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 :
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1. redis.host=192.168.1.20//redis的服务器地址
2. redis.port=6400//redis的服务端口
3. redis.pass=1234xxxxx//密码
4. redis.default.db=0//链接数据库
5. redis.timeout=100000//客户端超时时间单位是毫秒
6. redis.maxActive=300// 最大连接数
7. redis.maxIdle=100//最大空闲数
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1. redis.maxWait=1000//最大建立连接等待时间
2. 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
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1. <bean id="propertyConfigurerRedis" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
2. <property name="order" value="1" />
3. <property name="ignoreUnresolvablePlaceholders" value="true" />
4. <property name="locations">
5. <list>
6. <value>classpath:config/redis-manager-config.properties</value>
7. </list>
8. </property>
9. </bean>
10.
11. <!-- jedis pool配置 -->
12. <bean id="jedisPoolConfig" class="redis.clients.jedis.JedisPoolConfig">
13. <property name="maxActive" value="${redis.maxActive}" />
14. <property name="maxIdle" value="${redis.maxIdle}" />
15. <property name="maxWait" value="${redis.maxWait}" />
16. <property name="testOnBorrow" value="${redis.testOnBorrow}" />
17. </bean>
18.
19. <!-- spring data redis -->
20. <bean id="jedisConnectionFactory" class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory">
21. <property name="usePool" value="true"></property>
22. <property name="hostName" value="${redis.host}" />
23. <property name="port" value="${redis.port}" />
24. <property name="password" value="${redis.pass}" />
25. <property name="timeout" value="${redis.timeout}" />
26. <property name="database" value="${redis.default.db}"></property>
27. <constructor-arg index="0" ref="jedisPoolConfig" />
28. </bean>
29.
30. <bean id="redisTemplate" class="org.springframework.data.redis.core.StringRedisTemplate">
31. <property name="connectionFactory" ref="jedisConnectionFactory" />
32. </bean>
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- <!--配置一个基础类(之后的业务类继承于该类)、将redisTemplate注入 -->
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1. <bean id="redisBase" abstract="true">
2. <property name="template" ref="redisTemplate"></property>
3. </bean>
java代码:
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1. public class RedisBase {
2.
3. private StringRedisTemplate template;
4.
5. /**
6. * @return the template
7. */
8. public StringRedisTemplate getTemplate() {
9. return template;
10. }
11.
12. /**
13. * @param template the template to set
14. */
15. public void setTemplate(StringRedisTemplate template) {
16. this.template = template;
17. }
18.
19. }
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
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1. public class StudentCountDO {
2.
3. private Long id;
4.
5. private String studentId;
6.
7. private Long commentHeadCount;
8.
9. private Long docAttitudeScores;
10.
11. private Long guideServiceScores;
12.
13. private Long treatEffectCount;
14.
15. private Long treatEffectScores;
16.
17. private String gmtModified;
18.
19. private String gmtCreated;
20.
21. private Long waitingTimeScores;
22.
23. }
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1. StringRedisTemplate template = getTemplate();//获得上面注入的template
2. // save as hash 一般key都要加一个前缀,方便清除所有的这类key
3. "student:"+studentCount.getStudentId());
4.
