有些Java开发人员库有大量无法在Android上运行的方法。
我开始使用像OpenCSV这样的库，但不幸的是Excel有known issues和打开的CSV文件。
然后我试着用：
我的问题是，如何在Android上创建.xlsx格式的简单Excel文件，而不超过65k方法？
第一个答案：做服务器端。
如果那是不可能的，只需使用JExecelAPI - 几乎所有读取xlsx文件的内容都会读取xls文件。
每个其他Excel库都会太大了。
另一个想法 - 手动编写csv文件，或者使用许多可用的csv库之一。同样，大多数读取Excel文件的应用程序也会读取csv文件。
因为这个问题似乎是：“为Excel创建Office Open XML文件的最轻量级方法是什么？（*.xlsx）？”，我将提供一个不需要任何库的示例，除了默认的java.lang，java.io和java.util.zip。
*.xlsx文件只不过是包含XML文件和目录结构中其他文件的ZIP存档。因此，我们所需要的是创建，读取和编写ZIP存档以及创建，读取和编写XML文件的可能性。对于ZIP部分，我使用java.util.zip，对于XML部分，我使用字符串操作。这通过字符串操作创建和操作XML并不是最常用的操作XML的方法，但它是最轻量级的方式，因为它不需要任何额外的XML库。
完整的例子：
import java.io.OutputStream;
import java.io.ByteArrayOutputStream;
import java.util.zip.*;
public class CreateXLSXFromScratch {
//some static parts of the XLSX file:
static String content_types_xml = "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\"?><Types xmlns=\"http://schemas.openxmlformats.org/package/2006/content-types\"><Default ContentType=\"application/vnd.openxmlformats-package.relationships+xml\" Extension=\"rels\"/><Default ContentType=\"application/xml\" Extension=\"xml\"/><Override ContentType=\"application/vnd.openxmlformats-officedocument.extended-properties+xml\" PartName=\"/docProps/app.xml\"/><Override ContentType=\"application/vnd.openxmlformats-package.core-properties+xml\" PartName=\"/docProps/core.xml\"/><Override ContentType=\"application/vnd.openxmlformats-officedocument.spreadsheetml.sharedStrings+xml\" PartName=\"/xl/sharedStrings.xml\"/><Override ContentType=\"application/vnd.openxmlformats-officedocument.spreadsheetml.styles+xml\" PartName=\"/xl/styles.xml\"/><Override ContentType=\"application/vnd.openxmlformats-officedocument.spreadsheetml.sheet.main+xml\" PartName=\"/xl/workbook.xml\"/><Override ContentType=\"application/vnd.openxmlformats-officedocument.spreadsheetml.worksheet+xml\" PartName=\"/xl/worksheets/sheet1.xml\"/></Types>";
static String docProps_app_xml = "<?xml version=\"1.0\" encoding=\"UTF-8\"?><Properties xmlns=\"http://schemas.openxmlformats.org/officeDocument/2006/extended-properties\"><Application>" + "Created Low level From Scratch" + "</Application></Properties>";
static String docProps_core_xml = "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\"?><cp:coreProperties xmlns:cp=\"http://schemas.openxmlformats.org/package/2006/metadata/core-properties\" xmlns:dc=\"http://purl.org/dc/elements/1.1/\" xmlns:dcterms=\"http://purl.org/dc/terms/\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\"><dcterms:created xsi:type=\"dcterms:W3CDTF\">" + java.time.Instant.now().truncatedTo(java.time.temporal.ChronoUnit.SECONDS).toString() + "</dcterms:created><dc:creator>" + "Axel Richter from scratch" + "</dc:creator></cp:coreProperties>";
static String _rels_rels_xml = "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\"?><Relationships xmlns=\"http://schemas.openxmlformats.org/package/2006/relationships\"><Relationship Id=\"rId1\" Target=\"xl/workbook.xml\" Type=\"http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument\"/><Relationship Id=\"rId2\" Target=\"docProps/app.xml\" Type=\"http://schemas.openxmlformats.org/officeDocument/2006/relationships/extended-properties\"/><Relationship Id=\"rId3\" Target=\"docProps/core.xml\" Type=\"http://schemas.openxmlformats.org/package/2006/relationships/metadata/core-properties\"/></Relationships>";
