百木园Spring简介:
Spring框架是一个开放源代码的J2EE应用程序框架，由Rod Johnson发起，是针对bean的生命周期进行管理的轻量级容器（lightweight container）。 Spring解决了开发者在J2EE开发中遇到的许多常见的问题，提供了功能强大IOC、AOP及Web MVC等功能。Spring可以单独应用于构筑应用程序，也可以和Struts、Webwork、Tapestry等众多Web框架组合使用，并且可以与 Swing等桌面应用程序AP组合。因此， Spring不仅仅能应用于J2EE应用程序之中，也可以应用于桌面应用程序以及小应用程序之中。Spring框架主要由七部分组成，分别是 Spring Core、 Spring AOP、 Spring ORM、 Spring DAO、Spring Context、 Spring Web和 Spring Web MVC。
MultipartFile是springframe封装好的一个专门用于文件上传的接口
MultipartFile是一个接口，如下所示:
public interface MultipartFile { /** * Return the name of the parameter in the multipart form. * @return the name of the parameter (never {@code null} or empty) */ String getName(); /** * Return the original filename in the client\'s filesystem. * <p>This may contain path information depending on the browser used, * but it typically will not with any other than Opera. * @return the original filename, or the empty String if no file * has been chosen in the multipart form, or {@code null} * if not defined or not available */ String getOriginalFilename(); /** * Return the content type of the file. * @return the content type, or {@code null} if not defined * (or no file has been chosen in the multipart form) */ String getContentType(); /** * Return whether the uploaded file is empty, that is, either no file has * been chosen in the multipart form or the chosen file has no content. */ boolean isEmpty(); /** * Return the size of the file in bytes. * @return the size of the file, or 0 if empty */ long getSize(); /** * Return the contents of the file as an array of bytes. * @return the contents of the file as bytes, or an empty byte array if empty * @throws IOException in case of access errors (if the temporary store fails) */ byte[] getBytes() throws IOException; /** * Return an InputStream to read the contents of the file from. * The user is responsible for closing the stream. * @return the contents of the file as stream, or an empty stream if empty * @throws IOException in case of access errors (if the temporary store fails) */ InputStream getInputStream() throws IOException; /** * Transfer the received file to the given destination file. * <p>This may either move the file in the filesystem, copy the file in the * filesystem, or save memory-held contents to the destination file. * If the destination file already exists, it will be deleted first. * <p>If the file has been moved in the filesystem, this operation cannot * be invoked again. Therefore, call this method just once to be able to * work with any storage mechanism. * @param dest the destination file * @throws IOException in case of reading or writing errors * @throws IllegalStateException if the file has already been moved * in the filesystem and is not available anymore for another transfer */ void transferTo(File dest) throws IOException, IllegalStateException; }
commons 实现类
/* * Copyright 2002-2012 the original author or authors. * * Licensed under the Apache License, Version 2.0 (the \"License\"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an \"AS IS\" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.springframework.web.multipart.commons; import java.io.ByteArrayInputStream; import java.io.File; import java.io.IOException; import java.io.InputStream; import java.io.Serializable; import org.apache.commons.fileupload.FileItem; import org.apache.commons.fileupload.FileUploadException; import org.apache.commons.fileupload.disk.DiskFileItem; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.springframework.web.multipart.MultipartFile; /** * MultipartFile implementation for Jakarta Commons FileUpload. * * @author Trevor D. Cook * @author Juergen Hoeller * @since 29.09.2003 * @see CommonsMultipartResolver */ @SuppressWarnings(\"serial\") public class CommonsMultipartFile implements MultipartFile, Serializable { protected static final Log logger = LogFactory.getLog(CommonsMultipartFile.class); private final FileItem fileItem; private final long size; /** * Create an instance wrapping the given FileItem. * @param fileItem the FileItem to wrap */ public CommonsMultipartFile(FileItem fileItem) { this.fileItem = fileItem; this.size = this.fileItem.getSize(); } /** * Return the underlying {@code org.apache.commons.fileupload.FileItem} * instance. There is hardly any need to access this. */ public final FileItem getFileItem() { return this.fileItem; } @Override public String getName() { return this.fileItem.getFieldName(); } @Override public String getOriginalFilename() { String filename = this.fileItem.getName(); if (filename == null) { // Should never happen. return \"\"; } // check for Unix-style path int pos = filename.lastIndexOf(\"/\"); if (pos == -1) { // check for Windows-style path pos = filename.lastIndexOf(\"\\\\\"); } if (pos != -1) { // any sort of path separator found return filename.substring(pos + 1); } else { // plain name return filename; } } @Override public String getContentType() { return this.fileItem.getContentType(); } @Override public boolean isEmpty() { return (this.size == 0); } @Override public long getSize() { return this.size; } @Override public