急求实例：jsp 上传文件并显示文件内容

Question

如题，最好能给例子，谢谢

Answer 1

上传文件可以用SmartUpload，这个控件网上很多。打开文件也可以用这个，不过是出现下载框的时候选择打开

Answer 2

做的项目里的一段代码，看着参考一下吧  有些东西涉及其他的没拷
大概意思应该明白了  
写一个jsp页面，有文件上传框的，用MultipartContent 方式提交
再参照下面代码写个servlet 应该就行了
用的包是 fileupload
DiskFileUpload uploadFile = new DiskFileUpload();
        //no more than 200M
        uploadFile.setSizeMax(1024*1024*200);
        //no more than 5M buffer
        uploadFile.setSizeThreshold(1024*1024*5);
        //temporary folder
        File tempFile = new File(getServletContext().getRealPath("/edi/file/temp"));
        log.info("Set path '" + tempFile.getPath() + "' as temporary directory.");
        if (!tempFile.exists()) {
            log.info("Directory '" + tempFile.getPath() + "' does not exist!");
            if (!tempFile.mkdirs()) {
                throw new BusinessException("Failed to create temp directory!");
            }
            log.info("Create directory '" + tempFile.getPath() + "' successfully!");
        }
        uploadFile.setRepositoryPath(tempFile.getAbsolutePath());
        //encode type
        uploadFile.setHeaderEncoding("gb2312");
        
        List fileItems = null;
        try{
            fileItems = uploadFile.parseRequest(request);
            log.info("Parse request to create a list of " + fileItems.size() + " fileItems.");
        } catch (FileUploadException e) {
            throw e;
        }Iterator it = fileItems.iterator();
        while (it.hasNext()) {
            FileItem fileItem = (FileItem)it.next();
            log.info("Begin to deal with FileItem '" + fileItem.getFieldName() + "' : ");
            if(!fileItem.isFormField()){
                try {
                    //get absolute path of uploaded file
                    String pathSrc = fileItem.getName();
                    log.info("Source path of FileItem on Client is '" + pathSrc + "'.");
                    if (StringUtils.isEmpty(pathSrc)) {
                        throw new BusinessException("Path 'null' cannot be resovled!");
                    }
                    
                    log.info("Size of FileItem is " + fileItem.getSize()/1000 + " k.");
                    if (fileItem.getSize() == 0) {
                        log.error("Size of FileItem '" + pathSrc + "' is 0.");
                        throw new BusinessException("Size of FileItem '" + pathSrc + "' is 0.");
                    } else if (StringUtils.isEmpty(fileItem.getString())) {
                        log.error("FileItem '" + pathSrc + "' is empty.");
                        throw new BusinessException("FileItem '" + pathSrc + "' is empty.");
                    }
int start = pathSrc.lastIndexOf('\\');
                    //get file name of uploaded file
                    String fileName = pathSrc.substring(start + 1);
                    log.info("File name is '" + fileName + "'.");
                    if (!isFileNameLegal(fileName)) {
                        log.error("File '" + fileName + "' isn't accepted as System refuses file with a extension '" + getExtension(fileName) + "'");
                        throw new BusinessException("File '" + fileName + "' isn't accepted as System refuses file with a extension '" + getExtension(fileName) + "'");
                    }
                    
                    /*
                     * If folder to place uploaded files does not exist,it will be created. Or do nothing.
                     */
    //                    File dir = new File(SurecompParameter.getEntityParameter().getEdiUploadedFilePath());
                    File dir = new File(SystemService.getRealPath(SurecompParameter.getEntityParameter().getEdiUploadedFilePath()));
                    log.info("Directory on Server to save files is '" + dir.getPath() + "'.");
                    if(!dir.exists()){
                        log.info("Directory '" + dir.getPath() + "' isn't exist!");
                        if(!dir.mkdirs()){
                            throw new BusinessException("Can not create path for upload!");
                        }
                        log.info("Create directory '" + dir.getPath() + "' successfully!");
                    }
                    
                    // Data file to be uploaded
                    File dataFile = new File(dir, fileName);
                    log.info("System intends to save file as '" + dataFile.getPath() + "'.");
                    int i = 1;
                    while (dataFile.exists()) {
                        log.warn("File name '" + dataFile.getName() + "' already exists in directory '" + dataFile.getParent() + "'.");
                        dataFile = new File(dir, nextFileName(fileName,i));
                        log.info("File name is changed to '" + dataFile.getName() + "'.");
                        i++;
                    }
                    
                    // create file
                    if (dataFile.createNewFile()) {
                        log.info("Create data file '" + dataFile.getName() + "' in directory '" + dataFile.getParent() + "'.");
                        try {
                            log.info("Begin to write content to file '" + dataFile.getName() + "'.");
                            fileItem.write(dataFile);
                            log.info("Write content to file '" + dataFile.getName() + "' end.");
                        } catch (Exception e) {
                            log.info("Failed to write content to file '" + dataFile.getName() + "'.");
                            throw new BusinessException(e.getMessage());
                        }
} finally {
                    fileItem.delete();
                    log.info("Delete FileItem for file '" + fileItem.getName() + "'.");
                }
            } else {
                log.info("FileItem '" + fileItem.getFieldName() + "' isn't a file field! Next ----");
            }
        } //End of while

Answer 3

前几天刚写了一个，楼主看看吧
package om.fileupload.zhangc;import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;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 FileUpLoadServlet extends HttpServlet {


/**
 * 
 */
private static final long serialVersionUID = 1L;
private static final String CONTENT_TYPE = "text/html;charset=UTF-8";
/**
 * The doPost method of the servlet. <br>
 *
 * This method is called when a form has its tag value method equals to post.
 * 
 * @param request the request send by the client to the server
 * @param response the response send by the server to the client
 * @throws ServletException if an error occurred
 * @throws IOException if an error occurred
 */
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
ServletFileUpload upload = new ServletFileUpload();
upload.setFileItemFactory(new DiskFileItemFactory());
upload.setHeaderEncoding("UTF-8");
response.setContentType(CONTENT_TYPE);
PrintWriter out = response.getWriter();
try {
List items = upload.parseRequest(request);
if(items != null){
for(int i = 0 ; i < items.size() ; i ++ ){
FileItem item = (FileItem)items.get(i);
if(item.isFormField()){
out.println("表单字段" + item.getFieldName() + "的值为:" + item.getString("UTF-8") + "<br>");
}else{
out.println("表单字段" + item.getFieldName() + "是文件,文件名为:" + item.getName() + ",文件内容为:<br>");
out.println(item.getString("gb2312"));
}
}
}
} catch (FileUploadException e) {
out.println("文件上传失败<br>");
e.printStackTrace(out);
}
out.flush();
out.close();
}}