主要学习https://github.com/thinkgem/jeesite。一下代码均参考于此并稍作修改。
首先,需要添加jedis:
<!--jedis-->
<dependency>
<groupId>redis.clients</groupId>
<artifactId>jedis</artifactId>
<version>2.8.0</version>
</dependency>
然后,springmvc完成基本配置。添加jedispool的bean即可。在spring容器中添加applicationContext-jedis.xml:
在applicationContext-jedis.xml中添加:
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.2.xsd">
<!-- 加载配置属性文件 -->
<context:property-placeholder ignore-unresolvable="true" location="classpath:db.properties" />
<bean id="jedisPoolConfig" class="redis.clients.jedis.JedisPoolConfig">
<property name="maxIdle" value="300"/> <!--最大能够保持idel状态的对象数-->
<property name="maxTotal" value="60000"/><!--最大分配的对象数-->
<property name="testOnBorrow" value="true"/><!--当调用borrow Oject方法时,是否进行有效性检查-->
</bean>
<bean id="jedisPool" class="redis.clients.jedis.JedisPool">
<constructor-arg index="0" ref="jedisPoolConfig"/>
<constructor-arg index="1" value="${redis.host}"/>
<constructor-arg index="2" value="${redis.port}" type="int"/>
<constructor-arg index="3" value="${redis.timeout}" type="int"/>
<constructor-arg index="4" value="${redis.auth}"/>
</bean>
</beans>
注解:参考的源码中的jedisPool配置只有三个参数:config,host,port。我复制后的结果总是getResource失败,因为我的redis添加了auth,所以猜测是不是没通过auth的原因。于是打开JedisPool的源码:
1 package redis.clients.jedis;
2
3 import java.net.URI;
4
5 import org.apache.commons.pool2.impl.GenericObjectPool;
6 import org.apache.commons.pool2.impl.GenericObjectPoolConfig;
7
8 import redis.clients.jedis.exceptions.JedisException;
9 import redis.clients.util.JedisURIHelper;
10 import redis.clients.util.Pool;
11
12 public class JedisPool extends Pool<Jedis> {
13
14 public JedisPool() {
15 this(Protocol.DEFAULT_HOST, Protocol.DEFAULT_PORT);
16 }
17
18 public JedisPool(final GenericObjectPoolConfig poolConfig, final String host) {
19 this(poolConfig, host, Protocol.DEFAULT_PORT, Protocol.DEFAULT_TIMEOUT, null,
20 Protocol.DEFAULT_DATABASE, null);
21 }
22
23 public JedisPool(String host, int port) {
24 this(new GenericObjectPoolConfig(), host, port, Protocol.DEFAULT_TIMEOUT, null,
25 Protocol.DEFAULT_DATABASE, null);
26 }
27
28 public JedisPool(final String host) {
29 URI uri = URI.create(host);
30 if (JedisURIHelper.isValid(uri)) {
31 String h = uri.getHost();
32 int port = uri.getPort();
33 String password = JedisURIHelper.getPassword(uri);
34 int database = JedisURIHelper.getDBIndex(uri);
35 this.internalPool = new GenericObjectPool<Jedis>(new JedisFactory(h, port,
36 Protocol.DEFAULT_TIMEOUT, Protocol.DEFAULT_TIMEOUT, password, database, null),
37 new GenericObjectPoolConfig());
38 } else {
39 this.internalPool = new GenericObjectPool<Jedis>(new JedisFactory(host,
40 Protocol.DEFAULT_PORT, Protocol.DEFAULT_TIMEOUT, Protocol.DEFAULT_TIMEOUT, null,
41 Protocol.DEFAULT_DATABASE, null), new GenericObjectPoolConfig());
42 }
43 }
44
45 public JedisPool(final URI uri) {
46 this(new GenericObjectPoolConfig(), uri, Protocol.DEFAULT_TIMEOUT);
47 }
48
49 public JedisPool(final URI uri, final int timeout) {
50 this(new GenericObjectPoolConfig(), uri, timeout);
51 }
52
53 public JedisPool(final GenericObjectPoolConfig poolConfig, final String host, int port,
54 int timeout, final String password) {
55 this(poolConfig, host, port, timeout, password, Protocol.DEFAULT_DATABASE, null);
56 }
57
58 public JedisPool(final GenericObjectPoolConfig poolConfig, final String host, final int port) {
