如何在android中实现Export sqlite To excel/csv文件？
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时间：2020-08-20 04:34:57 来源:igfitidea点击:
How to implement Export sqlite To excel/csv file in android?
提问by Aditi K
I am developing android app where SQlite as a database.I want to export certain result from DB in to excel file format programatically, want to store that excel to local device path I have come across following links
我正在开发 android 应用程序，其中 SQlite 作为数据库。我想以编程方式将某些结果从数据库导出为 excel 文件格式，想要将该 excel 存储到本地设备路径我遇到了以下链接
So what is exact procedure to implement Export to Excel for android apps ?
那么为 android 应用程序实现导出到 Excel 的确切程序是什么？
采纳答案by Aditi K
Guys here is answer that I have implemented successfully
这里的人是我已成功实施的答案
//new async task for file export to csv
private class ExportDatabaseCSVTask extends AsyncTask<String, String, Boolean> {
private final ProgressDialog dialog = new ProgressDialog(SearchResultActivity.this);
boolean memoryErr = false;
// to show Loading dialog box
@Override
protected void onPreExecute() {
this.dialog.setMessage("Exporting database...");
this.dialog.show();
}
// to write process
protected Boolean doInBackground(final String... args) {
boolean success = false;
String currentDateString = new SimpleDateFormat(Constants.SimpleDtFrmt_ddMMyyyy).format(new Date());
File dbFile = getDatabasePath("HLPL_FRETE.db");
Log.v(TAG, "Db path is: " + dbFile); // get the path of db
File exportDir = new File(Environment.getExternalStorageDirectory() + File.separator + Constants.FileNm.FILE_DIR_NM, "");
long freeBytesInternal = new File(getApplicationContext().getFilesDir().getAbsoluteFile().toString()).getFreeSpace();
long megAvailable = freeBytesInternal / 1048576;
if (megAvailable < 0.1) {
System.out.println("Please check"+megAvailable);
memoryErr = true;
}else {
exportDirStr = exportDir.toString();// to show in dialogbox
Log.v(TAG, "exportDir path::" + exportDir);
if (!exportDir.exists()) {
exportDir.mkdirs();
}
try {
List<SalesActivity> listdata = salesLst;
SalesActivity sa = null;
String lob = null;
for (int index = 0; index < listdata.size();) {
sa = listdata.get(index);
lob = sa.getLob();
break;
}
if (Constants.Common.OCEAN_LOB.equals(lob)) {
file = new File(exportDir, Constants.FileNm.FILE_OFS + currentDateString + ".csv");
} else {
file = new File(exportDir, Constants.FileNm.FILE_AFS + currentDateString + ".csv");
}
file.createNewFile();
CSVWriter csvWrite = new CSVWriter(new FileWriter(file));
// this is the Column of the table and same for Header of CSV
// file
if (Constants.Common.OCEAN_LOB.equals(lob)) {
csvWrite.writeNext(Constants.FileNm.CSV_O_HEADER);
}else{
csvWrite.writeNext(Constants.FileNm.CSV_A_HEADER);
}
String arrStr1[] = { "SR.No", "CUTSOMER NAME", "PROSPECT", "PORT OF LOAD", "PORT OF DISCHARGE" };
csvWrite.writeNext(arrStr1);
if (listdata.size() > 0) {
for (int index = 0; index < listdata.size(); index++) {
sa = listdata.get(index);
String pol;
String pod;
if (Constants.Common.OCEAN_LOB.equals(sa.getLob())) {
pol = sa.getPortOfLoadingOENm();
pod = sa.getPortOfDischargeOENm();
} else {
pol = sa.getAirportOfLoadNm();
pod = sa.getAirportOfDischargeNm();
}
int srNo = index;
String arrStr[] = { String.valueOf(srNo + 1), sa.getCustomerNm(), sa.getProspectNm(), pol, pod };
csvWrite.writeNext(arrStr);
}
success = true;
}
csvWrite.close();
} catch (IOException e) {
Log.e("SearchResultActivity", e.getMessage(), e);
return success;
}
}
return success;
}
// close dialog and give msg
protected void onPostExecute(Boolean success) {
if (this.dialog.isShowing()) {
this.dialog.dismiss();
}
if (success) {
dialogBox(Constants.Flag.FLAG_EXPRT_S);
} else {
if (memoryErr==true) {
dialogBox(Constants.Flag.FLAG_MEMORY_ERR);
} else {
dialogBox(Constants.Flag.FLAG_EXPRT_F);
}
}
}
}
回答by user3530687
this is my answer: And this works ! Excel file is the same as a .csv file. Step 1: download this jar file https://code.google.com/p/opencsv/downloads/detail?name=opencsv-2.4.jar&can=2&q=
