| Web Development | |
A Panther web application can run as a Java servlet. For this feature, you need a servlet engine using Java Virtual Machine Version 1.1.5 or later with native thread support enabled.
Java servlets extend the functionality of a Java-enabled HTTP servers. They are server-side components which interact with servlet engines running on HTTP servers through requests and responses. For example, a client program running on a web browser sends a request to an HTTP server. This request is processed by the servlet engine that runs with the HTTP server. The HTTP server returns a response to the servlet which in turn sends a response in HTTP format to the client.
Java servlets are an alternative to CGI programs and to vendor-specific APIs, such as NSAPI or ISAPI. By being both platform-independent and threaded, Java servlets have advantages over other protocols.
Installing Java Servlet Support |  |
The files for Java servlet support are located at WebInstallDir/servlet, as in /usr/panther/servlet on UNIX or C:\Prolifics\Panther\Servlet on Windows.
The servlet directory of your Panther web installation contains the following files:
proweb.jar—servlet class files
proweb.java—sample source code
filtered.java—sample source code
prowebjni.dll—servlet native code (Windows only)
libprowebjni.so—servlet native code (UNIX only)
*.html—HTML documentation of Java classes and usage instructions
To install Java servlet support:
proweb.jar to the servlet engine's CLASSPATH. You must specify the full path.prowebjni.dll (libprowebjni.so on UNIX) to the servlet engine's PATH. Alternatively, on Windows you could copy prowebjni.dll to the Windows directory.Accessing the Panther Web Application | |
http://HostName/proweb/WebAppName/ScreenName
The following URL accesses the dstord.scr screen in the vidstore web application:
http://myhost.com/proweb/vidstore/dstord.scr
Panther's Java Servlet Classes | |
Panther's Java servlet implementation extends the javax.servlet and the javax.servlet.http packages in the Java Servlet API.
The Java classes in proweb.jar include:
ProlificsHttpServlet
For more information on the following methods, refer to the Java Servlet API documentation at Methods
http://java.sun.com and to the HTML version of the Java class files.
Panther HTTP Servlet
The following methods are in
ProlificsHttpServlet:
doGet- Passes the
GETrequest to a Panther application.public void doGet(HttpServletRequest req,
HttpServletResponse res)
throws ServletException, IOException;
public void doGet(HttpServletRequest req,
HttpServletResponse res, String appname,
Boolean chunked)
throws ServletException, IOException;doPost- Passes the
POSTrequest to a Panther application.public void doPost(HttpServletRequest req,
HttpServletResponse res)
throws ServletException, IOException;
public void doPost(HttpServletRequest req,
HttpServletResponse res, String appname,
Boolean chunked)
throws ServletException, IOException;getServletInfo- Describes the servlet.
public String getServletInfo();initIf specified, it overrides the init method in the
GenericServletclass which the servlet engine calls when the servlet is loaded.public void init(ServletConfig config)throws ServletException;
The following methods in the
HttpServletRequestinterface are used byProlificsHttpServlet:
getAuthType- Gets the authentication scheme of this request. Same as the CGI variable
AUTH_TYPE.public String getAuthType();getContentLength- Returns the size of the request entity data, or -1 if not known. Same as the CGI variable
CONTENT_LENGTH.public int getContentLength();getContentType()- Returns the Internet Media Type of the request entity data, or null if not known. Same as the CGI variable
CONTENT_TYPE.public String getContentType();getCookies- Gets the array of cookies found in this request.
public Cookie[] getCookies();getHeader- Gets the value of the requested header field of this request.
public String getHeader(String name);getHeaderNames- Gets the header names for this request.
public Enumeration getHeaderNames();getInputStream- Returns an input stream for reading binary data in the request body.
