Add example for mapping Map to Bean

Closes #126

Author: filiphr

mapstruct-mapping-from-map/src/main/java/org/mapstruct/example/dto/Department.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.example.dto;
+
+/**
+ * @author Filip Hrisafov
+ */
+public class Department {
+
+    private String id;
+    private String name;
+
+    public String getId() {
+        return id;
+    }
+
+    public void setId(String id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+}

mapstruct-mapping-from-map/src/main/java/org/mapstruct/example/dto/Employee.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.example.dto;
+
+/**
+ * @author Filip Hrisafov
+ */
+public class Employee {
+
+    private String id;
+    private String name;
+    private Department department;
+
+    public String getId() {
+        return id;
+    }
+
+    public void setId(String id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public Department getDepartment() {
+        return department;
+    }
+
+    public void setDepartment(Department department) {
+        this.department = department;
+    }
+}

mapstruct-mapping-from-map/src/main/java/org/mapstruct/example/mapper/MapToBeanMapper.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.example.mapper;
+
+import java.lang.annotation.Target;
+import java.util.Map;
+
+import org.mapstruct.AfterMapping;
+import org.mapstruct.Mapper;
+import org.mapstruct.Mapping;
+import org.mapstruct.MappingTarget;
+import org.mapstruct.example.dto.Department;
+import org.mapstruct.example.dto.Employee;
+import org.mapstruct.factory.Mappers;
+
+/**
+ * @author Filip Hrisafov
+ */
+@Mapper
+public interface MapToBeanMapper {
+
+    MapToBeanMapper INSTANCE = Mappers.getMapper(MapToBeanMapper.class);
+
+    @Mapping(target = "department", ignore = true)
+    Employee fromMap(Map<String, String> map);
+
+    @AfterMapping
+    default void finishEmployee(@MappingTarget Employee employee, Map<String, String> map) {
+        employee.setDepartment(fromMapToDepartment(map));
+    }
+
+    @Mapping(target = "id", source = "did")
+    @Mapping(target = "name", source = "dname")
+    Department fromMapToDepartment(Map<String, String> map);
+}

mapstruct-mapping-from-map/src/test/java/org/mapstruct/example/MapToBeanMapperTest.java

@@ -0,0 +1,38 @@
+package org.mapstruct.example;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.junit.Test;
+import org.mapstruct.example.dto.Department;
+import org.mapstruct.example.dto.Employee;
+import org.mapstruct.example.mapper.MapToBeanMapper;
+
+/**
+ * @author Filip Hrisafov
+ */
+public class MapToBeanMapperTest {
+
+    @Test
+    public void shouldMapMapToBean() {
+        Map<String, String> map = new HashMap<>();
+        map.put("id", "1234");
+        map.put("name", "Tester");
+        map.put("did", "4321"); //Department Id
+        map.put("dname", "Test");// Depart name
+
+        Employee employee = MapToBeanMapper.INSTANCE.fromMap(map);
+
+        assertNotNull(employee);
+        assertEquals(employee.getId(), "1234");
+        assertEquals(employee.getName(), "Tester");
+
+        Department department = employee.getDepartment();
+        assertNotNull(department);
+        assertEquals(department.getId(), "4321");
+        assertEquals(department.getName(), "Test");
+    }
+}