Java项目使用Redis缓存数据

一、Redis的下载安装

1、下载gcc编译器

yum install gcc-c++

安装完成后检查是否安装成功，查看版本

gcc --version

2、使用weget下载redis

wget http://download.redis.io/releases/redis-6.2.4.tar.gz

下载成功后使用 ll 或 ls 命令查看当前目录下有redis压缩包

使用命令解压缩

tar -zxvf redis-6.2.4.tar.gz

解压成功后当前目录下有redis解压后的文件

3、进入解压后的redis文件，使用make进行编译

编译后默认安装目录就是redis文件夹所在目录
4、在解压后目录下执行make install 命令安装redis

5、进入安装目录启动redis服务

redis-server redis.conf

6、在xshell复制一个会话，cd进入redis安装目录，进行客户端连接

redis-cli -h 127.0.0.1 -p 6379

避雷：我本来想在Redisdesktopmanager里面连接我虚拟机里装的redis，然后一直报错

在网上搜解决方案采用修改redis.conf后成功
具体步骤如下
（1）如果已经启动redis，ctrl+c退出关闭redis，vim redis.conf修改配置文件，把原来的bind的IP改成虚拟机IP，protectedmode改成no，保存并退出

（2）重新启动redis

redis-server redis.conf

再次打开Redisdesktopmanager测试连接成功

这种情况下，虚拟机内客户端连接目录中IP记得改成redis.conf里改成的bindIP

redis-cli -h 127.0.0.1 -p 6379

另外，目前redis启动必须在一个会话终端里，启动redis之后就不能切换目录，退出等操作了，如果切换目录或退出就会关闭redis服务，如果要允许在启动redis的会话终端还能做别的操作还需要在redis.conf配置文件中更改配置daemonize yes；即作为守护进程启动，这样redis就可以后台启运行了。

这时候我们再来重新启动redis就不会显示像第五点的图一样的redis服务器启动后的画面，可以做别的操作

二、Java项目中整合Redis

1、添加依赖

<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId></dependency>

2、redis连接配置
Redis实例默认创建了16个数据库，且不支持自定义命名，以dbX的方式命名（db0~db15）；
此处我使用的redis的14数据库，没设置密码，若设置了密码则相应在password处输入密码

spring:redis:host: 127.0.0.1port: 6379database: 14password:

3、代码实现
（1）基础缓存DAO

@Repository
public class BaseCacheOperate {private final GsonBuilder gsonBuilder = new GsonBuilder().setDateFormat("yyyy-MM-dd HH:mm:ss");/*** @description boundList-Add*/public void add(BoundListOperations<String, String> boundListOperations, Object obj) {try {boundListOperations.rightPush(gsonBuilder.create().toJson(obj));} catch (Exception e) {e.printStackTrace();}}/*** @description boundList-Delete*/public void remove(BoundListOperations<String, String> boundListOperations, String cacheStr) {try {boundListOperations.remove(1, cacheStr);} catch (Exception e) {e.printStackTrace();}}/*** @description boundList-Query*/public List<String> list(BoundListOperations<String, String> boundListOperations, long count) {List<String> result = null;try {result = boundListOperations.range(0, count - 1);} catch (Exception e) {e.printStackTrace();}return result;}/*** @description boundHash-Add*/public void put(BoundHashOperations<String, String, String> boundHashOperations,String key, Object value) {try {boundHashOperations.put(key, gsonBuilder.create().toJson(value));} catch (Exception e) {e.printStackTrace();}}/*** @description boundHash-Remove*/public void remove(BoundHashOperations<String, String, String> boundHashOperations,String key) {try {boundHashOperations.delete(key);} catch (Exception e) {e.printStackTrace();}}/*** @description boundHash-Entries（Value单实体）*/public <T> Map<String, T> entries(BoundHashOperations<String, String, String> cacheOperations, Class<T> valueClass) {Map<String, T> result = new HashMap<>();Map<String, String> entries = cacheOperations.entries();if (DataStructureUtils.isValid(entries)) {entries.forEach((key, value) -> result.put(key, gsonBuilder.create().fromJson(value, valueClass)));}return result;}/*** @description boundHash-Get（Value单实体）*/public <T> T get(BoundHashOperations<String, String, String> cacheOperations,String key, Class<T> valueClass) {String cacheStr = get(cacheOperations, key);return StringUtils.isNotBlank(cacheStr) ? gsonBuilder.create().fromJson(cacheStr, valueClass) : null;}/*** @description boundHash-Get（Value为List）*/public <T> List<T> getList(BoundHashOperations<String, String, String> cacheOperations,String key, Class<T> valueClass) {String cacheStr = get(cacheOperations, key);return StringUtils.isNotBlank(cacheStr) ? gsonBuilder.create().fromJson(cacheStr, new TypeToken<List<T>>() {}.getType()) : null;}/*** @description boundHash-Get*/public String get(BoundHashOperations<String, String, String> cacheOperations,String key) {String result = null;try {result = cacheOperations.get(key);} catch (Exception e) {e.printStackTrace();}return result;}/*** @param cacheOperations Hash缓存操作实例* @param keyList         Key值集* @param valueClass      Value的类* @return 缓存数据集* @description 根据Key值集获取多条Value*/public <T> List<T> multiGet(BoundHashOperations<String, String, String> cacheOperations,List<String> keyList, Class<T> valueClass) {List<String> cacheStrList = multiGet(cacheOperations, keyList);List<T> result = new ArrayList<>();if (DataStructureUtils.isValid(cacheStrList)) {for (String cacheStr : cacheStrList) {result.add(gsonBuilder.create().fromJson(cacheStr, valueClass));}}return result;}/*** @param cacheOperations Hash缓存操作实例* @param keyList         Key值集* @param typeToken       Gson转换类型* @return 缓存数据集* @description 根据Key值集获取多条Value*/public <T> List<T> multiGet(BoundHashOperations<String, String, String> cacheOperations,List<String> keyList, TypeToken<List<T>> typeToken) {List<String> cacheStrList = multiGet(cacheOperations, keyList);List<T> result = new ArrayList<>();if (DataStructureUtils.isValid(cacheStrList)) {for (String cacheStr : cacheStrList) {result.addAll(gsonBuilder.create().fromJson(cacheStr, typeToken.getType()));}}return result;}/*** @param cacheOperations Hash缓存操作实例* @param keyList         Key值集* @return 缓存数据集* @description 根据Key值集获取多条Value*/public List<String> multiGet(BoundHashOperations<String, String, String> cacheOperations, List<String> keyList) {List<String> result = null;if (DataStructureUtils.isValid(keyList)) {try {result = cacheOperations.multiGet(keyList);if (result != null) {result.removeIf(Objects::isNull);}} catch (Exception e) {e.printStackTrace();}}return result;}}

（2）实际缓存业务

@Repository
public class TestDataDAO {private final BaseCacheOperate baseCacheOperate;private final BoundHashOperations<String, String, String> operations;@Autowiredpublic TestDataDAO(PublicCacheOperate baseCacheOperate, StringRedisTemplate redisTemplate) {this.baseCacheOperate = baseCacheOperate;this.operations = redisTemplate.boundHashOps("TEST_DATA");}/*** @description 缓存测试数据*/public void cache(TestData testData) {baseCacheOperate.put(operations, testData.getId().toString(), airSiteLatestData);}/*** @description 根据ID获取测试数据*/public TestData get(Long id) {return baseCacheOperate.get(operations, id.toString(), TestData.class);}/*** @description 根据ID集获取测试数据集*/public List<TestData> list(List<Long> idList) {return baseCacheOperate.multiGet(operations, idList.stream().map(Objects::toString).collect(Collectors.toList()), TestData.class);}
}