59 this(poolConfig, host, port, Protocol.DEFAULT_TIMEOUT, null, Protocol.DEFAULT_DATABASE, null);
60 }
61
62 public JedisPool(final GenericObjectPoolConfig poolConfig, final String host, final int port,
63 final int timeout) {
64 this(poolConfig, host, port, timeout, null, Protocol.DEFAULT_DATABASE, null);
65 }
66
67 public JedisPool(final GenericObjectPoolConfig poolConfig, final String host, int port,
68 int timeout, final String password, final int database) {
69 this(poolConfig, host, port, timeout, password, database, null);
70 }
71
72 public JedisPool(final GenericObjectPoolConfig poolConfig, final String host, int port,
73 int timeout, final String password, final int database, final String clientName) {
74 this(poolConfig, host, port, timeout, timeout, password, database, clientName);
75 }
76
77 public JedisPool(final GenericObjectPoolConfig poolConfig, final String host, int port,
78 final int connectionTimeout, final int soTimeout, final String password, final int database,
79 final String clientName) {
80 super(poolConfig, new JedisFactory(host, port, connectionTimeout, soTimeout, password,
81 database, clientName));
82 }
83
84 public JedisPool(final GenericObjectPoolConfig poolConfig, final URI uri) {
85 this(poolConfig, uri, Protocol.DEFAULT_TIMEOUT);
86 }
87
88 public JedisPool(final GenericObjectPoolConfig poolConfig, final URI uri, final int timeout) {
89 this(poolConfig, uri, timeout, timeout);
90 }
91
92 public JedisPool(final GenericObjectPoolConfig poolConfig, final URI uri,
93 final int connectionTimeout, final int soTimeout) {
94 super(poolConfig, new JedisFactory(uri, connectionTimeout, soTimeout, null));
95 }
96
97 @Override
98 public Jedis getResource() {
99 Jedis jedis = super.getResource();
100 jedis.setDataSource(this);
101 return jedis;
102 }
103
104 /**
105 * @deprecated starting from Jedis 3.0 this method will not be exposed.
106 * Resource cleanup should be done using @see {@link redis.clients.jedis.Jedis#close()}
107 */
108 @Override
109 @Deprecated
110 public void returnBrokenResource(final Jedis resource) {
111 if (resource != null) {
112 returnBrokenResourceObject(resource);
113 }
114 }
115
116 /**
117 * @deprecated starting from Jedis 3.0 this method will not be exposed.
118 * Resource cleanup should be done using @see {@link redis.clients.jedis.Jedis#close()}
119 */
120 @Override
121 @Deprecated
122 public void returnResource(final Jedis resource) {
123 if (resource != null) {
124 try {
125 resource.resetState();
126 returnResourceObject(resource);
127 } catch (Exception e) {
128 returnBrokenResource(resource);
129 throw new JedisException("Could not return the resource to the pool", e);
130 }
131 }
132 }
133 }
看到有password的参数配置,如果没有配置的话默认为null。到这一步我便没有往下深入看了,因为我连接的redis中有auth,原谅我的不求甚解。于是,我接着配置timeout和auth。timeout直接还是源码的默认值。后面的代码测试通过。在这里我了解到spring的bean注入的几个参数含义:比如property表示属性注入,constructor表示构造函数的参数注入。
为了更清楚的表达,redis要设置db,配置文件参数也做一下改动:
<bean id="jedisPoolConfig" class="redis.clients.jedis.JedisPoolConfig">
<property name="maxIdle" value="300" /> <!-- 最大能够保持idel状态的对象数 -->
<property name="maxTotal" value="60000" /> <!-- 最大分配的对象数 -->
<property name="testOnBorrow" value="true" /> <!-- 当调用borrow Object方法时,是否进行有效性检查 -->
</bean>
<bean id="jedisPool" class="redis.clients.jedis.JedisPool">
<constructor-arg name="poolConfig" ref="jedisPoolConfig" />
<constructor-arg name="host" value="${redis.host}" />
<constructor-arg name="port" value="${redis.port}" type="int" />
