Core Servlets and JavaServer Pages™

A.4. Handling the Client Request: HTTP Request Headers

Methods That Read Request Headers

These are all methods in HttpServletRequest.

• public String getHeader(String headerName)

  Returns value of an arbitrary header. Returns null if header not in request.

• public Enumeration getHeaders(String headerName)

  Returns values of all occurrences of header in request. 2.2 only.

• public Enumeration getHeaderNames()

  Returns names of all headers in current request.

• public long getDateHeader(String headerName)

  Reads header that represents a date and converts it to Java date format (milliseconds since 1970).

• public int getIntHeader(String headerName)

  Reads header that represents an integer and converts it to an int. Returns -1 if header not in request. Throws NumberFormatException ...