spring-data-redis連接操作redis的實(shí)現(xiàn)
Java連接redis的客戶端有很多,其中比較常用的是Jedis. (參考:redis client)
spring-data-redis則是對(duì)Jedis進(jìn)行了高度封裝,使用起來非常方便。下面就以代碼為例說明spring-data-redis的使用。
整個(gè)項(xiàng)目使用maven管理jar包,pom文件如下:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.snow</groupId>
<artifactId>redis-test</artifactId>
<version>0.0.1</version>
<packaging>jar</packaging>
<name>redis-test</name>
<url>http://maven.apache.org</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<spring.version>4.3.2.RELEASE</spring.version>
<slf4j.version>1.7.12</slf4j.version>
<log4j.version>1.2.17</log4j.version>
<junit.version>4.12</junit.version>
<spring-data-redis.version>1.7.2.RELEASE</spring-data-redis.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>${spring.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>redis.clients</groupId>
<artifactId>jedis</artifactId>
<version>2.5.0</version>
<type>jar</type>
</dependency>
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-redis</artifactId>
<version>${spring-data-redis.version}</version>
<type>jar</type>
</dependency>
<!-- log -->
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>${log4j.version}</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>${slf4j.version}</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>${slf4j.version}</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>${junit.version}</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>
主要用到的jia包是spring-context、spring-data-redis、jedis以及日志打印相關(guān)的三個(gè)jar包
配置spring-data-redis如下application-context-redis.xml:
<!-- 配置方法見 //www.dbjr.com.cn/database/201311/254449.html -->
<bean id="jedisPoolConfig" class="redis.clients.jedis.JedisPoolConfig">
<property name="maxTotal" value="500"/> <!-- 控制一個(gè)pool可分配多少個(gè)jedis實(shí)例 -->
<property name="maxIdle" value="100"/><!-- 最大能夠保持idel狀態(tài)的對(duì)象數(shù) -->
<property name="maxWaitMillis" value="1000"/><!-- 表示當(dāng)borrow一個(gè)jedis實(shí)例時(shí),最大的等待時(shí)間,如果超過等待時(shí)間,則直接拋出JedisConnectionException -->
<property name="timeBetweenEvictionRunsMillis" value="30000"/><!-- 多長(zhǎng)時(shí)間檢查一次連接池中空閑的連接 -->
<property name="minEvictableIdleTimeMillis" value="30000"/><!-- 空閑連接多長(zhǎng)時(shí)間后會(huì)被收回, 單位是毫秒 -->
<property name="testOnBorrow" value="true"/> <!-- 當(dāng)調(diào)用borrow Object方法時(shí),是否進(jìn)行有效性檢查 -->
<property name="testOnReturn" value="true"/> <!-- 當(dāng)調(diào)用return Object方法時(shí),是否進(jìn)行有效性檢查 -->
<property name="testWhileIdle" value="true"/>
</bean>
<span style="white-space:pre"> </span><!-- 直連master -->
<bean id="jedisConnectionFactory"
class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory">
<constructor-arg ref="jedisPoolConfig" />
<property name="hostName" value="${redis.hostName}" />
<property name="port" value="${redis.port}" />
<!-- <property name="password" value ="${redis.password}" /> -->
</bean>
<span style="white-space:pre"> </span><bean id="redisTemplate" class="org.springframework.data.redis.core.StringRedisTemplate" >
<span style="white-space:pre"> </span><property name="connectionFactory" ref="jedisConnectionFactory" />
<span style="white-space:pre"> </span></bean>
在配置文件中先配置一個(gè)連接池,然后配置一個(gè)connection工廠,最后配置bean redisTemplate,我們使用的class是StringRedisTemplate,從而決定我們后面的操作key及value都必須是String類型的。而通常我們希望將一個(gè)對(duì)象存入到redis中,這個(gè)時(shí)候可以將對(duì)象轉(zhuǎn)為json字符串之后再存儲(chǔ),取出來的時(shí)候再將json字符串轉(zhuǎn)換為對(duì)象。這種操作還是比較方便的,都有線程的jar包。除了StringRedisTemplate之外,我們還可以使用RedisTemplate類,這里暫不介紹。
在application-context-redis.xml這個(gè)配置文件中還需要用到redis的host和port信息,我們可以配置一個(gè)文件properties文件如下:redis.properties
redis.hostName=127.0.0.1 redis.port=6379
這個(gè)配置文件需要在application-contex.xml中加載,同時(shí)application-context.xml還需要加載application-context-redis.xml配置文件
<bean id="dbPropertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="ignoreUnresolvablePlaceholders" value="true" />
<property name="locations">
<list>
<value>classpath:redis.properties</value>
</list>
</property>