这是我的答案：这是有效的！Excel 文件与 .csv 文件相同。第一步：下载这个jar文件https://code.google.com/p/opencsv/downloads/detail?name=opencsv-2.4.jar&can=2&q=
Step 2:
第2步：
private class ExportDatabaseCSVTask extends AsyncTask<String ,String, String>{
private final ProgressDialog dialog = new ProgressDialog(MainActivity.this);
@Override
protected void onPreExecute() {
this.dialog.setMessage("Exporting database...");
this.dialog.show();
}
protected String doInBackground(final String... args){
File exportDir = new File(Environment.getExternalStorageDirectory(), "");
if (!exportDir.exists()) {
exportDir.mkdirs();
}
File file = new File(exportDir, "ExcelFile.csv");
try {
file.createNewFile();
CSVWriter csvWrite = new CSVWriter(new FileWriter(file));
//data
ArrayList<String> listdata= new ArrayList<String>();
listdata.add("Aniket");
listdata.add("Shinde");
listdata.add("pune");
listdata.add("anything@anything");
//Headers
String arrStr1[] ={"First Name", "Last Name", "Address", "Email"};
csvWrite.writeNext(arrStr1);
String arrStr[] ={listdata.get(0), listdata.get(1), listdata.get(2), listdata.get(3)};
csvWrite.writeNext(arrStr);
csvWrite.close();
return "";
}
catch (IOException e){
Log.e("MainActivity", e.getMessage(), e);
return "";
}
}
@SuppressLint("NewApi")
@Override
protected void onPostExecute(final String success) {
if (this.dialog.isShowing()){
this.dialog.dismiss();
}
if (success.isEmpty()){
Toast.makeText(MainActivity.this, "Export successful!", Toast.LENGTH_SHORT).show();
}
else {
Toast.makeText(MainActivity.this, "Export failed!", Toast.LENGTH_SHORT).show();
}
}
}
Write Asynctask in your .java file
Async在 .java 文件中写入任务
Step3: Add call this task
Step3：添加调用此任务
ExportDatabaseCSVTask task=new ExportDatabaseCSVTask();
task.execute();
ExcelFile.csvfile will be created in your sdcard.
ExcelFile.csv文件将在您的 SD 卡中创建。
回答by Hardip
ExportDatabaseCSVTask:
导出数据库CSV任务：
public class ExportDatabaseCSVTask extends AsyncTask<String, Void, Boolean> {
private final ProgressDialog dialog = new ProgressDialog(MainActivity.this);
@Override
protected void onPreExecute() {
this.dialog.setMessage("Exporting database...");
this.dialog.show();
}
protected Boolean doInBackground(final String... args) {
String currentDBPath = "/data/"+ "your Package name" +"/databases/abc.db";
File dbFile = getDatabasePath(""+currentDBPath);
System.out.println(dbFile); // displays the data base path in your logcat
File exportDir = new File(Environment.getExternalStorageDirectory(), "/your Folder Name/");
if (!exportDir.exists()) { exportDir.mkdirs(); }
File file = new File(exportDir, "myfile.csv");
try {
file.createNewFile();
CSVWriter csvWrite = new CSVWriter(new FileWriter(file));
Cursor curCSV = simpledb.rawQuery("select * from " + tablename,null);
csvWrite.writeNext(curCSV.getColumnNames());
while(curCSV.moveToNext()) {
String arrStr[]=null;
String[] mySecondStringArray = new String[curCSV.getColumnNames().length];
for(int i=0;i<curCSV.getColumnNames().length;i++)
{
mySecondStringArray[i] =curCSV.getString(i);
}
csvWrite.writeNext(mySecondStringArray);
}
csvWrite.close();
curCSV.close();
return true;
} catch (IOException e) {
Log.e("MainActivity", e.getMessage(), e);
return false;
}
}
protected void onPostExecute(final Boolean success) {
if (this.dialog.isShowing()) { this.dialog.dismiss(); }
if (success) {
Toast.makeText(MainActivity.this, "Export successful!", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(MainActivity.this, "Export failed", Toast.LENGTH_SHORT).show();
}
}
}
CSVWriter:
CSV 编写器：
public class CSVWriter {
private PrintWriter pw;
private char separator;
private char quotechar;
private char escapechar;
private String lineEnd;
/** The character used for escaping quotes. */
public static final char DEFAULT_ESCAPE_CHARACTER = '"';
/** The default separator to use if none is supplied to the constructor. */
public static final char DEFAULT_SEPARATOR = ',';
/**
* The default quote character to use if none is supplied to the
* constructor.
