When operating Excel files in Android to export reports, the open source library jxl is mainly used. It was first used in java, but it can also be used in Android. Similar POI can only be used in java, not Android, because there are many dependency libraries.
Using JXL needs to import jxl.jar package into Android project. JXL can complete the basic read and write operation of Excel. Its support and disapproval are as follows:
1. jxl only supports Excel 2003 format, not Excel 2007 format. That is to say, support xls files, not xlsx files.
2. jxl does not support modifying excel files directly, but it can be modified indirectly by copying new files to overwrite the original files.
3. jxl can only recognize pictures in PNG format, but can not recognize pictures in other formats.
As can be seen above, jxl does not support Excel 2007, which is very bad, especially when Excel 2007 has become the mainstream format of Excel. But now there's a temporary way for Android to read the 2007 format. If we carefully analyze the file format of xlsx, we will find that the xlsx file is actually a compression package. There are various files in the compression package, and the data is usually placed in "xl/sharedStrings.xml" and "xl/worksheets/sheet1.xml". Accordingly, when we judge Excel file as 2007 format, we can decompress it, extract sharedStrings. XML and sheet1. XML from it, and then parse the specific data using XML parsing tools.
Below is an example of Excel file reading and writing code, which supports the 2003 format reading and writing, as well as the 2007 format reading:
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipException;
import java.util.zip.ZipFile;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import android.util.Log;
import android.util.Xml;
import jxl.Sheet;
import jxl.Workbook;
import jxl.write.Label;
import jxl.write.WritableSheet;
import jxl.write.WritableWorkbook;
public class ExcelUtil {
private final static String TAG = "ExcelUtil";
public static List<List<Object>> read(String file_name) {
String extension = file_name.lastIndexOf(".") == -1 ? "" : file_name
.substring(file_name.lastIndexOf(".") + 1);
if ("xls".equals(extension)) {// 2003
Log.d(TAG, "read2003XLS, extension:" + extension);
return read2003XLS(file_name);
} else if ("xlsx".equals(extension)) {
Log.d(TAG, "read2007XLSX, extension:" + extension);
return read2007XLSX(file_name);
} else {
Log.d(TAG, "Unsupported file types, extension:" + extension);
return null;
}
}
public static List<List<Object>> read2003XLS(String path) {
List<List<Object>> dataList = new ArrayList<List<Object>>();
try {
Workbook book = Workbook.getWorkbook(new File(path));
//book.getNumberOfSheets(); // Number of sheet pages obtained
//Get the first worksheet object
Sheet sheet = book.getSheet(0);
int Rows = sheet.getRows();
int Cols = sheet.getColumns();
Log.d(TAG, "Name of the current worksheet:" + sheet.getName());
Log.d(TAG, "Total number of banks:" + Rows + ", Total column number:" + Cols);
List<Object> objList = new ArrayList<Object>();
String val = null;
for (int i = 0; i < Rows; i++) {
boolean null_row = true;
for (int j = 0; j < Cols; j++) {
//GettCell (Col, Row) gets the value of the cell. Note that the getCell format is column-first-row, not the usual row-first-column format.
Log.d(TAG, (sheet.getCell(j, i)).getContents() + "\t");
val = (sheet.getCell(j, i)).getContents();
if (val == null || val.equals("")) {
val = "null";
} else {
null_row = false;
}
objList.add(val);
}
Log.d(TAG, "\n");
if (null_row != true) {
dataList.add(objList);
null_row = true;
}
objList = new ArrayList<Object>();
}
book.close();
} catch (Exception e) {
Log.d(TAG, e.getMessage());
}
return dataList;
}
public static List<List<Object>> read2007XLSX(String path) {
List<List<Object>> dataList = new ArrayList<List<Object>>();
String str_c = "";
String v = null;
boolean flat = false;
List<String> ls = new ArrayList<String>();
try {
ZipFile xlsxFile = new ZipFile(new File(path));
ZipEntry sharedStringXML = xlsxFile.getEntry("xl/sharedStrings.xml");
if (sharedStringXML == null) {
Log.d(TAG, "Empty file:" + path);
return dataList;
}
InputStream inputStream = xlsxFile.getInputStream(sharedStringXML);
XmlPullParser xmlParser = Xml.newPullParser();
xmlParser.setInput(inputStream, "utf-8");
int evtType = xmlParser.getEventType();
while (evtType != XmlPullParser.END_DOCUMENT) {
switch (evtType) {
case XmlPullParser.START_TAG:
String tag = xmlParser.getName();
if (tag.equalsIgnoreCase("t")) {
ls.add(xmlParser.nextText());
}
break;
case XmlPullParser.END_TAG:
break;
default:
break;
}
evtType = xmlParser.next();
}
ZipEntry sheetXML = xlsxFile.getEntry("xl/worksheets/sheet1.xml");
InputStream inputStreamsheet = xlsxFile.getInputStream(sheetXML);
XmlPullParser xmlParsersheet = Xml.newPullParser();
xmlParsersheet.setInput(inputStreamsheet, "utf-8");
int evtTypesheet = xmlParsersheet.getEventType();
List<Object> objList = new ArrayList<Object>();
String val = null;
boolean null_row = true;
while (evtTypesheet != XmlPullParser.END_DOCUMENT) {
switch (evtTypesheet) {
case XmlPullParser.START_TAG:
String tag = xmlParsersheet.getName();
if (tag.equalsIgnoreCase("row")) {
} else if (tag.equalsIgnoreCase("c")) {
String t = xmlParsersheet.getAttributeValue(null, "t");
if (t != null) {
flat = true; //String type
//Log.d(TAG, flat + yes);
} else { //Non-string, possibly integer.
//Log.d(TAG, flat + no);
flat = false;
}
} else if (tag.equalsIgnoreCase("v")) {
v = xmlParsersheet.nextText();
if (v != null) {
if (flat) {
str_c += ls.get(Integer.parseInt(v)) + " ";
val = ls.get(Integer.parseInt(v));
null_row = false;
} else {
str_c += v + " ";
val = v;
}
objList.add(val);
}
}
break;
case XmlPullParser.END_TAG:
if (xmlParsersheet.getName().equalsIgnoreCase("row") && v != null) {
str_c += "\n";
if (null_row != true) {
dataList.add(objList);
null_row = true;
}
objList = new ArrayList<Object>();
}
break;
}
evtTypesheet = xmlParsersheet.next();
}
Log.d(TAG, str_c);
} catch (ZipException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (XmlPullParserException e) {
e.printStackTrace();
}
if (str_c == null) {
str_c = "Problems with parsing files";
Log.d(TAG, str_c);
}
return dataList;
}
public static int writeExcel(String file_name, List<List<Object>> data_list) {
try {
WritableWorkbook book = Workbook.createWorkbook(new File(file_name));
WritableSheet sheet1 = book.createSheet("sheet1", 0);
for (int i = 0; i < data_list.size(); i++) {
List<Object> obj_list = data_list.get(i);
for (int j = 0; j < obj_list.size(); j++) {
Label label = new Label(j, i, obj_list.get(j).toString());
sheet1.addCell(label);
}
}
book.write();
book.close();
} catch (Exception e) {
e.printStackTrace();
return -1;
}
return 0;
}