<property name="fileEncoding" value="UTF-8" /><!-- 資源文件的編碼 -->
</bean>
<import resource="classpath:application-context-redis.xml" />
接下來可以寫個(gè)redis操作的接口
public interface RedisService {
public void setStr(String key, String value);
public String getStr(String key);
public void rPushList(String key, String value);
public String lPopList(String key);
public void delKey(String key);
}
接口實(shí)現(xiàn)如下:
@Service(value = "redisService")
public class RedisServiceImpl extends AbstractRedisDao<String, String> implements RedisService {
@Override
public void setStr(String key, String value) {
getRedisTemplate().opsForValue().set(key, value);
}
@Override
public String getStr(String key) {
return getRedisTemplate().opsForValue().get(key);
}
@Override
public void rPushList(String key, String value) {
getRedisTemplate().opsForList().rightPush(key, value);
}
@Override
public String lPopList(String key) {
return getRedisTemplate().opsForList().leftPop(key);
}
@Override
public void delKey(String key) {
getRedisTemplate().delete(key);
}
}
在該實(shí)現(xiàn)中繼承了一個(gè)AbstractRedisDao,這個(gè)主要是提供getRedisTemplate()函數(shù),使我們能夠調(diào)用在application-context-redis.xml中配置的redisTemplate bean實(shí)例
public abstract class AbstractRedisDao<K, V> {
@Autowired
protected RedisTemplate<K, V> redisTemplate;
// 設(shè)置redisTemplate
public void setRedisTemplate(RedisTemplate<K, V> redisTemplate) {
this.redisTemplate = redisTemplate;
}
public RedisTemplate<K, V> getRedisTemplate() {
return redisTemplate;
}
}
主要的程序都已經(jīng)寫完了,接下來可以用Junit寫個(gè)單元測(cè)試對(duì)接口測(cè)試下。
public class RedisServiceTest extends AbstractUnitTest {
private static final Logger logger = LoggerFactory.getLogger(RedisServiceTest.class);
@Resource
private RedisService redisService;
@Test
public void testSetStr() {
String key = "test";
String value = "valuetest";
redisService.setStr(key, value);
}
@Test
public void testGetStr() {
String key = "test";
String value = redisService.getStr(key);
logger.info("The value is {}", value);
}
@Test
public void testRPushList() {
String key = "list";
for (int i = 0; i < 10; i++) {
redisService.rPushList(key, String.valueOf(i));
}
}
@Test
public void testLPopList() {
String key = "list";
for(int i = 0; i < 9; i++) {
String value = redisService.lPopList(key);
logger.info("lpop value is {}", value);
}
}
@Test
public void testDelKey() {
String key = "list";
redisService.delKey(key);
}
}
在這個(gè)測(cè)試類中,為了能夠運(yùn)行這些測(cè)試函數(shù),需要對(duì)所有的bean進(jìn)行實(shí)例化,這個(gè)過程是在 AbstractUnitTest中實(shí)現(xiàn)的,代碼如下:
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {"classpath:application-context.xml"})
public abstract class AbstractUnitTest {
private static final Logger logger = LoggerFactory.getLogger(AbstractUnitTest.class);
// @Test
// public void stub() {
// logger.info("msg from abstract unit test, just ignore this.");
// }
@After
public void teardown() throws InterruptedException {
logger.info("unit test complete.");
TimeUnit.MILLISECONDS.sleep(500);// 因?yàn)橛行y(cè)試是需要異步插入操作記錄的,sleep一下等待線程結(jié)束
}
}
AbstractUnitTest類可以作為測(cè)試spring的一個(gè)通用類。
主要的代碼就這些了,運(yùn)行下可以看到結(jié)果是沒有問題的。下面我摘抄一段打印輸出說明一個(gè)問題:
016-08-02 20:43:16,608 DEBUG RedisConnectionUtils:125 - Opening RedisConnection
2016-08-02 20:43:16,609 DEBUG RedisConnectionUtils:205 - Closing Redis Connection
2016-08-02 20:43:16,610 INFO RedisServiceTest:54 - lpop value is 0
2016-08-02 20:43:16,610 DEBUG RedisConnectionUtils:125 - Opening RedisConnection
2016-08-02 20:43:16,611 DEBUG RedisConnectionUtils:205 - Closing Redis Connection
2016-08-02 20:43:16,611 INFO RedisServiceTest:54 - lpop value is 1
2016-08-02 20:43:16,611 DEBUG RedisConnectionUtils:125 - Opening RedisConnection
2016-08-02 20:43:16,611 DEBUG RedisConnectionUtils:205 - Closing Redis Connection
2016-08-02 20:43:16,612 INFO RedisServiceTest:54 - lpop value is 2
2016-08-02 20:43:16,612 DEBUG RedisConnectionUtils:125 - Opening RedisConnection
2016-08-02 20:43:16,612 DEBUG RedisConnectionUtils:205 - Closing Redis Connection