byte[] getBytes() { if (!isAvailable()) { throw new IllegalStateException(\"File has been moved - cannot be read again\"); } byte[] bytes = this.fileItem.get(); return (bytes != null ? bytes : new byte[0]); } @Override public InputStream getInputStream() throws IOException { if (!isAvailable()) { throw new IllegalStateException(\"File has been moved - cannot be read again\"); } InputStream inputStream = this.fileItem.getInputStream(); return (inputStream != null ? inputStream : new ByteArrayInputStream(new byte[0])); } @Override public void transferTo(File dest) throws IOException, IllegalStateException { if (!isAvailable()) { throw new IllegalStateException(\"File has already been moved - cannot be transferred again\"); } if (dest.exists() && !dest.delete()) { throw new IOException( \"Destination file [\" + dest.getAbsolutePath() + \"] already exists and could not be deleted\"); } try { this.fileItem.write(dest); if (logger.isDebugEnabled()) { String action = \"transferred\"; if (!this.fileItem.isInMemory()) { action = isAvailable() ? \"copied\" : \"moved\"; } logger.debug(\"Multipart file \'\" + getName() + \"\' with original filename [\" + getOriginalFilename() + \"], stored \" + getStorageDescription() + \": \" + action + \" to [\" + dest.getAbsolutePath() + \"]\"); } } catch (FileUploadException ex) { throw new IllegalStateException(ex.getMessage()); } catch (IOException ex) { throw ex; } catch (Exception ex) { logger.error(\"Could not transfer to file\", ex); throw new IOException(\"Could not transfer to file: \" + ex.getMessage()); } } /** * Determine whether the multipart content is still available. * If a temporary file has been moved, the content is no longer available. */ protected boolean isAvailable() { // If in memory, it\'s available. if (this.fileItem.isInMemory()) { return true; } // Check actual existence of temporary file. if (this.fileItem instanceof DiskFileItem) { return ((DiskFileItem) this.fileItem).getStoreLocation().exists(); } // Check whether current file size is different than original one. return (this.fileItem.getSize() == this.size); } /** * Return a description for the storage location of the multipart content. * Tries to be as specific as possible: mentions the file location in case * of a temporary file. */ public String getStorageDescription() { if (this.fileItem.isInMemory()) { return \"in memory\"; } else if (this.fileItem instanceof DiskFileItem) { return \"at [\" + ((DiskFileItem) this.fileItem).getStoreLocation().getAbsolutePath() + \"]\"; } else { return \"on disk\"; } } }
另一个实现类 standard
/* * Copyright 2002-2014 the original author or authors. * * Licensed under the Apache License, Version 2.0 (the \"License\"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an \"AS IS\" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.springframework.web.multipart.support; import java.io.File; import java.io.IOException; import java.io.InputStream; import java.util.ArrayList; import java.util.Collection; import java.util.Collections; import java.util.Enumeration; import java.util.LinkedHashMap; import java.util.LinkedHashSet; import java.util.Map; import java.util.Set; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.Part; import org.springframework.http.HttpHeaders; import org.springframework.util.FileCopyUtils; import org.springframework.util.LinkedMultiValueMap; import org.springframework.util.MultiValueMap; import org.springframework.web.multipart.MultipartException; import org.springframework.web.multipart.MultipartFile; /** * Spring MultipartHttpServletRequest adapter, wrapping a Servlet 3.0 HttpServletRequest * and its Part objects. Parameters get exposed through the native request\'s getParameter * methods - without any custom processing on our side. * * @author Juergen Hoeller * @since 3.1 */ public class StandardMultipartHttpServletRequest extends AbstractMultipartHttpServletRequest { private static final String CONTENT_DISPOSITION = \"content-disposition\"; private static final String FILENAME_KEY = \"filename=\"; private Set<String> multipartParameterNames; /** * Create a new StandardMultipartHttpServletRequest wrapper for the given request, * immediately parsing the multipart content. * @param request the servlet request to wrap * @throws MultipartException if parsing failed */ public StandardMultipartHttpServletRequest(HttpServletRequest request) throws MultipartException { this(request, false); } /** * Create a new StandardMultipartHttpServletRequest wrapper for the given request. * @param request the servlet request to wrap * @param lazyParsing whether multipart parsing should be triggered lazily on * first access of multipart files or parameters * @throws MultipartException if an immediate parsing attempt failed */ public StandardMultipartHttpServletRequest(HttpServletRequest request, boolean lazyParsing) throws MultipartException { super(request); if (!lazyParsing) { parseRequest(request); } } private void parseRequest(HttpServletRequest request) { try { Collection<Part> parts = request.getParts(); this.multipartParameterNames = new