我有一个 .csv 文件，我想将此文件导入到我的 android 数据库中。
例如，.csv 文件：
| id | name | dt1 | dt2 | dt3 |
| 1 | Paul | 21 | 98 | 91 |
| 2 | John | 22 | 44 | 11 |
| 3 | George| 21 | 31 | 22 |
| 4 | Ringo | 20 | 10 | 15 |
对于这样的事情：
Cursor cursor = getWritableDatabase().
rawQuery("Insert into table1(_id, name, dt1, dt2, dt3)
values ( 1, Paul, 21, 98, 91)
values ( 2, John, 22, 44, 11)
values ( 3, George, 21,31,22)
values ( 4, Ringo, 20, 10,15);");
那么请问，我该怎么做呢？
试试下面的代码，
FileReader file = new FileReader(fileName);
BufferedReader buffer = new BufferedReader(file);
String line = "";
String tableName ="TABLE_NAME";
String columns = "_id, name, dt1, dt2, dt3";
String str1 = "INSERT INTO " + tableName + " (" + columns + ") values(";
String str2 = ");";
db.beginTransaction();
while ((line = buffer.readLine()) != null) {
StringBuilder sb = new StringBuilder(str1);
String[] str = line.split(",");
sb.append("'" + str[0] + "',");
sb.append(str[1] + "',");
sb.append(str[2] + "',");
sb.append(str[3] + "'");
sb.append(str[4] + "'");
sb.append(str2);
db.execSQL(sb.toString());
}
db.setTransactionSuccessful();
db.endTransaction();
我建议使用ContentValues来插入记录。它更容易，会转义引号，并且不那么冗长。
像这样，（它也会跳过坏行）：
...
BufferedReader buffer = new BufferedReader(new InputStreamReader(inStream));
String line = "";
db.beginTransaction();
try {
while ((line = buffer.readLine()) != null) {
String[] colums = line.split(",");
if (colums.length != 4) {
Log.d("CSVParser", "Skipping Bad CSV Row");
continue;
}
ContentValues cv = new ContentValues(3);
cv.put(dbCol0, colums[0].trim());
cv.put(dbCol1, colums[1].trim());
cv.put(dbCol2, colums[2].trim());
cv.put(dbCol3, colums[3].trim());
cv.put(dbCol4, colums[4].trim());
db.insert(TABLE, null, cv);
}
} catch (IOException e) {
e.printStackTrace();
}
db.setTransactionSuccessful();
db.endTransaction();
dbCol0 等是数据库的列名，例如_id, name, dt1, dt2, dt3.
db 是您
public SQLiteDatabase getReadableDatabase ()在SQLiteOpenHelper中获取的数据库
将file.csv复制到 assets 文件夹中，然后像这样读取它：
String mCSVfile = "file.csv";
AssetManager manager = context.getAssets();
InputStream inStream = null;
try {
inStream = manager.open(mCSVfile);
} catch (IOException e) {
e.printStackTrace();
}
BufferedReader buffer = new BufferedReader(new InputStreamReader(inStream));
...
我使用这些类添加了一些类，您可以轻松导入和导出文件或数据库
对于这些操作，您必须将这两个 jar 文件导入您的项目
(1) opencsv-1.7.jar http://www.java2s.com/Code/Jar/o/Downloadopencsv17jar.htm
(2) poi-3.8-20120326 .jar http://code.google.com/p/mipgsmca12-108-126--online-library/downloads/detail?name=poi-3.8-20120326.jar&can=2&q=
然后导入所有这四个类，然后根据要求使用...
ExportFileModule `
public class ExportDatabaseToCSV extends AsyncTask<Void, Boolean, Boolean>{
Context context;
ProgressDialog dialog;
public ExportDatabaseToCSV(Context context)
{
this.context=context;
}
@Override
protected void onPreExecute() {
dialog=new ProgressDialog(context);
dialog.setTitle("Exporting SecureIt Data to CSV file");
dialog.setMessage("Please wait...");
dialog.setCancelable(false);
dialog.setIcon(android.R.drawable.ic_dialog_info);
dialog.show();
}
@Override
protected Boolean doInBackground(Void... params) {
CredentialDb db = new CredentialDb(context);//here CredentialDb is my database. you can create your db object.
