import java.io.*;
import java.util.*;
import javax.servlet.*;

public class MultipartRequest {

private static final int DEFAULT_MAX_POST_SIZE = 1024 * 1024;

private ServletRequest req;
private File dir;
private int maxSize;
private int nr;

private Hashtable parameters = new Hashtable();
private Hashtable files = new Hashtable();

public MultipartRequest(ServletRequest request,	String saveDirectory) throws IOException {
  this(request,saveDirectory,DEFAULT_MAX_POST_SIZE);
}

public MultipartRequest(ServletRequest request,	String saveDirectory, int maxPostSize) throws IOException {

  nr=0;
  
//Test de nulitate
  if(request == null) throw new IllegalArgumentException(" Trebuie sa fie furnizati parametrii");
  if(saveDirectory == null)  throw new IllegalArgumentException("Directorul in care se salveaza nu poate fi null");
  if(maxPostSize <= 0) throw new IllegalArgumentException("Dimensiunea maxima de dowload trebuie sa fie un nr. pozitiv");

  req=request;
  dir=new File(saveDirectory);
  maxSize=maxPostSize;

// saveDirectory este director ?
  if(!dir.isDirectory())
    throw new IllegalArgumentException("Nu este director: " + saveDirectory);

//saveDirectory este protejat la scriere?
  if(!dir.canWrite())
    throw new IllegalArgumentException("Director protejat la scriere:" + saveDirectory );

//se citesc parametrii
  readRequest();
}

//functii pentru accesul la campuri private

//denumirile parametrilor
public Enumeration getParameterNames() {  return parameters.keys(); }

//denumirile fisierelor
public Enumeration getFileNames() { return files.keys(); }

//valoarea unui parametru
public String getParameter(String name) {
  try{
    String param = (String)parameters.get(name);
    if(param.equals(""))return null;
  return param;
  }
  catch(Exception e){return null;}
}

//numele unui fisier din lista
public String getFilesystemName(String name) {
  try {
    UploadedFile file = (UploadedFile)files.get(name);
    return file.getFilesystemName();
  }
  catch(Exception e) {return null;}
}

//tipul unui fisier din lista
public String getContentType(String name) {
  try {
    UploadedFile file = (UploadedFile)files.get(name);
    return file.getContentType();
  }
  catch(Exception e) {return null;}
}

//fisierul de pe discul local
public File getFile(String name) {
  try {
    UploadedFile file=(UploadedFile)files.get(name);
    return file.getFile(); 
  }
  catch(Exception e) {return null;}
}

//citirea 
protected void readRequest() throws IOException {
//Se verifica daca metoda utilizata la criptarea este "multipart/form-data"
  String type=req.getContentType();
  if(type == null || !type.toLowerCase().startsWith("multipart/form-data")) {
    throw new IOException("Metoda de criptare nu este multipart/form-data");
  }

//verificarea dimensiunii contextului
  int length = req.getContentLength();
  if(length > maxSize) {
    throw new IOException("Dimensiunea " + length + " depaseste limita maxima admisa " + maxSize);
  }

//se ia sirul separator, de forma  "--AaB03x--" din continut 
  String boundary=extractBoundary(type);
  if(boundary == null) {
    throw new IOException("Sirul separator nespecificat");
  }

//se asociaza continutul 
  MultipartInputStreamHandler in = new MultipartInputStreamHandler(req.getInputStream(),boundary,length);

//se citeste prima linie; trebuie sa fie sirul separator
  String line =in.readLine();
  if(line == null) {
    throw new IOException("Sfarsit prematur!!");
  }
//se verifica daca prima linie este sirul separator
  if(!line.startsWith(boundary)) {
    throw new IOException("Date corupte; sirul separator nu este in cap");
  }
//se citeste continutul dintre sirurile separatoare
  boolean done=false;
  while(!done) {
    done=readNextPart(in,boundary);
  }
}

