图片的压缩处理（为了节省服务器带宽）

package com.wzkj.vzone.org.util;

import android.annotation.TargetApi;
import android.content.ContentUris;
import android.content.Context;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Build;
import android.os.Environment;
import android.provider.DocumentsContract;
import android.provider.MediaStore;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.lang.ref.WeakReference;

/**
 * Tools for handler picture
 *
 * @author Ryan.Tang
 *
 */
public final class ImageTools {



    /**
     * Save image to the SD card 
     * @param photoBitmap
     * @param photoName
     * @param path
     */
    public static void savePhotoToSDCard(Bitmap photoBitmap,String path,String photoName){
        if (checkSDCardAvailable()) {
            File photoFile = new File(path , photoName);
            FileOutputStream fileOutputStream = null;
            try {
                fileOutputStream = new FileOutputStream(photoFile);
                if (photoBitmap != null) {
                    if (photoBitmap.compress(Bitmap.CompressFormat.PNG, 100, fileOutputStream)) {
                        fileOutputStream.flush();
                    }
                }
            } catch (Exception e) {
                photoFile.delete();
                e.printStackTrace();
            }finally{
                try {
                    fileOutputStream.close();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
    }

    public static void savePhotoToSDCard(Bitmap photoBitmap,String path){
        if (checkSDCardAvailable()) {
            File photoFile = new File(path);
            FileOutputStream fileOutputStream = null;
            try {
                fileOutputStream = new FileOutputStream(photoFile);
                if (photoBitmap != null) {
                    if (photoBitmap.compress(Bitmap.CompressFormat.PNG, 100, fileOutputStream)) {
                        fileOutputStream.flush();
                    }
                }
            } catch (Exception e) {
                photoFile.delete();
                e.printStackTrace();
            } finally{
                try {
                    fileOutputStream.close();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
    }

    /**
     * Check the SD card 
     * @return
     */
    public static boolean checkSDCardAvailable(){
        return Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED);
    }

    /**
     * 根据路径加载bitmap
     *
     * @param path
     *            路径
     * @param w
     *            款
     * @param h
     *            长
     * @return
     */
    public static final Bitmap convertToBitmap(String path, int w, int h) {
        try {
            BitmapFactory.Options opts = new BitmapFactory.Options();
            // 设置为ture只获取图片大小
            opts.inJustDecodeBounds = true;
            opts.inPreferredConfig = Bitmap.Config.ARGB_8888;
            // 返回为空
            BitmapFactory.decodeFile(path, opts);
            int width = opts.outWidth;
            int height = opts.outHeight;
            float scaleWidth = 0.f, scaleHeight = 0.f;
            if (width > w || height > h) {
                // 缩放
                scaleWidth = ((float) width) / w;
                scaleHeight = ((float) height) / h;
            }
            opts.inJustDecodeBounds = false;
            float scale = Math.max(scaleWidth, scaleHeight);
            opts.inSampleSize = (int) scale;
            WeakReference<Bitmap> weak = new WeakReference<Bitmap>(BitmapFactory.decodeFile(path, opts));
            Bitmap bMapRotate = Bitmap.createBitmap(weak.get(), 0, 0, weak.get().getWidth(), weak.get().getHeight(), null, true);
            if (bMapRotate != null) {
                return bMapRotate;
            }
            return null;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }


    @TargetApi(Build.VERSION_CODES.KITKAT)
    public static String getPath(final Context context, final Uri uri) {
        final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;
        // DocumentProvider
        if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
            // ExternalStorageProvider
            if (isExternalStorageDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];
                if ("primary".equalsIgnoreCase(type)) {
                    return Environment.getExternalStorageDirectory() + "/"
                            + split[1];
                }
                // TODO handle non-primary volumes
            }
            // DownloadsProvider
            else if (isDownloadsDocument(uri)) {
                final String id = DocumentsContract.getDocumentId(uri);
                final Uri contentUri = ContentUris.withAppendedId(
                        Uri.parse("content://downloads/public_downloads"),
                        Long.valueOf(id));
                return getDataColumn(context, contentUri, null, null);
            }
            // MediaProvider
            else if (isMediaDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];
                Uri contentUri = null;
                if ("image".equals(type)) {
                    contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
                } else if ("video".equals(type)) {
                    contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
                } else if ("audio".equals(type)) {
                    contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
                }
                final String selection = MediaStore.MediaColumns._ID + "=?";
                final String[] selectionArgs = new String[] { split[1] };
                return getDataColumn(context, contentUri, selection,
                        selectionArgs);
            }
        }
        // MediaStore (and general)
        else if ("content".equalsIgnoreCase(uri.getScheme())) {
            // Return the remote address
            if (isGooglePhotosUri(uri))
                return uri.getLastPathSegment();
            return getDataColumn(context, uri, null, null);
        }
        // File
        else if ("file".equalsIgnoreCase(uri.getScheme())) {
            return uri.getPath();
        }
        return null;
    }

