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ACache【轻量级的开源缓存框架】

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前言

官方介绍

ASimpleCache 是一个为android制定的 轻量级的 开源缓存框架。轻量到只有一个java文件(由十几个类精简而来)。

1、它可以缓存什么东西?

普通的字符串、JsonObject、JsonArray、Bitmap、Drawable、序列化的java对象,和 byte数据。

2、它有什么特色?

特色主要是: 
1:轻,轻到只有一个JAVA文件。 
2:可配置,可以配置缓存路径,缓存大小,缓存数量等。 
3:可以设置缓存超时时间,缓存超时自动失效,并被删除。 
4:支持多进程。

3、它在android中可以用在哪些场景?

1、替换SharePreference当做配置文件 
2、可以缓存网络请求数据,比如oschina的android客户端可以缓存http请求的新闻内容,缓存时间假设为1个小时,超时后自动失效,让客户端重新请求新的数据,减少客户端流量,同时减少服务器并发量

4、如何使用 ASimpleCache? 以下有个小的demo,希望您能喜欢:

缓存数据

ACache.get(MainActivity.this).put("username_key", "admin"); 
ACache.get(MainActivity.this).put("password_key", "123456789", 10);//保存10秒,如果超过10秒去获取这个key,将为null
ACache.get(MainActivity.this).put("password_key", "123456789", 2 * ACache.TIME_DAY);//保存两天,如果超过两天去获取这个key,将为null

获取数据

ACache.get(MainActivity.this).getAsString("username_key");

效果图

 技术分享

代码分析

缓存文件放置在/data/data/app-package-name/cache/路径下,缓存的目录默认为ACache,缓存大小和数量均由ACache中的final变量控制。

存在的一个问题是,在部分机型(比如华为荣耀6)上当使用猎豹清理大师进行垃圾清理的时候会把acache中缓存的数据清理掉。

使用步骤

一、项目组织结构图

技术分享

注意事项:

1、导入类文件后需要change包名以及重新import R文件路径

2、Values目录下的文件(strings.xml、dimens.xml、colors.xml等),如果项目中存在,则复制里面的内容,不要整个覆盖

二、导入步骤

将Acache复制到项目中

技术分享
/** * 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 com.why.project.acachedemo.utils;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;import org.json.JSONArray;import org.json.JSONObject;import java.io.BufferedReader;import java.io.BufferedWriter;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.FileReader;import java.io.FileWriter;import java.io.IOException;import java.io.InputStream;import java.io.ObjectInputStream;import java.io.ObjectOutputStream;import java.io.OutputStream;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;/** * https://github.com/yangfuhai/ASimpleCache * 缓存文件放置在/data/data/app-package-name/cache/路径下,缓存的目录默认为ACache,缓存大小和数量均由ACache中的final变量控制。 */public class ACache {    /**设置的缓存的时间*/    public static final int TIME_HOUR = 60 * 60;//1小时    public static final int TIME_DAY = TIME_HOUR * 24;//1天    /**设置的缓存的大小*/    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    /**声明一个Map,用于存放ACache对象*/    private static Map<String, ACache> mInstanceMap = new HashMap<String, ACache>();    /**缓存管理器*/    private ACacheManager mCacheManager;        //ACache类的构造方法为private的,所以只能通过get方式获取实例。    private ACache(File cacheDir, long max_size, int max_count) {        //如果cacheDir文件不存在并且无法新建子目录,则报错        if (!cacheDir.exists() && !cacheDir.mkdirs()) {            throw new RuntimeException("can‘t make dirs in " + cacheDir.getAbsolutePath());        }        //实例化缓存管理器对象        mCacheManager = new ACacheManager(cacheDir, max_size, max_count);    }    //默认情况下调用该方法    public static ACache get(Context ctx) {        return get(ctx, "ACache");    }        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(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);    }    //最终默认调用的实例方法    public static ACache get(File cacheDir, long max_zise, int max_count) {        //Map中的Key值为cacheDir.getAbsoluteFile() + myPid(),例如:/data/data/com.yangfuhai.asimplecachedemo/cache/ACache_16609        ACache manager = mInstanceMap.get(cacheDir.getAbsoluteFile() + myPid());        if (manager == null) {            manager = new ACache(cacheDir, max_zise, max_count);            //Log.v("ACache", cacheDir.getAbsolutePath() + myPid());            mInstanceMap.put(cacheDir.getAbsolutePath() + myPid(), manager);        }        return manager;    }        private static String myPid() {        return "_" + android.os.Process.myPid();    }    /**     * Provides a means to save a cached file before the data are available.     * Since writing about the file is complete, and its close method is called,     * its contents will be registered in the cache. Example of use:     *      * ACache cache = new ACache(this) try { OutputStream stream =     * cache.put("myFileName") stream.write("some bytes".getBytes()); // now     * update cache! stream.close(); } catch(FileNotFoundException e){     * e.printStackTrace() }     */    class xFileOutputStream extends FileOutputStream {        File file;        public xFileOutputStream(File file) throws FileNotFoundException {            super(file);            this.file = file;        }        public void close() throws IOException {            super.close();            mCacheManager.put(file);        }    }    // =======================================    // ============ 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     */    //在ACache目录下创建一个文件,文件名为:File(cacheDir, key.hashCode() + “”)。然后将数据存入文件    public void put(String key, String value) {        File file = mCacheManager.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();                }            }            mCacheManager.put(file);        }    }    /**     * 保存 String数据 到 缓存中一定时间     *      * @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 = mCacheManager.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);        if(JSONString != null){            try {                JSONObject obj = new JSONObject(JSONString);                return obj;            } catch (Exception e) {                e.printStackTrace();                return null;            }        }else{            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 = mCacheManager.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();                }            }            mCacheManager.put(file);        }    }    /**     * Cache for a stream     *      * @param key     *            the file name.     * @return OutputStream stream for writing data.     * @throws FileNotFoundException     *             if the file can not be created.     */    public OutputStream put(String key) throws FileNotFoundException {        return new xFileOutputStream(mCacheManager.newFile(key));    }    /**     *      * @param key     *            the file name.     * @return (InputStream or null) stream previously saved in cache.     * @throws FileNotFoundException     *             if the file can not be opened     */    public InputStream get(String key) throws FileNotFoundException {        File file = mCacheManager.get(key);        if (!file.exists())            return null;        return new FileInputStream(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 = mCacheManager.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 =http://www.mamicode.com/ 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 =http://www.mamicode.com/ 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 = mCacheManager.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 mCacheManager.remove(key);    }    /**     * 清除所有数据     */    public void clear() {        mCacheManager.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 = http://www.mamicode.com/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;            }            BitmapDrawable bd=new BitmapDrawable(bm);            bd.setTargetDensity(bm.getDensity());            return new BitmapDrawable(bm);        }    }}
ACache.java

