struts2文件上传

文件上传的方法，使用了struts的拦截器拦截action请求，把文件信息和存储字段信息保存到中间表中，这里只把保存的代码贴出来，展示和下载的方法实现起来比较多样，但是简单！

这里有一篇博客讲的是文件上传流程，可以参考学习：http://www.cnblogs.com/yjhrem/articles/2243007.html

public class UploadFile extends SysEntity {

    private static final long serialVersionUID = 1L;
    
    存储文件名 6     private String storageFileName;
    上传文件名 8     private String uploadFileName;
    上传文件大小10     private String size;
    文件类型12     private String contentType;
    文件扩展名14     private String extName;
    
    public UploadFile() {
    }
    
    public UploadFile(String storageFileName, String uploadFileName, String size,String contentType, String extName) {
        this.storageFileName = storageFileName;
        this.uploadFileName = uploadFileName;
        this.size = size;
        this.contentType = contentType;
        this.extName = extName;
    }
　　get set方法 省略.......
}

 
import java.io.File;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.List;
import java.util.UUID;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.servlet.http.HttpServletRequest;

import org.apache.commons.beanutils.PropertyUtils;
import org.apache.commons.io.FileUtils;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang3.ArrayUtils;
import org.apache.struts2.ServletActionContext;
import org.apache.struts2.dispatcher.multipart.MultiPartRequestWrapper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.mock.web.MockMultipartHttpServletRequest;
import org.springframework.web.multipart.MultipartFile; 34 import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.AbstractInterceptor;

/**
 * 存储文件到服务器
 * 
 * 文件中可定义storageDIR属性（存储目录）[系统默认路径为应用发布路径/uploadFiles目录] 如果与
 * <interceptor name="fileUpload" class="org.apache.struts2.interceptor.FileUploadInterceptor"/> 一同使用需要放置在其后面
 * @see org.apache.struts2.interceptor.FileUploadInterceptor
 */
public class UploadFileInterceptor extends AbstractInterceptor {

    private static final long serialVersionUID = 1L;

    private static final Logger LOG = LoggerFactory.getLogger(UploadFileInterceptor.class);
    public final static String[] NO_SUFFIX_ALLOWED = new String[] { "sql", "jsp", "cmd", "bat", "sh", "exe" };//例外的文件格式

    public String intercept(ActionInvocation invocation) throws Exception {
        ActionContext ac = invocation.getInvocationContext();
        HttpServletRequest request = (HttpServletRequest) ac.get(ServletActionContext.HTTP_REQUEST);
        if (request instanceof MultiPartRequestWrapper && invocation.getAction() instanceof ActionParam) {
            savedFilesToServer((MultiPartRequestWrapper) request, invocation.getAction());
        }
        return invocation.invoke();
    }

    /**
     * 将文件存储到服务器
     * 
     * @return 存储文件名,上传文件名
     * @throws IOException
     */
    private void savedFilesToServer(MultiPartRequestWrapper multiWrapper, Object actionObj) {
        Enumeration<String> fileParameterNames = multiWrapper.getFileParameterNames();
        while (fileParameterNames != null && fileParameterNames.hasMoreElements()) {
            String formItemName = fileParameterNames.nextElement();
            if (!checkEntityProperty(actionObj, formItemName)) {// 检查目标是否符合要求
                continue;
            }
            File storageDIRFile = SysUtils.getUploadDir();//这里获得上传文件的路径，配置在配置文件中
            if (!storageDIRFile.exists() || !storageDIRFile.isDirectory()) {
                if (!storageDIRFile.mkdir()) {
                    LOG.error("[附件]文件上传失败，无法创建存储目录。请手工修改app.properties中的storageDIR存储路径[存储目录：" + storageDIRFile.getAbsoluteFile() + "]");
                    break;
                }
            }

            File[] file = multiWrapper.getFiles(formItemName);
            String[] fileName = multiWrapper.getFileNames(formItemName);
            String[] contentType = multiWrapper.getContentTypes(formItemName);
            String uploadFileIds = "";
            List<UploadFile> ufs = new ArrayList<UploadFile>();
            BaseDAO dao = SpringContextUtil.getBean("baseDAO");//获得带有sessionFactory的对象
            for (int index = 0; index < file.length; index++) {
                File currentFile = file[index];
                if (!currentFile.exists()) {
                    continue;
                }

                String uploadFileName = fileName[index];
                String extName = getExtName(uploadFileName);
                if (ArrayUtils.contains(NO_SUFFIX_ALLOWED, extName.toLowerCase())) {
                    LOG.warn("[附件]：" + extName);
                    throw new BizException("不被允许上传的文件！文件名：" + uploadFileName);
                }
                if (currentFile.length() < 1) {
                    throw new BizException("上传的文件大小为0，请重新选择！");
                }

                String storageFileName = UUID.randomUUID().toString() + "." + extName;
                File storageFile = new File(storageDIRFile, storageFileName);
                // 步骤1:存储文件到文件系统
                try {
                    FileUtils.copyFile(currentFile, storageFile);
                    LOG.debug("[附件]已将文件" + uploadFileName + "存储到 " + storageDIRFile.getAbsolutePath() + " 目录中,存储文件名为: " + storageFileName);
                } catch (Exception e) {
                    LOG.error("[附件]文件存储失败，文件信息[文件名:" + uploadFileName + ",文件大小:" + currentFile.length() + "]", e);
                }

