package me.rainking;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
import cn.hutool.core.io.file.FileReader;
import cn.hutool.core.io.file.FileWriter;
import com.itextpdf.text.DocumentException;
import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.io.FileUtil;
import cn.hutool.core.util.ReUtil;
import cn.hutool.core.util.StrUtil;
import cn.hutool.http.HtmlUtil;
import cn.hutool.http.HttpUtil;
import cn.hutool.json.JSONUtil;
import cn.hutool.log.StaticLog;
/**
* @author Rain
* @description 文档浏览，包含获取起始页和全部预览图的方法
* @date 2018/3/7 19:26
*/
class DocumentBrowser {
private static final String TEMP_PATH = "./temp";
private static final String DES_PATH = "./out";
private static final String TASK_LIST_FILE = DES_PATH + "/tasklist.txt";
private static final String FILE_DOWNLOAD_PAGE = TEMP_PATH + "/%s/page.txt";
List<String> readTaskList() {
List<String> aTaskDocumentId = new ArrayList<>();
if (FileUtil.exist(TASK_LIST_FILE)) {
FileReader fileReader = new FileReader(TASK_LIST_FILE);
aTaskDocumentId = fileReader.readLines().stream()
.map(StrUtil::trim).filter(StrUtil::isNotBlank).collect(Collectors.toList());
}
return aTaskDocumentId;
}
void writeTaskList(List<String> pLists) {
if (!FileUtil.exist(DES_PATH)) {
FileUtil.mkdir(DES_PATH);
}
FileWriter fileWriter = new FileWriter(TASK_LIST_FILE);
fileWriter.appendLines(pLists);
}
private int readDownloadedPage(String sDocumentId) {
int nPage = 1;
String filePath = String.format(FILE_DOWNLOAD_PAGE, sDocumentId);
if (FileUtil.exist(filePath)) {
FileReader fileReader = new FileReader(filePath);
String sPage = fileReader.readString();
nPage = Integer.valueOf(sPage);
}
return nPage;
}
private void writeDownloadedPage(String sDocumentId, int nPage) {
String filePath = String.format(FILE_DOWNLOAD_PAGE, sDocumentId);
FileWriter fileWriter = new FileWriter(filePath);
fileWriter.write(String.valueOf(nPage));
}
private String moveToNextPage(PdfInfo pInfo) {
String sNextPage = getNextPage(pInfo);
try {
pInfo.setImg(URLEncoder.encode(sNextPage, "utf8"));
} catch (Exception e) {
StaticLog.error("moveToNextPage error", e);
}
return sNextPage;
}
/**
* 下载文档的全部图片
*
* @param documentId 文档编号
* @throws IOException pdf创建错误
* @throws DocumentException pdf创建错误
*/
void downloadWholeDocument(String documentId) throws IOException, DocumentException {
String srcPath = TEMP_PATH + "/" + documentId;
FileUtil.mkdir(new File(srcPath));
FileUtil.mkdir(new File(DES_PATH));
int page = 1, nDownloadedPage;
// 断点下载
nDownloadedPage = readDownloadedPage(documentId);
if (nDownloadedPage != 1) {
System.out.println(String.format("下载继续，当前已完成 %d 页", nDownloadedPage));
nDownloadedPage ++;
}
StringBuilder currentDownPage = new StringBuilder();
PdfInfo pdfInfo = getPdfInfo(documentId);
String imgUrl;
StaticLog.info("\n开始下载...");
while (pdfInfo != null) {
String nextPage = moveToNextPage(pdfInfo);
if (!Constants.TAG_OF_END.contains(nextPage)) {
//跳过已下载的文件
if (page < nDownloadedPage) {
System.out.print(String.format("\r当前页码: [%d] 已跳过", page));
page ++; continue;
}
imgUrl = (pdfInfo.getHost() + Constants.IMG_PREFIX_URL + nextPage);
downloadFile(imgUrl, srcPath + "/" + autoGenericCode(page, Constants.MAX_BIT_OF_PAGE) + ".gif");
currentDownPage.append("\r").append(String.format("已下载页数：[%d] 页", page));
System.out.print(currentDownPage);
// 保存当前下载完成页码
writeDownloadedPage(documentId, page);
page++;
} else {
break;
}
}
StaticLog.info("\n开始生成...");
PdfGenerator.creatPDF(srcPath, DES_PATH + "/" + documentId + ".pdf", "gif");
FileUtil.del(new File(srcPath));
}
/**
* 将数字字符串的左边补充0，使其长度达到指定长度
*
* @param number 需要处理的数字
* @param width 补充后字符串长度
* @return 通过填充0达到长度的数字字符串
*/
private String autoGenericCode(int number, int width) {
return String.format("%0" + width + "d", number);
}
/**
* 获取文档的预览地址
*
* @param documentId 文档的编号
* @return 预览地址
*/
private PdfInfo getPdfInfo(String documentId) {
String url = Constants.OPEN_FULL_URL + documentId;
String pdfPageUrlStr = HttpUtil.get(url);
if (StrUtil.isNotBlank(pdfPageUrlStr)) {
pdfPageUrlStr = "https:" + pdfPageUrlStr;
} else {
StaticLog.error("获取失败！");
return null;
}
int endOfHost = pdfPageUrlStr.indexOf("?");
String viewHost = pdfPageUrlStr.substring(0, endOfHost);
String redirectPage = HttpUtil.get(pdfPageUrlStr);
String href = ReUtil.get(Constants.HREF_PATTERN, redirectPage, 1);
String fullUrl;
if(href != null){
fullUrl = viewHost.substring(0, viewHost.length()-1) + HtmlUtil.unescape(href);
}else {
fullUrl = pdfPageUrlStr;
}
String pdfPageHtml = HttpUtil.get(fullUrl);
if (pdfPageHtml.contains(Constants.FILE_NOT_EXIST)) {
StaticLog.error("获取预览地址失败，请稍后再试！");
return null;
}
List<String> result = ReUtil.findAllGroup0(Constants.INPUT_PATTERN, pdfPageHtml);
Map<String, String> pdfInfoMap = new HashMap<>(6);
pdfInfoMap.put("host", viewHost);
for (String inputStr : result) {
String id = ReUtil.get(Constants.ID_PATTERN, inputStr, 1);
String value = ReUtil.get(Constants.VALUE_PATTERN, inputStr, 1);
if (StrUtil.isNotBlank(id) && StrUtil.isNotBlank(value)) {
id = id.toLowerCase();
try {
value = URLEncoder.encode(value, "utf8");
} catch (Exception e) {
StaticLog.error("URLEncoder Error", e);
}
pdfInfoMap.put(id, value);
}
}
return BeanUtil.mapToBean(pdfInfoMap, PdfInfo.class, true);
}
private String getNextPage(PdfInfo pdfInfo) {
String nextUrl = pdfInfo.getNextUrl();
String nextPageJson = HttpUtil.get(nextUrl);
PageInfo pageInfo = JSONUtil.toBean(nextPageJson, PageInfo.class);
return pageInfo.getNextPage();
}
/**
* 下载文件到本地
*
* @param url 文件的 url
* @param localPath 本地存储路径
*/
private void downloadFile(String url, String localPath) {
File file = new File(localPath);
try (FileOutputStream fileOutputStream = new FileOutputStream(file); BufferedOutputStream out = new BufferedOutputStream(fileOutputStream)) {
HttpUtil.download(url, out, true);
} catch (IOException e) {
StaticLog.error(e.getMessage());
}
}
}
