BAEL-5192 Code samples for the article (#11483)

* BAEL-5192 implement code samples

* BAEL-5192 simplify some methods

* BAEL-5192 remove duplicated test method

Co-authored-by: Yavuz Tas <ytas@vwd.com>

jackson-modules/jackson-conversions-2/src/main/java/com/baeldung/jackson/booleanAsInt/Game.java

@@ -0,0 +1,49 @@
+package com.baeldung.jackson.booleanAsInt;
+
+public class Game {
+
+    private Long id;
+    private String name;
+    private Boolean paused;
+    private Boolean over;
+
+    public Game() {
+    }
+
+    public Game(Long id, String name) {
+        this.id = id;
+        this.name = name;
+    }
+
+    public Long getId() {
+        return this.id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return this.name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public Boolean isPaused() {
+        return paused;
+    }
+
+    public void setPaused(Boolean paused) {
+        this.paused = paused;
+    }
+
+    public Boolean isOver() {
+        return over;
+    }
+
+    public void setOver(Boolean over) {
+        this.over = over;
+    }
+}

jackson-modules/jackson-conversions-2/src/main/java/com/baeldung/jackson/booleanAsInt/GameAnnotatedByJsonFormat.java

@@ -0,0 +1,56 @@
+package com.baeldung.jackson.booleanAsInt;
+
+import com.fasterxml.jackson.annotation.JsonFormat;
+import com.fasterxml.jackson.annotation.JsonFormat.Shape;
+
+public class GameAnnotatedByJsonFormat {
+
+    private Long id;
+    private String name;
+
+    @JsonFormat(shape = Shape.NUMBER)
+    private boolean paused;
+
+    @JsonFormat(shape = Shape.NUMBER)
+    private boolean over;
+
+    public GameAnnotatedByJsonFormat() {
+    }
+
+    public GameAnnotatedByJsonFormat(Long id, String name) {
+        this.id = id;
+        this.name = name;
+    }
+
+    public Long getId() {
+        return this.id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return this.name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public boolean isPaused() {
+        return paused;
+    }
+
+    public void setPaused(boolean paused) {
+        this.paused = paused;
+    }
+
+    public boolean isOver() {
+        return over;
+    }
+
+    public void setOver(boolean over) {
+        this.over = over;
+    }
+}

jackson-modules/jackson-conversions-2/src/main/java/com/baeldung/jackson/booleanAsInt/GameAnnotatedByJsonSerializeDeserialize.java

@@ -0,0 +1,58 @@
+package com.baeldung.jackson.booleanAsInt;
+
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+
+public class GameAnnotatedByJsonSerializeDeserialize {
+
+    private Long id;
+    private String name;
+
+    @JsonSerialize(using = NumericBooleanSerializer.class)
+    @JsonDeserialize(using = NumericBooleanDeserializer.class)
+    private Boolean paused;
+
+    @JsonSerialize(using = NumericBooleanSerializer.class)
+    @JsonDeserialize(using = NumericBooleanDeserializer.class)
+    private Boolean over;
+
+    public GameAnnotatedByJsonSerializeDeserialize() {
+    }
+
+    public GameAnnotatedByJsonSerializeDeserialize(Long id, String name) {
+        this.id = id;
+        this.name = name;
+    }
+
+    public Long getId() {
+        return this.id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return this.name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public Boolean isPaused() {
+        return paused;
+    }
+
+    public void setPaused(Boolean paused) {
+        this.paused = paused;
+    }
+
+    public Boolean isOver() {
+        return over;
+    }
+
+    public void setOver(Boolean over) {
+        this.over = over;
+    }
+}

jackson-modules/jackson-conversions-2/src/main/java/com/baeldung/jackson/booleanAsInt/NumericBooleanDeserializer.java

@@ -0,0 +1,23 @@
+package com.baeldung.jackson.booleanAsInt;
+
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonDeserializer;
+import java.io.IOException;
+
+public class NumericBooleanDeserializer extends JsonDeserializer<Boolean> {
+
+    @Override
+    public Boolean deserialize(JsonParser p, DeserializationContext ctxt)
+      throws IOException {
+        if ("1".equals(p.getText())) {
+            return Boolean.TRUE;
+        }
+        if ("0".equals(p.getText())) {
+            return Boolean.FALSE;
+        }
+        // for other than "1" or "0" throw exception by using Jackson internals
+        throw ctxt.weirdStringException(p.getText(), Boolean.class, "only \"1\" or \"0\" recognized");
+    }
+
+}

jackson-modules/jackson-conversions-2/src/main/java/com/baeldung/jackson/booleanAsInt/NumericBooleanSerializer.java

@@ -0,0 +1,15 @@
+package com.baeldung.jackson.booleanAsInt;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.JsonSerializer;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import java.io.IOException;
+
+public class NumericBooleanSerializer extends JsonSerializer<Boolean> {
+
+    @Override
+    public void serialize(Boolean value, JsonGenerator gen, SerializerProvider serializers)
+      throws IOException {
+        gen.writeString(value ? "1" : "0");
+    }
+}

jackson-modules/jackson-conversions-2/src/test/java/com/baeldung/jackson/booleanAsInt/BooleanAsIntegerUnitTest.java

