[JAVA]Filter를 이용한 multipart/form-data 처리 및 파일 업로드 처리

Filter를 이용한 multipart/form-data 처리 및 파일 업로드 처리

package com.xo.ddm.front.util.fileUtil;

import java.io.IOException;

import javax.servlet.Filter;

import javax.servlet.FilterChain;

import javax.servlet.FilterConfig;

import javax.servlet.ServletException;

import javax.servlet.ServletRequest;

import javax.servlet.ServletResponse;

import javax.servlet.http.HttpServletRequest;

public final class FileUploadFilter implements Filter{

public void init(FilterConfig aConfig) throws ServletException{

}

public void destroy(){

}

public void doFilter(

ServletRequest aRequest, ServletResponse aResponse, FilterChain aChain)

throws IOException, ServletException{

HttpServletRequest request = (HttpServletRequest) aRequest;

if(isFileUploadRequest(request)){

FileUploadWrapper wrapper = new FileUploadWrapper(request);

aChain.doFilter(wrapper, aResponse);

}else{

aChain.doFilter(aRequest, aResponse);

}

}

private boolean isFileUploadRequest(HttpServletRequest aRequest){

return

aRequest.getMethod().equalsIgnoreCase("POST") &&

aRequest.getContentType().startsWith("multipart/form-data");

}

}

---

package com.xo.ddm.front.util.fileUtil;

import java.io.IOException;

import java.io.UnsupportedEncodingException;

import java.util.ArrayList;

import java.util.Collections;

import java.util.Enumeration;

import java.util.LinkedHashMap;

import java.util.LinkedHashSet;

import java.util.List;

import java.util.Map;

import java.util.Set;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletRequestWrapper;

import org.apache.commons.fileupload.FileItem;

import org.apache.commons.fileupload.FileUploadException;

import org.apache.commons.fileupload.disk.DiskFileItemFactory;

import org.apache.commons.fileupload.servlet.ServletFileUpload;

public class FileUploadWrapper extends HttpServletRequestWrapper{

/*

* 생성자 설정

    */

public FileUploadWrapper(HttpServletRequest aRequest)

 throws IOException{

super(aRequest);

aRequest.setCharacterEncoding("UTF-8");

ServletFileUpload upload = new ServletFileUpload(

new DiskFileItemFactory());

try{

List<FileItem> fileItems = upload.parseRequest(aRequest);

convertToMaps(fileItems);

}catch (FileUploadException e){

//TODO Auto-generated catch block

throw new IOException("Cannot parse underlying request : "

+ e.toString());   

}

}

/*

     * 모든 파라메터 이름을 리턴 한다.(file type 필드 까지)

     */

@Override public Enumeration getParameterNames(){

Set<String> allNames = new LinkedHashSet<String>();

allNames.addAll(fRegularParams.keySet());

allNames.addAll(fFileParams.keySet());

return Collections.enumeration(allNames);

}

/*

     * file type 필드가 아닌 모든 파라메터 값(value)를 리턴 한다.

     * 

     * 파라메터가 존재 하지 않으면 null 리턴

     * 파라메터가 존재 하나 값이 없으면 공백 리턴

     * 파라메터가 여러개 일경우 최초의 값만 리턴

     */

@Override public String getParameter(String aName){

String result = null;

List<String> values = fRegularParams.get(aName);

if(values == null){

result = "";

}else if(values.isEmpty()){

result = "";

}else{

try{

result = new String(values.get(FIRST_VALUE).getBytes("ISO-8859-1"), "UTF-8");

}catch(UnsupportedEncodingException e){

// TODO Auto-generated catch block

e.printStackTrace();

}

}

return result;

}

/*

     * parameterValues[] 리턴

     */

@Override public String[] getParameterValues(String aName){

String[]result = null;

List<String> values = fRegularParams.get(aName);

if(values != null){

result = values.toArray(new String[values.size()]);

}

return result;

}

/*

     * 파라메터 Map 리턴

     */

@Override public Map getParameterMap(){

return Collections.unmodifiableMap(fRegularParams);

}

/*

     * fileItems 리턴

     */

public List<FileItem> getFileItems(){

return new ArrayList<FileItem>(fFileParams.values());

}

public FileItem getFileItem(String aFieldName){

return fFileParams.get(aFieldName);

}

private final Map<String, List<String>> fRegularParams = new

LinkedHashMap<String, List<String>>();

private final Map<String, FileItem>fFileParams = new

LinkedHashMap<String, FileItem>();

private static final int FIRST_VALUE = 0;

private void convertToMaps(List<FileItem> aFileItems){

for(FileItem item: aFileItems){

if(isFileUploadField(item)){

fFileParams.put(item.getFieldName(), item);

}else{

if(alreadyHasValue(item)){

addMultiValuedItem(item);

}else{

addSingleValueItem(item);

}

}

}

}

private boolean isFileUploadField(FileItem aFileItem){

return !aFileItem.isFormField();

}

private boolean alreadyHasValue(FileItem aItem){

return fRegularParams.get(aItem.getFieldName()) != null;

}

private void addSingleValueItem(FileItem aItem){

List<String> list = new ArrayList<String>();

list.add(aItem.getString());

fRegularParams.put(aItem.getFieldName(), list);

}

private void addMultiValuedItem(FileItem aItem){

List<String> values = fRegularParams.get(aItem.getFieldName());

values.add(aItem.getString());

}

}