Flask接口签名sign原理与实例代码浅析
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2023-06-19
详解java之redis篇(spring
详解java之redis篇(spring
1，利用spring-data-redis整合
项目使用的pom.xml：
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
除了log部分，只有一个spring core 和 spring-data-redis了
项目文件目录结构：
applicationContext.xml：
1，context:property-placeholder 标签用来导入properties文件。从而替换${redis.maxIdle}这样的变量。
2，context:component-scan 是为了在com.x.redis.dao报下的类能够实用spring的注解注入的方式。
3，事实上我们只需要把JedisPoolConfig配数来就好了，接下来就是spring的封装了。所以直接看UserDAOImpl的实现就明白了。
xmlns:xsi="http://w3.org/2001/XMLSchema-instance" xmlns:p="http://springframework.org/schema/p" xmlns:context="http://springframework.org/schema/context" xmlns:jee="http://springframework.org/schema/jee" xmlns:tx="http://springframework.org/schema/tx" xmlns:aop="http://springframework.org/schema/aop" xsi:schemaLocation=" http://springframework.org/schema/beans http://springframework.org/schema/beans/spring-beans.xsd http://springframework.org/schema/context http://springframework.org/schema/context/spring-context.xsd"> p:host-name="${redis.host}" p:port="${redis.port}" p:password="${redis.pass}" p:pool-config-ref="poolConfig"/>
xmlns:xsi="http://w3.org/2001/XMLSchema-instance" xmlns:p="http://springframework.org/schema/p"
xmlns:context="http://springframework.org/schema/context"
xmlns:jee="http://springframework.org/schema/jee" xmlns:tx="http://springframework.org/schema/tx"
xmlns:aop="http://springframework.org/schema/aop"
xsi:schemaLocation="
http://springframework.org/schema/beans http://springframework.org/schema/beans/spring-beans.xsd
http://springframework.org/schema/context http://springframework.org/schema/context/spring-context.xsd">
p:host-name="${redis.host}" p:port="${redis.port}" p:password="${redis.pass}" p:pool-config-ref="poolConfig"/>
p:host-name="${redis.host}" p:port="${redis.port}" p:password="${redis.pass}" p:pool-config-ref="poolConfig"/>
redis.properties：
# Redis settings
#redis.host=192.168.20.101
#redis.port=6380
#redis.pass=foobared
redis.host=127.0.0.1
redis.port=6379
redis.pass=
redis.maxIdle=300
redis.maxActive=600
redis.maxWait=1000
redis.testOnBorrow=true
UserDAOImpl：
1，spring对dao层的封装很多用了类似于下面代码的模板方式。
2，RedisTemplate就是spring对redis的一个封装而已。
public class UserDAOImpl implements UserDAO {
@Autowired
protected RedisTemplate
public void saveUser(final User user) {
redisTemplate.execute(new RedisCallback
@Override
public Object doInRedis(RedisConnection connection) throws DataAccessException {
connection.set(redisTemplate.getStringSerializer().serialize("user.uid." + user.getId()),
redisTemplate.getStringSerializer().serialize(user.getName()));
return null;
}
});
}
@Override
public User getUser(final long id) {
return redisTemplate.execute(new RedisCallback
@Override
public User doInRedis(RedisConnection connection) throws DataAccessException {
byte[] key = redisTemplate.getStringSerializer().serialize("user.uid." + id);
if (connection.exists(key)) {
byte[] value = connection.get(key);
String name = redisTemplate.getStringSerializer().deserialize(value);
User user = new User();
user.setName(name);
user.setId(id);
return user;
}
return null;
}
});
}
}
其他：
User：
public class User {
private long id;
private String name;
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
测试代码：
public static void main(String[] args) {
ApplicationContext ac = new ClassPathXmlApplicationContext("classpath:/applicationContext.xml");
UserDAO userDAO = (UserDAO)ac.getBean("userDAO");
User user1 = new User();
user1.setId(1);
user1.setName("obama");
userDAO.saveUser(user1);
User user2 = userDAO.getUser(1);
System.out.println(user2.getName());
}
2，不利用spring-data-redis整合
个人觉得这样整合灵活度更大，能够更加明了的完成任务。
pom.xml:
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
目录结构：
data-source.xml
1，context:property-placeholder 和 context:component-scan 前面解释过啦。
2，配置了一个ShardedJedisPool，在jdeis里 还有个JedisPool。这两个的区别:
一个是分片形式，可以连接有主备的redis服务端，一个是单个的。详细后续学习
3，因为不使用spring-data-redis的封装，所以自己要自己封装一个
