/*******************************************************************************
* *
* File: Servlet_01.java Revision: 1.0 *
* *
* Purpose: reading parameters sent along with a request *
* *
* Creation: 08.09.2000 Last Modification: 09.09.2000 *
* *
* Platform: IBM-compatible PC running Windows 98SE *
* *
* Environment: Java 1.3, Gefion Software LiteWebServer 2.2.1 *
* *
* Author: Andreas Rozek Phone: ++49 (711) 6770682 *
* Kirschblütenweg 15 Fax: - *
* D-70569 Stuttgart EMail: Andreas.Rozek@T-Online.De *
* Germany *
* *
* URL: http://Home.T-Online.De/home/Andreas.Rozek *
* *
* Copyright: this software is published under the "GNU General Public Li- *
* cense" (see "http://www.gnu.org/copyleft/gpl.html" for addi- *
* tional information) *
* *
* Comments: the paths in this servlet assume that the LiteWebServer is *
* still in its default configuration *
* *
* Warning: for the sake of simplicity, this servlet is not able *
* to handle several requests concurrently *
* *
*******************************************************************************/
import java.io.*; // Java file handling and stream IO
import java.util.*; // Java utility classes and data structures
import javax.servlet.*; // servlet implementation classes
import javax.servlet.http.*; // servlet HTTP support
public class Servlet_01 extends HttpServlet {
/*******************************************************************************
* *
* Non-Public Instance Variables *
* *
*******************************************************************************/
PrintWriter OutStream; // is used to construct this servlet's response
boolean oddTableRow; // a simple table row "counter"
/*******************************************************************************
* *
* Public Instance Methods *
* *
*******************************************************************************/
/*******************************************************************************
* *
* doGet handles a GET request *
* *
*******************************************************************************/
public void doGet (HttpServletRequest Request, HttpServletResponse Response)
throws ServletException, IOException {
try {
Response.setContentType("text/html");
/**** send HTML document with input form in case of missing parameters ****/
Enumeration NameList = Request.getParameterNames();
if (!NameList.hasMoreElements()) {
System.out.println("Servlet_01: processing request without parameters");
try {
BufferedReader InputStream = new BufferedReader(new FileReader("../HTML/Servlet_01.html"));
ArrayList LineList = new ArrayList();
String Line = InputStream.readLine();
while (Line != null) {
LineList.add(Line);
Line = InputStream.readLine();
};
int LineCount = LineList.size();
OutStream = Response.getWriter();
for (int i = 0; i < LineCount; i++) {
OutStream.println((String) LineList.get(i));
};
OutStream.close();
InputStream.close();
} catch (IOException Signal) {
OutStream = Response.getWriter();
insertHeader("Servlet_01 - Error Report");
OutStream.println("IOException
");
OutStream.println("An error occured while reading file \"../HTML/Servlet_01.html\"
");
OutStream.print ("Reason: ");
String Message = Signal.getMessage();
if (Message == null) {
OutStream.print("(unknown)");
} else {
OutStream.print("\"" + Message + "\"");
};
OutStream.println("
");
insertTrailer();
OutStream.close();
};
System.out.println("Servlet_01: finished processing the request");
return;
};
/**** process all given parameters and show their contents ****/
System.out.println("Servlet_01: processing parameterized request");
OutStream = Response.getWriter();
insertHeader("Servlet_01 - Form Input Display");
OutStream.println(" Parameter List
");
OutStream.println(" ");
OutStream.println(" The following table contains an overview of all request parameters:");
OutStream.println("
");
OutStream.println("
");
oddTableRow = true;
while (NameList.hasMoreElements()) {
String ParameterName = (String) NameList.nextElement();
String[] ValueList = Request.getParameterValues(ParameterName);
if (ValueList.length == 0) {
showParameter(ParameterName, null);
} else {
showParameter(ParameterName, ValueList[0]);
for (int i = 1; i < ValueList.length; i++) {
showParameter(null, ValueList[i]);
};
};
};
OutStream.println("
");
insertTrailer();
OutStream.close();
} catch (IOException Signal) {
log(
"caught IOException " + Signal.getClass().getName() + " while constructing " +
"the response (reason: \"" + Signal.getMessage() + "\")"
);
};
System.out.println("Servlet_01: finished processing the request");
};
/*******************************************************************************
* *
* doPost handles a POST request *
* *
*******************************************************************************/
public void doPost (HttpServletRequest Request, HttpServletResponse Response)
throws ServletException, IOException {
doGet(Request, Response);
};
/*******************************************************************************
* *
* getLastModified yields the timestamp of the requested object *
* *
*******************************************************************************/
public long getLastModified (HttpServletRequest Request) {
return -1L;
};
/*******************************************************************************
* *
* insertHeader inserts a page header into the "Response" *
* *
*******************************************************************************/
public void insertHeader (String Title) {
OutStream.println("");
OutStream.println("");
OutStream.println(" ");
OutStream.println(" " + Title + "");
OutStream.println(" ");
OutStream.println();
OutStream.println(" ");
OutStream.println(" ");
OutStream.println(" ");
OutStream.println(" | " + Title + " | ");
OutStream.println(" | ");
OutStream.println("
");
OutStream.println();
OutStream.println(" ");
OutStream.println(" ![](\"/Line_600.gif\") | ");
OutStream.println("
");
OutStream.println("
");
OutStream.println(" ");
OutStream.println(" ");
OutStream.println(" | ");
};
/*******************************************************************************
* *
* insertTrailer inserts a page trailer into the "Response" *
* *
*******************************************************************************/
public void insertTrailer () {
OutStream.println(" | ");
OutStream.println("
");
OutStream.println("
");
OutStream.println(" ");
OutStream.println(" ");
OutStream.println(" | ");
OutStream.println("
");
OutStream.println();
OutStream.println(" ");
OutStream.println(" | Andreas Rozek | ");
OutStream.println(" | ");
OutStream.println("
");
OutStream.println("
");
OutStream.println(" ");
OutStream.println("");
};
/*******************************************************************************
* *
* showParameter displays a given parameter with its value *
* *
*******************************************************************************/
public void showParameter (String Name, String Value) {
/**** beware of values with multiple lines ****/
if (Value != null) {
if ((Value.indexOf('\r') >= 0) || (Value.indexOf('\n') >= 0)) {
StringTokenizer Parser = new StringTokenizer(Value, "\r\n");
switch (Parser.countTokens()) {
case 0: Value = "";
break;
case 1: Value = Parser.nextToken();
break;
default: showParameter(Name, Parser.nextToken());
while (Parser.hasMoreTokens()) {
showParameter(null, Parser.nextToken());
};
return;
};
};
};
/**** now handle missing values or those without CR or LF ****/
OutStream.println(" ");
OutStream.println(" ![](\"/PaperHole.gif\") | ");
if (Name == null) {
OutStream.println(" | ");
} else {
OutStream.println(" " + Name + ": | ");
};
OutStream.print (" ");
if (Value == null) {
OutStream.print("(not available)");
} else {
OutStream.print("\"" + Value + "\"");
};
OutStream.println(" | ");
OutStream.println(" | ");
OutStream.println("
");
oddTableRow = !oddTableRow;
};
};