今天看了一些redis的客户端实现、主要分为spring-redis-data 、jredis
今天先记录下spring-redis-data的学习心得;
spring-redis-data 中我目前主要用了它的存、取、清除。
先看配置吧redis-manager-config.properties :
- redis.host=192.168.1.20//redis的服务器地址
- redis.port=6400//redis的服务端口
- redis.pass=1234xxxxx//密码
- redis.default.db=0//链接数据库
- redis.timeout=100000//客户端超时时间单位是毫秒
- redis.maxActive=300// 最大连接数
- redis.maxIdle=100//最大空闲数
- redis.maxWait=1000//最大建立连接等待时间
- redis.testOnBorrow=true//<span style="font-size:12px;">指明是否在从池中取出连接前进行检验,如果检验失败,则从池中去除连接并尝试取出另一个</span>
spring 中配置
- <bean id="propertyConfigurerRedis" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
- <property name="order" value="1" />
- <property name="ignoreUnresolvablePlaceholders" value="true" />
- <property name="locations">
- <list>
- <value>classpath:config/redis-manager-config.properties</value>
- </list>
- </property>
- </bean>
- <!-- jedis pool配置 -->
- <bean id="jedisPoolConfig" class="redis.clients.jedis.JedisPoolConfig">
- <property name="maxActive" value="${redis.maxActive}" />
- <property name="maxIdle" value="${redis.maxIdle}" />
- <property name="maxWait" value="${redis.maxWait}" />
- <property name="testOnBorrow" value="${redis.testOnBorrow}" />
- </bean>
- <!-- spring data redis -->
- <bean id="jedisConnectionFactory" class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory">
- <property name="usePool" value="true"></property>
- <property name="hostName" value="${redis.host}" />
- <property name="port" value="${redis.port}" />
- <property name="password" value="${redis.pass}" />
- <property name="timeout" value="${redis.timeout}" />
- <property name="database" value="${redis.default.db}"></property>
- <constructor-arg index="0" ref="jedisPoolConfig" />
- </bean>
- <bean id="redisTemplate" class="org.springframework.data.redis.core.StringRedisTemplate">
- <property name="connectionFactory" ref="jedisConnectionFactory" />
- </bean>
- <!--配置一个基础类(之后的业务类继承于该类)、将redisTemplate注入 -->
- <bean id="redisBase" abstract="true">
- <property name="template" ref="redisTemplate"></property>
- </bean>
java代码:
- public class RedisBase {
- private StringRedisTemplate template;
- /**
- * @return the template
- */
- public StringRedisTemplate getTemplate() {
- return template;
- }
- /**
- * @param template the template to set
- */
- public void setTemplate(StringRedisTemplate template) {
- this.template = template;
- }
- }
继续:
下面就是具体redis的值的写入、读出、清除缓存喽!
第一:写入
- public class StudentCountDO {
- private Long id;
- private String studentId;
- private Long commentHeadCount;
- private Long docAttitudeScores;
- private Long guideServiceScores;
- private Long treatEffectCount;
- private Long treatEffectScores;
- private String gmtModified;
- private String gmtCreated;
- private Long waitingTimeScores;
- }
- StringRedisTemplate template = getTemplate();//获得上面注入的template
- // save as hash 一般key都要加一个前缀,方便清除所有的这类key
- BoundHashOperations<String, String, String> ops = template.boundHashOps("student:"+studentCount.getStudentId());
- Map<String, String> data = new HashMap<String, String>();
- data.put("studentId", CommentUtils.convertNull(studentCount.getStudentId()));
- data.put("commentHeadCount", CommentUtils.convertLongToString(studentCount.getCommentHeadCount()));
- data.put("docAttitudeScores", CommentUtils.convertLongToString(studentCount.getDocAttitudeScores()));
- data.put("guideServicesScores", CommentUtils.convertLongToString(studentCount.getGuideServiceScores()));
- data.put("treatEffectCount", CommentUtils.convertLongToString(studentCount.getTreatEffectCount()));
- data.put("treatEffectScores", CommentUtils.convertLongToString(studentCount.getTreatEffectScores()));
- data.put("waitingTimeScores", CommentUtils.convertLongToString(studentCount.getWaitingTimeScores()));
- try {
- ops.putAll(data);
- } catch (Exception e) {
- logger.error(CommentConstants.WRITE_EXPERT_COMMENT_COUNT_REDIS_ERROR + studentCount.studentCount(), e);
- }
第二、 取出
- public StudentCountDO getStudentCommentCountInfo(String studentId) {
- final String strkey = "student:"+ studentId;
- return getTemplate().execute(new RedisCallback<StudentCountDO>() {
- @Override
- public StudentCountDO doInRedis(RedisConnection connection) throws DataAccessException {
- byte[] bkey = getTemplate().getStringSerializer().serialize(strkey);
- if (connection.exists(bkey)) {
- List<byte[]> value = connection.hMGet(bkey,
- getTemplate().getStringSerializer().serialize("studentId"), getTemplate()
- .getStringSerializer().serialize("commentHeadCount"), getTemplate()
- .getStringSerializer().serialize("docAttitudeScores"), getTemplate()
- .getStringSerializer().serialize("guideServicesScores"), getTemplate()
- .getStringSerializer().serialize("treatEffectCount"), getTemplate()
- .getStringSerializer().serialize("treatEffectScores"), getTemplate()
- .getStringSerializer().serialize("waitingTimeScores"));
- StudentCountDO studentCommentCountDO = new StudentCountDO();
- studentCommentCountDO.setExpertId(getTemplate().getStringSerializer().deserialize(value.get(0)));
- studentCommentCountDO.setCommentHeadCount(Long.parseLong(getTemplate().getStringSerializer()
- .deserialize(value.get(1))));
- studentCommentCountDO.setDocAttitudeScores(Long.parseLong(getTemplate().getStringSerializer()
- .deserialize(value.get(2))));
- studentCommentCountDO.setGuideServiceScores(Long.parseLong(getTemplate().getStringSerializer()
- .deserialize(value.get(3))));
- studentCommentCountDO.setTreatEffectCount(Long.parseLong(getTemplate().getStringSerializer()
- .deserialize(value.get(4))));
- studentCommentCountDO.setTreatEffectScores(Long.parseLong(getTemplate().getStringSerializer()
- .deserialize(value.get(5))));
- studentCommentCountDO.setWaitingTimeScores(Long.parseLong(getTemplate().getStringSerializer()
- .deserialize(value.get(6))));
- return studentCommentCountDO;
- }
- return null;
- }
- });
- }
这个存和取的过程其实是把对象中的各个字段序列化之后存入到hashmap 、取出来的时候在进行按照存入进去的顺序进行取出。
第三 清除
这个就根据前面的前缀很简单了,一句代码就搞定啦!
