BAEL 2879 (#6767)

* BAEL-2727 Example Code

* Example code for BAEL-2879 Jackson YAML

jackson-2/pom.xml

@@ -22,6 +22,20 @@
             <version>${jackson.version}</version>
         </dependency>
 
+        <!-- YAML -->
+        <dependency>
+            <groupId>com.fasterxml.jackson.dataformat</groupId>
+            <artifactId>jackson-dataformat-yaml</artifactId>
+            <version>2.9.8</version>
+        </dependency>
+
+        <!-- Allow use of LocalDate -->
+        <dependency>
+            <groupId>com.fasterxml.jackson.datatype</groupId>
+            <artifactId>jackson-datatype-jsr310</artifactId>
+            <version>2.9.8</version>
+        </dependency>
+
 
         <!-- test scoped -->
 

jackson-2/src/main/java/com/baeldung/jackson/entities/Order.java

@@ -0,0 +1,68 @@
+package com.baeldung.jackson.entities;
+
+import java.time.LocalDate;
+import java.util.ArrayList;
+import java.util.List;
+
+public class Order {
+    private String orderNo;
+    private LocalDate date;
+    private String customerName;
+    private List<OrderLine> orderLines;
+
+    public Order() {
+
+    }
+
+    public Order(String orderNo, LocalDate date, String customerName, List<OrderLine> orderLines) {
+        super();
+        this.orderNo = orderNo;
+        this.date = date;
+        this.customerName = customerName;
+        this.orderLines = orderLines;
+    }
+
+    public String getOrderNo() {
+        return orderNo;
+    }
+
+    public void setOrderNo(String orderNo) {
+        this.orderNo = orderNo;
+    }
+
+    public LocalDate getDate() {
+        return date;
+    }
+
+    public void setDate(LocalDate date) {
+        this.date = date;
+    }
+
+    public String getCustomerName() {
+        return customerName;
+    }
+
+    public void setCustomerName(String customerName) {
+        this.customerName = customerName;
+    }
+
+    public List<OrderLine> getOrderLines() {
+        if (orderLines == null) {
+            orderLines = new ArrayList<>();
+        }
+        return orderLines;
+    }
+
+    public void setOrderLines(List<OrderLine> orderLines) {
+        if (orderLines == null) {
+            orderLines = new ArrayList<>();
+        }
+        this.orderLines = orderLines;
+    }
+
+    @Override
+    public String toString() {
+        return "Order [orderNo=" + orderNo + ", date=" + date + ", customerName=" + customerName + ", orderLines=" + orderLines + "]";
+    }
+
+}

jackson-2/src/main/java/com/baeldung/jackson/entities/OrderLine.java

@@ -0,0 +1,49 @@
+package com.baeldung.jackson.entities;
+
+import java.math.BigDecimal;
+
+public class OrderLine {
+    private String item;
+    private int quantity;
+    private BigDecimal unitPrice;
+    
+    public OrderLine() {
+        
+    }
+
+    public OrderLine(String item, int quantity, BigDecimal unitPrice) {
+        super();
+        this.item = item;
+        this.quantity = quantity;
+        this.unitPrice = unitPrice;
+    }
+
+    public String getItem() {
+        return item;
+    }
+
+    public void setItem(String item) {
+        this.item = item;
+    }
+
+    public int getQuantity() {
+        return quantity;
+    }
+
+    public void setQuantity(int quantity) {
+        this.quantity = quantity;
+    }
+
+    public BigDecimal getUnitPrice() {
+        return unitPrice;
+    }
+
+    public void setUnitPrice(BigDecimal unitPrice) {
+        this.unitPrice = unitPrice;
+    }
+
+    @Override
+    public String toString() {
+        return "OrderLine [item=" + item + ", quantity=" + quantity + ", unitPrice=" + unitPrice + "]";
+    }
+}

jackson-2/src/main/resources/orderInput.yaml

@@ -0,0 +1,11 @@
+orderNo: A001
+date: 2019-04-17
+customerName: Customer, Joe
+orderLines:
+    - item: No. 9 Sprockets
+      quantity: 12
+      unitPrice: 1.23
+    - item: Widget (10mm)
+      quantity: 4
+      unitPrice: 3.45
+      

jackson-2/src/test/java/com/baeldung/jackson/yaml/YamlUnitTest.java

@@ -0,0 +1,63 @@
+package com.baeldung.jackson.yaml;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import java.io.File;
+import java.io.IOException;
+import java.math.BigDecimal;
+import java.math.RoundingMode;
+import java.time.LocalDate;
+import java.time.format.DateTimeFormatter;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import com.baeldung.jackson.entities.Order;
+import com.baeldung.jackson.entities.OrderLine;
+import com.fasterxml.jackson.core.JsonGenerationException;
+import com.fasterxml.jackson.core.JsonParseException;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationFeature;
+import com.fasterxml.jackson.dataformat.yaml.YAMLFactory;
+import com.fasterxml.jackson.dataformat.yaml.YAMLGenerator.Feature;
+
+public class YamlUnitTest {
+    private ObjectMapper mapper;
+
+    @Before
+    public void setup() {
+        mapper = new ObjectMapper(new YAMLFactory().disable(Feature.WRITE_DOC_START_MARKER));
+        mapper.findAndRegisterModules();
+        mapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
+    }
+
+    @Test
+    public void givenYamlInput_ObjectCreated() throws JsonParseException, JsonMappingException, IOException {
+        Order order = mapper.readValue(new File("src/main/resources/orderInput.yaml"), Order.class);
+        assertEquals("A001", order.getOrderNo());
+        assertEquals(LocalDate.parse("2019-04-17", DateTimeFormatter.ISO_DATE), order.getDate());
+        assertEquals("Customer, Joe", order.getCustomerName());
+        assertEquals(2, order.getOrderLines()
+            .size());
+    }
+
+    @Test
+    public void givenYamlObject_FileWritten() throws JsonGenerationException, JsonMappingException, IOException {
+        List<OrderLine> lines = new ArrayList<>();
+        lines.add(new OrderLine("Copper Wire (200ft)", 1, new BigDecimal(50.67).setScale(2, RoundingMode.HALF_UP)));
+        lines.add(new OrderLine("Washers (1/4\")", 24, new BigDecimal(.15).setScale(2, RoundingMode.HALF_UP)));
+        Order order = new Order(
+            "B-9910", 
+            LocalDate.parse("2019-04-18", DateTimeFormatter.ISO_DATE), 
+            "Customer, Jane", 
+            lines);
+        mapper.writeValue(new File("src/main/resources/orderOutput.yaml"), order);
+
+        File outputYaml = new File("src/main/resources/orderOutput.yaml");
+        assertTrue(outputYaml.exists());
+    }
+}