@@ -0,0 +1,132 @@
+package com.baeldung.jackson.booleanAsInt;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import com.fasterxml.jackson.annotation.JsonFormat;
+import com.fasterxml.jackson.annotation.JsonFormat.Shape;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.exc.InvalidFormatException;
+import com.fasterxml.jackson.databind.module.SimpleModule;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+public class BooleanAsIntegerUnitTest {
+
+    private ObjectMapper mapper;
+
+    @BeforeEach
+    public void setup() {
+        mapper = new ObjectMapper();
+    }
+
+    @Test
+    public void givenBoolean_serializedAsInteger() throws Exception {
+        GameAnnotatedByJsonFormat
+          game = new GameAnnotatedByJsonFormat(1L, "My Game");
+        game.setPaused(true);
+        game.setOver(false);
+        String json = mapper.writeValueAsString(game);
+
+        assertThat(json)
+          .isEqualTo("{\"id\":1,\"name\":\"My Game\",\"paused\":1,\"over\":0}");
+    }
+
+    @Test
+    public void givenInteger_deserializedAsBooleanByDefault() throws Exception {
+        // Integer "1" and "0" values deserialized correctly out of the box.
+        // No configuration or @JsonFormat annotation needed.
+        String json = "{\"id\":1,\"name\":\"My Game\",\"paused\":1,\"over\":0}";
+        Game game = mapper.readValue(json, Game.class);
+
+        assertThat(game.isPaused()).isEqualTo(true);
+        assertThat(game.isOver()).isEqualTo(false);
+    }
+
+    @Test
+    public void givenBoolean_serializedAsIntegerGlobally() throws Exception {
+        // global configuration override for the type Boolean
+        mapper.configOverride(Boolean.class)
+          .setFormat(JsonFormat.Value.forShape(Shape.NUMBER));
+
+        Game game = new Game(1L, "My Game");
+        game.setPaused(true);
+        game.setOver(false);
+        String json = mapper.writeValueAsString(game);
+
+        assertThat(json)
+          .isEqualTo("{\"id\":1,\"name\":\"My Game\",\"paused\":1,\"over\":0}");
+    }
+
+    @Test
+    public void givenBooleanWithCustomSerializer_serializedAsNumericString() throws Exception {
+        GameAnnotatedByJsonSerializeDeserialize
+          game = new GameAnnotatedByJsonSerializeDeserialize(1L, "My Game");
+        game.setPaused(true);
+        game.setOver(false);
+        String json = mapper.writeValueAsString(game);
+
+        assertThat(json)
+          .isEqualTo("{\"id\":1,\"name\":\"My Game\",\"paused\":\"1\",\"over\":\"0\"}");
+    }
+
+    @Test
+    public void givenNumericStringWithCustomDeserializer_deserializedAsBoolean() throws Exception {
+        String json = "{\"id\":1,\"name\":\"My Game\",\"paused\":\"1\",\"over\":\"0\"}";
+        GameAnnotatedByJsonSerializeDeserialize
+          game = mapper.readValue(json, GameAnnotatedByJsonSerializeDeserialize.class);
+
+        assertThat(game.isPaused()).isEqualTo(true);
+        assertThat(game.isOver()).isEqualTo(false);
+    }
+
+    @Test
+    public void givenBooleanWithCustomSerializer_serializedAsNumericStringGlobally() throws Exception {
+        // setting serializers globally
+        SimpleModule module = new SimpleModule();
+        module.addSerializer(Boolean.class, new NumericBooleanSerializer());
+        mapper.registerModule(module);
+
+        Game game = new Game(1L, "My Game");
+        game.setPaused(true);
+        game.setOver(false);
+        String json = mapper.writeValueAsString(game);
+
+        assertThat(json)
+          .isEqualTo("{\"id\":1,\"name\":\"My Game\",\"paused\":\"1\",\"over\":\"0\"}");
+    }
+
+    @Test
+    public void givenNumericStringWithCustomDeserializer_deserializedAsBooleanGlobally() throws Exception {
+        // setting deserializers globally
+        SimpleModule module = new SimpleModule();
+        module.addDeserializer(Boolean.class, new NumericBooleanDeserializer());
+        mapper.registerModule(module);
+
+        String json = "{\"id\":1,\"name\":\"My Game\",\"paused\":\"1\",\"over\":\"0\"}";
+        Game game = mapper.readValue(json, Game.class);
+
+        assertThat(game.isPaused()).isEqualTo(true);
+        assertThat(game.isOver()).isEqualTo(false);
+    }
+
+    @Test
+    public void givenInvalidStringWithCustomDeserializer_throwsInvalidFormatException() {
+        // another number other than "1" or "0"
+        String json = "{\"id\":1,\"name\":\"My Game\",\"paused\":\"5\"}";
+        InvalidFormatException e = Assertions.assertThrows(
+          InvalidFormatException.class, () -> mapper.readValue(json, GameAnnotatedByJsonSerializeDeserialize.class)
+        );
+
+        assertThat(e.getValue()).isEqualTo("5");
+
+        // non-numeric string
+        String json2 = "{\"id\":1,\"name\":\"My Game\",\"paused\":\"xxx\"}";
+        InvalidFormatException e2 = Assertions.assertThrows(
+          InvalidFormatException.class, () -> mapper.readValue(json2, GameAnnotatedByJsonSerializeDeserialize.class)
+        );
+
+        assertThat(e2.getValue()).isEqualTo("xxx");
+    }
+
+}