xmlns:xsi="http://w3.org/2001/XMLSchema-instance" xmlns:p="http://springframework.org/schema/p" xmlns:context="http://springframework.org/schema/context" xmlns:jee="http://springframework.org/schema/jee" xmlns:tx="http://springframework.org/schema/tx" xmlns:aop="http://springframework.org/schema/aop" xsi:schemaLocation=" http://springframework.org/schema/beans http://springframework.org/schema/beans/spring-beans.xsd http://springframework.org/schema/context http://springframework.org/schema/context/spring-context.xsd">
xmlns:xsi="http://w3.org/2001/XMLSchema-instance" xmlns:p="http://springframework.org/schema/p"
xmlns:context="http://springframework.org/schema/context"
xmlns:jee="http://springframework.org/schema/jee" xmlns:tx="http://springframework.org/schema/tx"
xmlns:aop="http://springframework.org/schema/aop"
xsi:schemaLocation="
http://springframework.org/schema/beans http://springframework.org/schema/beans/spring-beans.xsd
http://springframework.org/schema/context http://springframework.org/schema/context/spring-context.xsd">
RedisDataSource:定义三个方法
public interface RedisDataSource {
public abstract ShardedJedis getRedisClient();
public void returnResource(ShardedJedis shardedJedis);
public void returnResource(ShardedJedis shardedJedis,boolean broken);
}
实现redisDataSource:
1, 注入配置好的ShardedJehttp://disPool，这三个方法的作用：
getRedisClient() ： 取得redis的客户端，可以执行命令了。
returnResource(ShardedJedis shardedJedis) ： 将资源返还给pool
returnResource(ShardedJedis shardedJedis, boolean broken) : 出现异常后，将资源返还给pool （其实不需要第二个方法）
@Repository("redisDataSource")
public class RedisDataSourceImpl implements RedisDataSource {
private static final Logger log = LoggerFactory.getLogger(RedisDataSourceImpl.class);
@Autowired
private ShardedJedisPool shardedJedisPool;
public ShardedJedis getRedisClient() {
try {
ShardedJedis shardJedis = shardedJedisPool.getResource();
return shardJedis;
} catch (Exception e) {
log.error("getRedisClent error", e);
}
return null;
}
public void returnResource(ShardedJedis shardedJedis) {
shardedJedisPool.returnResource(shardedJedis);
}
public void returnResource(ShardedJedis shardedJedis, boolean broken) {
if (broken) {
shardedJedisPool.returnBrokenResource(shardedJedis);
} else {
shardedJedisPool.returnResource(shardedJedis);
}
}
}
第二层的封装：RedisClientTemplate，例子实现了放值和取值。最后代码提供了全部命令的实现。
代码就是映射性质的又一次调用jedis的方法而已，用了个broken来做标示符，决定返还资源的方式。
这一层的目的主要也是让再上层的调用不需要关心pool中链接的取得和返还问题了。
@Repository("redisClientTemplate")
public class RedisClientTemplate {
private static final Logger log = LoggerFactory.getLogger(RedisClientTemplate.class);
@Autowired
private RedisDataSource redisDataSource;
public void disconnect() {
ShardedJedis shardedJedis = redisDataSource.getRedisClient();
shardedJedis.disconnect();
}
/**
* 设置单个值
*
* @param key
* @param value
* @return
*/
public String set(String key, String value) {
String result = null;
ShardedJedis shardedJedis = redisDataSource.getRedisClient();
if (shardedJedis == null) {
return result;
}
boolean broken = false;
try {
result = shardedJedis.set(key, value);
} catch (Exception e) {
log.error(e.getMessage(), e);
broken = true;
} finally {
redisDataSource.returnResource(shardedJedis, broken);
}
return result;
}
/**
* 获取单个值
*
* @param key
* @return
*/
public String get(String key) {
String result = null;
ShardedJedis shardedJedis = redisDataSource.getRedisClient();
if (shardedJedis == null) {
return result;
}
boolean broken = false;
try {
result = shardedJedis.get(key);
} catch (Exception e) {
log.error(e.getMessage(), e);
broken = true;
} finally {
redisDataSource.returnResource(shardedJedis, broken);
}
return result;
}
}
测试代码：
public static void main(String[] args) {
ApplicationContext ac = new ClassPathXmlApplicationContext("classpath:/data-source.xml");
RedisClientTemplate redisClient = (RedisClientTemplate)ac.getBean("redisClientTemplate");
redisClient.set("a", "abc");
System.out.println(redisClient.get("a"));
}
附上RedisClientTemplate全部实现：
RedisClientTemplate代码太多，附上下载地址：http://xiazai.jb51.net/201701/yuanma/RedisClientTemplate_jb51.rar
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