FileOperateTools

最新推荐文章于 2019-06-26 16:50:50 发布

原创最新推荐文章于 2019-06-26 16:50:50 发布 · 168 阅读

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#android 文件操作

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本文介绍如何在Android应用中使用ContentResolver保存图片到相册，并实现图片压缩功能，包括使用ContentValues插入图片元数据，以及通过Bitmap的compress方法进行高效压缩。

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Enumeration;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;

import android.content.ContentResolver;
import android.content.ContentValues;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Bitmap.CompressFormat;
import android.net.Uri;
import android.provider.MediaStore.Images;
import android.util.Log;

public class FileOperateTools {

    /**
    *
    * @param context
    * @param title
    * @param fname
    * @param path
    */
    @Deprecated
    public static void saveImageToPhotos(Context context,String title,String fname,String path){
        final Uri STORAGE_URI = Images.Media.EXTERNAL_CONTENT_URI;
        final String IMAGE_MIME_TYPE = "image/png";

        ContentValues values = new ContentValues(4);
        values.put(Images.Media.TITLE, title);
        values.put(Images.Media.DISPLAY_NAME, fname);
        values.put(Images.Media.MIME_TYPE, IMAGE_MIME_TYPE);
        values.put(Images.Media.DATA, path);

        ContentResolver contentResolver = context.getContentResolver();
        contentResolver.insert(STORAGE_URI, values);
    }

    /**
    *
    * @param context
    * @param src
    * @param name
    * @param title
    * @param dir
    * @return
    */
    public static boolean saveBitmapToPhotos(Context context,Bitmap src,String name,String title,File dir){
        File f=new File(dir,name);
        try {
            if(!f.exists()) {
                f.createNewFile();
            }
            OutputStream os=new FileOutputStream(f);
            src.compress(CompressFormat.JPEG, 50, os);

            //saveImageToDb("VcDownload"+id, fn, f.getAbsolutePath());
            //Write info. to Database
            final Uri STORAGE_URI = Images.Media.EXTERNAL_CONTENT_URI;
            final String IMAGE_MIME_TYPE = "image/png";

            ContentValues values = new ContentValues(4);
            values.put(Images.Media.TITLE, title);
            values.put(Images.Media.DISPLAY_NAME, name);
            values.put(Images.Media.MIME_TYPE, IMAGE_MIME_TYPE);
            values.put(Images.Media.DATA, f.getAbsolutePath());

            ContentResolver contentResolver = context.getContentResolver();
            Uri dataUri = contentResolver.insert(STORAGE_URI, values);

            return true;
        } catch (IOException e) {
            e.printStackTrace();
            return false;
        }

    }




    public static int ExtractFromApk(Context mCon,String sourceDir,String destDir, boolean replace) {
        ZipFile zipFile = null ;
        File src_dir =new File(mCon.getApplicationInfo().sourceDir);


        Log.v("Test", "src_dir="+src_dir);

        File dest_dir=new File(destDir);

        if(!src_dir.exists() || !dest_dir.exists()){
            return -1;
        }




//        if ( targetPathFile.exists() ) {
//            if (!isForceMove ) {
//                //根文件夹存在且不强制移动不移动文件
//                return targetPath;
//            }else{
//                FileUtils.deleteQuietly( targetPathFile );
//            }
//        }
        int f_n=0;
        try {

            int BUFFER=1024;

            //targetPathFile.mkdir();
            zipFile = new ZipFile(src_dir);
            Enumeration<?> emu = zipFile.entries();
            int currentByte;

            int sdl=sourceDir.length();
            while (emu.hasMoreElements()) {
                ZipEntry entry = (ZipEntry) emu.nextElement();
                String ename = entry.getName();
                if (ename.startsWith(sourceDir) && !entry.isDirectory()) {

                    String nnn=ename.substring(sdl);
                    File destFile = new File(dest_dir, nnn.length()>0?("/" + nnn):nnn);

                    File destinationParent = destFile.getParentFile();
                    if( !destinationParent.exists() ){
                        destinationParent.mkdirs();
                    }
                    BufferedInputStream is = new BufferedInputStream( zipFile.getInputStream( entry ) , BUFFER );
                    byte data[] = new byte[BUFFER];
                    FileOutputStream fos = new FileOutputStream(destFile);
                    BufferedOutputStream dest = new BufferedOutputStream(fos, BUFFER);
                    while ((currentByte = is.read(data, 0, BUFFER)) != -1) {
                        dest.write(data, 0, currentByte);
                    }
                    dest.flush();
                    dest.close();
                    is.close();
                    f_n++;
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
            return -1;
        }
        return f_n;

    }

}