package edu.hebtu.movingcampus.utils;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.lang.ref.SoftReference;
import java.util.LinkedHashMap;
import org.apache.http.util.EncodingUtils;
import android.annotation.SuppressLint;
import android.content.Context;
import android.database.Cursor;
import android.os.Build;
import android.os.Environment;
import edu.hebtu.movingcampus.AppInfo;
import edu.hebtu.movingcampus.config.Configs;
import edu.hebtu.movingcampus.config.Constants;
import edu.hebtu.movingcampus.db.DBHelper;
import edu.hebtu.movingcampus.db.RequestCacheColumn;
//整个调用方法就是异步，这里不需要异步
public class RequestCacheUtil {
private static final String TAG = "RequestCacheUtil";
private static LinkedHashMap<String, SoftReference<String>> RequestCache = new LinkedHashMap<String, SoftReference<String>>(
20);
// [start] 公有方法
/**
* it is a get way to visit a websit
* @param context
* @param RequestUrl
* @param source_type
* @param content_type
* @param UseCache
* @return
*/
public static String getRequestContentByGet(Context context, String RequestUrl,
String source_type, String content_type, boolean UseCache) {
DBHelper dbHelper = DBHelper.getInstance(context);
String md5 = MD5.encode(RequestUrl);
// 缓存目录
if (!CommonUtil.sdCardIsAvailable())/* true 为可用 */{
String cachePath = AppInfo.cacheDir + "/"
+ md5; // data里的缓存
return getCacheRequestByGet(context, RequestUrl, cachePath, source_type,
content_type, dbHelper, UseCache);
} else {
String imagePath = AppInfo.cacheDir + File.separator
+ md5; // sd卡
return getCacheRequestByGet(context, RequestUrl, imagePath, source_type,
content_type, dbHelper, UseCache);
}
}
/**
* it is a post way to visit a websit
* @param context
* @param RequestUrl
* @param source_type
* @param content_type
* @param UseCache
* @return
*/
public static String getRequestContentByPost(Context context, String RequestUrl,
String source_type, String content_type, boolean UseCache) {
DBHelper dbHelper = DBHelper.getInstance(context);
String md5 = MD5.encode(RequestUrl);
// 缓存目录
if (!CommonUtil.sdCardIsAvailable())/* true 为可用 */{
String cachePath = context.getCacheDir().getAbsolutePath() + "/"
+ md5; // data里的缓存
return getCacheRequestByPost(context, RequestUrl, cachePath, source_type,
content_type, dbHelper, UseCache);
} else {
String imagePath = getExternalCacheDir(context) + File.separator
+ md5; // sd卡
return getCacheRequestByPost(context, RequestUrl, imagePath, source_type,
content_type, dbHelper, UseCache);
}
}
// [end]
// [start] 私有方法
/**
* 获得程序在sd|root上的cahce目录
*
* @param context
* The context to use
* @return The external cache dir
*/
//TODO not used
@SuppressLint("NewApi")
public static File getExternalCacheDir(Context context) {
// android 2.2 以后才支持的特性
if (hasExternalCacheDir()) {
if(context.getExternalCacheDir()!=null)
return new File(context.getExternalCacheDir().getPath() + File.separator
+ "request");
}else{
// Before Froyo we need to construct the external cache dir ourselves
// 2.2以前我们需要自己构造
final String cacheDir = "/Android/data/" + context.getPackageName()
+ "/cache/request/";
if(Environment.getExternalStorageDirectory()!=null)
return new File(Environment.getExternalStorageDirectory().getPath() + cacheDir);
}
return new File(context.getCacheDir().getPath() + File.separator + "request");
}
private static boolean hasExternalCacheDir() {
return Build.VERSION.SDK_INT >= Build.VERSION_CODES.FROYO;
}
/**
* it is a get method that used to connect to web
* @param context
* @param requestUrl
* @param requestPath
* @param source_type
* @param content_type
* @param dbHelper
* @param useCache
* @return
*/
