我在处理代码时遇到了一些问题。我试图循环遍历一个包含许多PDF文件的Drive文件夹，然后将这些文件合并成一个文件。当我使用我的代码时，它只会创建一个包含Drive文件夹中最后一个PDF文件的PDF文件，并没有像预期的那样将它们全部合并在一起。
function MergeFiles(){
var folder = DocsList.getFolderById('myFolderID');
var files = folder.getFiles();
var blobs = [];
for( var i in files )
blobs.push(files[i].getBlob().getBytes());
Logger.log(blobs.push(files[i].getBlob().getBytes()));
var myPDF = Utilities.newBlob(blobs.pop(), "application/pdf", "newPDF.pdf");
folder.createFile(myPDF);
}
这不仅仅是简单地合并每个文件的数据。每个文件的实际可用数据都与标记和其他代码打包在一起（类似于HTML和其他文档格式）。您需要解码每个PDF文件，组合必要的部分，然后使用新的“打包”重新编码。这需要对PDF规范和结构有工作知识，可以从Adobe 这里免费获取。
我利用这些信息编写了一个满足我的需求的脚本。但是，它不能考虑到每种可能性，因此，特别是合并任何需要PDF-1.4及更高版本的文档时，需要进行相当多的工作。
/**
* Merges all given PDF files into one.
*
* @param {Folder} directory the folder to store the output file
* @param {string} name the desired name of the output file
* @param {File} pdf1 the first PDF file
* @param {File} pdf2 the second PDF file
* @param {File} opt_pdf3 [optional] the third PDF file; add as many more as you like
*
* @return {File} the merged file
*/
function mergePdfs(directory, name, pdf1, pdf2, opt_pdf3) {
if (name.slice(-4) != '.pdf') {
name = name + '.pdf';
}
var newObjects = ['1 0 obj\r\n<</Type/Catalog/Pages 2 0 R >>\r\nendobj'];
var pageAddresses = [];
for (var argumentIndex = 2; argumentIndex < arguments.length; argumentIndex++) {
var bytes = arguments[argumentIndex].getBlob().getBytes();
var xrefByteOffset = '';
var byteIndex = bytes.length - 1;
while (!/\sstartxref\s/.test(xrefByteOffset)) {
xrefByteOffset = String.fromCharCode(bytes[byteIndex]) + xrefByteOffset;
byteIndex--;
}
xrefByteOffset = +(/\s\d+\s/.exec(xrefByteOffset)[0]);
var objectByteOffsets = [];
var trailerDictionary = '';
var rootAddress = '';
do {
var xrefTable = '';
var trailerEndByteOffset = byteIndex;
byteIndex = xrefByteOffset;
for (byteIndex; byteIndex <= trailerEndByteOffset; byteIndex++) {
xrefTable = xrefTable + String.fromCharCode(bytes[byteIndex]);
}
xrefTable = xrefTable.split(/\s*trailer\s*/);
trailerDictionary = xrefTable[1];
if (objectByteOffsets.length < 1) {
rootAddress = /\d+\s+\d+\s+R/.exec(/\/Root\s*\d+\s+\d+\s+R/.exec(trailerDictionary)[0])[0].replace('R', 'obj');
}
xrefTable = xrefTable[0].split('\n');
xrefTable.shift();
while (xrefTable.length > 0) {
var xrefSectionHeader = xrefTable.shift().split(/\s+/);
var objectNumber = +xrefSectionHeader[0];
var numberObjects = +xrefSectionHeader[1];
for (var entryIndex = 0; entryIndex < numberObjects; entryIndex++) {
var entry = xrefTable.shift().split(/\s+/);
objectByteOffsets.push([[objectNumber, +entry[1], 'obj'], +entry[0]]);
objectNumber++;
}
}
if (/\s*\/Prev/.test(trailerDictionary)) {
xrefByteOffset = +(/\s*\d+\s/.exec(/\s*\/Prev\s*\d+\s/.exec(trailerDictionary)[0])[0]);
}
} while (/\s*\/Prev/.test(trailerDictionary));
var rootObject = getObject(rootAddress, objectByteOffsets, bytes);
var pagesAddress = /\d+\s+\d+\s+R/.exec(/\/Pages\s*\d+\s+\d+\s+R/.exec(rootObject)[0])[0].replace('R', 'obj');
var pagesObject = getObject(pagesAddress, objectByteOffsets, bytes);
var objects = getDependencies(pagesObject, objectByteOffsets, bytes);
var newObjectsInsertionIndex = newObjects.length;
for (var objectIndex = 0; objectIndex < objects.length; objectIndex++) {
var newObjectAddress = [(newObjects.length + 3) + '', 0 + '', 'obj'];
if (!Array.isArray(objects[objectIndex])) {
objects[objectIndex] = [objects[objectIndex]];
}
