首页加载图片优化

app/src/main/java/com/sheep/gamegroup/view/activity/SplashAct.java

@@ -34,6 +34,8 @@ import com.sheep.jiuyan.samllsheep.BuildConfig;
 import com.sheep.jiuyan.samllsheep.R;
 import com.sheep.jiuyan.samllsheep.SheepApp;
 
+import org.afinal.simplecache.ACache;
+
 import java.util.List;
 
 import butterknife.BindView;
@@ -86,6 +88,11 @@ public class SplashAct extends BaseActivity implements EasyPermissions.Permissio
         } catch (Exception e) {
             e.printStackTrace();
         }
+        ACache mCache = ACache.get(this);
+        Object object = mCache.getAsObject(Advertising.class.getSimpleName());
+        if(object instanceof Advertising){
+            Glide.with(activity).load(((Advertising) object).getDisplay_src()).into(splash_bg);
+        }
     }
 
     @Override
@@ -176,6 +183,8 @@ public class SplashAct extends BaseActivity implements EasyPermissions.Permissio
 
     private void loadAdvertising() {
         if(advertising.isImage()) {
+            ACache mCache = ACache.get(this);
+            mCache.put(Advertising.class.getSimpleName(), advertising);
             Glide.with(activity).load(advertising.getDisplay_src()).into(splash_bg);
 //            btnJoin.setVisibility(View.GONE);
             splash_video_view.setVisibility(View.GONE);

app/src/main/java/org/afinal/simplecache/ACache.java

@@ -0,0 +1,871 @@
+/**
+ * Copyright (c) 2012-2013, Michael Yang 杨福海 (www.yangfuhai.com).
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.afinal.simplecache;
+
+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.FileReader;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.RandomAccessFile;
+import java.io.Serializable;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
+
+import org.json.JSONArray;
+import org.json.JSONObject;
+
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
+import android.graphics.Canvas;
+import android.graphics.PixelFormat;
+import android.graphics.drawable.BitmapDrawable;
+import android.graphics.drawable.Drawable;
+
+/**
+ * @author Michael Yang（www.yangfuhai.com） update at 2013.08.07
+ */
+public class ACache {
+    public static final int TIME_HOUR = 60 * 60;
+    public static final int TIME_DAY = TIME_HOUR * 24;
+    private static final int MAX_SIZE = 1000 * 1000 * 50; // 50 mb
+    private static final int MAX_COUNT = Integer.MAX_VALUE; // 不限制存放数据的数量
+    private static Map<String, ACache> mInstanceMap = new HashMap<String, ACache>();
+    private ACacheManager mCache;
+
+    public static ACache get(Context ctx) {
+        return get(ctx, "ACache");
+    }
+
+    public static ACache get(Context ctx, String cacheName) {
+        File f = new File(ctx.getCacheDir(), cacheName);
+        return get(f, MAX_SIZE, MAX_COUNT);
+    }
+
+    public static ACache get(File cacheDir) {
+        return get(cacheDir, MAX_SIZE, MAX_COUNT);
+    }
+
+    public static ACache get(Context ctx, long max_zise, int max_count) {
+        File f = new File(ctx.getCacheDir(), "ACache");
+        return get(f, max_zise, max_count);
+    }
+
+    public static ACache get(File cacheDir, long max_zise, int max_count) {
+        ACache manager = mInstanceMap.get(cacheDir.getAbsoluteFile() + myPid());
+        if (manager == null) {
+            manager = new ACache(cacheDir, max_zise, max_count);
+            mInstanceMap.put(cacheDir.getAbsolutePath() + myPid(), manager);
+        }
+        return manager;
+    }
+
+    private static String myPid() {
+        return "_" + android.os.Process.myPid();
+    }
+
+    private ACache(File cacheDir, long max_size, int max_count) {
+        if (!cacheDir.exists() && !cacheDir.mkdirs()) {
+            throw new RuntimeException("can't make dirs in "
+                    + cacheDir.getAbsolutePath());
+        }
+        mCache = new ACacheManager(cacheDir, max_size, max_count);
+    }
+
+    // =======================================
+    // ============ String数据 读写 ==============
+    // =======================================
+    /**
+     * 保存 String数据 到 缓存中
+     *
+     * @param key
+     *            保存的key
+     * @param value
+     *            保存的String数据
+     */
+    public void put(String key, String value) {
+        File file = mCache.newFile(key);
+        BufferedWriter out = null;
+        try {
+            out = new BufferedWriter(new FileWriter(file), 1024);
