获取缓存的大小和清除缓存

             获取缓存的大小和清除缓存是每个APP都会用的的，下面我们来看看怎么做呢：：：：

1.首先，我们要写一个清除缓存大小的工具类：

DataCleanManager.class

import java.io.File;import java.math.BigDecimal;import android.annotation.SuppressLint;import android.content.Context;import android.os.Environment;import android.text.TextUtils;/** * 获取缓存文件大小及清除缓存 *  * @author zhangjingjing * @date 2016-7-18 */public class DataCleanManager {/** * * 清除本应用内部缓存(/data/data/com.xxx.xxx/cache) * * *  * @param context */public static void cleanInternalCache(Context context) {deleteFilesByDirectory(context.getCacheDir());}/** * * 清除本应用所有数据库(/data/data/com.xxx.xxx/databases) * * *  * @param context */@SuppressLint("SdCardPath")public static void cleanDatabases(Context context) {deleteFilesByDirectory(new File("/data/data/"+ context.getPackageName() + "/databases"));}/** * * 清除本应用SharedPreference(/data/data/com.xxx.xxx/shared_prefs) * *  * @param context */@SuppressLint("SdCardPath")public static void cleanSharedPreference(Context context) {deleteFilesByDirectory(new File("/data/data/"+ context.getPackageName() + "/shared_prefs"));}/** * * 按名字清除本应用数据库 * * *  * @param context * @param dbName */public static void cleanDatabaseByName(Context context, String dbName) {context.deleteDatabase(dbName);}/** * * 清除/data/data/com.xxx.xxx/files下的内容 * * *  * @param context */public static void cleanFiles(Context context) {deleteFilesByDirectory(context.getFilesDir());}/** * * 清除外部cache下的内容(/mnt/sdcard/android/data/com.xxx.xxx/cache) *  * @param context */public static void cleanExternalCache(Context context) {if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {deleteFilesByDirectory(context.getExternalCacheDir());}}/** * * 清除自定义路径下的文件，使用需小心，请不要误删。而且只支持目录下的文件删除 * * *  * @param filePath * */public static void cleanCustomCache(String filePath) {deleteFilesByDirectory(new File(filePath));}/** * * 清除本应用所有的数据 * * *  * @param context * @param filepath */public static void cleanApplicationData(Context context, String... filepath) {cleanInternalCache(context);cleanExternalCache(context);cleanDatabases(context);cleanSharedPreference(context);cleanFiles(context);if (filepath == null) {return;}for (String filePath : filepath) {cleanCustomCache(filePath);}}/** * * 删除方法 这里只会删除某个文件夹下的文件，如果传入的directory是个文件，将不做处理 * * *  * @param directory */private static void deleteFilesByDirectory(File directory) {if (directory != null && directory.exists() && directory.isDirectory()) {for (File item : directory.listFiles()) {item.delete();}}}// 获取文件// Context.getExternalFilesDir() --> SDCard/Android/data/你的应用的包名/files/// 目录，一般放一些长时间保存的数据// Context.getExternalCacheDir() -->// SDCard/Android/data/你的应用包名/cache/目录，一般存放临时缓存数据public static long getFolderSize(File file) throws Exception {long size = 0;try {File[] fileList = file.listFiles();for (int i = 0; i < fileList.length; i++) {// 如果下面还有文件if (fileList[i].isDirectory()) {size = size + getFolderSize(fileList[i]);} else {size = size + fileList[i].length();}}} catch (Exception e) {e.printStackTrace();}return size;}/** * 删除指定目录下文件及目录 *  * @param deleteThisPath * @param filepath * @return */public static void deleteFolderFile(String filePath, boolean deleteThisPath) {if (!TextUtils.isEmpty(filePath)) {try {File file = new File(filePath);if (file.isDirectory()) {// 如果下面还有文件File files[] = file.listFiles();for (int i = 0; i < files.length; i++) {deleteFolderFile(files[i].getAbsolutePath(), true);}}if (deleteThisPath) {if (!file.isDirectory()) {// 如果是文件，删除file.delete();} else {// 目录if (file.listFiles().length == 0) {// 目录下没有文件或者目录，删除file.delete();}}}} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}}}/** * 格式化单位 *  * @param size * @return */public static String getFormatSize(double size) {double kiloByte = size / 1024;if (kiloByte < 1) {return size + "Byte";}double megaByte = kiloByte / 1024;if (megaByte < 1) {BigDecimal result1 = new BigDecimal(Double.toString(kiloByte));return result1.setScale(2, BigDecimal.ROUND_HALF_UP).toPlainString() + "KB";}double gigaByte = megaByte / 1024;if (gigaByte < 1) {BigDecimal result2 = new BigDecimal(Double.toString(megaByte));return result2.setScale(2, BigDecimal.ROUND_HALF_UP).toPlainString() + "MB";}double teraBytes = gigaByte / 1024;if (teraBytes < 1) {BigDecimal result3 = new BigDecimal(Double.toString(gigaByte));return result3.setScale(2, BigDecimal.ROUND_HALF_UP).toPlainString() + "GB";}BigDecimal result4 = new BigDecimal(teraBytes);return result4.setScale(2, BigDecimal.ROUND_HALF_UP).toPlainString()+ "TB";}/** * 获取文件大小 *  * @param file * @return * @throws Exception */public static String getCacheSize(File file) throws Exception {return getFormatSize(getFolderSize(file));}}