objects[objectIndex].unshift(newObjectAddress);
var objectAddress = objects[objectIndex][1].match(/\d+\s+\d+\s+obj/)[0].split(/\s+/);
objects[objectIndex].splice(1, 0, objectAddress);
if (/\/Type\s*\/Page[^s]/.test(objects[objectIndex][2])) {
objects[objectIndex][2] = objects[objectIndex][2].replace(/\/Parent\s*\d+\s+\d+\s+R/.exec(objects[objectIndex][2])[0], '/Parent 2 0 R');
pageAddresses.push(newObjectAddress.join(' ').replace('obj', 'R'));
}
var addressRegExp = new RegExp(objectAddress[0] + '\\s+' + objectAddress[1] + '\\s+' + 'obj');
objects[objectIndex][2] = objects[objectIndex][2].replace(addressRegExp.exec(objects[objectIndex][2])[0], newObjectAddress.join(' '));
newObjects.push(objects[objectIndex]);
}
for (var referencingObjectIndex = newObjectsInsertionIndex; referencingObjectIndex < newObjects.length; referencingObjectIndex++) {
var references = newObjects[referencingObjectIndex][2].match(/\d+\s+\d+\s+R/g);
if (references != null) {
var string = newObjects[referencingObjectIndex][2];
var referenceIndices = [];
var currentIndex = 0;
for (var referenceIndex = 0; referenceIndex < references.length; referenceIndex++) {
referenceIndices.push([]);
referenceIndices[referenceIndex].push(string.slice(currentIndex).indexOf(references[referenceIndex]) + currentIndex);
referenceIndices[referenceIndex].push(references[referenceIndex].length);
currentIndex += string.slice(currentIndex).indexOf(references[referenceIndex]);
}
for (var referenceIndex = 0; referenceIndex < references.length; referenceIndex++) {
var objectAddress = references[referenceIndex].replace('R', 'obj').split(/\s+/);
for (var objectIndex = newObjectsInsertionIndex; objectIndex < newObjects.length; objectIndex++) {
if (arrayEquals(objectAddress, newObjects[objectIndex][1])) {
var length = string.length;
newObjects[referencingObjectIndex][2] = string.slice(0, referenceIndices[referenceIndex][0]) + newObjects[objectIndex][0].join(' ').replace('obj', 'R') +
string.slice(referenceIndices[referenceIndex][0] + referenceIndices[referenceIndex][1]);
string = newObjects[referencingObjectIndex][2];
var newLength = string.length;
if (!(length == newLength)) {
for (var subsequentReferenceIndex = referenceIndex + 1; subsequentReferenceIndex < references.length; subsequentReferenceIndex++) {
referenceIndices[subsequentReferenceIndex][0] += (newLength - length);
}
}
break;
}
}
}
}
}
for (var objectIndex = newObjectsInsertionIndex; objectIndex < newObjects.length; objectIndex++) {
if (Array.isArray(newObjects[objectIndex])) {
if (newObjects[objectIndex][3] != undefined) {
newObjects[objectIndex] = newObjects[objectIndex].slice(2);
} else {
newObjects[objectIndex] = newObjects[objectIndex][2];
}
}
}
}
newObjects.splice(1, 0, '2 0 obj\r\n<</Type/Pages/Count ' + pageAddresses.length + ' /Kids [' + pageAddresses.join(' ') + ' ]>>\r\nendobj');
newObjects.splice(2, 0, '3 0 obj\r\n<</Title (' + name + ') /CreationDate (D' +
Utilities.formatDate(new Date(), CalendarApp.getDefaultCalendar().getTimeZone(), 'yyyyMMddHHmmssZ').slice(0, -2) + "'00) /ModDate (D" + Utilities.formatDate(new Date(),
CalendarApp.getDefaultCalendar().getTimeZone(), 'yyyyMMddHHmmssZ').slice(0, -2) + "'00)>>\r\nendobj");
var byteOffsets = [0];
var bytes = [];
var header = '%PDF-1.3\r\n';
for (var headerIndex = 0; headerIndex < header.length; headerIndex++) {
bytes.push(header.charCodeAt(headerIndex));
}
bytes.push('%'.charCodeAt(0));
