在android中，图片压缩已经是必备技能，相信大家都有自己的工具类，但是在如果你的项目中使用了RxJava，那么为了保证代码的风统一性，使用LuBan或者Compressor就在合适不过了！
LuBan
Luban（鲁班） —— Android图片压缩工具，仿微信朋友圈压缩策略。
目前做App开发总绕不开图片这个元素。但是随着手机拍照分辨率的提升，图片的压缩成为一个很重要的问题。单纯对图片进行裁切，压缩已经有很多文章介绍。但是裁切成多少，压缩成多少却很难控制好，裁切过头图片太小，质量压缩过头则显示效果太差。
于是自然想到App巨头“微信”会是怎么处理，Luban（鲁班）就是通过在微信朋友圈发送近100张不同分辨率图片，对比原图与微信压缩后的图片逆向推算出来的压缩算法。
引入LuBan
compile 'top.zibin:Luban:1.1.3'
使用鲁班IO模式压缩
/*** 使用鲁班IO模式压缩** @param path*/private void initLuBanIO(String path) {final String newPath = FileUtils.createFile(this.getApplicationContext());Glide.with(this).load(path).into(mImageOld);Luban.with(this).load(path) // 传人要压缩的图片列表(包括file，path，List<String>).ignoreBy(100) // 忽略不压缩图片的大小.setTargetDir(newPath).setCompressListener(new OnCompressListener() {@Overridepublic void onStart() {// TODO 压缩开始前调用，可以在方法内启动 loading UILog.d("huangxiaoguo", "使用鲁班IO模式压缩,开始压缩");}@Overridepublic void onSuccess(File file) {// TODO 压缩成功后调用，返回压缩后的图片文件Log.d("huangxiaoguo", "使用鲁班IO模式压缩,压缩成功");Glide.with(CompressorActivity.this).load(file).into(mImageNew);mText.setText("压缩后大小" + FileUtils.getDataSize(file.length()));}@Overridepublic void onError(Throwable e) {// TODO 当压缩过程出现问题时调用Log.e("huangxiaoguo", "使用鲁班IO模式压缩,压缩过程出现问题" + e.getMessage());}}).launch(); //启动压缩}
使用鲁班RxJava模式压缩
首先需要引入RxJava和RxAndroid
compile 'io.reactivex.rxjava2:rxjava:2.1.7'compile 'io.reactivex.rxjava2:rxandroid:2.0.1'
/*** 使用鲁班RxJava模式压缩** @param path*/private void initLuBanRxJava(String path) {final String newPath = FileUtils.createFile(this.getApplicationContext());final List<String> photos = new ArrayList<>();photos.add(path);photos.add(path);photos.add(path);Flowable.just(photos)//注意，可以单个压缩，也可以list压缩.subscribeOn(Schedulers.io()).map(new Function<List<String>, List<File>>() {@Overridepublic List<File> apply(@io.reactivex.annotations.NonNull List<String> strings) throws Exception {/*** 如果需要保存到本地就使用setTargetDir方法*/return Luban.with(CompressorActivity.this).load(photos).setTargetDir(newPath).get();}}).observeOn(AndroidSchedulers.mainThread()).subscribe(new Consumer<List<File>>() {@Overridepublic void accept(List<File> files) throws Exception {Glide.with(CompressorActivity.this).load(files.get(0)).into(mImageNew);mText.setText("压缩后大小" + FileUtils.getDataSize(files.get(0).length()));}});}
这里我使用的是一张13.29M的图片，使用LuBan压缩后得到的图片大小为120.73KB，压缩可谓是高的。
Compressor：
LuBan压缩后获得图片返回结果一般为File类型，而Compressor可以指定返回结果为Bitmap，同时Compressor还可以自定义压缩尺寸，这样对开发者来说，相对比较~~~
引入Compressor
compile 'id.zelory:compressor:2.1.0'
使用Compressor IO模式压缩返回File
/*** 使用Compressor IO模式压缩返回File*/private void initCompressorIOFile(String path) {try {File file = new Compressor(this).compressToFile(new File(path));Glide.with(CompressorActivity.this).load(file).into(mImageNew);mText.setText("压缩后大小" + FileUtils.getDataSize(file.length()));//170.12KB} catch (IOException e) {e.printStackTrace();}}
使用Compressor IO模式压缩返回BitMap
/*** 使用Compressor IO模式压缩返回BitMap*/private void initCompressorIOBitMap(String path) {try {Bitmap bitmap = new Compressor(this).compressToBitmap(new File(path));mImageNew.setImageBitmap(bitmap);} catch (IOException e) {e.printStackTrace();}}
使用Compressor IO模式自定义压缩
/*** 使用Compressor IO模式自定义压缩** @param path*/private void initCompressorIO(String path) {try {File file = new Compressor(this).setMaxWidth(640).setMaxHeight(480).setQuality(75).setCompressFormat(pressFormat.WEBP).setDestinationDirectoryPath(FileUtils.createFile(this)).compressToFile(new File(path));Glide.with(CompressorActivity.this).load(file).into(mImageNew);mText.setText("压缩后大小" + FileUtils.getDataSize(file.length()));//32.64KB} catch (IOException e) {e.printStackTrace();}}
使用Compressor RxJava模式压缩
首先需要引入RxJava和RxAndroid
compile 'io.reactivex.rxjava2:rxjava:2.1.7'compile 'io.reactivex.rxjava2:rxandroid:2.0.1'