2.接着我们要写获取缓存大小的方法，一定要在oncreat方法中调用这个方法

getFileSize();// 调用获取缓存大小的方法

/** * 获取缓存文件大小并设置在控件上 */private void getFileSize() {// TODO Auto-generated method stubtry {cacheSize = DataCleanManager.getCacheSize(this.getCacheDir());} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}tv_data.setText("已缓存" + cacheSize);}

3.在接着就在点击事件的监听里写逻辑啦：

ACache aCache = ACache.get(Install_Activity.this);aCache.clear();// 先清除缓存// 获取文件大小getFileSize();Toast.makeText(Install_Activity.this, "已清除缓存", 0).show();

4.这个是缓存的工具类：ACache.class

/** * 缓存工具类 */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锛坵ww.yangfuhai.com锛�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 mbprivate static final int MAX_COUNT = Integer.MAX_VALUE; // 涓嶉檺鍒跺瓨鏀炬暟鎹殑鏁伴噺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鏁版嵁 璇诲啓 ==============// =======================================/** * 淇濆瓨 String鏁版嵁 鍒�缂撳瓨涓� *  * @param key *            淇濆瓨鐨刱ey * @param value *            淇濆瓨鐨凷tring鏁版嵁 */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);}}/** * 淇濆瓨 String鏁版嵁 鍒�缂撳瓨涓� *  * @param key *            淇濆瓨鐨刱ey * @param value *            淇濆瓨鐨凷tring鏁版嵁 * @param saveTime *            淇濆瓨鐨勬椂闂达紝鍗曚綅锛氱 */public void put(String key, String value, int saveTime) {put(key, Utils.newStringWithDateInfo(saveTime, value));}/** * 璇诲彇 String鏁版嵁 *  * @param key * @return String 鏁版嵁 */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 鏁版嵁 璇诲啓 ==============// =======================================/** * 淇濆瓨 JSONObject鏁版嵁 鍒�缂撳瓨涓� *  * @param key *            淇濆瓨鐨刱ey * @param value *            淇濆瓨鐨凧SON鏁版嵁 */public void put(String key, JSONObject value) {put(key, value.toString());}/** * 淇濆瓨 JSONObject鏁版嵁 鍒�缂撳瓨涓� *  * @param key *            淇濆瓨鐨刱ey * @param value *            淇濆瓨鐨凧SONObject鏁版嵁 * @param saveTime *            淇濆瓨鐨勬椂闂达紝鍗曚綅锛氱 */public void put(String key, JSONObject value, int saveTime) {put(key, value.toString(), saveTime);}/** * 璇诲彇JSONObject鏁版嵁 *  * @param key * @return JSONObject鏁版嵁 */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 鏁版嵁 璇诲啓 =============// =======================================/** * 淇濆瓨 JSONArray鏁版嵁 鍒�缂撳瓨涓� *  * @param key *            淇濆瓨鐨刱ey * @param value *            淇濆瓨鐨凧SONArray鏁版嵁 */public void put(String key, JSONArray value) {put(key, value.toString());}/** * 淇濆瓨 JSONArray鏁版嵁 鍒�缂撳瓨涓� *  * @param key *            淇濆瓨鐨刱ey * @param value *            淇濆瓨鐨凧SONArray鏁版嵁 * @param saveTime *            淇濆瓨鐨勬椂闂达紝鍗曚綅锛氱 */public void put(String