+            out.write(value);
+        } catch (IOException e) {
+            e.printStackTrace();
+        } finally {
+            if (out != null) {
+                try {
+                    out.flush();
+                    out.close();
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+            }
+            mCache.put(file);
+        }
+    }
+
+    /**
+     * 保存 String数据 到 缓存中
+     *
+     * @param key
+     *            保存的key
+     * @param value
+     *            保存的String数据
+     * @param saveTime
+     *            保存的时间，单位：秒
+     */
+    public void put(String key, String value, int saveTime) {
+        put(key, Utils.newStringWithDateInfo(saveTime, value));
+    }
+
+    /**
+     * 读取 String数据
+     *
+     * @param key
+     * @return String 数据
+     */
+    public String getAsString(String key) {
+        File file = mCache.get(key);
+        if (!file.exists())
+            return null;
+        boolean removeFile = false;
+        BufferedReader in = null;
+        try {
+            in = new BufferedReader(new FileReader(file));
+            String readString = "";
+            String currentLine;
+            while ((currentLine = in.readLine()) != null) {
+                readString += currentLine;
+            }
+            if (!Utils.isDue(readString)) {
+                return Utils.clearDateInfo(readString);
+            } else {
+                removeFile = true;
+                return null;
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+            return null;
+        } finally {
+            if (in != null) {
+                try {
+                    in.close();
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+            }
+            if (removeFile)
+                remove(key);
+        }
+    }
+
+    // =======================================
+    // ============= JSONObject 数据 读写 ==============
+    // =======================================
+    /**
+     * 保存 JSONObject数据 到 缓存中
+     *
+     * @param key
+     *            保存的key
+     * @param value
+     *            保存的JSON数据
+     */
+    public void put(String key, JSONObject value) {
+        put(key, value.toString());
+    }
+
+    /**
+     * 保存 JSONObject数据 到 缓存中
+     *
+     * @param key
+     *            保存的key
+     * @param value
+     *            保存的JSONObject数据
+     * @param saveTime
+     *            保存的时间，单位：秒
+     */
+    public void put(String key, JSONObject value, int saveTime) {
+        put(key, value.toString(), saveTime);
+    }
+
+    /**
+     * 读取JSONObject数据
+     *
+     * @param key
+     * @return JSONObject数据
+     */
+    public JSONObject getAsJSONObject(String key) {
+        String JSONString = getAsString(key);
+        try {
+            JSONObject obj = new JSONObject(JSONString);
+            return obj;
+        } catch (Exception e) {
+            e.printStackTrace();
+            return null;
+        }
+    }
+
+    // =======================================
+    // ============ JSONArray 数据 读写 =============
+    // =======================================
+    /**
+     * 保存 JSONArray数据 到 缓存中
+     *
+     * @param key
+     *            保存的key
+     * @param value
+     *            保存的JSONArray数据
+     */
+    public void put(String key, JSONArray value) {
+        put(key, value.toString());
+    }
+
+    /**
+     * 保存 JSONArray数据 到 缓存中
+     *
+     * @param key
+     *            保存的key
+     * @param value
+     *            保存的JSONArray数据
+     * @param saveTime
+     *            保存的时间，单位：秒
+     */
+    public void put(String key, JSONArray value, int saveTime) {
+        put(key, value.toString(), saveTime);
+    }
+
+    /**
+     * 读取JSONArray数据
+     *
+     * @param key
+     * @return JSONArray数据
+     */
+    public JSONArray getAsJSONArray(String key) {
+        String JSONString = getAsString(key);
+        try {
+            JSONArray obj = new JSONArray(JSONString);
+            return obj;
+        } catch (Exception e) {
+            e.printStackTrace();
+            return null;
+        }
+    }
+
+    // =======================================
+    // ============== byte 数据 读写 =============
+    // =======================================
+    /**
+     * 保存 byte数据 到 缓存中
+     *
+     * @param key
+     *            保存的key
+     * @param value
+     *            保存的数据
