Android 将数据库转换成Excel表格并通过蓝牙发送到其他设备

    最近项目要实现一个功能, 将android app里面的数据库导成Excel表格 , 并将Excel表格通过蓝牙发送到其他设备上.

先看看界面 ， 图二 为文件管理器里看到的文件。

大概的功能图片上都已经体现了, 下面来讲讲实现的思路

1. 数据的录入及保存到数据库 , 数据库我用的是郭神的litepal , 郭神也是最近刚更新到了2.0版本 , 大家有兴趣的可以看看他的博客.

2. 把数据库通过jxl.jar 转换成Excel表格, 

3. 将Excel表格用蓝牙发送到其他设备.

下面看代码  MainActivity.class

package com.example.admin.litepaltoexcel;

import android.Manifest;
import android.annotation.SuppressLint;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.os.Build;
import android.os.Environment;
import android.os.StrictMode;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.TextUtils;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import com.example.admin.litepaltoexcel.bean.Product;
import com.example.admin.litepaltoexcel.dao.ProductDao;
import com.example.admin.litepaltoexcel.excel.ExcelUtils;

import org.litepal.util.LogUtil;

import java.io.File;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

public class MainActivity extends AppCompatActivity {
    private static final int MY_PERMISSIONS_REQUEST = 111;
    private static final int CHECK_PERMISSION = 222;
    private String[] title = {"ID","船只名称", "时间", "产品名称", "产品批次", "捕捞区域", "纬度", "经度", "备注说明"};
    private EditText edtBoatName;
    private EditText edtDateTime;
    private EditText edtProductName;
    private EditText edtProductBatch;
    private EditText edtArea;
    private EditText edtLat;
    private EditText edtLon;
    private EditText edtNote;
    private Button mSaveBtn;
    private String[] saveData;
    private ProductDao mProductDao;
    private File file;
    private ArrayList> bill2List;
    private String mFileName;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewsById();
        mProductDao = new ProductDao();
        bill2List = new ArrayList>();
        getPermissions();
        initPhotoError();
    }

    private void initPhotoError(){
        // android 7.0系统解决获取文件和拍照的问题
        StrictMode.VmPolicy.Builder builder = new StrictMode.VmPolicy.Builder();
        StrictMode.setVmPolicy(builder.build());
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) {
            builder.detectFileUriExposure();
        }
    }

    private void getPermissions() {

        if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED
                && ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED
                && ContextCompat.checkSelfPermission(this, Manifest.permission.MOUNT_UNMOUNT_FILESYSTEMS) == PackageManager.PERMISSION_GRANTED) {

            //获取权限后 才能读写数据库

        } else {
            ActivityCompat.requestPermissions(this, new String[]{
                    Manifest.permission.WRITE_EXTERNAL_STORAGE,
                    Manifest.permission.READ_EXTERNAL_STORAGE,
                    Manifest.permission.MOUNT_UNMOUNT_FILESYSTEMS}, CHECK_PERMISSION);
        }
    }

    private void findViewsById() {
        edtBoatName = (EditText) findViewById(R.id.edt_boatName);
        edtDateTime = (EditText) findViewById(R.id.edt_dateTime);
        edtProductName = (EditText) findViewById(R.id.edt_productName);
        edtProductBatch = (EditText) findViewById(R.id.edt_productBatch);
        edtArea = (EditText) findViewById(R.id.edt_area);
        edtLat = (EditText) findViewById(R.id.edt_Lat);
        edtLon = (EditText) findViewById(R.id.edt_Lon);
        edtNote = (EditText) findViewById(R.id.edt_note);
        mSaveBtn = (Button) findViewById(R.id.btn_save);