File exportDir = new File(Environment.getExternalStorageDirectory(), "");
if (!exportDir.exists())
{
exportDir.mkdirs();
}
File file = new File(exportDir, "SecureItExportedFile.csv");
try
{
file.createNewFile();
CSVWriter csvWrite = new CSVWriter(new FileWriter(file));
SQLiteDatabase sql_db = db.getReadableDatabase();//returning sql
Cursor curCSV = sql_db.rawQuery("SELECT * FROM "+CredentialDb.TABLE_NAME,null);
csvWrite.writeNext(curCSV.getColumnNames());
while(curCSV.moveToNext())
{
//Which column you want to export you can add over here...
String arrStr[] ={curCSV.getString(0),curCSV.getString(1), curCSV.getString(2),curCSV.getString(3),curCSV.getString(4),curCSV.getString(5)};
csvWrite.writeNext(arrStr);
}
csvWrite.close();
curCSV.close();
return true;
}
catch(Exception sqlEx)
{
Log.e("Error:", sqlEx.getMessage(), sqlEx);
}
return false;
}
@Override
protected void onPostExecute(Boolean result) {
if (dialog.isShowing())
{
dialog.dismiss();
}
if(result)
Toast.makeText(context, "SqLite Data has been Exported!", Toast.LENGTH_LONG).show();
else
Toast.makeText(context, "SqLite Data has not Exported", Toast.LENGTH_LONG).show();
}
}
导入模块
import java.io.File;
import android.app.Activity;
import android.content.Context;
import android.os.Environment;
public class MyCSVFileReader {
public static void openDialogToReadCSV(final Activity activity,final Context context)
{
File mPath = new File(Environment.getExternalStorageDirectory() + "//DIR//");
FileDialog fileDialog = new FileDialog(activity, mPath);
fileDialog.setFileEndsWith(".txt");
fileDialog.addFileListener(new FileDialog.FileSelectedListener() {
@Override
public void fileSelected(File file) {
new ImportCVSToSQLiteDataBase(context,activity,file).execute(); //execute asyncTask to import data into database from selected file.
}
});
fileDialog.showDialog();
}
}
import java.io.File;
import java.io.FilenameFilter;
import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
import android.os.Environment;
import android.util.Log;
import com.export.importmodule.ListenerList.FireHandler;
public class FileDialog {
private static final String PARENT_DIR = "..";
private final String TAG = getClass().getName();
private String[] fileList;
private File currentPath;
public interface FileSelectedListener {
void fileSelected(File file);
}
public interface DirectorySelectedListener {
void directorySelected(File directory);
}
private ListenerList<FileSelectedListener> fileListenerList = new ListenerList<FileDialog.FileSelectedListener>();
private ListenerList<DirectorySelectedListener> dirListenerList = new ListenerList<FileDialog.DirectorySelectedListener>();
private final Activity activity;
private boolean selectDirectoryOption;
private String fileEndsWith;
/**
* @param activity
* @param initialPath
*/
public FileDialog(Activity activity, File path) {
this.activity = activity;
if (!path.exists()) path = Environment.getExternalStorageDirectory();
loadFileList(path);
}
/**
* @return file dialog
*/
public Dialog createFileDialog() {
Dialog dialog = null;
AlertDialog.Builder builder = new AlertDialog.Builder(activity);
builder.setTitle(currentPath.getPath());
if (selectDirectoryOption) {
builder.setPositiveButton("Select directory", new OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Log.d(TAG, currentPath.getPath());
fireDirectorySelectedEvent(currentPath);
}
});
}
builder.setItems(fileList, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
String fileChosen = fileList[which];
File chosenFile = getChosenFile(fileChosen);
if (chosenFile.isDirectory()) {
loadFileList(chosenFile);
dialog.cancel();
dialog.dismiss();
showDialog();
} else fireFileSelectedEvent(chosenFile);
}
});
dialog = builder.show();
return dialog;
}
public void addFileListener(FileSelectedListener listener) {
fileListenerList.add(listener);
}
public void removeFileListener(FileSelectedListener listener) {
fileListenerList.remove(listener);
}
public void setSelectDirectoryOption(boolean selectDirectoryOption) {
this.selectDirectoryOption = selectDirectoryOption;
}
public void addDirectoryListener(DirectorySelectedListener listener) {
dirListenerList.add(listener);
}
