1. import java.io.*;
  2. import java.nio.file.*;
  3. import java.util.List;
  4. import java.util.ArrayList;
  5. import org.json.JSONArray;
  6. import org.json.JSONObject;
  8. public class RecordSerializer {
  10. /**
  11. * Serializes a list of records to a JSON file based on a configuration.
  12. * @param records The list of records to serialize.
  13. * @param configPath The path to the configuration file.
  14. * @param outputFilePath The path to the output JSON file.
  15. * @throws IOException If an I/O error occurs.
  16. */
  17. public static void serializeRecords(List<Record> records, String configPath, String outputFilePath) throws IOException {
  19. // Load configuration
  20. Configuration config = loadConfiguration(configPath);
  22. // Validate configuration
  23. if (config == null || config.getRecordFieldSelector() == null || config.getOutputFormat() == null) {
  24. throw new IllegalArgumentException("Invalid configuration file.");
  25. }
  27. // Prepare data for JSON serialization
  28. List<Record> filteredRecords = filterRecords(records, config.getRecordFieldSelector());
  30. // Convert records to JSON array
  31. JSONArray jsonArray = convertRecordsToJsonArray(filteredRecords);
  33. // Write JSON array to file
  34. try (FileWriter fileWriter = new FileWriter(outputFilePath)) {
  35. fileWriter.write(jsonArray.toString(2)); // Use 2 spaces for indentation
  36. }
  37. }
  40. /**
  41. * Loads the configuration from a JSON file.
  42. * @param configPath The path to the configuration file.
  43. * @return The configuration object.
  44. * @throws IOException If an I/O error occurs.
  45. */
  46. private static Configuration loadConfiguration(String configPath) throws IOException {
  47. try (FileReader fileReader = new FileReader(configPath)) {
  48. JSONObject configJson = new JSONObject(fileReader);
  49. return new Configuration(configJson);
  50. }
  51. }
  53. /**
  54. * Filters records based on the specified field selector in the configuration.
  55. * @param records The list of records.
  56. * @param fieldSelector The field selector from the configuration.
  57. * @return The filtered list of records.
  58. */
  59. private static List<Record> filterRecords(List<Record> records, String fieldSelector) {
  60. List<Record> filteredRecords = new ArrayList<>();
  61. for (Record record : records) {
  62. if (record.getData().containsKey(fieldSelector)) {
  63. filteredRecords.add(record);
  64. }
  65. }
  66. return filteredRecords;
  67. }
  70. /**
  71. * Converts a list of records to a JSON array.
  72. * @param records The list of records.
  73. * @return A JSONArray representing the records.
  74. */
  75. private static JSONArray convertRecordsToJsonArray(List<Record> records) {
  76. JSONArray jsonArray = new JSONArray();
  77. for (Record record : records) {
  78. JSONObject recordJson = new JSONObject(record.getData());
  79. jsonArray.put(recordJson);
  80. }
  81. return jsonArray;
  82. }
  85. // Define a simple Record class for demonstration
  86. public static class Record {
  87. private JSONObject data;
  89. public Record(JSONObject data) {
  90. this.data = data;
  91. }
  93. public JSONObject getData() {
  94. return data;
  95. }
  96. }
  98. // Define a simple Configuration class
  99. public static class Configuration {
  100. private JSONObject json;
  102. public Configuration(JSONObject json) {
  103. this.json = json;
  104. }
  106. public String getRecordFieldSelector() {
  107. return json.getString("recordFieldSelector");
  108. }
  110. public String getOutputFormat() {
  111. return json.getString("outputFormat");
  112. }
  113. }
  116. public static void main(String[] args) throws IOException {
  117. // Example usage:
  118. List<Record> records = new ArrayList<>();
  120. JSONObject record1Data = new JSONObject();
  121. record1Data.put("id", 1);
  122. record1Data.put("name", "Alice");
  123. record1Data.put("age", 30);
  124. records.add(new Record(record1Data));
  126. JSONObject record2Data = new JSONObject();
  127. record2Data.put("id", 2);
  128. record2Data.put("name", "Bob");
  129. record2Data.put("city", "New York");
  130. records.add(new Record(record2Data));
  132. JSONObject record3Data =

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