for (var characterCode = -127; characterCode < -123; characterCode++) {
bytes.push(characterCode);
}
bytes.push('\r'.charCodeAt(0));
bytes.push('\n'.charCodeAt(0));
while (newObjects.length > 0) {
byteOffsets.push(bytes.length);
var object = newObjects.shift();
if (Array.isArray(object)) {
var streamKeyword = /stream\s*\n/.exec(object[0])[0];
if (streamKeyword.indexOf('\n\n') > streamKeyword.length - 3) {
streamKeyword = streamKeyword.slice(0, -1);
} else if (streamKeyword.indexOf('\r\n\r\n') > streamKeyword.length - 5) {
streamKeyword = streamKeyword.slice(0, -2);
}
var streamIndex = object[0].indexOf(streamKeyword) + streamKeyword.length;
for (var objectIndex = 0; objectIndex < streamIndex; objectIndex++) {
bytes.push(object[0].charCodeAt(objectIndex))
}
bytes = bytes.concat(object[1]);
for (var objectIndex = streamIndex; objectIndex < object[0].length; objectIndex++) {
bytes.push(object[0].charCodeAt(objectIndex));
}
} else {
for (var objectIndex = 0; objectIndex < object.length; objectIndex++) {
bytes.push(object.charCodeAt(objectIndex));
}
}
bytes.push('\r'.charCodeAt(0));
bytes.push('\n'.charCodeAt(0));
}
var xrefByteOffset = bytes.length;
var xrefHeader = 'xref\r\n';
for (var xrefHeaderIndex = 0; xrefHeaderIndex < xrefHeader.length; xrefHeaderIndex++) {
bytes.push(xrefHeader.charCodeAt(xrefHeaderIndex));
}
var xrefSectionHeader = '0 ' + byteOffsets.length + '\r\n';
for (var xrefSectionHeaderIndex = 0; xrefSectionHeaderIndex < xrefSectionHeader.length; xrefSectionHeaderIndex++) {
bytes.push(xrefSectionHeader.charCodeAt(xrefSectionHeaderIndex));
}
for (var byteOffsetIndex = 0; byteOffsetIndex < byteOffsets.length; byteOffsetIndex++) {
for (var byteOffsetStringIndex = 0; byteOffsetStringIndex < 10; byteOffsetStringIndex++) {
bytes.push(Utilities.formatString('%010d', byteOffsets[byteOffsetIndex]).charCodeAt(byteOffsetStringIndex));
}
bytes.push(' '.charCodeAt(0));
if (byteOffsetIndex == 0) {
for (var generationStringIndex = 0; generationStringIndex < 5; generationStringIndex++) {
bytes.push('65535'.charCodeAt(generationStringIndex));
}
for (var keywordIndex = 0; keywordIndex < 2; keywordIndex++) {
bytes.push(' f'.charCodeAt(keywordIndex));
}
} else {
for (var generationStringIndex = 0; generationStringIndex < 5; generationStringIndex++) {
bytes.push('0'.charCodeAt(0));
}
for (var keywordIndex = 0; keywordIndex < 2; keywordIndex++) {
bytes.push(' n'.charCodeAt(keywordIndex));
}
}
bytes.push('\r'.charCodeAt(0));
bytes.push('\n'.charCodeAt(0));
}
for (var trailerHeaderIndex = 0; trailerHeaderIndex < 9; trailerHeaderIndex++) {
bytes.push('trailer\r\n'.charCodeAt(trailerHeaderIndex));
}
var idBytes = Utilities.computeDigest(Utilities.DigestAlgorithm.MD5, (new Date).toString());
var id = '';
for (var idByteIndex = 0; idByteIndex < idBytes.length; idByteIndex++) {
id = id + ('0' + (idBytes[idByteIndex] & 0xFF).toString(16)).slice(-2);
}
var trailer = '<</Size ' + (byteOffsets.length) + ' /Root 1 0 R /Info 2 0 R /ID [<' + id + '> <' + id + '>]>>\r\nstartxref\r\n' + xrefByteOffset + '\r\n%%EOF';
for (var trailerIndex = 0; trailerIndex < trailer.length; trailerIndex++) {
bytes.push(trailer.charCodeAt(trailerIndex));
}
return directory.createFile(Utilities.newBlob(bytes, 'application/pdf', name));
function getObject(objectAddress, objectByteOffsets, bytes) {
objectAddress = objectAddress.split(/\s+/);
for (var addressIndex = 0; addressIndex < 2; addressIndex++) {
objectAddress[addressIndex] = +objectAddress[addressIndex];