        String time = new SimpleDateFormat("yyyy-MM-dd HH:mm").format(new Date());
        String times = new SimpleDateFormat("yyyy_MM_dd").format(new Date());
        edtDateTime.setText(time);
        edtProductBatch.setText(times+"_aaa");
        mSaveBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                saveDB();
            }
        });
    }

    private void saveDB()  {
        saveData = new String[]{edtBoatName.getText().toString().trim(), edtDateTime.getText().toString().trim(), edtProductName.getText().toString().trim(),
                edtProductBatch.getText().toString().trim(), edtArea.getText().toString().trim(), edtLat.getText().toString().trim(),
                edtLon.getText().toString().trim(), edtNote.getText().toString().trim()};
        if (canSave(saveData)) {
            Product product = new Product();
            product.setBoatName(edtBoatName.getText().toString().trim());
            product.setDateTime(edtDateTime.getText().toString().trim());
            product.setProductName(edtProductName.getText().toString().trim());
            product.setProductBatch(edtProductBatch.getText().toString().trim());
            product.setArea(edtArea.getText().toString().trim());
            product.setLat(edtLat.getText().toString().trim());
            product.setLon(edtLon.getText().toString().trim());
            product.setNote(edtNote.getText().toString().trim());
            boolean save = product.save();
            // mProductDao.save(product);
            int id = product.getId();
            Log.d("tag", id + "");
            if (save){
                Toast.makeText(MainActivity.this, "保存成功", Toast.LENGTH_SHORT).show();
            }else {
                Toast.makeText(MainActivity.this, "保存失败", Toast.LENGTH_SHORT).show();
            }

        } else {
            Toast.makeText(MainActivity.this, "请填写任意一项内容", Toast.LENGTH_SHORT).show();
        }
    }

    private boolean canSave(String[] data) {
        boolean isOk = false;
        for (int i = 0; i < data.length; i++) {
            if (i > 0 && i < data.length) {
                if (!TextUtils.isEmpty(data[i])) {
                    isOk = true;
                }
            }
        }
        return isOk;
    }


    /**
     * ----------------------------------------LItepal to Excel---------------------------------------------------------------
     **/

    //当客户点击MENU按钮的时候，调用该方法
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        menu.add(0, 1, 1, "查看数据库");
        menu.add(0, 2, 2, "保存到Excel");
        menu.add(0, 3, 3, "蓝牙发送Excel数据");
        return super.onCreateOptionsMenu(menu);
    }

    //当客户点击菜单当中的某一个选项时，会调用该方法
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if (item.getItemId() == 1) {

        Intent intent = new Intent(this , BillListActivity.class);
        startActivity(intent);

        }else if (item.getItemId() == 2) {
            Log.d("TAG", "保存到Excel");
            List productList = mProductDao.findAllByLimit();
            if (productList.size()>0){
                createExcel();
            }else {
                Toast.makeText(MainActivity.this, "数据库无内容", Toast.LENGTH_SHORT).show();
            }

        } else if (item.getItemId() == 3) {
            Log.d("TAG", "蓝牙发送Excel数据"); 
      
            checkBluetoothPermission();

        }

        return super.onOptionsItemSelected(item);
    }

    //创建Excel表格 并保存数据到Excel表格中
    @SuppressLint("SimpleDateFormat")
    private void createExcel() {
        //创建文件
        file = new File(getSDPath() + "/Trace");
        makeDir(file);
        //创建Excel表格
        mFileName = file.toString() + "/bill.xls";
        ExcelUtils.initExcel(file.toString() + "/bill.xls", title);
        //将数据写入Excel表格
        ExcelUtils.writeObjListToExcel(getBillData(), getSDPath() + "/Trace/bill.xls", this);

