Main.java Source code

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Here is the source code for Main.java

Source

//package com.java2s;
//License from project: Apache License 

import android.graphics.Bitmap;

import android.graphics.BitmapFactory;
import android.graphics.BitmapFactory.Options;

import java.io.File;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import java.util.UUID;

public class Main {
    public static Bitmap decodeSampledBitmapFromUrl(String urlpath, long allowedBmpMaxMemorySize) {

        String tmpDir = System.getProperty("java.io.tmpdir", ".");
        File saveFile = new File(tmpDir, UUID.randomUUID().toString());
        if (saveFile.exists()) {
            saveFile.delete();
        }
        try {
            saveFile.createNewFile();
            File ret = downloadFile(urlpath, saveFile);
            if (ret == null) {// fail.
                return null;
            }
            Bitmap bmp = decodeSampledBitmapFromPath(saveFile.getAbsolutePath(), allowedBmpMaxMemorySize);
            return bmp;
        } catch (Throwable err) {
            err.printStackTrace();

        } finally {
            if (saveFile.exists()) {
                saveFile.delete();// true.
            }
        }
        return null;
    }

    public static File downloadFile(String urlstr, File saveFile) {
        try {
            URL url = new URL(urlstr);// cause speed low.
            URLConnection con = url.openConnection();
            con.setDoInput(true);
            con.connect();
            InputStream ins = con.getInputStream();
            final int bufsize = 102400;

            byte[] buffer = new byte[bufsize];
            int len = -1;
            FileOutputStream bos = new FileOutputStream(saveFile);
            while ((len = ins.read(buffer)) != -1) {
                bos.write(buffer, 0, len);

            }
            ins.close();
            bos.close();
            return saveFile;
        } catch (Error e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

    public static Bitmap decodeSampledBitmapFromPath(String localpath, long allowedBmpMaxMemorySize) {
        try {
            final Options options = new Options();
            options.inJustDecodeBounds = true;
            BitmapFactory.decodeFile(localpath, options);
            options.inSampleSize = calculateInSampleSize(options, allowedBmpMaxMemorySize);
            options.inJustDecodeBounds = false;
            return BitmapFactory.decodeFile(localpath, options);
        } catch (Throwable err) {
            err.printStackTrace();

        }
        return null;
    }

    /**
     * assume one pix use 4 bytes.Bitmap.Config.ARGB_8888.
     */
    private final static int calculateInSampleSize(Options options, long reqMemorySize) {
        final int onePixBytes = 4;
        int reqPixs = (int) (reqMemorySize / onePixBytes);
        final int height = options.outHeight;
        final int width = options.outWidth;
        int orgPixs = height * width;
        int inSampleSize = 1;
        while (orgPixs / Math.pow(inSampleSize, 2) > reqPixs) {
            inSampleSize *= 2;

        }
        return inSampleSize;

    }
}