Implement basic serialization

1 files changed, 65 insertions, 0 deletions

diff --git a/src/main/java/design/persistence/JSONPersonalDatabase.java b/src/main/java/design/persistence/JSONPersonalDatabase.java
new file mode 100644
index 0000000..3ec0012
--- /dev/null
+++ b/src/main/java/design/persistence/JSONPersonalDatabase.java
@@ -0,0 +1,65 @@
+package design.persistence;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import design.model.Golfer;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+
+public class JSONPersonalDatabase implements PersonalDatabase {
+
+    private final Map<String, Golfer> cache;
+    private final ObjectMapper mapper;
+    private final File file;
+
+    public JSONPersonalDatabase(String filename) throws IOException {
+        this.file = new File(filename);
+        this.cache = new HashMap<>();
+        this.mapper = new ObjectMapper();
+
+        load();
+    }
+
+    private void load() throws IOException {
+        Golfer[] data = mapper.readValue(file, Golfer[].class);
+        cache.clear();
+        for (Golfer i : data) {
+            cache.put(i.getUsername(), i);
+        }
+    }
+
+    private void save() throws IOException {
+        Golfer[] data = cache.values().toArray(Golfer[]::new);
+        mapper.writeValue(file, data);
+    }
+
+    @Override
+    public Golfer[] getGolfers() {
+        return new Golfer[0];
+    }
+
+    @Override
+    public Golfer getGolfer(String username) {
+        return cache.get(username);
+    }
+
+    @Override
+    public void addGolfer(Golfer golfer) throws IOException {
+        cache.put(golfer.getUsername(), golfer);
+        save();
+    }
+
+    @Override
+    public void removeGolfer(Golfer golfer) throws IOException {
+        cache.remove(golfer.getUsername());
+        save();
+    }
+
+    @Override
+    public void updateGolfer(Golfer golfer) throws IOException {
+        cache.put(golfer.getUsername(), golfer);
+        save();
+    }
+}