key, JSONArray value, int saveTime) {put(key, value.toString(), saveTime);}/** * 璇诲彇JSONArray鏁版嵁 *  * @param key * @return JSONArray鏁版嵁 */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 鏁版嵁 璇诲啓 =============// =======================================/** * 淇濆瓨 byte鏁版嵁 鍒�缂撳瓨涓� *  * @param key *            淇濆瓨鐨刱ey * @param value *            淇濆瓨鐨勬暟鎹� */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);}}/** * 淇濆瓨 byte鏁版嵁 鍒�缂撳瓨涓� *  * @param key *            淇濆瓨鐨刱ey * @param value *            淇濆瓨鐨勬暟鎹� * @param saveTime *            淇濆瓨鐨勬椂闂达紝鍗曚綅锛氱 */public void put(String key, byte[] value, int saveTime) {put(key, Utils.newByteArrayWithDateInfo(saveTime, value));}/** * 鑾峰彇 byte 鏁版嵁 *  * @param key * @return byte 鏁版嵁 */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);}}// =======================================// ============= 搴忓垪鍖�鏁版嵁 璇诲啓 ===============// =======================================/** * 淇濆瓨 Serializable鏁版嵁 鍒�缂撳瓨涓� *  * @param key *            淇濆瓨鐨刱ey * @param value *            淇濆瓨鐨剉alue */public void put(String key, Serializable value) {put(key, value, -1);}/** * 淇濆瓨 Serializable鏁版嵁鍒�缂撳瓨涓� *  * @param key *            淇濆瓨鐨刱ey * @param value *            淇濆瓨鐨剉alue * @param saveTime *            淇濆瓨鐨勬椂闂达紝鍗曚綅锛氱 */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) {}}}/** * 璇诲彇 Serializable鏁版嵁 *  * @param key * @return Serializable 鏁版嵁 */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 鏁版嵁 璇诲啓 =============// =======================================/** * 淇濆瓨 bitmap 鍒�缂撳瓨涓� *  * @param key *            淇濆瓨鐨刱ey * @param value *            淇濆瓨鐨刡itmap鏁版嵁 */public void put(String key, Bitmap value) {put(key, Utils.Bitmap2Bytes(value));}/** * 淇濆瓨 bitmap 鍒�缂撳瓨涓� *  * @param key *            淇濆瓨鐨刱ey * @param value *            淇濆瓨鐨�bitmap 鏁版嵁 * @param saveTime *            淇濆瓨鐨勬椂闂达紝鍗曚綅锛氱 */public void put(String key, Bitmap value, int saveTime) {put(key, Utils.Bitmap2Bytes(value), saveTime);}/** * 璇诲彇 bitmap 鏁版嵁 *  * @param key * @return bitmap 鏁版嵁 */public Bitmap getAsBitmap(String key) {if (getAsBinary(key) == null) {return null;}return Utils.Bytes2Bimap(getAsBinary(key));}// =======================================// ============= drawable 鏁版嵁 璇诲啓 =============// =======================================/** * 淇濆瓨 drawable 鍒�缂撳瓨涓� *  * @param key *            淇濆瓨鐨刱ey * @param value *            淇濆瓨鐨刣rawable鏁版嵁 */public void put(String key, Drawable value) {put(key, Utils.drawable2Bitmap(value));}/** * 淇濆瓨 drawable 