软件定制公司设计方案,乐云seo可视化网站建设,杭州集团网站建设,h5四合一网站建设转#xff1a;https://www.cnblogs.com/JAYIT/p/5647924.html
所谓缓存#xff0c;就是将程序或系统经常要调用的对象存在内存中#xff0c;一遍其使用时可以快速调用#xff0c;不必再去创建新的重复的实例。这样做可以减少系统开销#xff0c;提高系统效率。 所谓缓存https://www.cnblogs.com/JAYIT/p/5647924.html
所谓缓存就是将程序或系统经常要调用的对象存在内存中一遍其使用时可以快速调用不必再去创建新的重复的实例。这样做可以减少系统开销提高系统效率。 所谓缓存就是将程序或系统经常要调用的对象存在内存中一遍其使用时可以快速调用不必再去创建新的重复的实例。这样做可以减少系统开销提高系统效率。
缓存主要可分为二大类:
一、通过文件缓存,顾名思义文件缓存是指把数据存储在磁盘上不管你是以XML格式序列化文件DAT格式还是其它文件格式
二、内存缓存也就是实现一个类中静态Map,对这个Map进行常规的增删查.
代码如下package lhm.hcy.guge.frameset.cache;import java.util.*;//Description: 管理缓存//可扩展的功能当chche到内存溢出时必须清除掉最早期的一些缓存对象这就要求对每个缓存对象保存创建时间public class CacheManager {private static HashMap cacheMap new HashMap();//单实例构造方法private CacheManager() {super();}//获取布尔值的缓存public static boolean getSimpleFlag(String key){try{return (Boolean) cacheMap.get(key);}catch(NullPointerException e){return false;}}public static long getServerStartdt(String key){try {return (Long)cacheMap.get(key);} catch (Exception ex) {return 0;}}//设置布尔值的缓存public synchronized static boolean setSimpleFlag(String key,boolean flag){if (flag getSimpleFlag(key)) {//假如为真不允许被覆盖return false;}else{cacheMap.put(key, flag);return true;}}public synchronized static boolean setSimpleFlag(String key,long serverbegrundt){if (cacheMap.get(key) null) {cacheMap.put(key,serverbegrundt);return true;}else{return false;}}//得到缓存。同步静态方法private synchronized static Cache getCache(String key) {return (Cache) cacheMap.get(key);}//判断是否存在一个缓存private synchronized static boolean hasCache(String key) {return cacheMap.containsKey(key);}//清除所有缓存public synchronized static void clearAll() {cacheMap.clear();}//清除某一类特定缓存,通过遍历HASHMAP下的所有对象来判断它的KEY与传入的TYPE是否匹配public synchronized static void clearAll(String type) {Iterator i cacheMap.entrySet().iterator();String key;ArrayList arr new ArrayList();try {while (i.hasNext()) {java.util.Map.Entry entry (java.util.Map.Entry) i.next();key (String) entry.getKey();if (key.startsWith(type)) { //如果匹配则删除掉arr.add(key);}}for (int k 0; k arr.size(); k) {clearOnly(arr.get(k));}} catch (Exception ex) {ex.printStackTrace();}}//清除指定的缓存public synchronized static void clearOnly(String key) {cacheMap.remove(key);}//载入缓存public synchronized static void putCache(String key, Cache obj) {cacheMap.put(key, obj);}//获取缓存信息public static Cache getCacheInfo(String key) {if (hasCache(key)) {Cache cache getCache(key);if (cacheExpired(cache)) { //调用判断是否终止方法cache.setExpired(true);}return cache;}elsereturn null;}//载入缓存信息public static void putCacheInfo(String key, Cache obj, long dt,boolean expired) {Cache cache new Cache();cache.setKey(key);cache.setTimeOut(dt System.currentTimeMillis()); //设置多久后更新缓存cache.setValue(obj);cache.setExpired(expired); //缓存默认载入时终止状态为FALSEcacheMap.put(key, cache);}//重写载入缓存信息方法public static void putCacheInfo(String key,Cache obj,long dt){Cache cache new Cache();cache.setKey(key);cache.setTimeOut(dtSystem.currentTimeMillis());cache.setValue(obj);cache.setExpired(false);cacheMap.put(key,cache);}//判断缓存是否终止public static boolean cacheExpired(Cache cache) {if (null cache) { //传入的缓存不存在return false;}long nowDt System.currentTimeMillis(); //系统当前的毫秒数long cacheDt cache.getTimeOut(); //缓存内的过期毫秒数if (cacheDt 0||cacheDtnowDt) { //过期时间小于等于零时,或者过期时间大于当前时间时则为FALSEreturn false;} else { //大于过期时间 即过期return true;}}//获取缓存中的大小public static int getCacheSize() {return cacheMap.size();}//获取指定的类型的大小public static int getCacheSize(String type) {int k 0;Iterator i cacheMap.entrySet().iterator();String key;try {while (i.hasNext()) {java.util.Map.Entry entry (java.util.Map.Entry) i.next();key (String) entry.getKey();if (key.indexOf(type) ! -1) { //如果匹配则删除掉k;}}} catch (Exception ex) {ex.printStackTrace();}return k;}//获取缓存对象中的所有键值名称public static ArrayList getCacheAllkey() {ArrayList a new ArrayList();try {Iterator i cacheMap.entrySet().iterator();while (i.hasNext()) {java.util.Map.Entry entry (java.util.Map.Entry) i.next();a.add((String) entry.getKey());}} catch (Exception ex) {} finally {return a;}}//获取缓存对象中指定类型 的键值名称public static ArrayList getCacheListkey(String type) {ArrayList a new ArrayList();String key;try {Iterator i cacheMap.entrySet().iterator();while (i.hasNext()) {java.util.Map.Entry entry (java.util.Map.Entry) i.next();key (String) entry.getKey();if (key.indexOf(type) ! -1) {a.add(key);}}} catch (Exception ex) {} finally {return a;}}}package lhm.hcy.guge.frameset.cache;public class Cache {private String key;//缓存IDprivate Object value;//缓存数据private long timeOut;//更新时间private boolean expired; //是否终止public Cache() {super();}public Cache(String key, Object value, long timeOut, boolean expired) {this.key key;this.value value;this.timeOut timeOut;this.expired expired;}public String getKey() {return key;}public long getTimeOut() {return timeOut;}public Object getValue() {return value;}public void setKey(String string) {key string;}public void setTimeOut(long l) {timeOut l;}public void setValue(Object object) {value object;}public boolean isExpired() {return expired;}public void setExpired(boolean b) {expired b;}
}//测试类
class Test {public static void main(String[] args) {System.out.println(CacheManager.getSimpleFlag(alksd));
// CacheManager.putCache(abc, new Cache());
// CacheManager.putCache(def, new Cache());
// CacheManager.putCache(ccc, new Cache());
// CacheManager.clearOnly();
// Cache c new Cache();
// for (int i 0; i 10; i) {
// CacheManager.putCache( i, c);
// }
// CacheManager.putCache(aaaaaaaa, c);
// CacheManager.putCache(abchcy;alskd, c);
// CacheManager.putCache(cccccccc, c);
// CacheManager.putCache(abcoqiwhcy, c);
// System.out.println(删除前的大小CacheManager.getCacheSize());
// CacheManager.getCacheAllkey();
// CacheManager.clearAll(aaaa);
// System.out.println(删除后的大小CacheManager.getCacheSize());
// CacheManager.getCacheAllkey();}
}
spring中的redis service实现package com.eshore.ismp.cache.redis;import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.dao.DataAccessException;
import org.springframework.data.redis.connection.RedisConnection;
import org.springframework.data.redis.core.RedisCallback;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Service;Service
public class RedisService {private static String redisCode utf-8;Autowiredprivate RedisTemplateString, String redisTemplate;/*** 从指定的列表右边出队,添加到目的列表中** param srckey* 源列表* param dstkey* 目的列表* return*/public String rpoppush(final String srckey, final String dstkey) {return redisTemplate.execute(new RedisCallbackString() {public String doInRedis(RedisConnection connection)throws DataAccessException {try {return new String (connection.rPopLPush(srckey.getBytes(), dstkey.getBytes()), redisCode);} catch (UnsupportedEncodingException e) {e.printStackTrace();}return ;}});}/*** 获取指定列表的范围数据** param key* 列表名* param start* 开始位置* param end* 结束位置* return*/public ListString lrange(final String key, final int start, final int end) {return redisTemplate.execute(new RedisCallbackListString() {ListString result new ArrayListString();public ListString doInRedis(RedisConnection connection)throws DataAccessException {Listbyte[] bytelist connection.lRange(key.getBytes(), start, end);for (byte[] b : bytelist) {try {result.add(new String(b, redisCode));} catch (UnsupportedEncodingException e) {e.printStackTrace();}}return result;}});}/*** 从队列的左边取出一条数据** param key* 列表名* return*/public String lpop(final String key) {return redisTemplate.execute(new RedisCallbackString() {public String doInRedis(RedisConnection connection)throws DataAccessException {byte[] result connection.lPop(key.getBytes());if (result ! null) {try {return new String (result , redisCode);} catch (UnsupportedEncodingException e) {e.printStackTrace();}}return ;}});}/*** 从队列的左边取出一条数据** param key* 列表名* return*/public List? lpop(final String key,final int size) {ListObject list redisTemplate.executePipelined(new RedisCallbackListObject() {public ListObject doInRedis(RedisConnection connection)throws