JSF自定义文件上传组件

package com.jsfx.filter; import java.io.File; import java.io.UnsupportedEncodingException; import java.util.Collections; import java.util.Enumeration; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Map; import javax.faces.application.FacesMessage; import javax.faces.context.FacesContext; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletRequestWrapper; import org.apache.commons.fileupload.FileItem; import org.apache.commons.fileupload.FileUploadBase; import org.apache.commons.fileupload.FileUploadException; import org.apache.commons.fileupload.disk.DiskFileItemFactory; import org.apache.commons.fileupload.servlet.ServletFileUpload; /** * Request的包装类，使jsf能解析表单数据 代码主要来自myFaces1.1的MultipartRequestWrapper类 * 主要区别是使用了commons-fileupload1.2处理文件上传 */ @SuppressWarnings("unchecked") public class MultipartRequestWrapper extends HttpServletRequestWrapper { public static final String UPLOADED_FILES_ATTRIBUTE = "org.apache.myfaces.uploadedFiles"; public static final String WWW_FORM_URLENCODED_TYPE = "application/x-www-form-urlencoded"; HttpServletRequest request = null; HashMap parametersMap = null;// 参数表 ServletFileUpload fileUpload = null; HashMap fileItems = null;// 上传文件表 int maxSize;// 表单最大大小 int thresholdSize;// 临界值大小 String repositoryPath;// 临时文件夹位置 public MultipartRequestWrapper(HttpServletRequest request, int maxSize, int thresholdSize, String repositoryPath) { super(request); this.request = request; this.maxSize = maxSize; this.thresholdSize = thresholdSize; this.repositoryPath = repositoryPath; } @Override public Enumeration getParameterNames() { if (parametersMap == null) parseRequest(); return Collections.enumeration(parametersMap.keySet()); } @Override public String getParameter(String name) { if (parametersMap == null) parseRequest(); String[] values = (String[]) parametersMap.get(name); if (values == null) return null; return values[0]; } @Override public String[] getParameterValues(String name) { if (parametersMap == null) parseRequest(); return (String[]) parametersMap.get(name); } @Override public Map getParameterMap() { if (parametersMap == null) parseRequest(); return parametersMap; } /** * 获取请求中的FileItem */ public FileItem getFileItem(String fieldName) { if (fileItems == null) parseRequest(); return (FileItem) fileItems.get(fieldName); } /** * 获取请求中的FileItem表 */ public Map getFileItems() { if (fileItems == null) parseRequest(); return fileItems; } @Override public Object getAttribute(String string) { if (string.equals(UPLOADED_FILES_ATTRIBUTE)) { return getFileItems(); } return super.getAttribute(string); } @Override public String getContentType() { return WWW_FORM_URLENCODED_TYPE; } /** * 最关键的部分，解析表单数据 */ private void parseRequest() { DiskFileItemFactory factory = new DiskFileItemFactory(); factory.setSizeThreshold(thresholdSize);// 设置临届大小 if (repositoryPath != null && repositoryPath.trim().length() > 0) factory.setRepository(new File(repositoryPath));// 设置临时文件夹 fileUpload = new ServletFileUpload(); fileUpload.setFileItemFactory(factory); fileUpload.setSizeMax(maxSize);// 设置表单最大大小 String charset = request.getCharacterEncoding(); fileUpload.setHeaderEncoding(charset); List requestParameters = null; try { requestParameters = fileUpload.parseRequest(request); } catch (FileUploadBase.SizeLimitExceededException e) { e.printStackTrace(); FacesContext.getCurrentInstance().addMessage("", new FacesMessage(e.getMessage()));// 文件超过大小时提示用户 requestParameters = Collections.EMPTY_LIST; } catch (FileUploadException fue) { fue.printStackTrace(); FacesContext.getCurrentInstance().addMessage("", new FacesMessage(fue.getMessage())); requestParameters = Collections.EMPTY_LIST; } parametersMap = new HashMap(requestParameters.size());// 建立参数表 fileItems = new HashMap(); for (Iterator iter = requestParameters.iterator(); iter.hasNext();) { FileItem fileItem = (FileItem) iter.next(); if (fileItem.isFormField()) {// 普通参数处理 String name = fileItem.getFieldName(); String value = null; if (charset == null) { value = fileItem.getString(); } else { try { value = new String(fileItem.get(), charset); } catch (UnsupportedEncodingException e) { value = fileItem.getString(); } } addTextParameter(name, value);// 添加参数 } else {// 参数是一个文件 if (fileItem.getName() != null) { fileItems.put(fileItem.getFieldName(), fileItem);// 添加Fileitem } } } for (Iterator it = request.getParameterMap().entrySet().iterator(); it .hasNext();) { Map.Entry entry = (Map.Entry) it.next(); Object value = entry.getValue(); if (value instanceof String[]) { String[] valuesArray = (String[]) entry.getValue(); for (int i = 0; i < valuesArray.length; i++) { addTextParameter((String) entry.getKey(), valuesArray[i]); } } else if (value instanceof String) { String strValue = (String) entry.getValue(); addTextParameter((String) entry.getKey(), strValue); } else if (value != null) throw new IllegalStateException("value of type : " + value.getClass() + " for key : " + entry.getKey() + " cannot be handled."); } } private void addTextParameter(String name, String value) { if (!parametersMap.containsKey(name)) { String[] valuesArray = { value }; parametersMap.put(name, valuesArray); } else { String[] storedValues = (String[]) parametersMap.get(name); int lengthSrc = storedValues.length; String[] valuesArray = new String[lengthSrc + 1]; System.arraycopy(storedValues, 0, valuesArray, 0, lengthSrc); valuesArray[lengthSrc] = value; parametersMap.put(name, valuesArray); } } }