Add jacksonJsonFilter

doc/source/utils/jackson/index.rst

@@ -5,4 +5,5 @@ Jackson
     :maxdepth: 3
     :numbered: 0
 
-    jacksonObjectMapper
+    jacksonObjectMapper
+    jacksonJsonFilter

doc/source/utils/jackson/jacksonJsonFilter.md

@@ -0,0 +1,44 @@
+# Jackson @JsonFilter
+
+## Using @JsonFilter
+**Step-1**: Create a class annotated with `@JsonFilter` and assign a filter name.
+
+**Step-2**: Create the instance of `SimpleFilterProvider` and add our filter `studentFilter` using `addFilter()` method.
+```
+SimpleFilterProvider filterProvider = new SimpleFilterProvider();
+filterProvider.addFilter("studentFilter",
+        SimpleBeanPropertyFilter.serializeAllExcept("stdName", "stdCity"));
+```
+
+**Step-3**: Set the instance of `SimpleFilterProvider` to `ObjectMapper` using `setFilterProvider()` method.
+```
+ObjectMapper mapper = new ObjectMapper();
+mapper.setFilterProvider(filterProvider);
+```
+
+**Step-4**: Now serialize the instance of `Student` class.
+```
+Student student = new Student("Mohit", 30, "ABCD", "Varanasi");
+String jsonData = mapper.writerWithDefaultPrettyPrinter()
+       .writeValueAsString(student);
+System.out.println(jsonData);
+```
+`stdName` and `stdCity` properties will not be serialized. Find the output.
+```
+{
+  "stdAge" : 30,
+  "stdCollege" : "ABCD"
+}
+```
+
+## SimpleBeanPropertyFilter
+`SimpleFilterProvider` is the implementation of `PropertyFilter` that only uses property name to determine if it should be serialized or filtered out. Find some methods of `SimpleFilterProvider`.
+- `serializeAllExcept()`: Serializes all properties except the properties configured to this method.
+- `filterOutAllExcept()`: Serializes properties only configured to this method.
+- `serializeAll()`: Serializes all properties and filters out nothing.
+
+## @JsonFilter at Property Level
+We can use `@JsonFilter` annotation on fields, methods and constructor parameters since Jackson 2.3. Here we will create two filters using `@JsonFilter` at property level and filter the properties using `serializeAllExcept()` and `filterOutAllExcept()` methods.
+
+## References
+- [Jackson @JsonFilter Example](https://www.concretepage.com/jackson-api/jackson-jsonfilter-example)

utils/README.md

@@ -13,6 +13,7 @@
 
 ### Jackson
 - [Jackson ObjectMapper](../doc/source/utils/jackson/jacksonObjectMapper.md)
+- [Jackson @JsonFilter](../doc/source/utils/jackson/jacksonJsonFilter.md)
 
 ### Properties
 - [Java Properties](../doc/source/utils/property/javaProperties.md)

utils/src/main/java/t5750/utils/jackson/entity/Address.java

@@ -0,0 +1,21 @@
+package t5750.utils.jackson.entity;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+public class Address {
+	@JsonProperty("city")
+	private String city;
+	@JsonProperty("state")
+	private String state;
+	@JsonProperty("country")
+	private String country;
+
+	public Address() {
+	}
+
+	public Address(String city, String state, String country) {
+		this.city = city;
+		this.state = state;
+		this.country = country;
+	}
+}

utils/src/main/java/t5750/utils/jackson/entity/Company.java

@@ -0,0 +1,24 @@
+package t5750.utils.jackson.entity;
+
+import com.fasterxml.jackson.annotation.JsonFilter;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+public class Company {
+	@JsonProperty("compName")
+	private String name;
+	@JsonFilter("ceoFilter")
+	@JsonProperty("compCeo")
+	private Employee ceo;
+	@JsonFilter("addressFilter")
+	@JsonProperty("compAddress")
+	private Address address;
+
+	public Company() {
+	}
+
+	public Company(String name, Employee ceo, Address address) {
+		this.name = name;
+		this.ceo = ceo;
+		this.address = address;
+	}
+}

utils/src/main/java/t5750/utils/jackson/entity/Employee.java

@@ -0,0 +1,21 @@
+package t5750.utils.jackson.entity;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+public class Employee {
+	@JsonProperty("empName")
+	private String name;
+	@JsonProperty("empAge")
+	private Integer age;
+	@JsonProperty("empProfile")
+	private String profile;
+
+	public Employee() {
+	}
+
+	public Employee(String name, Integer age, String profile) {
+		this.name = name;
+		this.age = age;
+		this.profile = profile;
+	}
+}