private static String getCacheRequestByGet(Context context, String requestUrl,
String requestPath, String source_type, String content_type,
DBHelper dbHelper, boolean useCache) {
String result = "";
if (useCache) {
result = getStringFromSoftReference(requestUrl);
if (!result.equals(null) && !result.equals("")) {
return result;
}
result = getStringFromLocal(requestPath, requestUrl, dbHelper);
if (!result.equals(null) && !result.equals("")) {
putStringForSoftReference(requestUrl, result);
return result;
}
}
// not using cache or cannot find any cache file in sqlite or localfile
// , getStringFromWeb instead
result = getStringFromWebByGet(context, requestPath, requestUrl,
source_type, content_type, dbHelper);
return result;
}
/**
* it is a post method that used to connect to web
* @param context
* @param requestUrl
* @param requestPath
* @param source_type
* @param content_type
* @param dbHelper
* @param useCache
* @return
*/
private static String getCacheRequestByPost(Context context, String requestUrl,
String requestPath, String source_type, String content_type,
DBHelper dbHelper, boolean useCache) {
String result = "";
if (useCache) {
result = getStringFromSoftReference(requestUrl);
if (!result.equals(null) && !result.equals("")) {
return result;
}
result = getStringFromLocal(requestPath, requestUrl, dbHelper);
if (!result.equals(null) && !result.equals("")) {
putStringForSoftReference(requestUrl, result);
return result;
}
}
// not using cache or cannot find any cache file in sqlite or localfile
// , getStringFromWeb instead
result = getStringFromWebByPost(context, requestPath, requestUrl,
source_type, content_type, dbHelper);
return result;
}
private static void putStringForSoftReference(String requestUrl,
String result) {
SoftReference<String> referece = new SoftReference<String>(result);
RequestCache.put(requestUrl, referece);
}
/**
* to visit a service by post method
* @param context
* @param requestPath
* @param requestUrl
* @param source_type
* @param content_type
* @param dbHelper
* @return
*/
private static String getStringFromWebByGet(Context context, String requestPath,
String requestUrl, String source_type, String content_type,
DBHelper dbHelper) {
String result = "";
try {
result = HttpUtils.getByHttpClient(context, requestUrl);
if (result.equals(null) || result.equals("")) {
return result;
}
// 更新数据库
Cursor cursor = getStringFromDB(requestUrl, dbHelper);
updateDB(cursor, requestUrl, source_type, content_type, dbHelper);
saveFileByRequestPath(requestPath, result);
putStringForSoftReference(requestUrl, result);
if (cursor != null)
cursor.close();
} catch (Exception e) {
e.printStackTrace();
}
return result;
}
/**
* to visit a service by post method
* @param context
* @param requestPath
* @param requestUrl
* @param source_type
* @param content_type
* @param dbHelper
* @return the result of request of web
*/
private static String getStringFromWebByPost(Context context, String requestPath,
String requestUrl, String source_type, String content_type,
DBHelper dbHelper) {
String result = "";
try {
result = HttpUtils.postByHttpClient(context, requestUrl);
if (result.equals(null) || result.equals("")) {
return result;
}
// 更新数据库
Cursor cursor = getStringFromDB(requestUrl, dbHelper);
updateDB(cursor, requestUrl, source_type, content_type, dbHelper);
saveFileByRequestPath(requestPath, result);
putStringForSoftReference(requestUrl, result);
if (cursor != null)
cursor.close();
} catch (Exception e) {
e.printStackTrace();
}
return result;
}
private static void saveFileByRequestPath(String requestPath, String result) {
deleteFileFromLocal(requestPath);
saveFileForLocal(requestPath, result);
