finished mbtiles

pom.xml

@@ -101,8 +101,8 @@
       <version>${jackson.version}</version>
     </dependency>
     <dependency>
-      <groupId>com.fasterxml.jackson.core</groupId>
-      <artifactId>jackson-annotations</artifactId>
+      <groupId>com.fasterxml.jackson.datatype</groupId>
+      <artifactId>jackson-datatype-jdk8</artifactId>
       <version>${jackson.version}</version>
     </dependency>
 

src/main/java/com/onthegomap/flatmap/write/Mbtiles.java

@@ -1,7 +1,11 @@
 package com.onthegomap.flatmap.write;
 
+import static com.fasterxml.jackson.annotation.JsonInclude.Include.NON_ABSENT;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.datatype.jdk8.Jdk8Module;
 import com.onthegomap.flatmap.geo.GeoUtils;
 import com.onthegomap.flatmap.geo.TileCoord;
 import java.io.Closeable;
@@ -41,7 +45,9 @@ public record Mbtiles(Connection connection) implements Closeable {
   public static final String METADATA_COL_VALUE = "value";
 
   private static final Logger LOGGER = LoggerFactory.getLogger(Mbtiles.class);
-  private static final ObjectMapper objectMapper = new ObjectMapper();
+  private static final ObjectMapper objectMapper = new ObjectMapper()
+    .registerModules(new Jdk8Module())
+    .setSerializationInclusion(NON_ABSENT);
 
   public static Mbtiles newInMemoryDatabase() {
     try {
@@ -121,7 +127,7 @@ public record Mbtiles(Connection connection) implements Closeable {
   public Mbtiles vacuumAnalyze() {
     return execute(
       "VACUUM;",
-      "ANALYZE"
+      "ANALYZE;"
     );
   }
 
@@ -133,7 +139,14 @@ public record Mbtiles(Connection connection) implements Closeable {
     return new Metadata();
   }
 
-  public static record MetadataJson(List<VectorLayer> vectorLayers) {
+  public static record MetadataJson(
+    @JsonProperty("vector_layers")
+    List<VectorLayer> vectorLayers
+  ) {
+
+    public MetadataJson(VectorLayer... layers) {
+      this(List.of(layers));
+    }
 
     public static MetadataJson fromJson(String json) {
       try {
@@ -152,43 +165,32 @@ public record Mbtiles(Connection connection) implements Closeable {
     }
 
     public enum FieldType {
-      NUMBER("Number"),
-      BOOLEAN("Boolean"),
-      STRING("String");
-
-      private final String name;
-
-      FieldType(String name) {
-        this.name = name;
-      }
-
-      @Override
-      public String toString() {
-        return name;
-      }
+      @JsonProperty("Number") NUMBER,
+      @JsonProperty("Boolean") BOOLEAN,
+      @JsonProperty("String") STRING
     }
 
     public static record VectorLayer(
-      String id,
-      Map<String, FieldType> fields,
-      Optional<String> description,
-      OptionalInt minzoom,
-      OptionalInt maxzoom
+      @JsonProperty("id") String id,
+      @JsonProperty("fields") Map<String, FieldType> fields,
+      @JsonProperty("description") Optional<String> description,
+      @JsonProperty("minzoom") OptionalInt minzoom,
+      @JsonProperty("maxzoom") OptionalInt maxzoom
     ) {
 
       public VectorLayer(String id, Map<String, FieldType> fields) {
         this(id, fields, Optional.empty(), OptionalInt.empty(), OptionalInt.empty());
       }
 
-      public VectorLayer copyWithDescription(String newDescription) {
+      public VectorLayer withDescription(String newDescription) {
         return new VectorLayer(id, fields, Optional.of(newDescription), minzoom, maxzoom);
       }
 
-      public VectorLayer copyWithMinzoom(int newMinzoom) {
+      public VectorLayer withMinzoom(int newMinzoom) {
         return new VectorLayer(id, fields, description, OptionalInt.of(newMinzoom), maxzoom);
       }
 
-      public VectorLayer copyWithMaxzoom(int newMaxzoom) {
+      public VectorLayer withMaxzoom(int newMaxzoom) {
         return new VectorLayer(id, fields, description, minzoom, OptionalInt.of(newMaxzoom));
       }
     }

src/test/java/com/onthegomap/flatmap/write/MbtilesTest.java

@@ -2,6 +2,7 @@ package com.onthegomap.flatmap.write;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
 import com.onthegomap.flatmap.geo.GeoUtils;
 import com.onthegomap.flatmap.geo.TileCoord;
 import java.io.IOException;
@@ -134,7 +135,67 @@ public class MbtilesTest {
     }
   }
 
-  // TODO: json encoding
+  private void testMetadataJson(Mbtiles.MetadataJson object, String expected) throws IOException {
+    var objectMapper = new ObjectMapper();
+    try (Mbtiles db = Mbtiles.newInMemoryDatabase()) {
+      var metadata = db.setupSchema().tuneForWrites().metadata();
+      metadata.setJson(object);
+      var actual = metadata.getAll().get("json");
+      assertEquals(
+        objectMapper.readTree(expected),
+        objectMapper.readTree(actual)
+      );
+    }
+  }
+
+  @Test
+  public void testMetadataJsonNoLayers() throws IOException {
+    testMetadataJson(new Mbtiles.MetadataJson(), """
+      {
+        "vector_layers": []
+      }
+      """);
+  }
+
+  @Test
+  public void testFullMetadataJson() throws IOException {
+    testMetadataJson(new Mbtiles.MetadataJson(
+      new Mbtiles.MetadataJson.VectorLayer(
+        "full",
+        Map.of(
+          "NUMBER_FIELD", Mbtiles.MetadataJson.FieldType.NUMBER,
+          "STRING_FIELD", Mbtiles.MetadataJson.FieldType.STRING,
+          "boolean field", Mbtiles.MetadataJson.FieldType.BOOLEAN
+        )
+      ).withDescription("full description")
+        .withMinzoom(0)
+        .withMaxzoom(5),
+      new Mbtiles.MetadataJson.VectorLayer(
+        "partial",
+        Map.of()
+      )
+    ), """
+      {
+        "vector_layers": [
+          {
+            "id": "full",
+            "description": "full description",
+            "minzoom": 0,
+            "maxzoom": 5,
+            "fields": {
+              "NUMBER_FIELD": "Number",
+              "STRING_FIELD": "String",
+              "boolean field": "Boolean"
+            }
+          },
+          {
+            "id": "partial",
+            "fields": {}
+          }
+        ]
+      }
+      """);
+  }
 
   private static Set<Mbtiles.TileEntry> getAll(Mbtiles db) throws SQLException {
     Set<Mbtiles.TileEntry> result = new HashSet<>();