+     */
+    public void put(String key, byte[] value) {
+        File file = mCache.newFile(key);
+        FileOutputStream out = null;
+        try {
+            out = new FileOutputStream(file);
+            out.write(value);
+        } catch (Exception e) {
+            e.printStackTrace();
+        } finally {
+            if (out != null) {
+                try {
+                    out.flush();
+                    out.close();
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+            }
+            mCache.put(file);
+        }
+    }
+
+    /**
+     * 保存 byte数据 到 缓存中
+     *
+     * @param key
+     *            保存的key
+     * @param value
+     *            保存的数据
+     * @param saveTime
+     *            保存的时间，单位：秒
+     */
+    public void put(String key, byte[] value, int saveTime) {
+        put(key, Utils.newByteArrayWithDateInfo(saveTime, value));
+    }
+
+    /**
+     * 获取 byte 数据
+     *
+     * @param key
+     * @return byte 数据
+     */
+    public byte[] getAsBinary(String key) {
+        RandomAccessFile RAFile = null;
+        boolean removeFile = false;
+        try {
+            File file = mCache.get(key);
+            if (!file.exists())
+                return null;
+            RAFile = new RandomAccessFile(file, "r");
+            byte[] byteArray = new byte[(int) RAFile.length()];
+            RAFile.read(byteArray);
+            if (!Utils.isDue(byteArray)) {
+                return Utils.clearDateInfo(byteArray);
+            } else {
+                removeFile = true;
+                return null;
+            }
+        } catch (Exception e) {
+            e.printStackTrace();
+            return null;
+        } finally {
+            if (RAFile != null) {
+                try {
+                    RAFile.close();
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+            }
+            if (removeFile)
+                remove(key);
+        }
+    }
+
+    // =======================================
+    // ============= 序列化 数据 读写 ===============
+    // =======================================
+    /**
+     * 保存 Serializable数据 到 缓存中
+     *
+     * @param key
+     *            保存的key
+     * @param value
+     *            保存的value
+     */
+    public void put(String key, Serializable value) {
+        put(key, value, -1);
+    }
+
+    /**
+     * 保存 Serializable数据到 缓存中
+     *
+     * @param key
+     *            保存的key
+     * @param value
+     *            保存的value
+     * @param saveTime
+     *            保存的时间，单位：秒
+     */
+    public void put(String key, Serializable value, int saveTime) {
+        ByteArrayOutputStream baos = null;
+        ObjectOutputStream oos = null;
+        try {
+            baos = new ByteArrayOutputStream();
+            oos = new ObjectOutputStream(baos);
+            oos.writeObject(value);
+            byte[] data = baos.toByteArray();
+            if (saveTime != -1) {
+                put(key, data, saveTime);
+            } else {
+                put(key, data);
+            }
+        } catch (Exception e) {
+            e.printStackTrace();
+        } finally {
+            try {
+                oos.close();
+            } catch (IOException e) {
+            }
+        }
+    }
+
+    /**
+     * 读取 Serializable数据
+     *
+     * @param key
+     * @return Serializable 数据
+     */
+    public Object getAsObject(String key) {
+        byte[] data = getAsBinary(key);
+        if (data != null) {
+            ByteArrayInputStream bais = null;
+            ObjectInputStream ois = null;
+            try {
+                bais = new ByteArrayInputStream(data);
+                ois = new ObjectInputStream(bais);
+                Object reObject = ois.readObject();
+                return reObject;
+            } catch (Exception e) {
+                e.printStackTrace();
+                return null;
+            } finally {
+                try {
+                    if (bais != null)
+                        bais.close();
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+                try {
+                    if (ois != null)
+                        ois.close();
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+            }
+        }
+        return null;
+
+    }
+
+    // =======================================
+    // ============== bitmap 数据 读写 =============
