feat: implement JSON file-based project persistence

Introduce `app.projects.file` configuration property to specify the JSON file path for project data. Add `JsonConfig` for `ObjectMapper` bean definition. Update `ProjectJsonReaderWriterImpl` to handle reading and writing `Project` objects as JSON.

Author: dmccoystephenson

src/main/java/com/preponderous/parpt/config/JsonConfig.java

@@ -0,0 +1,14 @@
+package com.preponderous.parpt.config;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class JsonConfig {
+
+    @Bean
+    public ObjectMapper objectMapper() {
+        return new ObjectMapper();
+    }
+}

src/main/java/com/preponderous/parpt/repo/ProjectJsonReaderWriterImpl.java

@@ -1,19 +1,55 @@
+
 package com.preponderous.parpt.repo;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
 import com.preponderous.parpt.domain.Project;
+import org.springframework.beans.factory.annotation.Value;
 import org.springframework.stereotype.Component;
 
+import java.io.File;
+import java.io.IOException;
+import java.util.ArrayList;
 import java.util.List;
 
 @Component
 public class ProjectJsonReaderWriterImpl implements ProjectJsonReaderWriter {
+
+    private final String projectsFilePath;
+    private final ObjectMapper objectMapper;
+
+    public ProjectJsonReaderWriterImpl(
+            @Value("${app.projects.file}") String projectsFilePath,
+            ObjectMapper objectMapper) {
+        this.projectsFilePath = projectsFilePath;
+        this.objectMapper = objectMapper;
+    }
+
     @Override
     public void writeJson(List<Project> projects) {
-        throw new UnsupportedOperationException("Not supported yet.");
+        if (projects == null) {
+            throw new IllegalArgumentException("Projects list cannot be null");
+        }
+
+        try {
+            objectMapper.writeValue(new File(projectsFilePath), projects);
+        } catch (IOException e) {
+            throw new RuntimeException("Failed to write projects to JSON file", e);
+        }
     }
 
     @Override
     public List<Project> readJson() {
-        throw new UnsupportedOperationException("Not supported yet.");
+        File file = new File(projectsFilePath);
+
+        if (!file.exists() || file.length() == 0) {
+            return new ArrayList<>();
+        }
+
+        try {
+            return objectMapper.readValue(file,
+                    objectMapper.getTypeFactory().constructCollectionType(List.class, Project.class));
+        } catch (IOException e) {
+            throw new RuntimeException("Failed to read projects from JSON file", e);
+        }
     }
-}
+}

src/main/resources/application.yaml

@@ -34,4 +34,7 @@ parpt:
       - "How long will this take to build? (1=very quick, 5=very long) "
       - "How many people need to be involved? (1=just a few people, 5=many teams) "
       - "Will this be hard to maintain? (1=very easy, 5=very difficult) "
-      - "Does this need ongoing work? (1=set and forget, 5=lots of upkeep) "
+      - "Does this need ongoing work? (1=set and forget, 5=lots of upkeep) "
+app:
+  projects:
+    file: projects.json