*/
public static final char DEFAULT_QUOTE_CHARACTER = '"';
/** The quote constant to use when you wish to suppress all quoting. */
public static final char NO_QUOTE_CHARACTER = '\u0000';
/** The escape constant to use when you wish to suppress all escaping. */
public static final char NO_ESCAPE_CHARACTER = '\u0000';
/** Default line terminator uses platform encoding. */
public static final String DEFAULT_LINE_END = "\n";
/**
* Constructs CSVWriter using a comma for the separator.
*
* @param writer
* the writer to an underlying CSV source.
*/
public CSVWriter(Writer writer) {
this(writer, DEFAULT_SEPARATOR, DEFAULT_QUOTE_CHARACTER,
DEFAULT_ESCAPE_CHARACTER, DEFAULT_LINE_END);
}
/**
* Constructs CSVWriter with supplied separator, quote char, escape char and line ending.
*
* @param writer
* the writer to an underlying CSV source.
* @param separator
* the delimiter to use for separating entries
* @param quotechar
* the character to use for quoted elements
* @param escapechar
* the character to use for escaping quotechars or escapechars
* @param lineEnd
* the line feed terminator to use
*/
public CSVWriter(Writer writer, char separator, char quotechar, char escapechar, String lineEnd) {
this.pw = new PrintWriter(writer);
this.separator = separator;
this.quotechar = quotechar;
this.escapechar = escapechar;
this.lineEnd = lineEnd;
}
/**
* Writes the next line to the file.
*
* @param nextLine
* a string array with each comma-separated element as a separate
* entry.
*/
public void writeNext(String[] nextLine) {
if (nextLine == null)
return;
StringBuffer sb = new StringBuffer();
for (int i = 0; i < nextLine.length; i++) {
if (i != 0) {
sb.append(separator);
}
String nextElement = nextLine[i];
if (nextElement == null)
continue;
if (quotechar != NO_QUOTE_CHARACTER)
sb.append(quotechar);
for (int j = 0; j < nextElement.length(); j++) {
char nextChar = nextElement.charAt(j);
if (escapechar != NO_ESCAPE_CHARACTER && nextChar == quotechar) {
sb.append(escapechar).append(nextChar);
} else if (escapechar != NO_ESCAPE_CHARACTER && nextChar == escapechar) {
sb.append(escapechar).append(nextChar);
} else {
sb.append(nextChar);
}
}
if (quotechar != NO_QUOTE_CHARACTER)
sb.append(quotechar);
}
sb.append(lineEnd);
pw.write(sb.toString());
}
/**
* Flush underlying stream to writer.
*
* @throws IOException if bad things happen
*/
public void flush() throws IOException {
pw.flush();
}
/**
* Close the underlying stream writer flushing any buffered content.
*
* @throws IOException if bad things happen
*
*/
public void close() throws IOException {
pw.flush();
pw.close();
}
}
回答by Haider Malik
I have recently implemented the excel export function in my app. I have also included my full code on how to export filtered data to excel instead of the whole table.