    }


    private ArrayList> getBillData() {
        List productList = mProductDao.findAllByLimit();

            for (Product product : productList) {
                ArrayList beanList = new ArrayList();
                beanList.add(product.getId()+"");
                beanList.add(product.getBoatName());
                beanList.add(product.getDateTime());
                beanList.add(product.getProductName());
                beanList.add(product.getProductBatch());
                beanList.add(product.getArea());
                beanList.add(product.getLat());
                beanList.add(product.getLon());
                beanList.add(product.getNote());
                bill2List.add(beanList);
            }
            return bill2List;
    }


    public static void makeDir(File dir) {
        if (!dir.getParentFile().exists()) {
            makeDir(dir.getParentFile());
        }
        dir.mkdir();
    }

    public String getSDPath() {
        File sdDir = null;
        boolean sdCardExist = Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED);
        if (sdCardExist) {
            sdDir = Environment.getExternalStorageDirectory();
        }
        String dir = sdDir.toString();
        return dir;

    }


    /***----------------------------蓝牙发送Excel文件------------------------------------------------------------------*/


    private void connectBluetooth() {

        String dir = getSDPath() + "/Trace/bill.xls";
        //mFileName
        File file = new File(dir);

        if(null==file || !file.exists()){
            Toast.makeText(this, "Excel文件不存在", Toast.LENGTH_SHORT).show();
            return;
        }

        Intent intent = new Intent();
        intent.setAction(Intent.ACTION_SEND);
//      intent.setType("application/octet-stream");
        intent.setType("*/*"); //
        intent.setClassName("com.android.bluetooth"
                , "com.android.bluetooth.opp.BluetoothOppLauncherActivity");
        //  intent.putExtra(Intent.EXTRA_STREAM, Uri.fromFile( new File("/sdcard/20095111013295162.jpg")));
        intent.putExtra(Intent.EXTRA_STREAM, Uri.fromFile( new File(dir)));
        startActivity(intent);

    }




    //校验蓝牙权限
    private void checkBluetoothPermission() {
        if (Build.VERSION.SDK_INT >= 23) {
            //校验是否已具有模糊定位权限
            if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
                //具有权限
                connectBluetooth();
            } else {
                ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, MY_PERMISSIONS_REQUEST);
            }
        } else {
            //系统不高于6.0直接执行
            connectBluetooth();
        }
    }



    // 对返回值进行处理，类似于startActivityForResult方法：
    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        doNext(requestCode, grantResults);
    }
    private void doNext(int requestCode, int[] grantResults) {
        if (requestCode == MY_PERMISSIONS_REQUEST) {
            if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                //同意权限
                connectBluetooth();
            } else {
                // 权限拒绝
                // 下面的方法最好写一个跳转，可以直接跳转到权限设置页面，方便用户
                //  denyPermission();
                Toast.makeText(this, "没有获取蓝牙权限,请先获取蓝牙权限", Toast.LENGTH_SHORT).show();
            }


        }else  if (requestCode == CHECK_PERMISSION //文件操作的权限
                && grantResults.length == 3
                && grantResults[0] == PackageManager.PERMISSION_GRANTED
                && grantResults[1] == PackageManager.PERMISSION_GRANTED
                && grantResults[2] == PackageManager.PERMISSION_GRANTED) {

            //获取权限后的操作

        }


    }

}

数据库转换用到的ExcelUtils.class

package com.example.admin.litepaltoexcel.excel;

import android.content.Context;
import android.widget.Toast;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;

import jxl.Workbook;
import jxl.WorkbookSettings;
import jxl.write.Label;
import jxl.write.WritableCell;
import jxl.write.WritableCellFormat;
import jxl.write.WritableFont;
import jxl.write.WritableSheet;
import jxl.write.WritableWorkbook;
import jxl.write.WriteException;

public class ExcelUtils {
   public static WritableFont arial14font = null;

   public static WritableCellFormat arial14format = null;
   public static WritableFont arial10font = null;
   public static WritableCellFormat arial10format = null;
   public static WritableFont arial12font = null;
   public static WritableCellFormat arial12format = null;

   public final static String UTF8_ENCODING = "UTF-8";
   public final static String GBK_ENCODING = "GBK";