static String xl_rels_workbook_xml_rels_xml = "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\"?><Relationships xmlns=\"http://schemas.openxmlformats.org/package/2006/relationships\"><Relationship Id=\"rId1\" Target=\"sharedStrings.xml\" Type=\"http://schemas.openxmlformats.org/officeDocument/2006/relationships/sharedStrings\"/><Relationship Id=\"rId2\" Target=\"styles.xml\" Type=\"http://schemas.openxmlformats.org/officeDocument/2006/relationships/styles\"/><Relationship Id=\"rId3\" Target=\"worksheets/sheet1.xml\" Type=\"http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet\"/></Relationships>";
static String xl_sharedstrings_xml = "<?xml version=\"1.0\" encoding=\"UTF-8\"?><sst count=\"0\" uniqueCount=\"0\" xmlns=\"http://schemas.openxmlformats.org/spreadsheetml/2006/main\"/>";
static String xl_styles_xml = "<?xml version=\"1.0\" encoding=\"UTF-8\"?><styleSheet xmlns=\"http://schemas.openxmlformats.org/spreadsheetml/2006/main\"><numFmts count=\"0\"/><fonts count=\"1\"><font><sz val=\"11.0\"/><color indexed=\"8\"/><name val=\"Calibri\"/><family val=\"2\"/><scheme val=\"minor\"/></font></fonts><fills count=\"2\"><fill><patternFill patternType=\"none\"/></fill><fill><patternFill patternType=\"darkGray\"/></fill></fills><borders count=\"1\"><border><left/><right/><top/><bottom/><diagonal/></border></borders><cellStyleXfs count=\"1\"><xf numFmtId=\"0\" fontId=\"0\" fillId=\"0\" borderId=\"0\"/></cellStyleXfs><cellXfs count=\"1\"><xf numFmtId=\"0\" fontId=\"0\" fillId=\"0\" borderId=\"0\" xfId=\"0\"/></cellXfs></styleSheet>";
static String xl_workbook_xml = "<?xml version=\"1.0\" encoding=\"UTF-8\"?><workbook xmlns=\"http://schemas.openxmlformats.org/spreadsheetml/2006/main\" xmlns:r=\"http://schemas.openxmlformats.org/officeDocument/2006/relationships\"><workbookPr date1904=\"false\"/><bookViews><workbookView activeTab=\"0\"/></bookViews><sheets><sheet name=\"" + "Sheet1" + "\" r:id=\"rId3\" sheetId=\"1\"/></sheets></workbook>";
static String xl_worksheets_sheet1_xml = "<?xml version=\"1.0\" encoding=\"UTF-8\"?><worksheet xmlns=\"http://schemas.openxmlformats.org/spreadsheetml/2006/main\"><dimension ref=\"A1\"/><sheetViews><sheetView workbookViewId=\"0\" tabSelected=\"true\"/></sheetViews><sheetFormatPr defaultRowHeight=\"15.0\"/><sheetData/><pageMargins bottom=\"0.75\" footer=\"0.3\" header=\"0.3\" left=\"0.7\" right=\"0.7\" top=\"0.75\"/></worksheet>";
public static void main(String[] args) throws Exception {
// result goes into a ByteArrayOutputStream
ByteArrayOutputStream resultout = new ByteArrayOutputStream();
// needed objects
ZipEntry zipentry = null;
byte[] data = null;
// create ZipOutputStream
ZipOutputStream zipout = new ZipOutputStream(resultout);
// create the static parts of the XLSX ZIP file:
zipentry = new ZipEntry("[Content_Types].xml");
zipout.putNextEntry(zipentry);
data = content_types_xml.getBytes();
zipout.write(data, 0, data.length);
zipout.closeEntry();
zipentry = new ZipEntry("docProps/app.xml");
zipout.putNextEntry(zipentry);
data = docProps_app_xml.getBytes();
zipout.write(data, 0, data.length);
zipout.closeEntry();
zipentry = new ZipEntry("docProps/core.xml");
zipout.putNextEntry(zipentry);
data = docProps_core_xml.getBytes();
zipout.write(data, 0, data.length);
zipout.closeEntry();
zipentry = new ZipEntry("_rels/.rels");
zipout.putNextEntry(zipentry);
data = _rels_rels_xml.getBytes();
zipout.write(data, 0, data.length);
zipout.closeEntry();
zipentry = new ZipEntry("xl/_rels/workbook.xml.rels");
zipout.putNextEntry(zipentry);
data = xl_rels_workbook_xml_rels_xml.getBytes();
zipout.write(data, 0, data.length);
zipout.closeEntry();
zipentry = new ZipEntry("xl/sharedStrings.xml");
zipout.putNextEntry(zipentry);
data = xl_sharedstrings_xml.getBytes();