+    // =======================================
+    /**
+     * 保存 bitmap 到 缓存中
+     *
+     * @param key
+     *            保存的key
+     * @param value
+     *            保存的bitmap数据
+     */
+    public void put(String key, Bitmap value) {
+        put(key, Utils.Bitmap2Bytes(value));
+    }
+
+    /**
+     * 保存 bitmap 到 缓存中
+     *
+     * @param key
+     *            保存的key
+     * @param value
+     *            保存的 bitmap 数据
+     * @param saveTime
+     *            保存的时间，单位：秒
+     */
+    public void put(String key, Bitmap value, int saveTime) {
+        put(key, Utils.Bitmap2Bytes(value), saveTime);
+    }
+
+    /**
+     * 读取 bitmap 数据
+     *
+     * @param key
+     * @return bitmap 数据
+     */
+    public Bitmap getAsBitmap(String key) {
+        if (getAsBinary(key) == null) {
+            return null;
+        }
+        return Utils.Bytes2Bimap(getAsBinary(key));
+    }
+
+    // =======================================
+    // ============= drawable 数据 读写 =============
+    // =======================================
+    /**
+     * 保存 drawable 到 缓存中
+     *
+     * @param key
+     *            保存的key
+     * @param value
+     *            保存的drawable数据
+     */
+    public void put(String key, Drawable value) {
+        put(key, Utils.drawable2Bitmap(value));
+    }
+
+    /**
+     * 保存 drawable 到 缓存中
+     *
+     * @param key
+     *            保存的key
+     * @param value
+     *            保存的 drawable 数据
+     * @param saveTime
+     *            保存的时间，单位：秒
+     */
+    public void put(String key, Drawable value, int saveTime) {
+        put(key, Utils.drawable2Bitmap(value), saveTime);
+    }
+
+    /**
+     * 读取 Drawable 数据
+     *
+     * @param key
+     * @return Drawable 数据
+     */
+    public Drawable getAsDrawable(String key) {
+        if (getAsBinary(key) == null) {
+            return null;
+        }
+        return Utils.bitmap2Drawable(Utils.Bytes2Bimap(getAsBinary(key)));
+    }
+
+    /**
+     * 获取缓存文件
+     *
+     * @param key
+     * @return value 缓存的文件
+     */
+    public File file(String key) {
+        File f = mCache.newFile(key);
+        if (f.exists())
+            return f;
+        return null;
+    }
+
+    /**
+     * 移除某个key
+     *
+     * @param key
+     * @return 是否移除成功
+     */
+    public boolean remove(String key) {
+        return mCache.remove(key);
+    }
+
+    /**
+     * 清除所有数据
+     */
+    public void clear() {
+        mCache.clear();
+    }
+
+    /**
+     * @title 缓存管理器
+     * @author 杨福海（michael） www.yangfuhai.com
+     * @version 1.0
+     */
+    public class ACacheManager {
+        private final AtomicLong cacheSize;
+        private final AtomicInteger cacheCount;
+        private final long sizeLimit;
+        private final int countLimit;
+        private final Map<File, Long> lastUsageDates = Collections
+                .synchronizedMap(new HashMap<File, Long>());
+        protected File cacheDir;
+
+        private ACacheManager(File cacheDir, long sizeLimit, int countLimit) {
+            this.cacheDir = cacheDir;
+            this.sizeLimit = sizeLimit;
+            this.countLimit = countLimit;
+            cacheSize = new AtomicLong();
+            cacheCount = new AtomicInteger();
+            calculateCacheSizeAndCacheCount();
+        }
+
+        /**
+         * 计算 cacheSize和cacheCount
+         */
+        private void calculateCacheSizeAndCacheCount() {
+            new Thread(new Runnable() {
+                @Override
+                public void run() {
+                    int size = 0;
+                    int count = 0;
+                    File[] cachedFiles = cacheDir.listFiles();
+                    if (cachedFiles != null) {
+                        for (File cachedFile : cachedFiles) {
+                            size += calculateSize(cachedFile);
+                            count += 1;
+                            lastUsageDates.put(cachedFile,
+                                    cachedFile.lastModified());
+                        }
+                        cacheSize.set(size);
+                        cacheCount.set(count);
+                    }
+                }
+            }).start();
+        }
+
+        private void put(File file) {
+            int curCacheCount = cacheCount.get();
+            while (curCacheCount + 1 > countLimit) {
