我的代码有一些问题。我正在尝试遍历包含许多 PDF 的 Drive 文件夹，然后将它们合并到一个文件中。当我使用我的代码时，它只是为 Drive 文件夹中的最后一个 PDF 创建一个 PDF，而不是按预期将它们合并在一起。
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);
}
因此，这不仅仅是简单地组合来自每个文件的数据。每个文件的实际可用数据与标记和其他代码（类似于 HTML 和其他文档格式）“打包”。您实际上必须解码每个 PDF 文件，组合必要的部分，然后使用新的“包装”重新编码。这需要了解 PDF 规范和结构的工作知识，可从 Adobe此处免费获得。
我使用这些信息编写了一个足以满足我需求的脚本。然而，它并没有考虑到所有可能性，因此特别是合并任何需要 PDF-1.4 和更高版本的文档，这将需要相当多的工作。
/**
* 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;
}
}
本质上，这里发生的是每个文件都具有包含其页面的对象及其内容和资源。然后这些对象被重新编号并使用新文件的新“打包”格式化。
我编写了这段代码用于两个文件，但我想可能需要更多，所以我让代码为此工作。要对函数开头的原始问题有效，
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();
我也有同样的问题，我暂时使用 RestFul API 来合并 PDF：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'));
}
}多页 pdf 绝对不是多个 pdf 文件内容的简单串联......我怀疑你能用这种方法得到任何结果，即使我承认它看起来很诱人......
我也一直在寻找类似的东西，但直到现在都没有成功。
The .getBytes() method returns a binary array for each file, so what you're created is an array of arrays with:
blobs.push(files[i].getBlob().getBytes());
Instead, I'd concatenate the array for the current item in the loop with an accumulator array that grows with each loop iteration. Then, after exiting the loop the contents of the accumulator array can be passed into .newBlob() or .setBytes()
您的代码的行为与您编写的代码完全相同。
blobs是一个数组，当您执行 a 时blobs.pop()，您将获得数组中的最后一项（这是您的最后一个 PDF）。
您应该做的是连接 blob，而不是在数组中，而是在单个blob对象中。但是，我不确定如何在 GAS 中做到这一点
这是连接 blob 的代码，但就像 Serge 提到的那样，它实际上不起作用，并且 PDF 出现损坏。
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);
}