}
var object = [];
var byteIndex = 0;
for each (var offset in objectByteOffsets) {
if (arrayEquals(objectAddress, offset[0])) {
byteIndex = offset[1];
break;
}
}
object.push('');
while (object[0].indexOf('endobj') <= -1) {
if (/stream\s*\n/.test(object[0])) {
var streamLength;
var lengthFinder = object[0].slice(object[0].indexOf(/\/Length/.exec(object[0])[0]));
if (/\/Length\s*\d+\s+\d+\s+R/.test(lengthFinder)) {
var lengthObjectAddress = /\d+\s+\d+\s+R/.exec(/\/Length\s*\d+\s+\d+\s+R/.exec(lengthFinder)[0])[0].split(/\s+/);
lengthObjectAddress[2] = 'obj';
for (var addressIndex = 0; addressIndex < 2; addressIndex++) {
lengthObjectAddress[addressIndex] = +lengthObjectAddress[addressIndex];
}
var lengthObject = ''
var lengthByteIndex = 0;
for each (var offset in objectByteOffsets) {
if (arrayEquals(lengthObjectAddress, offset[0])) {
lengthByteIndex = offset[1];
break;
}
}
while (lengthObject.indexOf('endobj') <= -1) {
lengthObject = lengthObject + String.fromCharCode(bytes[lengthByteIndex]);
lengthByteIndex++;
}
streamLength = +(lengthObject.match(/obj\s*\n\s*\d+\s*\n\s*endobj/)[0].match(/\d+/)[0]);
} else {
streamLength = +(/\d+/.exec(lengthFinder)[0]);
}
var streamBytes = bytes.slice(byteIndex, byteIndex + streamLength);
object.push(streamBytes);
byteIndex += streamLength;
while (object[0].indexOf('endobj') <= -1) {
object[0] = object[0] + String.fromCharCode(bytes[byteIndex]);
byteIndex++;
}
return object;
}
object[0] = object[0] + String.fromCharCode(bytes[byteIndex]);
byteIndex++;
}
return object[0];
}
function arrayEquals(array1, array2) {
if (array1 == array2) {
return true;
}
if (array1 == null && array2 == null) {
return true;
} else if (array1 == null || array2 == null) {
return false;
}
if (array1.length != array2.length) {
return false;
}
for (var index = 0; index < array1.length; index++) {
if (Array.isArray(array1[index])) {
if (!arrayEquals(array1[index], array2[index])) {
return false;
}
continue;
}
if (array1[index] != array2[index]) {
return false;
}
}
return true;
}
function getDependencies(objectString, objectByteOffsets, bytes) {
var dependencies = [];
var references = objectString.match(/\d+\s+\d+\s+R/g);
if (references != null) {
while (references.length > 0) {
if (/\/Parent/.test(objectString.slice(objectString.indexOf(references[0]) - 8, objectString.indexOf(references[0])))) {
references.shift();
continue;
}
var dependency = getObject(references.shift().replace('R', 'obj'), objectByteOffsets, bytes);
var dependencyExists = false;
for each (var entry in dependencies) {
dependencyExists = (arrayEquals(dependency, entry)) ? true : dependencyExists;
}
if (!dependencyExists) {
dependencies.push(dependency);
}
if (Array.isArray(dependency)) {
dependencies = dependencies.concat(getDependencies(dependency[0], objectByteOffsets, bytes));
} else {
dependencies = dependencies.concat(getDependencies(dependency, objectByteOffsets, bytes));
}
}
}
return dependencies;
}
}
基本上发生的事情是，每个文件都有包含其页面、内容和资源的对象进行识别。然后这些对象将被重新编号并用新的“包装”格式化为新文件。
我编写这段代码以供两个文件使用，但我想象可能需要更多，所以我让代码适用于那种情况。为了对原始问题有效，函数的开头
function(mergePdfs(directory, name, pdf1, pdf2, opt_pdf3) {
if (name.slice(-4) != '.pdf') {
name = name + '.pdf';
}
var newObjects = ['1 0 obj\r\n<</Type/Catalog/Pages 2 0 R >>r\nendobj'];
var pageAddresses = [];
for (var argumentIndex = 2; argumentIndex < arguments.length; argumentIndex++) {
var bytes = arguments[argumentIndex].getBlob().getBytes();