DataAccessException {byte[] keyBytes key.getBytes();for(int i 0 ; i size; i){connection.lPop(keyBytes);}return null;}});list.removeAll(Collections.singleton(null));return list;}/*** 从列表右边添加数据** param key* 列表名* param values* 数据* return*/public long rpush(final String key, final String... values) {return redisTemplate.execute(new RedisCallbackLong() {public Long doInRedis(RedisConnection connection)throws DataAccessException {long result 0;for (String v : values) {result connection.rPush(key.getBytes(), v.getBytes());}return result;}});}/*** 从列表右边添加数据** param key* 列表名* param values* 数据* return*/public long rpush(final String key, final CollectionString values) {return redisTemplate.opsForList().rightPushAll(key, values);}public int hmset(final String key, final MapString,String values) {try{redisTemplate.opsForHash().putAll(key, values);}catch(Exception e){e.printStackTrace();return -1;}return 0 ;}public String hget(final String key, final String field){Object obj redisTemplate.opsForHash().get(key, field);return String.valueOf(obj);}public List? hkeys(final String key){return redisTemplate.execute(new RedisCallbackListObject(){ListObject list new ArrayListObject();public ListObject doInRedis(RedisConnection connection)throws DataAccessException {Setbyte[] setsconnection.hKeys(key.getBytes());if(!sets.isEmpty()){for(byte[] b : sets){list.add(redisTemplate.getValueSerializer().deserialize(b).toString());}return list;}return null;}});}/*** 删除hash表中field*/public void hdel(final String key,final String field){redisTemplate.opsForHash().delete(key, field);}/*** 从列表右边添加数据,并且设置列表的存活时间** param key* 列表名* param liveTime* 存活时间(单位 秒)* param values* 数据* return*/public long rpush(final String key, final int liveTime, final String... values) {return redisTemplate.execute(new RedisCallbackLong() {public Long doInRedis(RedisConnection connection)throws DataAccessException {long result 0;for (String v : values) {connection.rPush(key.getBytes(), v.getBytes());}if (liveTime 0) {connection.expire(key.getBytes(), liveTime);} return result;}});}/*** 从队列的右边取出一条数据** param key* 列表名* return*/public String rpop(final String key) {return redisTemplate.execute(new RedisCallbackString() {public String doInRedis(RedisConnection connection)throws DataAccessException {byte[] result connection.rPop(key.getBytes());if(result ! null ){try {return new String (result, redisCode);} catch (UnsupportedEncodingException e) {e.printStackTrace();}}return ;}});}/*** 把一个值添加到对应列表中** param key* 列表名* param index* 添加的位置* param value* 数据* return*/public String lset(final String key, final long index, final String value) {return redisTemplate.execute(new RedisCallbackString() {public String doInRedis(RedisConnection connection)throws DataAccessException {connection.lSet(key.getBytes(), index, value.getBytes());return success;}});}/*** 把所有数据添加到一个列表中** param key* 列表名* param values* 数据* return*/public long lpush(String key, String... values) {return this.lpush(key, 0, values);}/*** 把所有数据添加到一个列表中,并且设置列表的存活时间** param key* 列表名* param values* 数据* param liveTime* 存活时间--单位(秒)* return*/public long lpush(final String key,final int liveTime, final String... values) {return redisTemplate.execute(new RedisCallbackLong() {public Long doInRedis(RedisConnection connection)throws DataAccessException {long result 0;for (String v : values){result connection.lPush(key.getBytes(), v.getBytes());}if (liveTime 0) {connection.expire(key.getBytes(), liveTime);}return result;}});}/*** 返回列表的长度** param key* return*/public long llen(final String key) {return redisTemplate.execute(new RedisCallbackLong() {public Long doInRedis(RedisConnection connection)throws DataAccessException {return connection.lLen(key.getBytes());}});}/*** 删除列表中对应值的元素** param key* 列表名* param count* 删除多少个相同的元素* param value* 数据* return*/public long lrem(final String key, final long count, final String value) {return redisTemplate.execute(new RedisCallbackLong() {public