<constructor-arg name="timeout" value="${redis.timeout}" type="int" />
<constructor-arg name="password" value="#{'${redis.password}'!=''?'${redis.password}':null}" />
<constructor-arg name="database" value="${redis.db.index}" type="int" />
</bean>
最后一项参数是选择redis的db,我认为通常默认连接的都是redis的0,那么我们的开发环境为了不冲突,应该另外设置。但JedisPool并没有只有指定db的构造函数,所以选择了这个构造函数。唯一的问题是,默认我们的redis是没有密码的,那么这里也填null而不是空字符串哦。所以,这里使用spring spEL表达式来填充空。对应的配置文件如下:
#redis settings
redis.keyPrefix=wz
redis.host=127.0.0.1
redis.port=6379
redis.timeout=2000
#注意,如果没有password,此处不设置值,但这一项要保留
redis.password=
redis.db.index=1
上面设置好了JedisPool,这里就要获取jedis。然后就可以利用jedis进行操作了。
1 /**
2 * 获取资源
3 * @return
4 */
5 public static Jedis getResource() {
6 Jedis jedis = null;
7 try {
8 jedis = jedisPool.getResource();
9 logger.debug("getResource:{}",jedis);
10 } catch (Exception e) {
11 logger.error("getResource:{}",e);
12 if (jedis!=null)
13 jedis.close();
14 throw e;
15 }
16 return jedis;
17 }
但是,为了更加自定义的设置db,这里也可以加一个db的选择:
public static Jedis getResource() throws JedisException {
Jedis jedis = null;
try {
jedis = jedisPool.getResource();
jedis.select(Integer.parseInt(DB_INDEX));
// logger.debug("getResource.", jedis);
} catch (JedisException e) {
logger.warn("getResource.", e);
returnBrokenResource(jedis);
throw e;
}
return jedis;
}
为了我们的key与其他app不冲突,我们最后为我们key统一增加一个标识,这种做法类似选择一个表。
private static String setPrefix(String key) {
key=KEY_PREFIX+"_"+key;
return key;
}
在任何使用到redis的地方,配置key的prefix。比如get 和 set:
public static String get(String key) {
key = setPrefix(key);
String value = null;
Jedis jedis = null;
try {
jedis = getResource();
if (jedis.exists(key)) {
value = jedis.get(key);
value = StringUtils.isNotBlank(value) && !"nil".equalsIgnoreCase(value) ? value : null;
logger.debug("get {} = {}", key, value);
}
} catch (Exception e) {
logger.warn("get {} = {}", key, value, e);
} finally {
returnResource(jedis);
}
return value;
}
public static String set(String key, String value, int cacheSeconds) {
key = setPrefix(key);
String result = null;
Jedis jedis = null;
try {
jedis = getResource();
result = jedis.set(key, value);
if (cacheSeconds != 0) {
jedis.expire(key, cacheSeconds);
}
logger.debug("set {} = {}", key, value);
} catch (Exception e) {
logger.warn("set {} = {}", key, value, e);
} finally {
returnResource(jedis);
}
return result;
}
通过使用jedis基本可以完成任何操作了。这里添加一个缓存对象的功能。java对象的缓存利用序列化实现,因此,需要缓存的对象必须实现了serializable接口。关于如何序列化,参考:将对象序列化和反序列化。
1 /**
2 * 设置缓存
3 * @param key String
4 * @param value Object对象
5 * @param cacheSeconds 超时时间,0为不超时
6 * @return
7 */
8 public static String setObject(String key,Object value,int cacheSeconds){
9 String result = null;
10 Jedis jedis = null;
11 try {
12 jedis = getResource();
13 result = jedis.set(getBytesKey(key),toBytes(value));
14 if (cacheSeconds!=0){
15 jedis.expire(key,cacheSeconds);
16 }
17 logger.debug("setObject {}={}",key,value);
18 } catch (Exception e) {
19 logger.warn("setObject {} 失败:{}",key,e);
20 } finally {
21 jedis.close();
22 }
23 return result;
24 }
25 /**
26 * 获取缓存
27 * @param key
28 * @return 对象(反序列化)
29 */
30 public static Object getObject(String key){
31 Object value = null;
32 Jedis jedis = null;
33 try {
34 jedis = getResource();
35 byte[] bytes = jedis.get(getBytesKey(key));
36 value = toObject(bytes);
37 logger.debug("getObject {}={}",key,value);
38 } catch (Exception e) {
39 logger.warn("getObject {}错误:{}",key,e.getMessage());