- private void clear(String pattern) {
- StringRedisTemplate template = getTemplate();
- Set<String> keys = template.keys(pattern);
- if (!keys.isEmpty()) {
- template.delete(keys);
- }
- }
pattern传入为student: 就可以将该类型的所有缓存清除掉喽!
- 1, Redis Hello World 的例子
- 这里用的包是Jedis。下载地址https://github.com/xetorthio/jedis/downloads
- 把jar包引入工程,打开redis的服务器(redis下载及安装见初步理解Redis及其安装配置)。开始打招呼的例子,如下
- 1: Jedis jedis = new Jedis("localhost");
- 2: jedis.set("key", "Hello World!");
- 3: String value = jedis.get("key");
- 4: System.out.println(value);
- 分别测试下各种数据结构
- System.out.println("==String==");
- Jedis jedis = new Jedis("localhost");
- //String
- jedis.set("key", "Hello World!");
- String value = jedis.get("key");
- System.out.println(value);
- //List
- System.out.println("==List==");
- jedis.rpush("messages", "Hello how are you?");
- jedis.rpush("messages", "Fine thanks. I'm having fun with redis.");
- jedis.rpush("messages", "I should look into this NOSQL thing ASAP");
- List<String> values = jedis.lrange("messages", 0, -1);
- System.out.println(values);
- //Set
- System.out.println("==Set==");
- jedis.sadd("myset", "1");
- jedis.sadd("myset", "2");
- jedis.sadd("myset", "3");
- jedis.sadd("myset", "4");
- Set<String> setValues = jedis.smembers("myset");
- System.out.println(setValues);
- //Sorted Set
- jedis.zadd("hackers", 1940, "Alan Kay");
- jedis.zadd("hackers", 1953, "Richard Stallman");
- jedis.zadd("hackers", 1965, "Yukihiro Matsumoto");
- jedis.zadd("hackers", 1916, "Claude Shannon");
- jedis.zadd("hackers", 1969, "Linus Torvalds");
- jedis.zadd("hackers", 1912, "Alan Turing");
- setValues = jedis.zrange("hackers", 0, -1);
- System.out.println(setValues);
- //Hash
- System.out.println("==Hash==");
- Map<String, String> pairs = new HashMap<String, String>();
- pairs.put("name", "Akshi");
- pairs.put("age", "2");
- pairs.put("sex", "Female");
- jedis.hmset("kid", pairs);
- values = jedis.hmget("kid", new String[]{"name", "age", "sex"});
- System.out.println(values);
- setValues = jedis.hkeys("kid");
- System.out.println(setValues);
- values = jedis.hvals("kid");
- System.out.println(values);
- pairs = jedis.hgetAll("kid");
- System.out.println(pairs);
- 然后解决持久化的问题
- redis是把所有的数据都放在内存的一种机制,需要经常同步到磁盘保证数据的持久化。数据全放在内存里,真的很担心我的小机器啊~回头数据大了调台式机上把,再大了就。。。
- 这个题目比较大些,以后可以单独写几篇,现在急着用,入门么,解决问题先。主要是两种机制,快照(Snapshotting)和AOF(Append-only file)。AOF每次写操作都会写日志,服务器当机的时候从那些日志文件里恢复。不过日志文件会特别大,我的机器肯定承受不起。快照是默认的方式,默认是每小时更新一次,手动调用save, shutdown, slave这些命令也会写日志。测试下save。
- 先用客户端查询一下刚才代码插入的东西。
- image
- 东西还是在内存里的。然后把服务器关了。重新开启,还是有结果。
- image
- 验证是不是因为时间过太久了自动保存了,用java代码新插入一个值。继续关服务器和重启等操作。
- image
- 没有值。证明之前的值存在确实是因为自动保存了,接着重新插入(这个如果覆盖是个什么情况呢:貌似直接无情地覆盖了),然后执行下保存。之后关闭,重启。
- jedis.set("newkey", "Hello New New World!");
- String value = jedis.get("newkey");
- System.out.println(value);
- jedis.save();
- image
- 可以看到newkey的值了,而且是覆盖后的。save执行后会进行一次日志备份。够用了,先到这里吧。
- 转载于http://blog.youkuaiyun.com/samtribiani/article/details/7609322