CreateJSONFile.java

// Fig. 11.4: CreateJSONFile.java
// Writing data to a JSON file using the Jackson open-source library.
import com.fasterxml.jackson.databind.ObjectMapper;
import java.io.IOException;
import java.nio.file.Path;
import java.util.List;

// record class to represent an account
record Account(int accountNumber, String name, double balance) {}

public class CreateJSONFile {
   public static void main(String[] args) {
      // account data to write to JSON
      List<Account> accounts = List.of(
         new Account(100, "Devi", 24.98),
         new Account(200, "Taylor", 345.67),
         new Account(300, "Huber", 0.00),
         new Account(400, "Ito", -42.16),
         new Account(500, "Lopez", 224.62)
      );

      // Path to clients.json in user's Documents folder
      Path filePath = Path.of(System.getProperty("user.home"), 
         "Documents", "clients.json");

      var mapper = new ObjectMapper(); // performs the serialization

      try {
         // Write accounts to a JSON file
         mapper.writeValue(filePath.toFile(), accounts);
         System.out.printf(
            "JSON file created at: %s%n", filePath.toAbsolutePath());
      } 
      catch (IOException e) {
         System.err.printf(
            "Error writing JSON file: %s%n", e.getMessage());
      }
   }
}


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