40 e.printStackTrace();
41 } finally {
42 jedis.close();
43 }
44 return value;
45 }
46 /**
47 * 将key转换为byte[]
48 * @param object
49 * @return
50 */
51 private static byte[] getBytesKey(Object object) {
52 if(object instanceof String){
53 return StringUtils.getBytes((String) object);
54 }else {
55 return ObjectUtils.serialize(object);
56 }
57 }
58
59 /**
60 * Object转换为byte[]类型
61 * @param value Object对象
62 * @return byte[]数组
63 */
64 private static byte[] toBytes(Object value) {
65 return ObjectUtils.serialize(value);
66 }
67
68 /**
69 * byte[]转换为object
70 * @param bytes
71 * @return
72 */
73 private static Object toObject(byte[] bytes) {
74 return ObjectUtils.unserialize(bytes);
75 }
我们平时用到的list基本都是ObjectList,即list的元素为object而不是String。这样就需要特定方法来缓存了。
采用同样的方式,将object序列化为字节数组,然后存储起来。取出的时候再反序列化,因此object必须实现了serializable接口,而且static的成员不能序列化或者说序列化的结果为默认值。原因参考:将对象序列化和反序列化。
1 /**
2 * 获取list缓存
3 * @param key
4 * @return
5 */
6 public static List<String> getList(String key){
7 key = addDatabaseName(key);
8 List<String> value = null;
9 Jedis jedis = null;
10 try {
11 jedis = getResource();
12 value = jedis.lrange(key, 0, -1);
13 logger.debug("getList {}={}",key,value);
14 } catch (Exception e) {
15 logger.warn("getList {}失败:{}",key,e);
16 e.printStackTrace();
17 } finally {
18 jedis.close();
19 }
20 return value;
21 }
22
23 /**
24 * 获取list缓存,元素是object
25 * @param key
26 * @return
27 */
28 public static List<Object> getObjectList(String key){
29 key = addDatabaseName(key);
30 List<Object> value = null;
31 Jedis jedis = null;
32 try {
33 jedis = getResource();
34 List<byte[]> list = jedis.lrange(getBytesKey(key), 0, -1);
35 value = Lists.newArrayList();
36 for (byte[] bytes : list) {
37 value.add(toObject(bytes));
38 }
39 logger.debug("getObjectList {}={}",key,value);
40 }catch (Exception e){
41 logger.warn("getObjectList {} 失败:{}",key,e);
42 e.printStackTrace();
43 }finally {
44 jedis.close();
45 }
46 return value;
47 }
48
49 /**
50 * 设置list缓存
51 * @param key
52 * @param value
53 * @param cacheSeconds
54 * @return
55 */
56 public static long setList(String key,List<String> value,int cacheSeconds){
57 key = addDatabaseName(key);
58 long result = 0;
59 Jedis jedis = null;
60 try {
61 jedis = getResource();
62 jedis.del(key);
63 String[] arr = new String[value.size()];
64 value.toArray(arr);
65 result = jedis.rpush(key,arr);
66 if (cacheSeconds!=0){
67 jedis.expire(key,cacheSeconds);
68 }
69 logger.debug("setList {}={}",key,value);
70 }catch (Exception e){
71 logger.warn("setList {} 错误:",key,e);
72 e.printStackTrace();
73 }finally {
74 jedis.close();
75 }
76 return result;
77 }
78
79 /**
80 * 设置list缓存,list的元素为object
81 * @param key
82 * @param value
83 * @param cacheSeconds
84 * @return
85 */
86 public static long setObjectList(String key,List<Object> value ,int cacheSeconds){
87 key = addDatabaseName(key);
88 long result = 0;
89 Jedis jedis = null;
90 try {
91 jedis = getResource();
92 jedis.del(key);
93 ArrayList<byte[]> list = Lists.newArrayList();
94 for (Object o : value) {
95 list.add(toBytes(o));
96 }
97 byte[] []arr = new byte[list.size()][];
98 list.toArray(arr);
99 result = jedis.rpush(getBytesKey(key),arr);
100 if(cacheSeconds!=0){
101 jedis.expire(key,cacheSeconds);
102 }
103 logger.debug("setObjectList {}={}",key,value);
104 }catch (Exception e){
105 logger.warn("setObjectList {} 错误:{}",key,e);
106 e.printStackTrace();
107 }
108 return result;
109 }