鍒�缂撳瓨涓� *  * @param key *            淇濆瓨鐨刱ey * @param value *            淇濆瓨鐨�drawable 鏁版嵁 * @param saveTime *            淇濆瓨鐨勬椂闂达紝鍗曚綅锛氱 */public void put(String key, Drawable value, int saveTime) {put(key, Utils.drawable2Bitmap(value), saveTime);}/** * 璇诲彇 Drawable 鏁版嵁 *  * @param key * @return Drawable 鏁版嵁 */public Drawable getAsDrawable(String key) {if (getAsBinary(key) == null) {return null;}return Utils.bitmap2Drawable(Utils.Bytes2Bimap(getAsBinary(key)));}/** * 鑾峰彇缂撳瓨鏂囦欢 *  * @param key * @return value 缂撳瓨鐨勬枃浠� */public File file(String key) {File f = mCache.newFile(key);if (f.exists())return f;return null;}/** * 绉婚櫎鏌愪釜key *  * @param key * @return 鏄惁绉婚櫎鎴愬姛 */public boolean remove(String key) {return mCache.remove(key);}/** * 娓呴櫎鎵�湁鏁版嵁 */public void clear() {mCache.clear();}/** * @title 缂撳瓨绠＄悊鍣� * @author 鏉ㄧ娴凤紙michael锛�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();}/** * 璁＄畻 cacheSize鍜宑acheCount */private void calculateCacheSizeAndCacheCount() {new Thread(new Runnable() {@Overridepublic 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();}}}/** * 绉婚櫎鏃х殑鏂囦欢 *  * @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 鏃堕棿璁＄畻宸ュ叿绫� * @author 鏉ㄧ娴凤紙michael锛�www.yangfuhai.com * @version 1.0 */private static class Utils {/** * 鍒ゆ柇缂撳瓨鐨凷tring鏁版嵁鏄惁鍒版湡 *  * @param str * @return true锛氬埌鏈熶簡 false锛氳繕娌℃湁鍒版湡 */private static boolean isDue(String str) {return isDue(str.getBytes());}/** * 鍒ゆ柇缂撳瓨鐨刡yte鏁版嵁鏄惁鍒版湡 *  * @param data * @return true锛氬埌鏈熶簡 false锛氳繕娌℃湁鍒版湡 */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 鈫�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[] 鈫�Bitmap */private static Bitmap Bytes2Bimap(byte[] b) {if (b.length == 0) {return null;}return BitmapFactory.decodeByteArray(b, 0, b.length);}/* * Drawable 鈫�Bitmap */private static Bitmap drawable2Bitmap(Drawable drawable) {if (drawable == null) {return null;}// 鍙�drawable 鐨勯暱瀹�int w = drawable.getIntrinsicWidth();int h = drawable.getIntrinsicHeight();// 鍙�drawable 鐨勯鑹叉牸寮�Bitmap.Config config = drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888: Bitmap.Config.RGB_565;// 寤虹珛瀵瑰簲 bitmapBitmap bitmap = Bitmap.createBitmap(w, h, config);// 寤虹珛瀵瑰簲 bitmap 鐨勭敾甯�Canvas canvas = new Canvas(bitmap);drawable.setBounds(0, 0, w, h);// 鎶�drawable 鍐呭鐢诲埌鐢诲竷涓�drawable.draw(canvas);return bitmap;}/* * Bitmap 鈫�Drawable */@SuppressWarnings("deprecation")private static Drawable bitmap2Drawable(Bitmap bm) {if (bm == null) {return null;}return new BitmapDrawable(bm);}}}