    /**
     * Get the value of the data column for this Uri . This is useful for
     * MediaStore Uris , and other file - based ContentProviders.
     *
     * @param context
     *            The context.
     * @param uri
     *            The Uri to query.
     * @param selection
     *            (Optional) Filter used in the query.
     * @param selectionArgs
     *            (Optional) Selection arguments used in the query.
     * @return The value of the _data column, which is typically a file path.
     */
    public static String getDataColumn(Context context, Uri uri,
                                       String selection, String[] selectionArgs) {
        Cursor cursor = null;
        final String column = MediaStore.MediaColumns.DATA;
        final String[] projection = { column };
        try {
            cursor = context.getContentResolver().query(uri, projection,
                    selection, selectionArgs, null);
            if (cursor != null && cursor.moveToFirst()) {
                final int index = cursor.getColumnIndexOrThrow(column);
                return cursor.getString(index);
            }
        } finally {
            if (cursor != null)
                cursor.close();
        }
        return null;
    }

    /**
     * @param uri
     *            The Uri to check.
     * @return Whether the Uri authority is ExternalStorageProvider.
     */
    public static boolean isExternalStorageDocument(Uri uri) {
        return "com.android.externalstorage.documents".equals(uri
                .getAuthority());
    }

    /**
     * @param uri
     *            The Uri to check.
     * @return Whether the Uri authority is DownloadsProvider.
     */
    public static boolean isDownloadsDocument(Uri uri) {
        return "com.android.providers.downloads.documents".equals(uri
                .getAuthority());
    }

    /**
     * @param uri
     *            The Uri to check.
     * @return Whether the Uri authority is MediaProvider.
     */
    public static boolean isMediaDocument(Uri uri) {
        return "com.android.providers.media.documents".equals(uri
                .getAuthority());
    }

    /**
     * @param uri
     *            The Uri to check.
     * @return Whether the Uri authority is Google Photos.
     */
    public static boolean isGooglePhotosUri(Uri uri) {
        return "com.google.android.apps.photos.content".equals(uri
                .getAuthority());
    }

    /**
     * @param url
     * @return
     */
    public static Bitmap getLoacalBitmap(String url) {
        try {
            FileInputStream fis = new FileInputStream(url);
            return BitmapFactory.decodeStream(fis);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
            return null;
        }
    }


    //==============================压缩图片开始===========================
    /**
     * Get bitmap from specified image path
     *
     * @param imgPath
     * @return
     */
    public static Bitmap getBitmap(String imgPath) {
        // Get bitmap through image path
        BitmapFactory.Options newOpts = new BitmapFactory.Options();
        newOpts.inJustDecodeBounds = false;
        newOpts.inPurgeable = true;
        newOpts.inInputShareable = true;
        // Do not compress
        newOpts.inSampleSize = 1;
        newOpts.inPreferredConfig = Bitmap.Config.RGB_565;
        return BitmapFactory.decodeFile(imgPath, newOpts);
    }

    /**
     * Store bitmap into specified image path
     *
     * @param bitmap
     * @param outPath
     * @throws FileNotFoundException
     */
    public static void storeImage(Bitmap bitmap, String outPath) throws FileNotFoundException {
        FileOutputStream os = new FileOutputStream(outPath);
        bitmap.compress(Bitmap.CompressFormat.JPEG, 100, os);
    }