2016-08-02 20:43:16,612 INFO RedisServiceTest:54 - lpop value is 3
2016-08-02 20:43:16,612 DEBUG RedisConnectionUtils:125 - Opening RedisConnection
2016-08-02 20:43:16,613 DEBUG RedisConnectionUtils:205 - Closing Redis Connection
2016-08-02 20:43:16,613 INFO RedisServiceTest:54 - lpop value is 4
2016-08-02 20:43:16,613 DEBUG RedisConnectionUtils:125 - Opening RedisConnection
2016-08-02 20:43:16,613 DEBUG RedisConnectionUtils:205 - Closing Redis Connection
2016-08-02 20:43:16,613 INFO RedisServiceTest:54 - lpop value is 5
2016-08-02 20:43:16,613 DEBUG RedisConnectionUtils:125 - Opening RedisConnection
2016-08-02 20:43:16,614 DEBUG RedisConnectionUtils:205 - Closing Redis Connection
2016-08-02 20:43:16,614 INFO RedisServiceTest:54 - lpop value is 6
2016-08-02 20:43:16,614 DEBUG RedisConnectionUtils:125 - Opening RedisConnection
2016-08-02 20:43:16,614 DEBUG RedisConnectionUtils:205 - Closing Redis Connection
2016-08-02 20:43:16,618 INFO RedisServiceTest:54 - lpop value is 7
2016-08-02 20:43:16,618 DEBUG RedisConnectionUtils:125 - Opening RedisConnection
2016-08-02 20:43:16,618 DEBUG RedisConnectionUtils:205 - Closing Redis Connection
2016-08-02 20:43:16,618 INFO RedisServiceTest:54 - lpop value is 8
2016-08-02 20:43:16,618 INFO AbstractUnitTest:34 - unit test complete.
這段輸出是運(yùn)行testLPopList得到的,這里面opening RedisConnection進(jìn)行了9次,然后又Closing Redis Connection 9次,這是不是說每次執(zhí)行redis操作都需要?jiǎng)?chuàng)建一個(gè)連接,操作完然后又關(guān)閉連接呢?實(shí)際上不是這樣的,閱讀源代碼我們可以發(fā)現(xiàn)我們對(duì)redis的所有操作都是通過回調(diào)execute函數(shù)執(zhí)行的,其代碼如下:
public <T> T execute(RedisCallback<T> action, boolean exposeConnection) {
return execute(action, exposeConnection, false);
}
// execute實(shí)現(xiàn)如下:
// org.springframework.data.redis.core.RedisTemplate<K, V> --- 最終實(shí)現(xiàn)
public <T> T execute(RedisCallback<T> action, boolean exposeConnection, boolean pipeline) {
Assert.isTrue(initialized, "template not initialized; call afterPropertiesSet() before using it");
Assert.notNull(action, "Callback object must not be null");
RedisConnectionFactory factory = getConnectionFactory();
RedisConnection conn = null;
try {
if (enableTransactionSupport) {
// only bind resources in case of potential transaction synchronization
conn = RedisConnectionUtils.bindConnection(factory, enableTransactionSupport);
} else {
conn = RedisConnectionUtils.getConnection(factory);
}
boolean existingConnection = TransactionSynchronizationManager.hasResource(factory);
RedisConnection connToUse = preProcessConnection(conn, existingConnection);
boolean pipelineStatus = connToUse.isPipelined();
if (pipeline && !pipelineStatus) {
connToUse.openPipeline();
}
RedisConnection connToExpose = (exposeConnection ? connToUse : createRedisConnectionProxy(connToUse));
T result = action.doInRedis(connToExpose);
// close pipeline
if (pipeline && !pipelineStatus) {
connToUse.closePipeline();
}
// TODO: any other connection processing?
return postProcessResult(result, connToUse, existingConnection);
} finally {
if (!enableTransactionSupport) {
RedisConnectionUtils.releaseConnection(conn, factory);
}
}
}
這里面每次執(zhí)行action.doInRedis(connToExpose)前都要調(diào)用RedisConnectionUtils.getConnection(factory);獲得一個(gè)連接,進(jìn)入RedisConnnectionUtils類中,getConnection(factory)最終調(diào)用的是doGetConnection(factory, true, false, enableTranactionSupport)這個(gè)函數(shù)。這個(gè)函數(shù)我們可以看下api文檔,發(fā)現(xiàn)實(shí)際上并不是真的創(chuàng)建一個(gè)新的redis連接,它只是在connectFactory中獲取一個(gè)連接,也就是從連接池中取出一個(gè)連接。當(dāng)然如果connectFactory沒有連接可用,此時(shí)如果allowCreate=true便會(huì)創(chuàng)建出一個(gè)新的連接,并且加入到connectFactory中。
基本上可以確定真實(shí)的情況是spring-data-redis已經(jīng)幫我們封裝了連接池管理,我們只需要調(diào)用一系列操作函數(shù)即可,這給操作redis帶來了極大的方便。
最后附上本文源代碼:redis-test
到此這篇關(guān)于spring-data-redis連接操作redis的實(shí)現(xiàn)的文章就介紹到這了,更多相關(guān)spring-data-redis連接操作redis內(nèi)容請(qǐng)搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持腳本之家!
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