public ServletInputStream getInputStream()throws IOException;getMethod- Gets the HTTP method (for example,
GET,POST,PUT) with which this request was made. Same as the CGI variableREQUEST_METHOD.public String getMethod();getPathInfo- Gets any optional extra path information following the servlet path of this request's URI, but immediately preceding its query string. Same as the CGI variable
PATH_INFO.public String getPathInfo();getPathTranslated- Gets any optional extra path information following the servlet path of this request's URI, but immediately preceding its query string, and translates it to a real path. Similar to the CGI variable
PATH_TRANSLATED.public String getPathTranslated();- getProtocol
- Returns the protocol and version of the request as a string in the form
protocol/major version.minor version. Same as the CGI variableSERVER_PROTOCOL.public String getProtocol();getQueryString- Gets any query string that is part of the HTTP request URI. Same as the CGI variable
QUERY_STRING.public String getQueryString();getRemoteAddr- Returns the IP address of the agent that sent the request. Same as the CGI variable
REMOTE_ADDR.public String getRemoteAddr();getRemoteHost- Returns the fully qualified host name of the agent that sent the request. Same as the CGI variable
REMOTE_HOST.public String getRemoteHost();getRemoteUser- Gets the name of the user making this request. The user name is set with HTTP authentication. Whether the user name will continue to be sent with each subsequent communication is browser-dependent. Same as the CGI variable
REMOTE_USER.public String getRemoteUser();- getRequestURI
- Gets, from the first line of the HTTP request, the part of this request's URI that is to the left of any query string.
public String getRequestURI();getServerName- Returns the host name of the server that received the request. Same as the CGI variable
SERVER_NAME.public String getServerName();getServerPort- Returns the port number on which this request was received. Same as the CGI variable
SERVER_PORT.public int getServerPort();getServletPath- Gets the part of this request's URI that refers to the servlet being invoked. Analogous to the CGI variable
SCRIPT_NAME.public String getServletPath();There are additional methods included in
FilterHttpServletRequestthat are not called byProlificsHttpServlet. See the HTML documentation for more information.
The following methods in the
HttpServletResponseinterface are used byProlificsHttpServlet:
addCookie- Adds the specified cookie to the response. It can be called multiple times to set more than one cookie.
public void addCookie(Cookie cookie);- getOutputStream
- Returns an output stream for writing binary response data.
public ServletOutputStream getOutputStream()
throws IOException;setContentLength- Sets the content length for this response.
public void setContentLength(int len);setContentType- Sets the content type for this response.
public void setContentType(String type);setHeader- Adds a field to the response header with the given name and value.
public void setHeader(String name, String value);setStatus- Sets the status code, or the status code and message, for this response.
public void setStatus(int sc);
public void setStatus(int sc, String sm);There are additional methods included in
FilterHttpServletResponsethat are not called byProlificsHttpServlet. See the HTML documentation for more information.
The following methods, if specified, override the methods in
InputStream:
availablepublic int available() throws IOException;closepublic void close() throws IOException;markpublic synchronized void mark(int readlimit);markSupportedpublic boolean markSupported();readpublic int read() throws IOException;
public int read(byte buf[]) throws IOException;
public int read(byte buf[], int off, int len)
throws IOException;readLinepublic int readLine(byte buf[], int off, int len);
throws IOExceptionresetpublic synchronized void reset() throws IOException;
The following methods, if specified, override the methods in
OutputStreamorServletOutputStream. See the HTML version of the class file for more information.
close- p
ublic void close() throws IOException;flushpublic void flush() throws IOException;public void print(boolean bval) throws IOException;
public void print(char cval) throws IOException;
public void print(double dval) throws IOException;
public void print(float fval) throws IOException;
public void print(int ival) throws IOException;
public void print(long lval) throws IOException;
public void print(String sval) throws IOException;printlnpublic void println() throws IOException;
public void println(boolean bval) throws IOException;
public void println(char cval) throws IOException;
public void println(double dval) throws IOException;
public void println(float fval) throws IOException;
public void println(int ival) throws IOException;
public void println(long lval) throws IOException;writepublic void write(byte buf[]) throws IOException;
public void write(int val) throws IOException;
public void write(byte buf[], int off, int len)
throws IOException;