记录一下,一个小小的硬盘缓存使用类SHDiskCache

2017-06-29 10:03:02来源:http://www.jianshu.com/p/45ee4d43e553作者:原来如此丶人点击


写这个主要还是用来记录一下,避免自己长时间不用后想不起来
之前项目里做数据缓存到本地,小的使用SP,大的用Litpal,但是后来想做一个用于存储网络请求下来的数据的工具,就有了现在这个基于DiskLruCache和Reservoir的封装,当然以自己目前的水平也就能拿别人的搞搞事情了,哈哈


正文:


介绍:

SHDiskCache是基于DiskLruCache和Reservoir的封装,能够实现网络请求下来的数据的本地存储,包括线程管理、缓存时间控制以及回调处理


1.关于DiskLruCache

各位大神对于对它都有介绍,我这边一张图来说明一下它的api



DiskLruCache视图.png
2.使用的前提

需在Application中初始化,初始化方式如下:Reservoir.init(this, 10 1024 1024),第二个参数表示缓存空间大小


该工具类缓存流程判断:

缓存逻辑流程图.png
该工具类:
public class SHDiskCache {
private static SHDiskCache cache;
private SHDiskCache() {}
public static SHDiskCache getInstance() {
if (cache == null) {
cache = new SHDiskCache();
}
return cache;
}
/**
* 异步存储缓存 普通方式putAsync putResponse专用于网络请求数据缓存
*
* @param t 要缓存的数据
* @param key 存储的key值 建议格式:userid + 对应模块英文
* @param minute 缓存保留的时间,单位:分钟
*/
public <T> void putAsync(T t, String key, int minute, final SHCachePutCallback callback) {
if (t == null) {
return;
}
Gson gson = new Gson();
DiskCacheData cacheData = new DiskCacheData();
cacheData.key = key;
cacheData.delayTime = minute * 60000;
cacheData.saveTime = System.currentTimeMillis();
cacheData.jsonString = gson.toJson(t);

Reservoir.putAsync(key, cacheData, new ReservoirPutCallback() {
@Override
public void onSuccess() {
callback.onSucceed();
}
@Override
public void onFailure(Exception e) {
callback.onFailed();
}
});
}
/**
* @param response 网络请求的数据
*/
public void putResponse(HttpResponse response, String key, int minute, final SHCachePutCallback callback) {
if (response == null) {
return;
}
DiskCacheData diskCacheData = new DiskCacheData();
diskCacheData.key = key;
diskCacheData.jsonString = response.getJson();
diskCacheData.saveTime = System.currentTimeMillis();
diskCacheData.delayTime = minute * 60000;
Reservoir.putAsync(key, diskCacheData, new ReservoirPutCallback() {
@Override
public void onSuccess() {
if (callback != null){
callback.onSucceed();
}
}
@Override
public void onFailure(Exception e) {
if (callback != null){
callback.onFailed();
}
}
});
}
/**
* 异步获取缓存 普通方式getAsync getResponse专用于网络请求数据缓存
*
* @param key 存储的key值 建议格式:userid + 对应模块英文
*/
public void getResponse(final String key, final SHCacheResponseCallBack callback) {
try {
if (!Reservoir.contains(key)) {
callback.onCallBack(null);
return;
}
Reservoir.getAsync(key, DiskCacheData.class, new ReservoirGetCallback<DiskCacheData>() {
@Override
public void onSuccess(DiskCacheData diskCacheData) {
if (diskCacheData == null || diskCacheData.jsonString == null) {
callback.onCallBack(null);
Log.e("getAsync:", "无缓存");
return;
}
if (diskCacheData.isDue()) {
delete(key);
callback.onCallBack(null);
Log.e("getAsync:", "超时删除");
return;
}
HttpResponse response = HttpResponse.createResponse(diskCacheData.jsonString);
callback.onCallBack(response);
}
@Override
public void onFailure(Exception e) {
callback.onCallBack(null);
}
});
} catch (IOException e) {
e.printStackTrace();
callback.onCallBack(null);
}
}
public <T> void getAsync(final String key, final Class dataClass, final SHCacheGetCallback<T> callback) {
try {
if (Reservoir.contains(key)) {
Reservoir.getAsync(key, DiskCacheData.class, new ReservoirGetCallback<DiskCacheData>() {
@Override
public void onSuccess(DiskCacheData diskCacheData) {
if (diskCacheData == null || diskCacheData.jsonString == null) {
callback.onCallBack(null);
Log.e("getAsync:", "无缓存");
return;
}
if (diskCacheData.isDue()) {
delete(key);
callback.onCallBack(null);
Log.e("getAsync:", "超时删除");
return;
}
Gson gson = new Gson();
Object t = gson.fromJson(diskCacheData.jsonString, dataClass);
callback.onCallBack((T) t);
Log.e("getAsync:", "未超时获取");
}
@Override
public void onFailure(Exception e) {
callback.onCallBack(null);
Log.e("getAsync:", "失败");
}
});
} else {
callback.onCallBack(null);
}
} catch (IOException e) {
e.printStackTrace();
callback.onCallBack(null);
}
}
/**
* 删除对应key的缓存
*/
public void delete(String key) {
try {
if (Reservoir.contains(key)) {
Reservoir.deleteAsync(key, null);
}
} catch (IOException e) {
e.printStackTrace();
}
}
public void deleteAsync(String key, ReservoirDeleteCallback callback) {
Reservoir.deleteAsync(key, callback);
}
/**
* 删除所有缓存
*/
public void clearAsync(ReservoirClearCallback callback) {
Reservoir.clearAsync(callback);
}
public void clear() {
Reservoir.clearAsync(null);
}

/**
* 用于数据存储的数据类
*/
private class DiskCacheData {
private String key;
private long saveTime;
private long delayTime;
private String jsonString;
public boolean isDue() {//用于超时判断
return System.currentTimeMillis() > saveTime + delayTime;
}
}
public interface SHCacheResponseCallBack {
void onCallBack(HttpResponse response);
}
public interface SHCacheGetCallback<T> {
void onCallBack(T t);
}
public interface SHCachePutCallback {
void onSucceed();
void onFailed();
}
}


SHDiskCache.png
举个例子:

结合我们的界面来使用一下这个类
ps:因为我们使用的是AsyncHttpClient,所以缓存的是HttpResponse,
代码:


private final String QUESTION_CACHE = "QquestionCache";//缓存key键
public void getResponse() {
SHDiskCache.getInstance().getResponse(QUESTION_CACHE, new SHDiskCache.SHCacheResponseCallBack() {
@Override
public void onCallBack(HttpResponse response) {
if (response == null) {//没有缓存的数据则去请求
loadData();
return;
}
handleResponse(response);//存在缓存则用于界面展示
}
});
}
/**
* 界面展示
*/
private void handleResponse(HttpResponse response) {
List<Question> questionList = response.getAsList("list", Question.class);
view.fillData(questionList);
}
/**
* 进行数据请求并存储
*/
private void loadData() {
RequestParams params = ResBox.commonRequestParams();
ApiHttpClient.post(context, ResBox.getInstance().loadQuestionList(), params, new HttpResponseHandler(view) {
@Override
public void onRequestSuccess(HttpResponse response) {
SHDiskCache.getInstance().putResponse(response, QUESTION_CACHE, 1, null);//存储
}
@Override
public void onRequestFail(HttpResponse response) { }
});
}
}

先记录到这,以后边做项目边补全一些其他的吧




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