/*** 使用Compressor RxJava模式压缩** @param path*/private void initCompressorRxJava(String path) {new Compressor(this).compressToFileAsFlowable(new File(path)).subscribeOn(Schedulers.io()).observeOn(AndroidSchedulers.mainThread()).subscribe(new Consumer<File>() {@Overridepublic void accept(File file) {Glide.with(CompressorActivity.this).load(file).into(mImageNew);mText.setText("压缩后大小" + FileUtils.getDataSize(file.length()));//170.27KB}}, new Consumer<Throwable>() {@Overridepublic void accept(Throwable throwable) {throwable.printStackTrace();mText.setText("压缩失败了");}});}
总结：
1、LuBan的优点：LuBan压缩方法在默认的情况下，压缩比要比Compressor要高，同时压缩的对象丰富，(包括file，path，List)，可以传入多张图片集合直接进行压缩等。
2、Compressor的优点，返回的对象相对丰富，可以返回File或者BitMap，同时Compressor可以自定义压缩比例，定制化比较高等。
LuBan的gitHub地址：/Curzibn/Luban
Compressor的gitHub地址：/zetbaitsu/Compressor
整个测试源码：
package .lubancompressor;import android.Manifest;import android.app.Activity;import android.content.Context;import android.content.Intent;import android.content.pm.PackageManager;import android.graphics.Bitmap;import android.os.Build;import android.os.Bundle;import android.support.annotation.NonNull;import android.support.v4.app.ActivityCompat;import android.support.v7.app.AppCompatActivity;import android.util.Log;import android.widget.ImageView;import android.widget.TextView;import android.widget.Toast;import com.bumptech.glide.Glide;import java.io.File;import java.io.IOException;import java.util.ArrayList;import java.util.List;import pressor;import io.reactivex.Flowable;import io.reactivex.android.schedulers.AndroidSchedulers;import io.reactivex.functions.Consumer;import io.reactivex.functions.Function;import io.reactivex.schedulers.Schedulers;import top.zibin.luban.Luban;import top.zibin.luban.OnCompressListener;public class CompressorActivity extends AppCompatActivity {private ImageView mImageOld;private ImageView mImageNew;private static final String TYPE = "type";public static final int REQUEST_PICK_IMAGE = 11101;String[] mPermissionList = new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE,Manifest.permission.READ_EXTERNAL_STORAGE};private int type;/*** LuBanCompressor*/private TextView mText;public static void actionStart(Context context, int type) {Intent intent = new Intent(context, CompressorActivity.class);intent.putExtra(TYPE, type);context.startActivity(intent);}@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_compressor);initData();initView();ActivityCompat.requestPermissions(CompressorActivity.this, mPermissionList, 100);}private void initData() {type = getIntent().getIntExtra(TYPE, -1);}private void initView() {mImageOld = (ImageView) findViewById(R.id.image_old);mImageNew = (ImageView) findViewById(R.id.image_new);mText = (TextView) findViewById(R.id.text);}@Overridepublic void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {super.onRequestPermissionsResult(requestCode, permissions, grantResults);switch (requestCode) {case 100:boolean writeExternalStorage = grantResults[0] == PackageManager.PERMISSION_GRANTED;boolean readExternalStorage = grantResults[1] == PackageManager.PERMISSION_GRANTED;if (grantResults.length > 0 && writeExternalStorage && readExternalStorage) {getImage();} else {Toast.makeText(this, "请设置必要权限", Toast.LENGTH_SHORT).show();}break;}}private void getImage() {if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {startActivityForResult(new Intent(Intent.ACTION_GET_CONTENT).setType("image/*"),REQUEST_PICK_IMAGE);} else {Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);intent.addCategory(Intent.CATEGORY_OPENABLE);intent.setType("image/*");startActivityForResult(intent, REQUEST_PICK_IMAGE);}}@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data) {super.onActivityResult(requestCode, resultCode, data);if (resultCode == Activity.RESULT_OK) {switch (requestCode) {case REQUEST_PICK_IMAGE:if (data != null) {compressImage(RealPathFromUriUtils.getRealPathFromUri(this, data.getData()));} else {Toast.makeText(this, "图片损坏，请重新选择", Toast.LENGTH_SHORT).show();}break;}}}private void compressImage(String path) {switch (type) {case 0:initLuBanIO(path);break;case 1:initLuBanRxJava(path);break;case 2:initCompressorIOFile(path);break;case 3:initCompressorIOBitMap(path);break;case 4:initCompressorIO(path);break;case 5:initCompressorRxJava(path);break;}}/*** 使用鲁班IO模式压缩** @param path*/private void initLuBanIO(String path) {final String newPath = FileUtils.createFile(this.getApplicationContext());Glide.with(this).load(path).into(mImageOld);Luban.with(this).load(path) // 传人要压缩的图片列表(包括file，path，List<String>).ignoreBy(100) // 忽略不压缩图片的大小.setTargetDir(newPath).setCompressListener(new OnCompressListener() {@Overridepublic void onStart() {// TODO 压缩开始前调用，可以在方法内启动 loading UILog.d("huangxiaoguo", "使用鲁班IO模式压缩,开始压缩");}@Overridepublic void onSuccess(File file) {// TODO 压缩成功后调用，返回压缩后的图片文件Log.d("huangxiaoguo", "使用鲁班IO模式压缩,压缩成功");Glide.with(CompressorActivity.this).load(file).into(mImageNew);mText.setText("压缩后大小" + FileUtils.getDataSize(file.length()));}@Overridepublic void onError(Throwable e) {// TODO 当压缩过程出现问题时调用Log.e("huangxiaoguo", "使用鲁班IO模式压缩,压缩过程出现问题" + e.getMessage());}}).launch(); //启动压缩}/*** 使用鲁班RxJava模式压缩** @param path*/private void initLuBanRxJava(String path) {final String newPath = FileUtils.createFile(this.getApplicationContext());final List<String> photos = new ArrayList<>();photos.add(path);photos.add(path);photos.add(path);Flowable.just(photos)//注意，可以单个压缩，也可以list压缩.subscribeOn(Schedulers.io()).map(new Function<List<String>, List<File>>() {@Overridepublic List<File> apply(@io.reactivex.annotations.NonNull List<String> strings) throws Exception {/*** 如果需要保存到本地就使用setTargetDir方法*/return Luban.with(CompressorActivity.this).load(photos).setTargetDir(newPath).get();}}).observeOn(AndroidSchedulers.mainThread()).subscribe(new Consumer<List<File>>() {@Overridepublic void accept(List<File> files) throws Exception {Glide.with(CompressorActivity.this).load(files.get(0)).into(mImageNew);mText.setText("压缩后大小" + FileUtils.getDataSize(files.get(0).length()));}});}/*** 使用Compressor IO模式压缩返回File*/private void initCompressorIOFile(String path) {try {File file = new Compressor(this).compressToFile(new File(path));Glide.with(CompressorActivity.this).load(file).into(mImageNew);mText.setText("压缩后大小" + FileUtils.getDataSize(file.length()));//170.12KB} catch (IOException e) {e.printStackTrace();}}/*** 使用Compressor IO模式压缩返回BitMap*/private void initCompressorIOBitMap(String path) {try {Bitmap bitmap = new Compressor(this).compressToBitmap(new File(path));mImageNew.setImageBitmap(bitmap);} catch (IOException e) {e.printStackTrace();}}/*** 使用Compressor IO模式自定义压缩** @param path*/private void initCompressorIO(String path) {try {File file = new Compressor(this).setMaxWidth(640).setMaxHeight(480).setQuality(75).setCompressFormat(pressFormat.WEBP).setDestinationDirectoryPath(FileUtils.createFile(this)).compressToFile(new File(path));Glide.with(CompressorActivity.this).load(file).into(mImageNew);mText.setText("压缩后大小" + FileUtils.getDataSize(file.length()));//32.64KB} catch (IOException e) {e.printStackTrace();}}/*** 使用Compressor RxJava模式压缩** @param path*/private void initCompressorRxJava(String path) {new Compressor(this).compressToFileAsFlowable(new File(path)).subscribeOn(Schedulers.io()).observeOn(AndroidSchedulers.mainThread()).subscribe(new Consumer<File>() {@Overridepublic void accept(File file) {Glide.with(CompressorActivity.this).load(file).into(mImageNew);mText.setText("压缩后大小" + FileUtils.getDataSize(file.length()));//170.27KB}}, new Consumer<Throwable>() {@Overridepublic void accept(Throwable throwable) {throwable.printStackTrace();mText.setText("压缩失败了");}});}}
FileUtils