Long doInRedis(RedisConnection connection)throws DataAccessException {return connection.lRem(key.getBytes(), count, value.getBytes());}});}/*** 通过keys批量删除** param key*/public long del(final String... keys) {return redisTemplate.execute(new RedisCallbackLong() {public Long doInRedis(RedisConnection connection)throws DataAccessException {long result 0;for (String k : keys) {result connection.del(k.getBytes());}return result;}});}/**** //DESC 删除单个key* time: 2016年5月27日 上午9:00:36* param key* return* throws*/public long del(final String key){return redisTemplate.execute(new RedisCallbackLong(){Overridepublic Long doInRedis(RedisConnection connection)throws DataAccessException {return connection.del(key.getBytes());}});}/*** 添加key value 并且设置存活时间(byte)** param key* param value* param liveTime*/public void set(final byte[] key, final byte[] value, final long liveTime) {redisTemplate.execute(new RedisCallbackLong() {public Long doInRedis(RedisConnection connection)throws DataAccessException {connection.set(key, value);if (liveTime 0) {connection.expire(key, liveTime);}return 1L;}});}/*** 添加key value 并且设置存活时间** param key* param value* param liveTime* 单位秒*/public void set(String key, String value, long liveTime) {this.set(key.getBytes(), value.getBytes(), liveTime);}/*** 添加key value** param key* param value*/public void set(String key, String value) {this.set(key, value, 0L);}/*** 添加key value** param key* param value*/public void setMulti(final MapString,String map) {setMulti(map,0L);}/*** 添加key value** param key* param value*/public void setMulti(final MapString,String map,final long liveTime) {redisTemplate.executePipelined(new RedisCallbackString() {public String doInRedis(RedisConnection connection)throws DataAccessException {SetMap.EntryString, String set map.entrySet();for (EntryString, String entry : set) {connection.set(entry.getKey().getBytes(), entry.getValue().getBytes());if (liveTime 0) {connection.expire(entry.getKey().getBytes(), liveTime);}}return null;}});}/*** 添加key value (字节)(序列化)** param key* param value*/public void set(byte[] key, byte[] value) {this.set(key, value, 0L);}/*** 获取redis value (String)** param key* return*/public String get(final String key) {return redisTemplate.execute(new RedisCallbackString() {public String doInRedis(RedisConnection connection)throws DataAccessException {byte[] result connection.get(key.getBytes());if (result ! null) {try {return new String (result ,redisCode);} catch (UnsupportedEncodingException e) {e.printStackTrace();} }return ;}});}/*** 如果key不存在添加key value 并且设置存活时间(byte)当key已经存在时就不做任何操作** param key* param value* param liveTime*/public long setnx(final byte[] key, final byte[] value, final long liveTime) {return redisTemplate.execute(new RedisCallbackLong() {public Long doInRedis(RedisConnection connection)throws DataAccessException {long result 0l;boolean isSuccess connection.setNX(key, value);if (isSuccess) {if (liveTime 0) {connection.expire(key, liveTime);}result 1l;}return result;}});}/*** 如果key不存在添加key value 并且设置存活时间当key已经存在时就不做任何操作** param key* param value* param liveTime* 单位秒*/public long setnx(String key, String value, long liveTime) {return this.setnx(key.getBytes(), value.getBytes(), liveTime);}/*** 如果key不存在添加key value当key已经存在时就不做任何操作** param key* param value*/public long setnx(String key, String value) {return this.setnx(key, value, 0L);}/*** 如果key不存在添加key value (字节)(序列化)当key已经存在时就不做任何操作** param key* param value*/public long setnx(byte[] key, byte[] value) {return this.setnx(key, value, 0L);}/*** 通过正则匹配keys** param pattern* return*/public SetString keys(final String pattern) {return redisTemplate.execute(new RedisCallbackSetString() {public SetString doInRedis(RedisConnection connection)throws DataAccessException {SetString result new HashSetString();Setbyte[] data connection.keys(pattern.getBytes());for(byte[] d : data){try {result.add(new String(d,redisCode));} catch (UnsupportedEncodingException e) {e.printStackTrace();}}return result;}});}/*** 检查key是否已经存在** param key* return*/public boolean exists(final String key) {return redisTemplate.execute(new RedisCallbackBoolean() {public Boolean doInRedis(RedisConnection connection)throws DataAccessException {return connection.exists(key.getBytes());}});}/*** 清空redis 所有数据** return*/public String flushDB() {return redisTemplate.execute(new RedisCallbackString() {public String doInRedis(RedisConnection connection)throws DataAccessException {connection.flushDb();return success;}});}/*** 查看redis里有多少数据*/public long dbSize() {return redisTemplate.execute(new RedisCallbackLong() {public Long doInRedis(RedisConnection connection)throws DataAccessException {return connection.dbSize();}});}/*** 检查是否连接成功** return*/public String ping() {return redisTemplate.execute(new RedisCallbackString() {public String doInRedis(RedisConnection connection)throws DataAccessException {return connection.ping();}});}/*** 设置key的生命周期** param key* param seconds* 单位(秒)* return*/public boolean expire(final String key, final long seconds) {return redisTemplate.execute(new RedisCallbackBoolean() {public Boolean doInRedis(RedisConnection connection)throws DataAccessException {return connection.expire(key.getBytes(), seconds);}});}/*** 自增长** param key* param length 增长步长* return*/public long incr (final String key){return redisTemplate.execute(new RedisCallbackLong() {public Long doInRedis(RedisConnection connection)throws DataAccessException {return connection.incr(key.getBytes());}});}/*** 自增长** param key* param length 增长步长* return*/public long incrBy (final String key, final long len){return redisTemplate.execute(new RedisCallbackLong() {public Long doInRedis(RedisConnection connection)throws DataAccessException {return connection.incrBy(key.getBytes(), len);}});}/*** 自增长** param key* param length 增长步长* return*/public double incrBy (final String key, final double len){return redisTemplate.execute(new RedisCallbackDouble() {public Double doInRedis(RedisConnection connection)throws DataAccessException {return connection.incrBy(key.getBytes(), len);}});}public long eval(final String luaCommand) {return redisTemplate.execute(new RedisCallbackLong() {public Long doInRedis(RedisConnection connection) throws DataAccessException {return connection.eval(luaCommand.getBytes(), null,0);}});}}缓存应用package com.eshore.ismp.cache.processor;import org.apache.log4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.util.StringUtils;import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.eshore.ismp.cache.redis.RedisService;
import com.eshore.ismp.common.entity.ResultInfo;/**** //DESC: 管理门户缓存接口* author zzx* date 2016年5月20日 上午11:50:25*/
Service
public class AdminWebProcessor {private static final Logger logger Logger.getLogger(AdminWebProcessor.class);private static final String ADMINWEB_USER ADMINWEB_USER_;private static final Long LIVETIME 60*30L;AutowiredRedisService redisService;public String put(JSONObject param){Long userId param.getLong(user_id);String userInfo param.getString(user_info);ResultInfo rs new ResultInfo();if(userIdnull || StringUtils.isEmpty(userInfo)){logger.error(参数错误);rs.setResult_code(2501);rs.setResult_detail(参数错误);return JSON.toJSONString(rs);}String key ADMINWEB_USERuserId;redisService.set(key , userInfo,LIVETIME);rs.setResult_code(0);rs.setResult_detail(success);return JSON.toJSONString(rs);}public String get(JSONObject param){Long userId param.getLong(user_id);String key ADMINWEB_USERuserId;ResultInfo rs new ResultInfo();String user redisService.get(key);rs.setResult_code(0);rs.setResult_detail(success);rs.setResult_data(user);return JSON.toJSONString(rs);}public String delete(JSONObject param){Long userId param.getLong(user_id);String key ADMINWEB_USERuserId;ResultInfo rs new ResultInfo();long isDel redisService.del(key);rs.setResult_code(0);rs.setResult_detail(success);return JSON.toJSONString(rs);}}
