1. import java.util.HashMap;
  2. import java.util.Map;
  4. public class HeaderWrapper {
  6. /**
  7. * Wraps existing logic for setting response headers with graceful failure handling.
  8. * @param response The response object (e.g., ServletResponse).
  9. * @param headers A map of header names to values to set.
  10. * @return True if headers were successfully set, false otherwise.
  11. */
  12. public boolean setResponseHeaders(Object response, Map<String, String> headers) {
  13. try {
  14. if (response == null) {
  15. System.err.println("Error: Response object is null.");
  16. return false;
  17. }
  19. // Check if the response object has a setHeader method. Handle potential ClassCastExceptions.
  20. if (response instanceof javax.servlet.http.HttpServletResponse) {
  21. HttpServletResponse servletResponse = (HttpServletResponse) response;
  22. for (Map.Entry<String, String> entry : headers.entrySet()) {
  23. servletResponse.setHeader(entry.getKey(), entry.getValue());
  24. }
  25. } else if (response instanceof java.io.OutputStream) {
  26. //Handle OutputStream (for example, for streaming)
  27. for (Map.Entry<String, String> entry : headers.entrySet()) {
  28. try {
  29. OutputStream os = (OutputStream) response;
  30. os.write(entry.getValue().getBytes()); //write the header value to the output stream
  31. } catch (Exception e) {
  32. System.err.println("Error writing header to OutputStream: " + e.getMessage());
  33. return false;
  34. }
  35. }
  36. }
  37. else {
  38. System.err.println("Error: Unsupported response type. Cannot set headers.");
  39. return false;
  40. }
  43. return true; // Headers set successfully
  44. } catch (Exception e) {
  45. System.err.println("Error setting response headers: " + e.getMessage());
  46. return false; // Indicate failure
  47. }
  48. }
  50. /**
  51. * Helper function for setting a single header.
  52. * @param response The response object.
  53. * @param headerName The name of the header.
  54. * @param headerValue The value of the header.
  55. * @return True if the header was set, false otherwise.
  56. */
  57. public boolean setResponseHeader(Object response, String headerName, String headerValue) {
  58. try {
  59. if (response == null) {
  60. System.err.println("Error: Response object is null.");
  61. return false;
  62. }
  64. if (response instanceof javax.servlet.http.HttpServletResponse) {
  65. HttpServletResponse servletResponse = (HttpServletResponse) response;
  66. servletResponse.setHeader(headerName, headerValue);
  67. return true;
  68. } else if (response instanceof java.io.OutputStream) {
  69. //Handle OutputStream (for example, for streaming)
  70. OutputStream os = (OutputStream) response;
  71. os.write(headerValue.getBytes());
  72. return true;
  74. } else {
  75. System.err.println("Error: Unsupported response type. Cannot set headers.");
  76. return false;
  77. }
  78. } catch (Exception e) {
  79. System.err.println("Error setting header: " + e.getMessage());
  80. return false;
  81. }
  82. }
  83. }
  85. //Example of HttpServletResponse
  86. class HttpServletResponseExample{
  88. public static void main(String[] args) {
  89. HeaderWrapper wrapper = new HeaderWrapper();
  90. HttpServletResponse response = new HttpServletResponse(); //mock response
  92. Map<String,String> headers = new HashMap<>();
  93. headers.put("Content-Type", "text/plain");
  94. headers.put("X-Custom-Header", "My Value");
  96. boolean success = wrapper.setResponseHeaders(response, headers);
  98. if(success){
  99. System.out.println("Headers set successfully.");
  100. } else{
  101. System.out.println("Headers failed to set.");
  102. }
  103. }
  104. }
  106. class HttpServletResponse {
  108. public void setHeader(String name, String value) {
  109. System.out.println("Setting header: " + name + " to " + value);
  110. }
  111. }
  113. class OutputStream {
  114. public void write(byte[] b) throws Exception{
  115. System.out.println("Writing to output stream: " + new String(b));
  116. }
  117. }

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