public void removeDirectoryListener(DirectorySelectedListener listener) {
dirListenerList.remove(listener);
}
/**
* Show file dialog
*/
public void showDialog() {
createFileDialog().show();
}
private void fireFileSelectedEvent(final File file) {
fileListenerList.fireEvent(new FireHandler<FileDialog.FileSelectedListener>() {
public void fireEvent(FileSelectedListener listener) {
listener.fileSelected(file);
}
});
}
private void fireDirectorySelectedEvent(final File directory) {
dirListenerList.fireEvent(new FireHandler<FileDialog.DirectorySelectedListener>() {
public void fireEvent(DirectorySelectedListener listener) {
listener.directorySelected(directory);
}
});
}
private void loadFileList(File path) {
this.currentPath = path;
List<String> r = new ArrayList<String>();
if (path.exists()) {
if (path.getParentFile() != null) r.add(PARENT_DIR);
FilenameFilter filter = new FilenameFilter() {
public boolean accept(File dir, String filename) {
File sel = new File(dir, filename);
if (!sel.canRead()) return false;
if (selectDirectoryOption) return sel.isDirectory();
else {
boolean endsWith = fileEndsWith != null ? filename.toLowerCase().endsWith(fileEndsWith) : true;
return endsWith || sel.isDirectory();
}
}
};
String[] fileList1 = path.list(filter);
for (String file : fileList1) {
r.add(file);
}
}
fileList = (String[]) r.toArray(new String[]{});
}
private File getChosenFile(String fileChosen) {
if (fileChosen.equals(PARENT_DIR)) return currentPath.getParentFile();
else return new File(currentPath, fileChosen);
}
//--------------------------------------------------------------
public void setFileEndsWith(String fileEndsWith) {
this.fileEndsWith = fileEndsWith != null ? fileEndsWith.toLowerCase() : fileEndsWith;
}
}
class ListenerList<L> {
private List<L> listenerList = new ArrayList<L>();
public interface FireHandler<L> {
void fireEvent(L listener);
}
public void add(L listener) {
listenerList.add(listener);
}
public void fireEvent(FireHandler<L> fireHandler) {
List<L> copy = new ArrayList<L>(listenerList);
for (L l : copy) {
fireHandler.fireEvent(l);
}
}
public void remove(L listener) {
listenerList.remove(listener);
}
public List<L> getListenerList() {
return listenerList;
}
}
import java.io.File;
import java.io.FileReader;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.util.Log;
import android.widget.Toast;
import au.com.bytecode.opencsv.CSVReader;
public class ImportCVSToSQLiteDataBase extends AsyncTask<String, String, String> {
Activity activity;
Context context;
File file=null;
private ProgressDialog dialog;
public ImportCVSToSQLiteDataBase(Context context, Activity activity,File file) {
this.context=context;
this.activity=activity;
this.file=file;
}
@Override
protected void onPreExecute()
{
dialog=new ProgressDialog(context);
dialog.setTitle("Importing Data into SecureIt DataBase");
dialog.setMessage("Please wait...");
dialog.setCancelable(false);
dialog.setIcon(android.R.drawable.ic_dialog_info);
dialog.show();
}
@Override
protected String doInBackground(String... params) {
String data="";
Log.d(getClass().getName(), file.toString());
try{
CSVReader reader = new CSVReader(new FileReader(file));
String [] nextLine;
//here I am just displaying the CSV file contents, and you can store your file content into db from while loop...
while ((nextLine = reader.readNext()) != null) {
// nextLine[] is an array of values from the line
String accId=nextLine[0];
String acc_name=nextLine[1];
data=data+"AccId:"+accId +" Account_name:"+acc_name+"\n";
}
return data;
} catch (Exception e) {
Log.e("Error", "Error for importing file");
}
return data="";
}
protected void onPostExecute(String data)
{
if (dialog.isShowing())
{
dialog.dismiss();
}
if (data.length()!=0)
{
Toast.makeText(context, "File is built Successfully!"+"\n"+data, Toast.LENGTH_LONG).show();
}else{
Toast.makeText(context, "File fail to build", Toast.LENGTH_SHORT).show();
}
}
}
使用步骤...
(1) 对于导出 SqLiteDb：
new ExportDatabaseToCSV(YourActivityClass.this).execute();
(2) 对于从您选择的文件中导入 SqLiteDb：
MyCSVFileReader.openDialogToReadCSV(this, YourActivityClass.this);
(3) 并且不要忘记在 AndroidManifest.xml 中添加这些权限
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />