主要学习https://github.com/thinkgem/jeesite。一下代码均参考于此并稍作修改。
1.jedis
首先，需要添加jedis：
<!--jedis-->
<dependency>
<groupId>redis.clients</groupId>
<artifactId>jedis</artifactId>
<version>2.8.0</version>
</dependency>
2.applicationContext-jedis.xml
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：
package redis.clients.jedis; import java.net.URI; import org.apache.commons.pool2.impl.GenericObjectPool;
import org.apache.commons.pool2.impl.GenericObjectPoolConfig; import redis.clients.jedis.exceptions.JedisException;
import redis.clients.util.JedisURIHelper;
import redis.clients.util.Pool; public class JedisPool extends Pool<Jedis> { public JedisPool() {
this(Protocol.DEFAULT_HOST, Protocol.DEFAULT_PORT);
} public JedisPool(final GenericObjectPoolConfig poolConfig, final String host) {
this(poolConfig, host, Protocol.DEFAULT_PORT, Protocol.DEFAULT_TIMEOUT, null,
Protocol.DEFAULT_DATABASE, null);
} public JedisPool(String host, int port) {
this(new GenericObjectPoolConfig(), host, port, Protocol.DEFAULT_TIMEOUT, null,
Protocol.DEFAULT_DATABASE, null);
} public JedisPool(final String host) {
URI uri = URI.create(host);
if (JedisURIHelper.isValid(uri)) {
String h = uri.getHost();
int port = uri.getPort();
String password = JedisURIHelper.getPassword(uri);
int database = JedisURIHelper.getDBIndex(uri);
this.internalPool = new GenericObjectPool<Jedis>(new JedisFactory(h, port,
Protocol.DEFAULT_TIMEOUT, Protocol.DEFAULT_TIMEOUT, password, database, null),
new GenericObjectPoolConfig());
} else {
this.internalPool = new GenericObjectPool<Jedis>(new JedisFactory(host,
Protocol.DEFAULT_PORT, Protocol.DEFAULT_TIMEOUT, Protocol.DEFAULT_TIMEOUT, null,
Protocol.DEFAULT_DATABASE, null), new GenericObjectPoolConfig());
}
} public JedisPool(final URI uri) {
this(new GenericObjectPoolConfig(), uri, Protocol.DEFAULT_TIMEOUT);
} public JedisPool(final URI uri, final int timeout) {
this(new GenericObjectPoolConfig(), uri, timeout);
} public JedisPool(final GenericObjectPoolConfig poolConfig, final String host, int port,
int timeout, final String password) {
this(poolConfig, host, port, timeout, password, Protocol.DEFAULT_DATABASE, null);
} public JedisPool(final GenericObjectPoolConfig poolConfig, final String host, final int port) {
this(poolConfig, host, port, Protocol.DEFAULT_TIMEOUT, null, Protocol.DEFAULT_DATABASE, null);
} public JedisPool(final GenericObjectPoolConfig poolConfig, final String host, final int port,
final int timeout) {
this(poolConfig, host, port, timeout, null, Protocol.DEFAULT_DATABASE, null);
} public JedisPool(final GenericObjectPoolConfig poolConfig, final String host, int port,
int timeout, final String password, final int database) {
this(poolConfig, host, port, timeout, password, database, null);
} public JedisPool(final GenericObjectPoolConfig poolConfig, final String host, int port,
int timeout, final String password, final int database, final String clientName) {
this(poolConfig, host, port, timeout, timeout, password, database, clientName);
} public JedisPool(final GenericObjectPoolConfig poolConfig, final String host, int port,
final int connectionTimeout, final int soTimeout, final String password, final int database,
final String clientName) {
super(poolConfig, new JedisFactory(host, port, connectionTimeout, soTimeout, password,
database, clientName));
} public JedisPool(final GenericObjectPoolConfig poolConfig, final URI uri) {
this(poolConfig, uri, Protocol.DEFAULT_TIMEOUT);
} public JedisPool(final GenericObjectPoolConfig poolConfig, final URI uri, final int timeout) {
this(poolConfig, uri, timeout, timeout);
} public JedisPool(final GenericObjectPoolConfig poolConfig, final URI uri,
final int connectionTimeout, final int soTimeout) {
super(poolConfig, new JedisFactory(uri, connectionTimeout, soTimeout, null));
} @Override
public Jedis getResource() {
Jedis jedis = super.getResource();
jedis.setDataSource(this);
return jedis;
} /**
* @deprecated starting from Jedis 3.0 this method will not be exposed.
* Resource cleanup should be done using @see {@link redis.clients.jedis.Jedis#close()}
*/
@Override
@Deprecated
public void returnBrokenResource(final Jedis resource) {
if (resource != null) {
returnBrokenResourceObject(resource);
}
} /**
* @deprecated starting from Jedis 3.0 this method will not be exposed.