LinkedHashSet<String>(parts.size()); MultiValueMap<String, MultipartFile> files = new LinkedMultiValueMap<String, MultipartFile>(parts.size()); for (Part part : parts) { String filename = extractFilename(part.getHeader(CONTENT_DISPOSITION)); if (filename != null) { files.add(part.getName(), new StandardMultipartFile(part, filename)); } else { this.multipartParameterNames.add(part.getName()); } } setMultipartFiles(files); } catch (Exception ex) { throw new MultipartException(\"Could not parse multipart servlet request\", ex); } } private String extractFilename(String contentDisposition) { if (contentDisposition == null) { return null; } // TODO: can only handle the typical case at the moment int startIndex = contentDisposition.indexOf(FILENAME_KEY); if (startIndex == -1) { return null; } String filename = contentDisposition.substring(startIndex + FILENAME_KEY.length()); if (filename.startsWith(\"\\\"\")) { int endIndex = filename.indexOf(\"\\\"\", 1); if (endIndex != -1) { return filename.substring(1, endIndex); } } else { int endIndex = filename.indexOf(\";\"); if (endIndex != -1) { return filename.substring(0, endIndex); } } return filename; } @Override protected void initializeMultipart() { parseRequest(getRequest()); } @Override public Enumeration<String> getParameterNames() { if (this.multipartParameterNames == null) { initializeMultipart(); } if (this.multipartParameterNames.isEmpty()) { return super.getParameterNames(); } // Servlet 3.0 getParameterNames() not guaranteed to include multipart form items // (e.g. on WebLogic 12) -> need to merge them here to be on the safe side Set<String> paramNames = new LinkedHashSet<String>(); Enumeration<String> paramEnum = super.getParameterNames(); while (paramEnum.hasMoreElements()) { paramNames.add(paramEnum.nextElement()); } paramNames.addAll(this.multipartParameterNames); return Collections.enumeration(paramNames); } @Override public Map<String, String[]> getParameterMap() { if (this.multipartParameterNames == null) { initializeMultipart(); } if (this.multipartParameterNames.isEmpty()) { return super.getParameterMap(); } // Servlet 3.0 getParameterMap() not guaranteed to include multipart form items // (e.g. on WebLogic 12) -> need to merge them here to be on the safe side Map<String, String[]> paramMap = new LinkedHashMap<String, String[]>(); paramMap.putAll(super.getParameterMap()); for (String paramName : this.multipartParameterNames) { if (!paramMap.containsKey(paramName)) { paramMap.put(paramName, getParameterValues(paramName)); } } return paramMap; } @Override public String getMultipartContentType(String paramOrFileName) { try { Part part = getPart(paramOrFileName); return (part != null ? part.getContentType() : null); } catch (Exception ex) { throw new MultipartException(\"Could not access multipart servlet request\", ex); } } @Override public HttpHeaders getMultipartHeaders(String paramOrFileName) { try { Part part = getPart(paramOrFileName); if (part != null) { HttpHeaders headers = new HttpHeaders(); for (String headerName : part.getHeaderNames()) { headers.put(headerName, new ArrayList<String>(part.getHeaders(headerName))); } return headers; } else { return null; } } catch (Exception ex) { throw new MultipartException(\"Could not access multipart servlet request\", ex); } } /** * Spring MultipartFile adapter, wrapping a Servlet 3.0 Part object. */ private static class StandardMultipartFile implements MultipartFile { private final Part part; private final String filename; public StandardMultipartFile(Part part, String filename) { this.part = part; this.filename = filename; } @Override public String getName() { return this.part.getName(); } @Override public String getOriginalFilename() { return this.filename; } @Override public String getContentType() { return this.part.getContentType(); } @Override public boolean isEmpty() { return (this.part.getSize() == 0); } @Override public long getSize() { return this.part.getSize(); } @Override public byte[] getBytes() throws IOException { return FileCopyUtils.copyToByteArray(this.part.getInputStream()); } @Override public InputStream getInputStream() throws IOException { return this.part.getInputStream(); } @Override public void transferTo(File dest) throws IOException, IllegalStateException { this.part.write(dest.getPath()); } } }
编写上传示例代码
//这里用到了getOriginalFilename()方法，为了获取文件名 String fileName=uploadFile.getOriginalFilename(); String fileType=fileName.substring(fileName.lastIndexOf(\".\")); if (! fileType.matches(\"^.(jpg|png|tif)$\")) { //这里的error=1时，表示操作不正常 result.setError(1); return result; } try { //这里用到了getInputStream()方法，为了将文件转换成流 //判断是否文件为恶意文件 BufferedImage bufferedImage=ImageIO.read(uploadFile.getInputStream()); int height=bufferedImage.getHeight(); int width=bufferedImage.getWidth(); if (width==0||height==0) { //这里的error=1时，表示操作不正常 result.setError(1); return result; } //这里用到了transferTo()方法，进行写盘操作 //这里的path需要自己设定，这里我就没有写，只是随便写的path代表路径 uploadFile.transferTo(path); return result; } catch (IOException e) { e.printStackTrace(); }
来源：https://www.cnblogs.com/java265/p/16318430.html
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