utils/src/main/java/t5750/utils/util/JacksonUtil.java

@@ -0,0 +1,41 @@
+package t5750.utils.util;
+
+import java.util.Set;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.ser.impl.SimpleBeanPropertyFilter;
+import com.fasterxml.jackson.databind.ser.impl.SimpleFilterProvider;
+
+/**
+ */
+public class JacksonUtil {
+	public static ObjectMapper objectMapper(String filterId,
+			SimpleBeanPropertyFilter filter) {
+		final SimpleFilterProvider filterProvider = new SimpleFilterProvider();
+		filterProvider.addFilter(filterId, filter);
+		final ObjectMapper objectMapper = new ObjectMapper();
+		objectMapper.setFilterProvider(filterProvider);
+		return objectMapper;
+	}
+
+	public static ObjectMapper objectMapperSerializeAllExcept(String filterId,
+			String... propertyArray) {
+		SimpleBeanPropertyFilter filter = SimpleBeanPropertyFilter
+				.serializeAllExcept(propertyArray);
+		return objectMapper(filterId, filter);
+	}
+
+	public static ObjectMapper objectMapperFilterOutAllExcept(String filterId,
+			Set<String> properties) {
+		SimpleBeanPropertyFilter filter = SimpleBeanPropertyFilter
+				.filterOutAllExcept(properties);
+		return objectMapper(filterId, filter);
+	}
+
+	public static ObjectMapper objectMapperFilterOutAllExcept(String filterId,
+			String... propertyArray) {
+		SimpleBeanPropertyFilter filter = SimpleBeanPropertyFilter
+				.filterOutAllExcept(propertyArray);
+		return objectMapper(filterId, filter);
+	}
+}

utils/src/test/java/t5750/utils/jackson/JacksonJsonFilterTest.java

@@ -1,25 +1,70 @@
 package t5750.utils.jackson;
 
+import java.util.HashSet;
+import java.util.Set;
+
 import org.junit.Test;
+import t5750.utils.jackson.entity.Address;
+import t5750.utils.jackson.entity.Company;
+import t5750.utils.jackson.entity.Employee;
 import t5750.utils.jackson.entity.Student;
+import t5750.utils.util.Global;
+import t5750.utils.util.JacksonUtil;
+import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.ser.impl.SimpleBeanPropertyFilter;
 import com.fasterxml.jackson.databind.ser.impl.SimpleFilterProvider;
 
-/**
- *
- */
 public class JacksonJsonFilterTest {
+	private static final Student STUDENT = new Student(Global.T5750, 30, "ABCD",
+			"Varanasi");
+
 	@Test
-	public void testJsonFilter() throws Exception {
-		final SimpleFilterProvider filterProvider = new SimpleFilterProvider();
-		filterProvider.addFilter("studentFilter", SimpleBeanPropertyFilter
-				.serializeAllExcept("stdName", "stdCity"));
-		final ObjectMapper objectMapper = new ObjectMapper();
-		objectMapper.setFilterProvider(filterProvider);
-		final Student student = new Student("Mohit", 30, "ABCD", "Varanasi");
+	public void testSerializeAllExcept() throws JsonProcessingException {
+		final ObjectMapper objectMapper = JacksonUtil
+				.objectMapperSerializeAllExcept("studentFilter", "stdName",
+						"stdCity");
+		final String jsonData = objectMapper.writerWithDefaultPrettyPrinter()
+				.writeValueAsString(STUDENT);
+		System.out.println(jsonData);
+	}
+
+	@Test
+	public void testFilterOutAllExcept() throws JsonProcessingException {
+		final ObjectMapper objectMapper = JacksonUtil
+				.objectMapperFilterOutAllExcept("studentFilter", "stdName",
+						"stdCity");
+		final String jsonData = objectMapper.writerWithDefaultPrettyPrinter()
+				.writeValueAsString(STUDENT);
+		System.out.println(jsonData);
+	}
+
+	@Test
+	public void testFilterOutAllExceptWithSet() throws JsonProcessingException {
+		Set<String> props = new HashSet<>();
+		props.add("stdName");
+		props.add("stdCity");
+		final ObjectMapper objectMapper = JacksonUtil
+				.objectMapperFilterOutAllExcept("studentFilter", props);
 		final String jsonData = objectMapper.writerWithDefaultPrettyPrinter()
-				.writeValueAsString(student);
+				.writeValueAsString(STUDENT);
+		System.out.println(jsonData);
+	}
+
+	@Test
+	public void testCompanyToJSON() throws JsonProcessingException {
+		final SimpleFilterProvider filterProvider = new SimpleFilterProvider();
+		filterProvider.addFilter("ceoFilter",
+				SimpleBeanPropertyFilter.serializeAllExcept("empProfile"));
+		filterProvider.addFilter("addressFilter", SimpleBeanPropertyFilter
+				.filterOutAllExcept("state", "country"));
+		final ObjectMapper mapper = new ObjectMapper();
+		mapper.setFilterProvider(filterProvider);
+		final Employee emp = new Employee(Global.T5750, 45, "Manager");
+		final Address address = new Address("Noida", "UP", "China");
+		final Company company = new Company("XYZ", emp, address);
+		final String jsonData = mapper.writerWithDefaultPrettyPrinter()
+				.writeValueAsString(company);
 		System.out.println(jsonData);
 	}
 }