* Resource cleanup should be done using @see {@link redis.clients.jedis.Jedis#close()}
*/
@Override
@Deprecated
public void returnResource(final Jedis resource) {
if (resource != null) {
try {
resource.resetState();
returnResourceObject(resource);
} catch (Exception e) {
returnBrokenResource(resource);
throw new JedisException("Could not return the resource to the pool", e);
}
}
}
}
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=
redis.timeout=
#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=
3. JedisUtil
3.1 getResource
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。
/**
* 获取资源
* @return
*/
public static Jedis getResource() {
Jedis jedis = null;
try {
jedis = jedisPool.getResource();
logger.debug("getResource:{}",jedis);
} catch (Exception e) {
logger.error("getResource:{}",e);
if (jedis!=null)
jedis.close();
throw e;
}
return jedis;
}
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;
}
3.1.1设置prefix
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;
}
3.2 Object对象的缓存
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。
/**
* 设置缓存
* @param key String
* @param value Object对象
* @param cacheSeconds 超时时间，0为不超时
* @return
*/
public static String setObject(String key,Object value,int cacheSeconds){
String result = null;
Jedis jedis = null;
try {
jedis = getResource();
result = jedis.set(getBytesKey(key),toBytes(value));
if (cacheSeconds!=0){
jedis.expire(key,cacheSeconds);
}
logger.debug("setObject {}={}",key,value);
} catch (Exception e) {
logger.warn("setObject {} 失败：{}",key,e);
} finally {
jedis.close();
}
return result;
}
/**
* 获取缓存
* @param key
* @return 对象(反序列化)
*/
public static Object getObject(String key){
Object value = null;
Jedis jedis = null;
try {
jedis = getResource();
byte[] bytes = jedis.get(getBytesKey(key));
value = toObject(bytes);
logger.debug("getObject {}={}",key,value);
} catch (Exception e) {
logger.warn("getObject {}错误：{}",key,e.getMessage());
e.printStackTrace();
} finally {
jedis.close();
}
return value;
}
/**
* 将key转换为byte[]
* @param object
* @return
*/
private static byte[] getBytesKey(Object object) {
if(object instanceof String){
return StringUtils.getBytes((String) object);
}else {
return ObjectUtils.serialize(object);
}
} /**
* Object转换为byte[]类型
* @param value Object对象
* @return byte[]数组
*/
private static byte[] toBytes(Object value) {
return ObjectUtils.serialize(value);
} /**
* byte[]转换为object
* @param bytes
* @return
*/
private static Object toObject(byte[] bytes) {
return ObjectUtils.unserialize(bytes);
}
3.3 ObjectList对象缓存
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。
/**
* 获取list缓存
* @param key
* @return
*/
public static List<String> getList(String key){
key = addDatabaseName(key);
List<String> value = null;
Jedis jedis = null;
try {
jedis = getResource();
value = jedis.lrange(key, 0, -1);
logger.debug("getList {}={}",key,value);
} catch (Exception e) {
logger.warn("getList {}失败：{}",key,e);
e.printStackTrace();
} finally {
jedis.close();
}
return value;
} /**
* 获取list缓存，元素是object
* @param key
* @return
*/
public static List<Object> getObjectList(String key){
key = addDatabaseName(key);
List<Object> value = null;
Jedis jedis = null;
try {
jedis = getResource();
List<byte[]> list = jedis.lrange(getBytesKey(key), 0, -1);
value = Lists.newArrayList();
for (byte[] bytes : list) {
value.add(toObject(bytes));
}
logger.debug("getObjectList {}={}",key,value);
}catch (Exception e){
logger.warn("getObjectList {} 失败：{}",key,e);
e.printStackTrace();
}finally {
jedis.close();
}
return value;
} /**
* 设置list缓存
* @param key
* @param value
* @param cacheSeconds
* @return
*/
public static long setList(String key,List<String> value,int cacheSeconds){
key = addDatabaseName(key);
long result = 0;
Jedis jedis = null;
try {
jedis = getResource();
jedis.del(key);
String[] arr = new String[value.size()];
value.toArray(arr);
result = jedis.rpush(key,arr);
if (cacheSeconds!=0){
jedis.expire(key,cacheSeconds);
}
logger.debug("setList {}={}",key,value);
}catch (Exception e){
logger.warn("setList {} 错误：",key,e);
e.printStackTrace();
}finally {
jedis.close();
}
return result;
} /**
* 设置list缓存，list的元素为object
* @param key
* @param value
* @param cacheSeconds
* @return
*/
public static long setObjectList(String key,List<Object> value ,int cacheSeconds){
key = addDatabaseName(key);
long result = 0;
Jedis jedis = null;
try {
jedis = getResource();
jedis.del(key);
ArrayList<byte[]> list = Lists.newArrayList();
for (Object o : value) {
list.add(toBytes(o));
}
byte[] []arr = new byte[list.size()][];
list.toArray(arr);
result = jedis.rpush(getBytesKey(key),arr);
if(cacheSeconds!=0){
jedis.expire(key,cacheSeconds);
}
logger.debug("setObjectList {}={}",key,value);
}catch (Exception e){
logger.warn("setObjectList {} 错误：{}",key,e);
e.printStackTrace();
}
return result;
}