * result + ((ignored == null) ? 0 : ignored.hashCode());
 		result = prime * result + ((stringParam == null) ? 0 : stringParam.hashCode());
 		long temp;
 		temp = Double.doubleToLongBits(testDouble);
@@ -42,6 +47,13 @@ public boolean equals(Object obj) {
 		} else if (!bigDecimal.equals(other.bigDecimal)) {
 			return false;
 		}
+		if (ignored == null) {
+			if (other.ignored != null) {
+				return false;
+			}
+		} else if (!ignored.equals(other.ignored)) {
+			return false;
+		}
 		if (stringParam == null) {
 			if (other.stringParam != null) {
 				return false;