file-online-preview/server/src/main/java/cn/keking/service/impl/OfficeFilePreviewImpl.java

package cn.keking.service.impl;

import cn.keking.config.ConfigConstants;
import cn.keking.model.FileAttribute;
import cn.keking.model.ReturnResponse;
import cn.keking.service.FileHandlerService;
import cn.keking.service.FilePreview;
import cn.keking.service.OfficeToPdfService;
import cn.keking.utils.DownloadUtils;
import cn.keking.utils.OfficeUtils;
import cn.keking.web.filter.BaseUrlFilter;
import org.artofsolving.jodconverter.office.OfficeException;
import org.springframework.stereotype.Service;
import org.springframework.ui.Model;
import org.springframework.util.StringUtils;

import java.util.List;

/**
 * Created by kl on 2018/1/17.
 * Content :处理office文件
 */
@Service
public class OfficeFilePreviewImpl implements FilePreview {

    public static final String OFFICE_PREVIEW_TYPE_IMAGE = "image";
    public static final String OFFICE_PREVIEW_TYPE_ALL_IMAGES = "allImages";
    private static final String FILE_DIR = ConfigConstants.getFileDir();

    private final FileHandlerService fileHandlerService;
    private final OfficeToPdfService officeToPdfService;
    private final OtherFilePreviewImpl otherFilePreview;

    public OfficeFilePreviewImpl(FileHandlerService fileHandlerService, OfficeToPdfService officeToPdfService, OtherFilePreviewImpl otherFilePreview) {
        this.fileHandlerService = fileHandlerService;
        this.officeToPdfService = officeToPdfService;
        this.otherFilePreview = otherFilePreview;
    }

    @Override
    public String filePreviewHandle(String url, Model model, FileAttribute fileAttribute) {
        // 预览Type，参数传了就取参数的，没传取系统默认
        String officePreviewType = fileAttribute.getOfficePreviewType();
        String baseUrl = BaseUrlFilter.getBaseUrl();
        String suffix = fileAttribute.getSuffix();
        String fileName = fileAttribute.getName();
        String filePassword = fileAttribute.getFilePassword();
        String userToken = fileAttribute.getUserToken();
        boolean isHtml = suffix.equalsIgnoreCase("xls") || suffix.equalsIgnoreCase("xlsx") || suffix.equalsIgnoreCase("csv");
        String pdfName = fileName.substring(0, fileName.lastIndexOf(".") + 1) + (isHtml ? "html" : "pdf");
        String cacheFileName = userToken == null ? pdfName : userToken + "_" + pdfName;
        String outFilePath = FILE_DIR + cacheFileName;

        // 下载远程文件到本地，如果文件在本地已存在不会重复下载
        ReturnResponse<String> response = DownloadUtils.downLoad(fileAttribute, fileName);
        if (response.isFailure()) {
            return otherFilePreview.notSupportedFile(model, fileAttribute, response.getMsg());
        }
        String filePath = response.getContent();

        /*
         * 1. 缓存判断-如果文件已经进行转换过，就直接返回，否则执行转换
         * 2. 缓存判断-加密文件基于userToken进行缓存，如果没有就不缓存
         */
        boolean isCached = false;
        boolean isUseCached = false;
        boolean isPwdProtectedOffice = false;
        if (ConfigConstants.isCacheEnabled()) {
            // 全局开启缓存
            isUseCached = true;
            if (fileHandlerService.listConvertedFiles().containsKey(cacheFileName)) {
                // 存在缓存
                isCached = true;
            }
            if (OfficeUtils.isPwdProtected(filePath)) {
                isPwdProtectedOffice = true;
                if (!StringUtils.hasLength(userToken)) {
                    // 不缓存没有userToken的加密文件
                    isUseCached = false;
                }
            }
        } else {
            isPwdProtectedOffice = OfficeUtils.isPwdProtected(filePath);
        }

        if (isCached == false) {
            // 没有缓存执行转换逻辑
            if (isPwdProtectedOffice && !StringUtils.hasLength(filePassword)) {
                // 加密文件需要密码
                model.addAttribute("needFilePassword", true);
                return EXEL_FILE_PREVIEW_PAGE;
            } else {
                if (StringUtils.hasText(outFilePath)) {
                    try {
                        officeToPdfService.openOfficeToPDF(filePath, outFilePath, fileAttribute);
                    } catch (OfficeException e) {
                        if (isPwdProtectedOffice && OfficeUtils.isCompatible(filePath, filePassword) == false) {
                            // 加密文件密码错误，提示重新输入
                            model.addAttribute("needFilePassword", true);
                            model.addAttribute("filePasswordError", true);
                            return EXEL_FILE_PREVIEW_PAGE;
                        }

                        return otherFilePreview.notSupportedFile(model, fileAttribute, "抱歉，该文件版本不兼容，文件版本错误。");
                    }

                    if (isHtml) {
                        // 对转换后的文件进行操作(改变编码方式)
                        fileHandlerService.doActionConvertedFile(outFilePath);
                    }
                    if (isUseCached) {
                        // 加入缓存
                        fileHandlerService.addConvertedFile(cacheFileName, fileHandlerService.getRelativePath(outFilePath));
                    }
                }
            }
        }

        if (!isHtml && baseUrl != null && (OFFICE_PREVIEW_TYPE_IMAGE.equals(officePreviewType) || OFFICE_PREVIEW_TYPE_ALL_IMAGES.equals(officePreviewType))) {
            return getPreviewType(model, fileAttribute, officePreviewType, baseUrl, cacheFileName, outFilePath, fileHandlerService, OFFICE_PREVIEW_TYPE_IMAGE, otherFilePreview);
        }

        model.addAttribute("pdfUrl", cacheFileName);
        return isHtml ? EXEL_FILE_PREVIEW_PAGE : PDF_FILE_PREVIEW_PAGE;
    }

    static String getPreviewType(Model model, FileAttribute fileAttribute, String officePreviewType, String baseUrl, String pdfName, String outFilePath, FileHandlerService fileHandlerService, String officePreviewTypeImage, OtherFilePreviewImpl otherFilePreview) {
        String suffix = fileAttribute.getSuffix();
        boolean isPPT = suffix.equalsIgnoreCase("ppt") || suffix.equalsIgnoreCase("pptx");
        List<String> imageUrls = fileHandlerService.pdf2jpg(outFilePath, pdfName, baseUrl);
        if (imageUrls == null || imageUrls.size() < 1) {
            return otherFilePreview.notSupportedFile(model, fileAttribute, "office转图片异常，请联系管理员");
        }
        model.addAttribute("imgurls", imageUrls);
        model.addAttribute("currentUrl", imageUrls.get(0));
        if (officePreviewTypeImage.equals(officePreviewType)) {
            // PPT 图片模式使用专用预览页面
            return (isPPT ? PPT_FILE_PREVIEW_PAGE : OFFICE_PICTURE_FILE_PREVIEW_PAGE);
        } else {
            return PICTURE_FILE_PREVIEW_PAGE;
        }
    }

}