应该被替换为
function mergePdfs(directory, name) {
if (name.slice(-4) != '.pdf') {
name = name + '.pdf';
}
var newObjects = ['1 0 obj\r\n<</Type/Catalog/Pages 2 0 R >>\r\nendobj'];
var pageAddresses = [];
var files = directory.getFiles();
for (var fileIndex = 0; fileIndex < files.length; fileIndex++) {
var bytes = files[fileIndex].getBlob().getBytes();
我也遇到了同样的问题，目前我正在暂时使用一个 RestFul API 来合并 PDF 文件：https://www.convertapi.com/pdf-to-merge
function merge() {
var folder = DriveApp.getFolderById('<ID FOLDER>'); // folder with files pdf
var files = folder.getFiles(); // get all files pdf
var formData = {};
var index = 0;
while(files.hasNext()) {
var file = files.next();
formData['Files[' + index + ']'] = file.getBlob();
index++;
}
var options = {
'method' : 'post',
'payload' : formData,
'muteHttpExceptions': true
};
var response = UrlFetchApp.fetch('https://v2.convertapi.com/pdf/to/merge?Secret=<YOUR SECRET>', options);
if(response.getResponseCode() == 200) {
var contentText = JSON.parse(response.getContentText());
var blob = Utilities.base64Decode(contentText.Files[0].FileData);
folder.createFile(Utilities.newBlob(blob, 'application/pdf', 'merge.pdf'));
}
}file.getBlob() 更改为 file.getBlob().getAs("application/pdf") 后，这对我起作用了。 - Yeti希望对于希望使用外部JavaScript库合并PDF文档的人有所帮助。我将合并PDF函数分离，以便于其他参考此问题的人更好地兼容。请注意，由于这是使用外部库，可能需要进行修改以使其在未来正常工作。
eval(UrlFetchApp.fetch("https://unpkg.com/pdf-lib/dist/pdf-lib.js").getContentText());
setTimeout = (func, sleep) => (Utilities.sleep(sleep), func())
/**
* Returns merged pdf, blobs are merged in the same order they are proivded.
* @param {Blob[]} blobs Blob array
* @param {String} fileName output PDF name
* @return {Promise} Promise object, blob of merged blobs
*/
async function mergeAllPDFs(blobs, fileName) {
const pdf = await PDFLib.PDFDocument.create();
for (let i = 0; i < blobs.length; i++) {
const tempBytes = await new Uint8Array(blobs[i].getBytes());
const tempPdf = await PDFLib.PDFDocument.load(tempBytes);
const pages = tempPdf.getPageCount();
for (let p = 0; p < pages; p++) {
const [tempPage] = await pdf.copyPages(tempPdf, [p]);
pdf.addPage(tempPage);
}
}
const pdfDoc = await pdf.save()
return Utilities.newBlob(pdfDoc).setName(fileName)
}
async function MergeFiles() {
var folder = DriveApp.getFolderById('myFolderID');
var files = folder.getFiles();
var blobs = [];
while (files.hasNext()) {
var file = files.next();
blobs.push(file.getBlob());
}
var myPDF = await mergeAllPDFs(blobs, "newPDF.pdf")
folder.createFile(myPDF);
}有用的资源：
const pageCount = tempPdf.getPageCount()const pageIndicesArray = [...Array(pageCount).keys()]const pages = await pdf.copyPages(tempPdf, pageIndicesArray)pages.forEach(page => pdf.addPage(page)) - mschwartz一个多页PDF绝对不是多个PDF文件内容的简单拼接...即使我承认这种方法似乎很诱人，我怀疑你也无法通过这种方法获得任何结果。
我也一直在寻找这样的东西，但迄今为止没有成功。
.getBytes() 方法为每个文件返回一个二进制数组，因此您创建的是一个包含以下内容的数组：
blobs.push(files[i].getBlob().getBytes());
相反，我会将循环中当前项的数组与一个累加器数组连接起来，该数组随着每次循环迭代而增长。然后，在退出循环后，可以将累加器数组的内容传递到.newBlob()或.setBytes()中。
你的代码正在按照你编写的方式运行。
blobs是一个数组，当你执行blobs.pop()时，你会得到数组中的最后一项（也就是你的最后一个PDF）。
你应该做的是将这些blob连接起来，不是在一个数组中，而是在单个的blob对象中。但是，我不确定在GAS中如何实现这一点。
function MergeFiles(){
var folder = DocsList.getFolderById('myFolderID');
var files = folder.getFiles();
var blobs = "";
for( var i in files )
blobs=blobs+(files[i].getBlob().getBytes());
Logger.log(blobs);
var myPDF = Utilities.newBlob(blobs, "application/pdf", "newPDF.pdf");
folder.createFile(myPDF);
}