+                long freedSize = removeNext();
+                cacheSize.addAndGet(-freedSize);
+
+                curCacheCount = cacheCount.addAndGet(-1);
+            }
+            cacheCount.addAndGet(1);
+
+            long valueSize = calculateSize(file);
+            long curCacheSize = cacheSize.get();
+            while (curCacheSize + valueSize > sizeLimit) {
+                long freedSize = removeNext();
+                curCacheSize = cacheSize.addAndGet(-freedSize);
+            }
+            cacheSize.addAndGet(valueSize);
+
+            Long currentTime = System.currentTimeMillis();
+            file.setLastModified(currentTime);
+            lastUsageDates.put(file, currentTime);
+        }
+
+        private File get(String key) {
+            File file = newFile(key);
+            Long currentTime = System.currentTimeMillis();
+            file.setLastModified(currentTime);
+            lastUsageDates.put(file, currentTime);
+
+            return file;
+        }
+
+        private File newFile(String key) {
+            return new File(cacheDir, key.hashCode() + "");
+        }
+
+        private boolean remove(String key) {
+            File image = get(key);
+            return image.delete();
+        }
+
+        private void clear() {
+            lastUsageDates.clear();
+            cacheSize.set(0);
+            File[] files = cacheDir.listFiles();
+            if (files != null) {
+                for (File f : files) {
+                    f.delete();
+                }
+            }
+        }
+
+        /**
+         * 移除旧的文件
+         *
+         * @return
+         */
+        private long removeNext() {
+            if (lastUsageDates.isEmpty()) {
+                return 0;
+            }
+
+            Long oldestUsage = null;
+            File mostLongUsedFile = null;
+            Set<Entry<File, Long>> entries = lastUsageDates.entrySet();
+            synchronized (lastUsageDates) {
+                for (Entry<File, Long> entry : entries) {
+                    if (mostLongUsedFile == null) {
+                        mostLongUsedFile = entry.getKey();
+                        oldestUsage = entry.getValue();
+                    } else {
+                        Long lastValueUsage = entry.getValue();
+                        if (lastValueUsage < oldestUsage) {
+                            oldestUsage = lastValueUsage;
+                            mostLongUsedFile = entry.getKey();
+                        }
+                    }
+                }
+            }
+
+            long fileSize = calculateSize(mostLongUsedFile);
+            if (mostLongUsedFile.delete()) {
+                lastUsageDates.remove(mostLongUsedFile);
+            }
+            return fileSize;
+        }
+
+        private long calculateSize(File file) {
+            return file.length();
+        }
+    }
+
+    /**
+     * @title 时间计算工具类
+     * @author 杨福海（michael） www.yangfuhai.com
+     * @version 1.0
+     */
+    private static class Utils {
+
+        /**
+         * 判断缓存的String数据是否到期
+         *
+         * @param str
+         * @return true：到期了 false：还没有到期
+         */
+        private static boolean isDue(String str) {
+            return isDue(str.getBytes());
+        }
+
+        /**
+         * 判断缓存的byte数据是否到期
+         *
+         * @param data
+         * @return true：到期了 false：还没有到期
+         */
+        private static boolean isDue(byte[] data) {
+            String[] strs = getDateInfoFromDate(data);
+            if (strs != null && strs.length == 2) {
+                String saveTimeStr = strs[0];
+                while (saveTimeStr.startsWith("0")) {
+                    saveTimeStr = saveTimeStr
+                            .substring(1, saveTimeStr.length());
+                }
+                long saveTime = Long.valueOf(saveTimeStr);
+                long deleteAfter = Long.valueOf(strs[1]);
+                if (System.currentTimeMillis() > saveTime + deleteAfter * 1000) {
+                    return true;
+                }
+            }
+            return false;
+        }
+
+        private static String newStringWithDateInfo(int second, String strInfo) {
+            return createDateInfo(second) + strInfo;
+        }
+
+        private static byte[] newByteArrayWithDateInfo(int second, byte[] data2) {