    /**
     * Compress image by pixel, this will modify image width/height.
     * Used to get thumbnail
     *
     * @param imgPath image path
     * @param pixelW target pixel of width
     * @param pixelH target pixel of height
     * @return
     */
    public Bitmap ratio(String imgPath, float pixelW, float pixelH) {
        BitmapFactory.Options newOpts = new BitmapFactory.Options();
        // 开始读入图片，此时把options.inJustDecodeBounds 设回true，即只读边不读内容
        newOpts.inJustDecodeBounds = true;
        newOpts.inPreferredConfig = Bitmap.Config.RGB_565;
        // Get bitmap info, but notice that bitmap is null now
        Bitmap bitmap = BitmapFactory.decodeFile(imgPath,newOpts);

        newOpts.inJustDecodeBounds = false;
        int w = newOpts.outWidth;
        int h = newOpts.outHeight;
        // 想要缩放的目标尺寸
        float hh = pixelH;// 设置高度为240f时，可以明显看到图片缩小了
        float ww = pixelW;// 设置宽度为120f，可以明显看到图片缩小了
        // 缩放比。由于是固定比例缩放，只用高或者宽其中一个数据进行计算即可
        int be = 1;//be=1表示不缩放
        if (w > h && w > ww) {//如果宽度大的话根据宽度固定大小缩放
            be = (int) (newOpts.outWidth / ww);
        } else if (w < h && h > hh) {//如果高度高的话根据宽度固定大小缩放
            be = (int) (newOpts.outHeight / hh);
        }
        if (be <= 0) be = 1;
        newOpts.inSampleSize = be;//设置缩放比例
        // 开始压缩图片，注意此时已经把options.inJustDecodeBounds 设回false了
        bitmap = BitmapFactory.decodeFile(imgPath, newOpts);
        // 压缩好比例大小后再进行质量压缩
//        return compress(bitmap, maxSize); // 这里再进行质量压缩的意义不大，反而耗资源，删除
        return bitmap;
    }

    /**
     * Compress image by size, this will modify image width/height.
     * Used to get thumbnail
     *
     * @param image
     * @param pixelW target pixel of width
     * @param pixelH target pixel of height
     * @return
     */
    public static Bitmap ratio(Bitmap image, float pixelW, float pixelH) {
        ByteArrayOutputStream os = new ByteArrayOutputStream();
        image.compress(Bitmap.CompressFormat.JPEG, 100, os);
        if( os.toByteArray().length / 1024>1024) {//判断如果图片大于1M,进行压缩避免在生成图片（BitmapFactory.decodeStream）时溢出
            os.reset();//重置baos即清空baos
            image.compress(Bitmap.CompressFormat.JPEG, 50, os);//这里压缩50%，把压缩后的数据存放到baos中
        }
        ByteArrayInputStream is = new ByteArrayInputStream(os.toByteArray());
        BitmapFactory.Options newOpts = new BitmapFactory.Options();
        //开始读入图片，此时把options.inJustDecodeBounds 设回true了
        newOpts.inJustDecodeBounds = true;
        newOpts.inPreferredConfig = Bitmap.Config.RGB_565;
        Bitmap bitmap = BitmapFactory.decodeStream(is, null, newOpts);
        newOpts.inJustDecodeBounds = false;
        int w = newOpts.outWidth;
        int h = newOpts.outHeight;
        float hh = pixelH;// 设置高度为240f时，可以明显看到图片缩小了
        float ww = pixelW;// 设置宽度为120f，可以明显看到图片缩小了
        //缩放比。由于是固定比例缩放，只用高或者宽其中一个数据进行计算即可
        int be = 1;//be=1表示不缩放
        if (w > h && w > ww) {//如果宽度大的话根据宽度固定大小缩放
            be = (int) (newOpts.outWidth / ww);
        } else if (w < h && h > hh) {//如果高度高的话根据宽度固定大小缩放
            be = (int) (newOpts.outHeight / hh);
        }
        if (be <= 0) be = 1;
        newOpts.inSampleSize = be;//设置缩放比例
        //重新读入图片，注意此时已经把options.inJustDecodeBounds 设回false了
        is = new ByteArrayInputStream(os.toByteArray());
        bitmap = BitmapFactory.decodeStream(is, null, newOpts);
        //压缩好比例大小后再进行质量压缩
//      return compress(bitmap, maxSize); // 这里再进行质量压缩的意义不大，反而耗资源，删除
        return bitmap;
    }

    /**
     * Compress by quality,  and generate image to the path specified
     *
     * @param image
     * @param outPath
     * @param maxSize target will be compressed to be smaller than this size.(kb)
     * @throws IOException
     */
    public static void compressAndGenImage(Bitmap image, String outPath, int maxSize) throws IOException {
        ByteArrayOutputStream os = new ByteArrayOutputStream();
        // scale
        int options = 100;
        // Store the bitmap into output stream(no compress)
        image.compress(Bitmap.CompressFormat.PNG, options, os);
        // Compress by loop
        while ( os.toByteArray().length / 1024 > maxSize) {
            // Clean up os
            os.reset();
            // interval 10
            options -= 10;
            image.compress(Bitmap.CompressFormat.PNG, options, os);
        }