将Globals复制到项目中(或者在类似文件(用于存放全局变量和公共方法)中添加以下代码)

package com.why.project.acachedemo.utils;/** * Created HaiyuKing * Used  全局变量和公共方法 */public class Globals {        /**==================缓存的key值===============================*/    /**用户名*/    public static final String USERNAME_KEY = "username";    }

三、使用方法

package com.why.project.acachedemo;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.view.View;import android.widget.Button;import android.widget.EditText;import android.widget.Toast;import com.why.project.acachedemo.utils.ACache;import com.why.project.acachedemo.utils.Globals;public class MainActivity extends AppCompatActivity {    private EditText mUsernameEdt;    private Button mLoginBtn;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initViews();        initDatas();        initEvents();    }    //初始化控件    private void initViews(){        mUsernameEdt = (EditText) findViewById(R.id.edt_username);        mLoginBtn = (Button) findViewById(R.id.btn_login);    }    //初始化数据    private void initDatas(){        //判断是否缓存了用户名,如果是的话,读取缓存的用户名并填充到输入框中        initNamePwdFromCache();    }    //初始化事件    private void initEvents(){        mLoginBtn.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                String userName = mUsernameEdt.getText().toString();                //缓存用户名                ACache.get(MainActivity.this).put(Globals.USERNAME_KEY,userName);                Toast.makeText(MainActivity.this,"已缓存用户名:"+userName,Toast.LENGTH_SHORT).show();            }        });    }    /**     * 从缓存中查询用户名是否保存,并加载用户名     * */    private void initNamePwdFromCache() {        //有缓存文件        String userNameCache = ACache.get(this).getAsString(Globals.USERNAME_KEY);        if (userNameCache != null) {            mUsernameEdt.setText(userNameCache);            Toast.makeText(MainActivity.this,"已加载缓存的用户名:"+userNameCache,Toast.LENGTH_SHORT).show();        }    }}

混淆配置

参考资料

【Android开源项目分析】android轻量级开源缓存框架——ASimpleCache(ACache)源码分析

http://blog.csdn.net/zhoubin1992/article/details/46379055

ASimpleCache框架源码链接

https://github.com/yangfuhai/ASimpleCache

ASimpleCache开源库使用分析

http://blog.csdn.net/yanbober/article/details/45306851

项目demo下载地址

链接:http://pan.baidu.com/s/1eRBIFi6 密码:gp79

ACache【轻量级的开源缓存框架】