我最近在我的应用程序中实现了 excel 导出功能。我还包含了关于如何将过滤后的数据导出到 excel 而不是整个表的完整代码。
You will need to create a second table for this. The second that will hold the data you require for this operation (In my second table I have removed my autoincrament ID column because I dont want it in my excel file).
您将需要为此创建第二个表。第二个将保存此操作所需的数据（在我的第二个表中，我删除了我的 autoincrament ID 列，因为我不希望它出现在我的 excel 文件中）。
You will need to clear the second table first and then add entries.
您需要先清除第二个表，然后添加条目。
Then use the SqLiteToExcel object to export db to excel and save the file somewhere.
然后使用 SqlLiteToExcel 对象将 db 导出到 excel 并将文件保存在某处。
Then I have an email intent with the excel file attached for sharing (allows sharing with other apps other than email). here is my method:
然后我有一个带有 excel 文件的电子邮件意图用于共享（允许与电子邮件以外的其他应用程序共享）。这是我的方法：
private void ExportData() {
//CHECK IF YOU HAVE WRITE PERMISSIONS OR RETURN
int permission = ActivityCompat.checkSelfPermission(getActivity(), Manifest.permission.WRITE_EXTERNAL_STORAGE);
if (permission != PackageManager.PERMISSION_GRANTED) {
Toast.makeText(getContext(), "Storage permissions not granted", Toast.LENGTH_SHORT).show();
return;
}
//get database object
myDbhelper = new MyDbHelper(getContext());
SQLiteDatabase database = myDbhelper.getWritableDatabase();
//delete all entries in the second table
database.delete("Table2",null,null);
//Create a cursor of the main database with your filters and sort order applied
Cursor cursor = getActivity().getContentResolver().query(
uri,
projections,
selection,
args,
sortOrder);
//loop through cursor and add entries from first table to second table
try {
while (cursor.moveToNext()) {
final String ColumnOneIndex = cursor.getString(cursor.getColumnIndexOrThrow("COLUMN_ONE"));
final String ColumnTwoIndex = cursor.getString(cursor.getColumnIndexOrThrow("COLUMN_TWO"));
final String ColumnThreeIndex = cursor.getString(cursor.getColumnIndexOrThrow("COLUMN_THREE"));
//add entries from table one into the table two
ContentValues values = new ContentValues();
values.put("TABLE2_COLUMN_1", ColumnOneIndex);
values.put("TABLE2_COLUMN_2", ColumnTwoIndex );
values.put("TABLE2_COLUMN_3", ColumnThreeIndex);
database.insert("table2", null, values);
}
} finally {
//close cursor after looping is complete
cursor.close();
}
//create a string for where you want to save the excel file
final String savePath = Environment.getExternalStorageDirectory() + "/excelfileTemp";
File file = new File(savePath);
if (!file.exists()) {
file.mkdirs();
}
//create the sqLiteToExcel object
SQLiteToExcel sqLiteToExcel = new SQLiteToExcel(getContext(), "databasefile.db",savePath);
//use sqLiteToExcel object to create the excel file
sqLiteToExcel.exportSingleTable("table2","excelfilename.xls", new SQLiteToExcel.ExportListener() {
@Override
public void onStart() {
}
@Override
public void onCompleted(String filePath) {
//now attach the excel file created and be directed to email activity
Uri newPath = Uri.parse("file://" + savePath + "/" +"excelfilename.xls");
StrictMode.VmPolicy.Builder builder = new StrictMode.VmPolicy.Builder();
StrictMode.setVmPolicy(builder.build());
Intent emailintent = new Intent(Intent.ACTION_SEND);
emailintent.setType("application/vnd.ms-excel");
emailintent.putExtra(Intent.EXTRA_SUBJECT, "Subject");
emailintent.putExtra(Intent.EXTRA_TEXT, "I'm email body.");
emailintent.putExtra(Intent.EXTRA_STREAM,newPath);
startActivity(Intent.createChooser(emailintent, "Send Email"));
}
@Override
public void onError(Exception e) {
System.out.println("Error msg: " + e);
Toast.makeText(getContext(), "Failed to Export data", Toast.LENGTH_SHORT).show();
}
});
}
I have this method implemented in my app and it works
我在我的应用程序中实现了这个方法并且它有效