5.在写下如何缓存的例子吧：

/** * 网络解析数据 */private void getHttp() {// TODO Auto-generated method stubHttpUtils httpUtils = new HttpUtils();String path = Urls.Detail_URL;// url 路径// target 目标位置下到什么位置// callback 回调httpUtils.send(HttpMethod.GET, path, new RequestCallBack<String>() {@Overridepublic void onFailure(HttpException arg0, String arg1) {// TODO Auto-generated method stub//读取(没有网的时候读取本地数据)String asString = aCache.getAsString("result");//判断本地有没有if(!TextUtils.isEmpty(asString)){Toast.makeText(getActivity(), "本地缓存", 0).show();Gson gson = new Gson();mData = gson.fromJson(asString, Data1.class);datalist = mData.data.briefs;hashMap = new HashMap<Integer, ArrayList<MyBriefs>>();ArrayList<MyBriefs> briefs2 = new ArrayList<MyBriefs>();ArrayList<MyBriefs> briefs3 = new ArrayList<MyBriefs>();ArrayList<MyBriefs> briefs4 = new ArrayList<MyBriefs>();for (int j = 0; j < datalist.size(); j++) {if (j < 6) {briefs2.add(datalist.get(j));} else if (j < 12) {briefs3.add(datalist.get(j));} else {briefs4.add(datalist.get(j));}}hashMap.put(0, briefs2);hashMap.put(1, briefs3);hashMap.put(2, briefs4);hashMap.put(3, briefs2);hashMap.put(4, briefs3);hashMap.put(5, briefs4);handler.sendEmptyMessageDelayed(0, 3000);//创建弹框，进行判断AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());builder.setTitle("网络提示!");builder.setPositiveButton("设置网络", new DialogInterface.OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {// TODO Auto-generated method stub//跳转到系统设置界面startActivity(new Intent(android.provider.Settings.ACTION_DATA_ROAMING_SETTINGS));}});builder.setNegativeButton("不理会", new DialogInterface.OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {// TODO Auto-generated method stub}});builder.show();}}@Overridepublic void onSuccess(ResponseInfo<String> arg0) {// TODO Auto-generated method stubString result = arg0.result;//存储aCache.put("result",result);Toast.makeText(mActivity, "保存数据", 0).show();//aCache.put(key, value, saveTime);//保存多长时间Gson gson = new Gson();mData = gson.fromJson(result, Data1.class);datalist = mData.data.briefs;hashMap = new HashMap<Integer, ArrayList<MyBriefs>>();ArrayList<MyBriefs> briefs2 = new ArrayList<MyBriefs>();ArrayList<MyBriefs> briefs3 = new ArrayList<MyBriefs>();ArrayList<MyBriefs> briefs4 = new ArrayList<MyBriefs>();for (int j = 0; j < datalist.size(); j++) {if (j < 6) {briefs2.add(datalist.get(j));} else if (j < 12) {briefs3.add(datalist.get(j));} else {briefs4.add(datalist.get(j));}}hashMap.put(0, briefs2);hashMap.put(1, briefs3);hashMap.put(2, briefs4);hashMap.put(3, briefs2);hashMap.put(4, briefs3);hashMap.put(5, briefs4);handler.sendEmptyMessageDelayed(0, 3000);// Home_ListView_Adapter home_GridView_Adapter = new// Home_ListView_Adapter(// getActivity(), images, hashMap);// home_listView.setAdapter(home_GridView_Adapter);// progressDialog.dismiss();}});}

 ***读取本地缓存(已经缓存下来的数据)：

//读取(没有网的时候读取本地数据)String asString = aCache.getAsString("result");

 ***存储数据：

//存储aCache.put("result",result);

                                 *******************************希望对大家有帮助******************************