//continutul dintre doua siruri separatoare 
protected boolean readNextPart(MultipartInputStreamHandler in,String boundary)throws IOException {
//prima linie; ar tebui sa fie: content-disposition:form-data;name="field1";filename="file1.txt"

  String line=in.readLine();
  if(line == null) {return true;}

//se extrag specificatiile de context
  String[] dispInfo=extractDispositionInfo(line);
  String disposition=dispInfo[0];
  String name=dispInfo[1];
  String filename=dispInfo[2];

//linie urmatoare ori este goala ori contine content-type si o linie goala
  line=in.readLine();
  if(line == null) {return true;}
  String contentType=extractContentType(line);
  if(contentType != null) {//se asteapta o linie goala
    line=in.readLine();
    if(line == null||line.length() > 0) {
      throw new IOException("Linie corupta dupa content-type: " + line);
    }
  }
  else {//content-type implicit
    contentType = "application/octet-stream";
  }

  //se citeste continutul
  if(filename == null) {  
    String value=readParameter(in,boundary); 
    parameters.put(name,value); 
  }
  else {//este fisier
    //new  

    if(filename.equals("unknown")) {
	  readAndSaveFile(in,boundary,filename);
      files.put(name,new UploadedFile(null,null,null));
    }
    else {
	  nr++; 
	  filename= nr + filename.substring(filename.indexOf("."),filename.length());
	  readAndSaveFile(in,boundary,filename);
      files.put(name,new UploadedFile(dir.toString(),filename,contentType));///aici denumirea fisierului
    }
  }
  return false;
}

//citirea parametrilor
protected String readParameter(MultipartInputStreamHandler in,String boundary) throws IOException {
  StringBuffer sbuf = new StringBuffer();
  String line;

  while((line = in.readLine()) != null) {
    if(line.startsWith(boundary)) break;//la intalnirea sirului separator
    sbuf.append(line + "\r\n");//la citirea mai multor linii
  }
  if(sbuf.length() == 0) {return null;}

  sbuf.setLength(sbuf.length() - 2);//cut off the last line's \r\n
  return sbuf.toString();  //no URL decoding is needed
}

//citirea si salvarea fisierului
protected void readAndSaveFile(MultipartInputStreamHandler in,String boundary,String filename) throws IOException{
  File f=new File(dir + File.separator + filename);
  FileOutputStream fos=new FileOutputStream(f);
  BufferedOutputStream out=new BufferedOutputStream(fos,8 * 1024);//maxim 8k, pentru citirea unei linii

  byte[]  bbuf=new byte[8 * 1024];
  int result;
  String line;

//ServletInputSteam.readLine() adauga \r\n la sfarsitul ultimei linii; le taiem

  boolean rnflag= false;
  while((result=in.readLine(bbuf,0,bbuf.length)) != -1 ){//se citesc octetii, cate o linie de 8k
    if(result > 2 && bbuf[0] == '-' && bbuf[1] == '-') {
      line=new String(bbuf,0,result,"ISO-8859-1");
	if(line.startsWith(boundary))break;//la intalnirea separatorului se opreste citirea
    }

    //? \r\n la ultima iteratie ?
    if(rnflag) {
      out.write('\r');
      out.write('\n');
      rnflag=false; 
    }
    //se scrie ceea ce s-a citit fara \r\n
    if(result >= 2 && bbuf[result - 2 ] == '\r' && bbuf[result - 1] == '\n' ) {
      out.write(bbuf,0,result - 2);
      rnflag=true;
    }
    else{
      out.write(bbuf,0,result);
    }
  }
  out.flush();
  out.close();
  fos.close();
}

//separatorul
private String extractBoundary(String line){
  int index=line.indexOf("boundary=");
  if (index==-1){return null;}//nu a gasit separator
  String boundary =line.substring(index+9);
  boundary="--"+boundary;
  return boundary;
}