package .lubancompressor;import android.content.Context;import android.os.Environment;import java.io.File;import java.text.DecimalFormat;public class FileUtils {public static String SDPATH = Environment.getExternalStorageDirectory() + "/huangxiaoguo/";public static String createFile(Context context) {if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {File dirFile = new File(SDPATH); //目录转化成文件夹if (!dirFile.exists()) { //如果不存在，那就建立这个文件夹dirFile.mkdirs();}// 在SDcard的目录下创建图片文,以当前时间为其命名File file = new File(SDPATH);return file.getAbsolutePath();} else {File file = new File(context.getExternalCacheDir() + "/huangxiaoguo/");return file.getAbsolutePath();}}/*** 返回byte的数据大小对应的文本** @param size* @return*/public static String getDataSize(long size) {DecimalFormat formater = new DecimalFormat("####.00");if (size < 1024) {return size + "bytes";} else if (size < 1024 * 1024) {float kbsize = size / 1024f;return formater.format(kbsize) + "KB";} else if (size < 1024 * 1024 * 1024) {float mbsize = size / 1024f / 1024f;return formater.format(mbsize) + "MB";} else if (size < 1024 * 1024 * 1024 * 1024) {float gbsize = size / 1024f / 1024f / 1024f;return formater.format(gbsize) + "GB";} else {return "size: error";}}}
RealPathFromUriUtils
package .lubancompressor;import android.annotation.SuppressLint;import android.content.ContentUris;import android.content.Context;import android.database.Cursor;import .Uri;import android.os.Build;import android.provider.DocumentsContract;import android.provider.MediaStore;/*** Created by Administrator on /1/5 0005.*/public class RealPathFromUriUtils {/*** 根据Uri获取图片的绝对路径** @param context 上下文对象* @param uri图片的Uri* @return 如果Uri对应的图片存在, 那么返回该图片的绝对路径, 否则返回null*/public static String getRealPathFromUri(Context context, Uri uri) {int sdkVersion = Build.VERSION.SDK_INT;if (sdkVersion >= 19) { // api >= 19return getRealPathFromUriAboveApi19(context, uri);} else { // api < 19return getRealPathFromUriBelowAPI19(context, uri);}}/*** 适配api19以下(不包括api19),根据uri获取图片的绝对路径** @param context 上下文对象* @param uri图片的Uri* @return 如果Uri对应的图片存在, 那么返回该图片的绝对路径, 否则返回null*/private static String getRealPathFromUriBelowAPI19(Context context, Uri uri) {return getDataColumn(context, uri, null, null);}/*** 适配api19及以上,根据uri获取图片的绝对路径** @param context 上下文对象* @param uri图片的Uri* @return 如果Uri对应的图片存在, 那么返回该图片的绝对路径, 否则返回null*/@SuppressLint("NewApi")private static String getRealPathFromUriAboveApi19(Context context, Uri uri) {String filePath = null;if (DocumentsContract.isDocumentUri(context, uri)) {// 如果是document类型的 uri, 则通过document id来进行处理String documentId = DocumentsContract.getDocumentId(uri);if (isMediaDocument(uri)) { // MediaProvider// 使用':'分割String id = documentId.split(":")[1];String selection = MediaStore.Images.Media._ID + "=?";String[] selectionArgs = {id};filePath = getDataColumn(context, MediaStore.Images.Media.EXTERNAL_CONTENT_URI, selection, selectionArgs);} else if (isDownloadsDocument(uri)) { // DownloadsProviderUri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), Long.valueOf(documentId));filePath = getDataColumn(context, contentUri, null, null);}} else if ("content".equalsIgnoreCase(uri.getScheme())) {// 如果是 content 类型的 UrifilePath = getDataColumn(context, uri, null, null);} else if ("file".equals(uri.getScheme())) {// 如果是 file 类型的 Uri,直接获取图片对应的路径filePath = uri.getPath();}return filePath;}/*** 获取数据库表中的 _data 列，即返回Uri对应的文件路径** @return*/private static String getDataColumn(Context context, Uri uri, String selection, String[] selectionArgs) {String path = null;String[] projection = new String[]{MediaStore.Images.Media.DATA};Cursor cursor = null;try {cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs, null);if (cursor != null && cursor.moveToFirst()) {int columnIndex = cursor.getColumnIndexOrThrow(projection[0]);path = cursor.getString(columnIndex);}} catch (Exception e) {if (cursor != null) {cursor.close();}}return path;}/*** @param uri the Uri to check* @return Whether the Uri authority is MediaProvider*/private 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 DownloadsProvider*/private static boolean isDownloadsDocument(Uri uri) {return "com.android.providers.downloads.documents".equals(uri.getAuthority());}}