        // Generate compressed image file
        FileOutputStream fos = new FileOutputStream(outPath);
        fos.write(os.toByteArray());
        fos.flush();
        fos.close();
    }

    /**
     * Compress by quality,  and generate image to the path specified
     *
     * @param imgPath
     * @param outPath
     * @param maxSize target will be compressed to be smaller than this size.(kb)
     * @param needsDelete Whether delete original file after compress
     * @throws IOException
     */
    public void compressAndGenImage(String imgPath, String outPath, int maxSize, boolean needsDelete) throws IOException {
        compressAndGenImage(getBitmap(imgPath), outPath, maxSize);

        // Delete original file
        if (needsDelete) {
            File file = new File (imgPath);
            if (file.exists()) {
                file.delete();
            }
        }
    }

    /**
     * Ratio and generate thumb to the path specified
     *
     * @param image
     * @param outPath
     * @param pixelW target pixel of width
     * @param pixelH target pixel of height
     * @throws FileNotFoundException
     */
    public static void ratioAndGenThumb(Bitmap image, String outPath, float pixelW, float pixelH) throws FileNotFoundException {
        Bitmap bitmap = ratio(image, pixelW, pixelH);
        storeImage( bitmap, outPath);
    }

    /**
     * Ratio and generate thumb to the path specified
     *
     * @param outPath
     * @param pixelW target pixel of width
     * @param pixelH target pixel of height
     * @param needsDelete Whether delete original file after compress
     * @throws FileNotFoundException
     */
    public void ratioAndGenThumb(String imgPath, String outPath, float pixelW, float pixelH, boolean needsDelete) throws FileNotFoundException {
        Bitmap bitmap = ratio(imgPath, pixelW, pixelH);
        storeImage( bitmap, outPath);

        // Delete original file
        if (needsDelete) {
            File file = new File (imgPath);
            if (file.exists()) {
                file.delete();
            }
        }
    }

    public static void compressBmpToFile(Bitmap bmp,File file){
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        int options = 80;//个人喜欢从80开始,
        bmp.compress(Bitmap.CompressFormat.JPEG, options, baos);
        while (baos.toByteArray().length / 1024 > 100) {
            baos.reset();
            options -= 10;
            bmp.compress(Bitmap.CompressFormat.JPEG, options, baos);
        }
        try {
            FileOutputStream fos = new FileOutputStream(file);
            fos.write(baos.toByteArray());
            fos.flush();
            fos.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private Bitmap compressImageFromFile(String srcPath) {
        BitmapFactory.Options newOpts = new BitmapFactory.Options();
        newOpts.inJustDecodeBounds = true;//只读边,不读内容
        Bitmap bitmap = BitmapFactory.decodeFile(srcPath, newOpts);

        newOpts.inJustDecodeBounds = false;
        int w = newOpts.outWidth;
        int h = newOpts.outHeight;
        float hh = 800f;//
        float ww = 480f;//
        int be = 1;
        if (w > h && w > ww) {
            be = (int) (newOpts.outWidth / ww);
        } else if (w < h && h > hh) {
            be = (int) (newOpts.outHeight / hh);
        }
        if (be <= 0)
            be = 1;
        newOpts.inSampleSize = be;//设置采样率

        newOpts.inPreferredConfig = Bitmap.Config.ARGB_8888;//该模式是默认的,可不设
        newOpts.inPurgeable = true;// 同时设置才会有效
        newOpts.inInputShareable = true;//。当系统内存不够时候图片自动被回收

        bitmap = BitmapFactory.decodeFile(srcPath, newOpts);
//      return compressBmpFromBmp(bitmap);//原来的方法调用了这个方法企图进行二次压缩
        //其实是无效的,大家尽管尝试
        return bitmap;
    }

    private Bitmap compressBmpFromBmp(Bitmap image) {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        int options = 100;
        image.compress(Bitmap.CompressFormat.JPEG, 100, baos);
        while (baos.toByteArray().length / 1024 > 100) {
            baos.reset();
            options -= 10;
            image.compress(Bitmap.CompressFormat.JPEG, options, baos);
        }
        ByteArrayInputStream isBm = new ByteArrayInputStream(baos.toByteArray());
        Bitmap bitmap = BitmapFactory.decodeStream(isBm, null, null);
        return bitmap;
    }

    //=====================================图片压缩结束======================

}