Part 1: write to String, File and pretty-printed String

src/main/java/com/ankurm/jackson3/part1objectmapper/B01WriteJson.java

@@ -0,0 +1,39 @@
+package com.ankurm.jackson3.part1objectmapper;
+
+import tools.jackson.databind.json.JsonMapper;
+
+import java.io.File;
+import java.nio.file.Files;
+import java.util.List;
+
+/**
+ * Post: Jackson ObjectMapper Guide — https://ankurm.com/jackson-objectmapper-guide/
+ * Section: "Serialising Java Objects to JSON"
+ *
+ * Every write target: String, File, and pretty-printed String.
+ */
+public class B01WriteJson {
+
+    public record Article(Long articleId, String title, List<String> tags) { }
+
+    public static void main(String[] args) throws Exception {
+        JsonMapper mapper = JsonMapper.builder().build();
+        Article article = new Article(1L, "Jackson Deep Dive", List.of("java", "json"));
+
+        // 1. Write to a String
+        String jsonOutput = mapper.writeValueAsString(article);
+        System.out.println(jsonOutput);
+
+        // 2. Write to a File
+        File target = File.createTempFile("article", ".json");
+        mapper.writeValue(target, article);
+        System.out.println("file     : " + Files.readString(target.toPath()));
+
+        // 3. Pretty-printed output
+        String pretty = mapper.writerWithDefaultPrettyPrinter().writeValueAsString(article);
+        System.out.println("pretty   :");
+        System.out.println(pretty);
+
+        target.deleteOnExit();
+    }
+}