zipout.write(data, 0, data.length);
zipout.closeEntry();
zipentry = new ZipEntry("xl/styles.xml");
zipout.putNextEntry(zipentry);
data = xl_styles_xml.getBytes();
zipout.write(data, 0, data.length);
zipout.closeEntry();
zipentry = new ZipEntry("xl/workbook.xml");
zipout.putNextEntry(zipentry);
data = xl_workbook_xml.getBytes();
zipout.write(data, 0, data.length);
zipout.closeEntry();
// preparing the sheet data:
Object[][] sheetData = new Object[][] {
{"Text", "Value", "Formula"},
{"Text1", 1.23456, "=SIN(B2)"},
{"Text2", 2.34567, "=SQRT(B3)"},
{"Text3", 123.456, "=B4/10"}
};
String sheetdata = "<sheetData>";
int r = 0;
char c = 'A'; --c;
for (Object[] rowData : sheetData) {
sheetdata += "<row r=\"" + ++r + "\">";
c = 'A'; --c;
for (Object cellData : rowData) {
sheetdata += "<c r=\"" + Character.toString(++c) + r + "\"";
if (cellData instanceof String && ((String)cellData).startsWith("=")) {
sheetdata += "><f>" + ((String)cellData).replace("=", "") + "</f></c>";
} else if (cellData instanceof String) {
sheetdata += " t=\"inlineStr\"><is><t>" + ((String)cellData) + "</t></is></c>";
} else if (cellData instanceof Double) {
sheetdata += "><v>" + ((Double)cellData) + "</v></c>";
}
}
sheetdata += "</row>";
}
sheetdata += "</sheetData>";
// get the static sheet xml into a buffer for further processing
StringBuffer xl_worksheets_sheet1_xml_buffer = new StringBuffer(xl_worksheets_sheet1_xml);
// get position of the <dimension ref=\"A1\"/> in the static xl_worksheets_sheet1_xml
int dimensionstart = xl_worksheets_sheet1_xml_buffer.indexOf("<dimension ref=\"A1\"/>");
// replace the <dimension ref=\"A1\"/> with the new dimension
xl_worksheets_sheet1_xml_buffer = xl_worksheets_sheet1_xml_buffer.replace(
dimensionstart,
dimensionstart + "<dimension ref=\"A1\"/>".length(),
"<dimension ref=\"A1:" + Character.toString(c) + r + "\"/>");
// get position of the <sheetData/> in the static xl_worksheets_sheet1_xml
int sheetdatastart = xl_worksheets_sheet1_xml_buffer.indexOf("<sheetData/>");
// replace the <sheetData/> with the prepared sheet date string
xl_worksheets_sheet1_xml_buffer = xl_worksheets_sheet1_xml_buffer.replace(
sheetdatastart,
sheetdatastart + "<sheetData/>".length(),
sheetdata);
// create the xl/worksheets/sheet1.xml
zipentry = new ZipEntry("xl/worksheets/sheet1.xml");
zipout.putNextEntry(zipentry);
data = xl_worksheets_sheet1_xml_buffer.toString().getBytes();
zipout.write(data, 0, data.length);
zipout.closeEntry();
zipout.finish();
// now ByteArrayOutputStream resultout contains the XLSX file data
// writing this data into a file
try (java.io.FileOutputStream fileout = new java.io.FileOutputStream("test.xlsx")) {
resultout.writeTo(fileout);
resultout.close();
}
}
}
它是2018.使用Microsoft Graph API并在O365中创建Excel文件。
Microsoft已在Angular和C＃中发布了一些示例。这不是Java，但它是一个很好的起点：https://developer.microsoft.com/en-us/graph/docs/concepts/excel-write-to-workbook。
MS Graph Java SDK与Android兼容。
限制 - 没有简单的方法可以使用API从头开始创建Excel文件。您可能希望保留一个空白工作簿并每次都克隆它。
使用Apache POI并通过简单地将compile "com.android.support:multidex:1.0.1"添加到build.gradle中的依赖项来启用multi dex。您还需要设置multiDexEnabled为true。这应该摆脱65k方法的限制。
如果您不需要从任何来源读取xlsx文件，我建议您使用CSV excel完全能够将该类型转换为其任何标准输出。
即使您需要公式，单元格格式化，也可以使用您引用的lib或使用您自己的xml解析器，就像我之前的许多人所说的那样，excel格式只是一个带有xml的zip。那些xml在这里描述：
https://msdn.microsoft.com/en-us/library/dd979921(v=office.12).aspx
正如您将发现excel是非常复杂的格式和简单的retrocompatibility不是他们的首要任务。因此，使用XPath或JAXB制作自己的受限解析器将是一项繁重的工作，但并非不可能。
但我不明白你为什么要限制数量的方法？如果它是关于制作一些嵌入式软件，在我看来，你不应该使用.xlsx，这是一个复杂而繁重的文件，只是为了节省网格......
xlsx是一个zip文件。因此，我们可以提取zip并获取内部的xml文件，然后我们可以自己解析它以获取工作表数据。
这对于xls和xlsx都适用。