+            byte[] data1 = createDateInfo(second).getBytes();
+            byte[] retdata = new byte[data1.length + data2.length];
+            System.arraycopy(data1, 0, retdata, 0, data1.length);
+            System.arraycopy(data2, 0, retdata, data1.length, data2.length);
+            return retdata;
+        }
+
+        private static String clearDateInfo(String strInfo) {
+            if (strInfo != null && hasDateInfo(strInfo.getBytes())) {
+                strInfo = strInfo.substring(strInfo.indexOf(mSeparator) + 1,
+                        strInfo.length());
+            }
+            return strInfo;
+        }
+
+        private static byte[] clearDateInfo(byte[] data) {
+            if (hasDateInfo(data)) {
+                return copyOfRange(data, indexOf(data, mSeparator) + 1,
+                        data.length);
+            }
+            return data;
+        }
+
+        private static boolean hasDateInfo(byte[] data) {
+            return data != null && data.length > 15 && data[13] == '-'
+                    && indexOf(data, mSeparator) > 14;
+        }
+
+        private static String[] getDateInfoFromDate(byte[] data) {
+            if (hasDateInfo(data)) {
+                String saveDate = new String(copyOfRange(data, 0, 13));
+                String deleteAfter = new String(copyOfRange(data, 14,
+                        indexOf(data, mSeparator)));
+                return new String[] { saveDate, deleteAfter };
+            }
+            return null;
+        }
+
+        private static int indexOf(byte[] data, char c) {
+            for (int i = 0; i < data.length; i++) {
+                if (data[i] == c) {
+                    return i;
+                }
+            }
+            return -1;
+        }
+
+        private static byte[] copyOfRange(byte[] original, int from, int to) {
+            int newLength = to - from;
+            if (newLength < 0)
+                throw new IllegalArgumentException(from + " > " + to);
+            byte[] copy = new byte[newLength];
+            System.arraycopy(original, from, copy, 0,
+                    Math.min(original.length - from, newLength));
+            return copy;
+        }
+
+        private static final char mSeparator = ' ';
+
+        private static String createDateInfo(int second) {
+            String currentTime = System.currentTimeMillis() + "";
+            while (currentTime.length() < 13) {
+                currentTime = "0" + currentTime;
+            }
+            return currentTime + "-" + second + mSeparator;
+        }
+
+        /*
+         * Bitmap → byte[]
+         */
+        private static byte[] Bitmap2Bytes(Bitmap bm) {
+            if (bm == null) {
+                return null;
+            }
+            ByteArrayOutputStream baos = new ByteArrayOutputStream();
+            bm.compress(Bitmap.CompressFormat.PNG, 100, baos);
+            return baos.toByteArray();
+        }
+
+        /*
+         * byte[] → Bitmap
+         */
+        private static Bitmap Bytes2Bimap(byte[] b) {
+            if (b.length == 0) {
+                return null;
+            }
+            return BitmapFactory.decodeByteArray(b, 0, b.length);
+        }
+
+        /*
+         * Drawable → Bitmap
+         */
+        private static Bitmap drawable2Bitmap(Drawable drawable) {
+            if (drawable == null) {
+                return null;
+            }
+            // 取 drawable 的长宽
+            int w = drawable.getIntrinsicWidth();
+            int h = drawable.getIntrinsicHeight();
+            // 取 drawable 的颜色格式
+            Bitmap.Config config = drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888
+                    : Bitmap.Config.RGB_565;
+            // 建立对应 bitmap
+            Bitmap bitmap = Bitmap.createBitmap(w, h, config);
+            // 建立对应 bitmap 的画布
+            Canvas canvas = new Canvas(bitmap);
+            drawable.setBounds(0, 0, w, h);
+            // 把 drawable 内容画到画布中
+            drawable.draw(canvas);
+            return bitmap;
+        }
+
+        /*
+         * Bitmap → Drawable
+         */
+        @SuppressWarnings("deprecation")
+        private static Drawable bitmap2Drawable(Bitmap bm) {
+            if (bm == null) {
+                return null;
+            }
+            return new BitmapDrawable(bm);
+        }
+    }
+
+}