5. new HashMap<String, String>();
6. "studentId", CommentUtils.convertNull(studentCount.getStudentId()));
7. "commentHeadCount", CommentUtils.convertLongToString(studentCount.getCommentHeadCount()));
8. "docAttitudeScores", CommentUtils.convertLongToString(studentCount.getDocAttitudeScores()));
9. "guideServicesScores", CommentUtils.convertLongToString(studentCount.getGuideServiceScores()));
10. "treatEffectCount", CommentUtils.convertLongToString(studentCount.getTreatEffectCount()));
11. "treatEffectScores", CommentUtils.convertLongToString(studentCount.getTreatEffectScores()));
12. "waitingTimeScores", CommentUtils.convertLongToString(studentCount.getWaitingTimeScores()));
13. try {
14. ops.putAll(data);
15. catch (Exception e) {
16. logger.error(CommentConstants.WRITE_EXPERT_COMMENT_COUNT_REDIS_ERROR + studentCount.studentCount(), e);
17. }
第二、 取出
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1. public StudentCountDO getStudentCommentCountInfo(String studentId) {
2. final String strkey = "student:"+ studentId;
3. return getTemplate().execute(new RedisCallback<StudentCountDO>() {
4. @Override
5. public StudentCountDO doInRedis(RedisConnection connection) throws DataAccessException {
6. byte[] bkey = getTemplate().getStringSerializer().serialize(strkey);
7. if (connection.exists(bkey)) {
8. byte[]> value = connection.hMGet(bkey,
9. "studentId"), getTemplate()
10. "commentHeadCount"), getTemplate()
11. "docAttitudeScores"), getTemplate()
12. "guideServicesScores"), getTemplate()
13. "treatEffectCount"), getTemplate()
14. "treatEffectScores"), getTemplate()
15. "waitingTimeScores"));
16. new StudentCountDO();
17. 0)));
18. studentCommentCountDO.setCommentHeadCount(Long.parseLong(getTemplate().getStringSerializer()
19. 1))));
20. studentCommentCountDO.setDocAttitudeScores(Long.parseLong(getTemplate().getStringSerializer()
21. 2))));
22. studentCommentCountDO.setGuideServiceScores(Long.parseLong(getTemplate().getStringSerializer()
23. 3))));
24. studentCommentCountDO.setTreatEffectCount(Long.parseLong(getTemplate().getStringSerializer()
25. 4))));
26. studentCommentCountDO.setTreatEffectScores(Long.parseLong(getTemplate().getStringSerializer()
27. 5))));
28. studentCommentCountDO.setWaitingTimeScores(Long.parseLong(getTemplate().getStringSerializer()
29. 6))));
30. return studentCommentCountDO;
31. }
32. return null;
33. }
34. });
35. }
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!
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1. private void clear(String pattern) {
2. StringRedisTemplate template = getTemplate();
3. Set<String> keys = template.keys(pattern);
4. if (!keys.isEmpty()) {
5. template.delete(keys);
6. }
7. }
pattern传入为student: 就可以将该类型的所有缓存清除掉喽!
1. 1, Redis Hello World 的例子
2.
3. 这里用的包是Jedis。下载地址https://github.com/xetorthio/jedis/downloads
4.
5. 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
6.
7. 1: Jedis jedis = new Jedis("localhost");
8.
9. 2: jedis.set("key", "Hello World!");
10.
11. 3: String value = jedis.get("key");
12.
13. 4: System.out.println(value);
14.
15. 分别测试下各种数据结构
16.
17. "==String==");
18.
19. new Jedis("localhost");
20.
21. //String
22.
23. "key", "Hello World!");
24.
25. "key");
26.
27. System.out.println(value);
28.
29.
30.
31. //List
32.
33. "==List==");
34.
35. "messages", "Hello how are you?");
36.
37. "messages", "Fine thanks. I'm having fun with redis.");
38.
39. "messages", "I should look into this NOSQL thing ASAP");
40.
41. "messages", 0, -1);
42.
43. System.out.println(values);
44.
45.
46.
47. //Set
48.
49. "==Set==");
50.
51. "myset", "1");
52.
53. "myset", "2");
54.
55. "myset", "3");
56.
57. "myset", "4");
58.
59. "myset");
60.
61. System.out.println(setValues);
62.
63.
64.
65. //Sorted Set
66.
67. "hackers", 1940, "Alan Kay");
68.
69. "hackers", 1953, "Richard Stallman");
70.
71. "hackers", 1965, "Yukihiro Matsumoto");
72.
73. "hackers", 1916, "Claude Shannon");
74.
75. "hackers", 1969, "Linus Torvalds");
76.
77. "hackers", 1912, "Alan Turing");
78.
79. "hackers", 0, -1);
80.
81. System.out.println(setValues);
82.
83.
84.
85. //Hash
86.
87. "==Hash==");
88.
89. new
90.
91. "name", "Akshi");
92.
93. "age", "2");
94.
95. "sex", "Female");
96.
97. "kid", pairs);
98.
99. "kid", new String[]{"name", "age", "sex"});
100.
101. System.out.println(values);
102.
103.
104.
105. "kid");
106.
107. System.out.println(setValues);
108.
109. "kid");
110.
111. System.out.println(values);
112.
113. "kid");
114.
115. 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。
1.
2. jedis.set("newkey", "Hello New New World!");
3. String value = jedis.get("newkey");
4. System.out.println(value);
5. jedis.save();
6.
7. 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。