                // 步骤2:存储文件信息到文件表
                UploadFile uf = new UploadFile(storageFileName, uploadFileName, String.valueOf(currentFile.length()), contentType[index], extName);
                try {
                    dao.saveUpdate(uf);//将文件信息保存到数据中库
                    ufs.add(uf);
                    dao.flush();//flush session
                } catch (Exception e) {
                    LOG.error("[附件]无法将文件信息存入文件表，错误信息：", e);
                    FileUtils.deleteQuietly(storageFile);// 回滚事务
                    break;
                }

                uploadFileIds += "," + uf.getId();
            }

            // 步骤3:添加编辑中的文件(id存储在hidden中)
            String[] hiddenFileIds = multiWrapper.getParameterValues(formItemName);
            if (hiddenFileIds != null && hiddenFileIds.length > 0) {
                uploadFileIds += "," + StringUtils.join(hiddenFileIds, ",");
            }

            try {
                // 步骤4:存储文件表ID到业务实体属性
                if (uploadFileIds.length() > 1) {
                    uploadFileIds = uploadFileIds.substring(1);
                }
                //匹配一对多关系中多的一方需要上传附件
                Matcher matcher = Pattern.compile("\[\d*\]").matcher(formItemName);
                if (matcher.find()) {
                    String[] fileSystemNames = multiWrapper.getFileSystemNames(formItemName);
                    String[] fields = matcher.replaceAll("").split("\.");
                    if (fields.length == 1) {// members[1] 仅支持集合，不支持数组
                        setFileId2Collection(uploadFileIds, fileSystemNames, fields[0], PropertyUtils.getProperty(actionObj, fields[0]), actionObj);
                    } else if (fields.length == 2) {// members[1].fileId
                        setFileId2Collection(uploadFileIds, fileSystemNames, fields[1], PropertyUtils.getProperty(actionObj, fields[0]), null);
                    } else if (fields.length == 3) {// entity.members[1].fileId
                        setFileId2Collection(uploadFileIds, fileSystemNames, fields[2],
                                PropertyUtils.getProperty(actionObj, fields[0] + "." + fields[1]), null);
                    } else {
                        PropertyUtils.setProperty(actionObj, formItemName, uploadFileIds);
                    }
                } else {
                    PropertyUtils.setProperty(actionObj, formItemName, uploadFileIds);
                }
            } catch (Exception e) {
                LOG.error("[附件]无法为附件属性赋值[Action对象名:" + actionObj.toString() + ",属性名：" + formItemName + "]", e);
                for (UploadFile uf : ufs) {
                    dao.delEntity(uf);
                    FileUtils.deleteQuietly(new File(storageDIRFile, uf.getStorageFileName()));// 回滚事务
                }
                dao.flush();
            }
        }
    }

    private void setFileId2Collection(String uploadFileIds, String[] fileSystemNames, String field, Object obj, Object root)
            throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {
        Iterator<?> iterator = Collection.class.cast(obj).iterator();
        boolean setted = false;
        int index = 0;
        while (iterator.hasNext()) {
            if (setted) {
                break;
            }

            Object next = iterator.next();
            String tempFilePath = String.valueOf(null == root ? PropertyUtils.getProperty(next, field) : next);
            for (int i = 0; i < fileSystemNames.length; i++) {
                if (tempFilePath.indexOf(fileSystemNames[i]) != -1) {
                    if (null == root) {
                        PropertyUtils.setProperty(next, field, uploadFileIds);
                    } else {
                        PropertyUtils.setProperty(root, field + "[" + index + "]", uploadFileIds);
                    }
                    setted = true;
                    break;
                }
            }

            index++;
        }
    }

    /**
     * 获取扩展名
     * 
     * @param fileName
     * @return
     */
    private String getExtName(String fileName) {
        return StringUtils.substringAfterLast(fileName, ".");
    }

    /**
     * 检查实体属性
     * 
     * @param bean
     * @param formItemName
     * @return
     */
    private boolean checkEntityProperty(Object bean, String formItemName) {
        boolean flag = true;
        try {
            Matcher matcher = Pattern.compile("\[\d*\]").matcher(formItemName);
            if (matcher.find()) {
                formItemName = matcher.replaceAll("[0]");
            }

            Class<?> type = PropertyUtils.getPropertyType(bean, formItemName);
            if (!String.class.equals(type)) {
                LOG.warn("[附件上传]业务实体中提供接收附件的属性非String类型，无法将附件表ID赋值到该属性中。修改属性类型。[Action对象名:" + bean.toString() + ",属性名" + formItemName + "，属性类型:"
                        + type.getName() + "]");
                flag = false;
            }
        } catch (Exception e) {
            LOG.warn("[附件上传]未找到对应属性，无法为附件属性赋值。请确认属性名和表单项名是否一致[附件表单项名：" + formItemName + "]");
            flag = false;
        }

        return flag;
    }
}

这里需要考虑的是输入我这条记录的文件在删除的时候并不会删除UploadFile表中的数据，当然也不会删除我们保存的文件，长远考虑应该删除；