明日计划：团队开发Fooks第五天

一、明日计划

继续完成PDF文件的上传与展示

二、今天遇到的问题

在开发过程中，先是完成了数据库层的基本操作语句，之后修改表结构，添加文件的二进制转化，最后卡在了byte[]数组转化为Blob类型上，尝试了许多解决办法如hibernate，并不是很有效

这是目前的项目结构

这是当下的表结构，明天继续加油

 部分原码

package com.example.fooks;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.net.Uri;
import android.nfc.Tag;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;

import androidx.annotation.Nullable;

import com.example.fooks.dao.dao;
import com.example.fooks.entity.Book;
import com.example.fooks.utils.BooksAdapter;
import com.example.fooks.utils.ViewHolder;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.sql.Blob;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

public class ReadActivity extends Activity {
    private Button mHome;
    private Button mBook;
    private Button mPerson;
    private Button mUpload;
    private ListView mListView;
    private List<Book> mShowBooks  =new ArrayList<>();
    private List <ViewHolder> mViewHolder;
    private static final int FILE_SELECT_CODE = 0;
    private static String Tag="ReadActivity";

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_read);

        mListView=(ListView) this.findViewById(R.id.book_list) ;
        //初始化控件
        initView();

        initListener();

        ListView ShowBookList=(ListView)findViewById(R.id.book_list);

        //获取数据
        dao dao=new dao();
        mShowBooks=dao.Query();

        BooksAdapter booksAdapter=new BooksAdapter(mShowBooks,this);
        ShowBookList.setAdapter(booksAdapter);

    }

    private void initListener() {
        mUpload.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                upLoad();
            }
        });
    }

    private void upLoad() {
        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
        intent.setType("*/*");//过滤文件类型（所有）
        intent.addCategory(Intent.CATEGORY_OPENABLE);

        try {
            startActivityForResult(Intent.createChooser(intent, "请选择文件！"), FILE_SELECT_CODE);
        } catch (android.content.ActivityNotFoundException ex) {
            Toast.makeText(this, "未安装文件管理器！", Toast.LENGTH_SHORT).show();
        }

    }


    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        switch (requestCode) {
            case FILE_SELECT_CODE:
                if (resultCode == RESULT_OK) {
                    Uri uri = data.getData();
                    String path = FileUtils.getPath(this, uri);//得到文件路径
                    Log.e(Tag,path);
                    File file=new File(path);
                    int dot = file.getName().lastIndexOf('.');
                    String name =file.getName().substring(0,dot);
                    Book book=new Book();
                    book.setBookName(name);
                    book.setBookPath(path);
                     ResultSet rs = null;
                    Blob blob=null ;
                    try {
                        blob.setBytes(1,getBytesFromFile(file));
                    } catch (SQLException e) {
                        e.printStackTrace();
                    }
                    book.setUpBook(blob);
                    book.setCreateUser("张志伟");
                    SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH-mm-ss");
                    Date date = new Date();
                    String createdate = simpleDateFormat.format(date);
                    book.setCreateDate(createdate);
                }
                break;
        }
    }

    /**
     * 把文件转换为byte文件以保存到数据库
     */
    public static byte[] getBytesFromFile(File f){
        if (f == null){
            return null;
        }
        try {
            FileInputStream stream = new FileInputStream(f);
            ByteArrayOutputStream out = new ByteArrayOutputStream(1000);
            byte[] b = new byte[1000];
            int n;
            while ((n = stream.read(b)) != -1)
                out.write(b, 0, n);
            stream.close();
            out.close();
            return out.toByteArray();
        } catch (IOException e){
        }
        return null;
    }

    static class FileUtils {
        public static String getPath(Context context, Uri uri) {

            if ("content".equalsIgnoreCase(uri.getScheme())) {
                String[] projection = { "_data" };
                Cursor cursor = null;

                try {
                    cursor = context.getContentResolver().query(uri, projection, null, null, null);
                    int column_index = cursor.getColumnIndexOrThrow("_data");
                    if (cursor.moveToFirst()) {
                        return cursor.getString(column_index);
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                }
            } else if ("file".equalsIgnoreCase(uri.getScheme())) {
                return uri.getPath();
            }
            return null;
        }
    }


    private void initView() {
        mBook=(Button) this.findViewById(R.id.btn_book);
        mHome=(Button) this.findViewById(R.id.btn_home);
        mPerson=(Button) this.findViewById(R.id.btn_person);
        mUpload=(Button) this.findViewById(R.id.book_upload);
    }
}