//specificatiile de continut
private String[] extractDispositionInfo(String line) throws IOException {
  String[] retval=new String[3];
  String origline=line;
  line=origline.toLowerCase();

  int start =line.indexOf("content-disposition");
  int end =line.indexOf(";");
  if (start==-1||end==-1){
    throw new IOException("Specificatii de continut corupte" + origline);
  }

  String disposition=line.substring(start+21,end);
  if (!disposition.equals("form-data")){
    throw new IOException ("Specificatii de continut invalide"+disposition);
  }

  //se verifica daca valoare parametrului este incadrata de ghilimele: "value"
  start=line.indexOf("name=\"",end);
  end=line.indexOf("\"",start+7);
  if (start==-1||end==-1){
    throw new IOException("Specificatiile de continut corupte"+origline);
  }
  //se citeste valoare lui nume dintre ghilimele
  String name=origline.substring(start+6,end);

  //se citeste numele fisierului atasat; se elimina calea
  String filename=null;
  start =line.indexOf("filename=\"",end+2);
  end=line.indexOf("\"",start+10);
  if (start!=-1 && end!=-1){
    filename=origline.substring(start+10,end);
    int slash=Math.max(filename.lastIndexOf('/'),filename.lastIndexOf('\\'));
    if (slash >-1){
      filename=filename.substring(slash+1);
    }
    if (filename.equals("")) filename="unknown";
  }
  retval[0]=disposition;
  retval[1]=name;
  retval[2]=filename;
  return retval;
}

//tipul continutului (pentru fisiere)
private String extractContentType(String line) throws IOException {

  String contentType=null;
  String origline = line;
  line = origline.toLowerCase();
  if(line.startsWith("content-type")) {
    int start=line.indexOf(" ");
    if(start == -1) {
       throw new IOException("Tipul continutului corupt: " + origline);
    }
    contentType=line.substring(start + 1);
  }
  else
    if(line.length() != 0) {
      throw new IOException("Dupa specificatii linie corupta:" + origline);
    }
  return contentType;
}
}//end classe


//clasa folosita pentru extragerea informatiilor despre fisier
class UploadedFile {
  private String dir;
  private String filename;
  private String type;

  //constructorul
  UploadedFile(String dir,String filename,String type) {
    this.dir=dir;
    this.filename=filename;
    this.type=type;
  }
  
  //returneaza valorile datelor private
  public String getContentType() {return type;}
  public String getFilesystemName() {return filename;}
  public File getFile() {//datele despre fisiere acum de pe harddisc-ul local
    if(dir == null || filename == null) {return null;} 
    else {return new File(dir + File.separator + filename);
  }
}
}



//aceasta clasa este utila pentru citirea multipart/form-data de la ServletInputStream
//contorizeaza cati octeti s-au citit si detecteaza cand s-a atins limita 
//content-Length; necesar pt. ca unele containere pt. servlet-uri nu detecteaza rapid sf. de fisier

class MultipartInputStreamHandler {

  ServletInputStream in;
  String boundary;
  int totalExpected;
  int totalRead=0;
  byte[] buf = new byte[8*1024];

  public MultipartInputStreamHandler(ServletInputStream in,	String boundary,int totalExpected) {
     this.in=in;
     this.boundary=boundary;
     this.totalExpected=totalExpected;
  }

  public String readLine() throws IOException {
    StringBuffer sbuf=new StringBuffer();
    int result;
    String line;
    do {
      result=this.readLine(buf,0,buf.length);
	if(result != -1){
	   sbuf.append(new String(buf,0,result,"ISO-8859-1"));
      }
    }while(result == buf.length);
    if(sbuf.length() == 0 ) {return null;}

    sbuf.setLength(sbuf.length() - 2);//fara \r\n
    return sbuf.toString();
  }

  public int readLine(byte b[],int off,int len) throws IOException {
    if(totalRead >= totalExpected) {
      return -1;
    }
    else {
      int result=in.readLine(b,off,len);
    if(result > 0) {
      totalRead += result;
    }
    return result;
  }
}
}