}
private static void saveFileForLocal(String requestPath, String result) {
File file = new File(requestPath);
if (!file.exists()) {
try {
File parentFile = file.getParentFile();
if (!parentFile.exists()) {
parentFile.mkdirs();
}
file.createNewFile();
FileOutputStream fout = new FileOutputStream(file);
byte[] buffer = result.getBytes();
fout.write(buffer);
fout.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
private static void updateDB(Cursor cursor, String requestUrl,
String source_type, String content_type, DBHelper dbHelper) {
if (cursor != null && cursor.moveToFirst()) {
// 更新
int id = cursor.getInt(cursor
.getColumnIndex(RequestCacheColumn._ID));
long timestamp = System.currentTimeMillis();
String SQL = "update " + RequestCacheColumn.TABLE_NAME + " set "
+ RequestCacheColumn.Timestamp + "=" + timestamp
+ " where " + RequestCacheColumn._ID + "=" + id;
dbHelper.ExecSQL(SQL);
} else {
// 添加
String SQL = "insert into " + RequestCacheColumn.TABLE_NAME + "("
+ RequestCacheColumn.URL + ","
+ RequestCacheColumn.SOURCE_TYPE + ","
+ RequestCacheColumn.Content_type + ","
+ RequestCacheColumn.Timestamp + ") values('" + requestUrl
+ "','" + source_type + "','" + content_type + "','"
+ System.currentTimeMillis() + "')";
dbHelper.ExecSQL(SQL);
}
}
private static String getStringFromSoftReference(String requestUrl) {
if (RequestCache.containsKey(requestUrl)) {
SoftReference<String> reference = RequestCache.get(requestUrl);
String result = (String) reference.get();
if (result != null && !result.equals("")) {
return result;
}
}
return "";
}
private static String getStringFromLocal(String requestPath,
String requestUrl, DBHelper dbHelper) {
String result = "";
Cursor cursor = getStringFromDB(requestUrl, dbHelper);
if (cursor != null && cursor.moveToFirst()) {
Long timestamp = cursor.getLong(cursor
.getColumnIndex(RequestCacheColumn.Timestamp));
String strContentType = cursor.getString(cursor
.getColumnIndex(RequestCacheColumn.Content_type));
long span = getSpanTimeFromConfigs(strContentType);
long nowTime = System.currentTimeMillis();
if ((nowTime - timestamp) > span * 60 * 1000) {
// 过期
deleteFileFromLocal(requestPath);
} else {
// 没过期
result = getFileFromLocal(requestPath);
}
cursor.close();
}
return result;
}
/**
* 从db中查找数据
*
* @param requestUrl
* @param dbHelper
* @return
*/
private static Cursor getStringFromDB(String requestUrl, DBHelper dbHelper) {
String SQL = "select * from " + RequestCacheColumn.TABLE_NAME
+ " where " + RequestCacheColumn.URL + "='" + requestUrl + "'";
return dbHelper.rawQuery(SQL, new String[] {});
}
private static String getFileFromLocal(String requestPath) {
// TODO Auto-generated method stub
File file = new File(requestPath);
String result = "";
if (file.exists()) {
FileInputStream fileIn;
try {
fileIn = new FileInputStream(file);
int length = fileIn.available();
byte[] buffer = new byte[length];
fileIn.read(buffer);
result = EncodingUtils.getString(buffer, "UTF-8");
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return result;
}
return "";
}
private static void deleteFileFromLocal(String requestPath) {
// TODO Auto-generated method stub
File file = new File(requestPath);
if (file.exists()) {
file.delete();
}
}
/**
* 根据类型获取缓存时间
*
* @param str
* @return
*/
private static long getSpanTimeFromConfigs(String str) {
long span = 0;
if (str.equals(Constants.DBContentType.Content_list)) {
span = Configs.Content_ListCacheTime;
} else if (str.equals(Constants.DBContentType.Content_content)) {
span = Configs.Content_ContentCacheTime;
} else {
span = Configs.Content_DefaultCacheTime;
}
return span;
}
// [end]
}