   public static void format() {
      try {
         arial14font = new WritableFont(WritableFont.ARIAL, 14, WritableFont.BOLD);
         arial14font.setColour(jxl.format.Colour.LIGHT_BLUE);
         arial14format = new WritableCellFormat(arial14font);
         arial14format.setAlignment(jxl.format.Alignment.CENTRE);
         arial14format.setBorder(jxl.format.Border.ALL, jxl.format.BorderLineStyle.THIN);
         arial14format.setBackground(jxl.format.Colour.VERY_LIGHT_YELLOW);
         arial10font = new WritableFont(WritableFont.ARIAL, 10, WritableFont.BOLD);
         arial10format = new WritableCellFormat(arial10font);
         arial10format.setAlignment(jxl.format.Alignment.CENTRE);
         arial10format.setBorder(jxl.format.Border.ALL, jxl.format.BorderLineStyle.THIN);
         arial10format.setBackground(jxl.format.Colour.LIGHT_BLUE);
         arial12font = new WritableFont(WritableFont.ARIAL, 12);
         arial12format = new WritableCellFormat(arial12font);
         arial12format.setBorder(jxl.format.Border.ALL, jxl.format.BorderLineStyle.THIN);
      }
      catch (WriteException e) {

         e.printStackTrace();
      }
   }

   public static void initExcel(String fileName, String[] colName) {
      format();
      WritableWorkbook workbook = null;
      try {
         File file = new File(fileName);
         if (!file.exists()) {
            file.createNewFile();
         }
         workbook = Workbook.createWorkbook(file);
         WritableSheet sheet = workbook.createSheet("捕捞明细表", 0);
         sheet.addCell((WritableCell) new Label(0, 0, fileName, arial14format));
         for (int col = 0; col < colName.length; col++) {
            sheet.addCell(new Label(col, 0, colName[col], arial10format));
         }
         workbook.write();
      }
      catch (Exception e) {
         e.printStackTrace();
      }
      finally {
         if (workbook != null) {
            try {
               workbook.close();
            }
            catch (Exception e) {
               // TODO Auto-generated catch block
               e.printStackTrace();
            }
         }
      }

   }

   @SuppressWarnings("unchecked")
   public static <T> void writeObjListToExcel(List<T> objList, String fileName, Context c) {
      if (objList != null && objList.size() > 0) {
         WritableWorkbook writebook = null;
         InputStream in = null;
         try {
            WorkbookSettings setEncode = new WorkbookSettings();
            setEncode.setEncoding(UTF8_ENCODING);
            in = new FileInputStream(new File(fileName));
            Workbook workbook = Workbook.getWorkbook(in);
            writebook = Workbook.createWorkbook(new File(fileName), workbook);
            WritableSheet sheet = writebook.getSheet(0);
            for (int j = 0; j < objList.size(); j++) {
               ArrayList list=(ArrayList) objList.get(j);
               for (int i = 0; i < list.size(); i++) {
                  sheet.addCell(new Label(i, j+1, list.get(i), arial12format));
               }
            }
            writebook.write();
            Toast.makeText(c, "保存Excel成功", Toast.LENGTH_SHORT).show();
         }
         catch (Exception e) {
            e.printStackTrace();
         }
         finally {
            if (writebook != null) {
               try {
                  writebook.close();
               }
               catch (Exception e) {
                  e.printStackTrace();
               }

            }
            if (in != null) {
               try {
                  in.close();
               }
               catch (IOException e) {
                  e.printStackTrace();
               }
            }
         }

      }
   }

   public static Object getValueByRef(Class cls, String fieldName) {
      Object value = null;
      fieldName = fieldName.replaceFirst(fieldName.substring(0, 1), fieldName.substring(0, 1).toUpperCase());
      String getMethodName = "get" + fieldName;
      try {
         Method method = cls.getMethod(getMethodName);
         value = method.invoke(cls);
      }
      catch (Exception e) {
         e.printStackTrace();
      }
      return value;
   }
}

重点是这两个类的代码 ， 下面是整个项目的结构 ，数据库的代码就不展示了 ， Excel的转换需要一个jxl.jar 包

整个项目完整的demo