Redis中opsForValue()方法的使用介绍

package com.example.datestruct.utils;import org.springframework.beans.BeansException;import org.springframework.context.ApplicationContext;import org.springframework.context.ApplicationContextAware;im

m0_55208404

12227人浏览 · 2021-02-06 17:49:30

m0_55208404 · 2021-02-06 17:49:30 发布

package com.example.datestruct.utils;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

@Component
public class ApplicationTextUtils implements ApplicationContextAware {

    private static ApplicationContext context;

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.context=applicationContext;
    }
    //传入注入SpringBoot容器中的类对象 传入对象名字 首字母小写
    public static Object getBeanObj(String BeanName){
        return context.getBean(BeanName);
    }
}

package com.example.datestruct.utils;

import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.StringRedisSerializer;

public class redisUtils {
    //通过工厂类获取redisTemplete对象
    public static RedisTemplate getRedisTemplete(){

        RedisTemplate redisTemplate=(RedisTemplate) ApplicationTextUtils.getBeanObj("redisTemplate");
        redisTemplate.setHashKeySerializer(new StringRedisSerializer());
        redisTemplate.setKeySerializer(new StringRedisSerializer());
        return redisTemplate;
    }
}

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

spring.redis.host=localhost
spring.redis.port=6379
spring.redis.pool.max-active=8
spring.redis.pool.max-idle=8
spring.redis.pool.min-idle=0
spring.redis.database=0
spring.redis.lettuce.pool.min-idle=1
spring.redis.lettuce.pool.max-idle=30
spring.redis.lettuce.pool.max-active=100
spring.redis.lettuce.pool.max_wait=PT10S

package com.example.datestruct;

import com.example.datestruct.domain.student;
import com.example.datestruct.utils.redisUtils;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.data.redis.core.HashOperations;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.ValueOperations;

import java.nio.channels.SocketChannel;
import java.util.Iterator;
import java.util.List;
import java.util.Set;

@SpringBootTest
class DatestructApplicationTests {
    //切记 对象一定要序列化
    @Test
    public void test1(){
        redisUtils.getRedisTemplete().opsForValue().set("student",new student("1","2","3"));
    }

    @Test
    public void test9(){
        student stu=(student)redisUtils.getRedisTemplete().opsForValue().get("student");
        System.out.println(stu);
    }

    @Test
    public void test2(){
        redisUtils.getRedisTemplete().opsForHash().put("a","b","c");
        redisUtils.getRedisTemplete().opsForHash().put("a","b","c2");
        redisUtils.getRedisTemplete().opsForHash().put("a","b3","c2");
    }
   @Test
    public void test3(){
        RedisTemplate redisTemplate= (RedisTemplate)ApplicationTextUtils.getBeanObj("redisTemplateMsg");
        Set<String> HK=redisTemplate.opsForHash().keys("a");
        System.out.println(HK.toString());//[b1, b2, b3]map的key
        System.out.println(redisTemplate.opsForHash().values("a"));//[C1, c2, c3] map的values
        System.out.println(HK.size());

//        Iterator<String> it= HK.iterator();
//        while (it.hasNext()){
//            System.out.println(it.next());
//            System.out.println((student)redisTemplate.opsForHash().get("a","b"));
//            redisTemplate.opsForHash().get("a",it.next());
//        }
        
        
    }
    @Test
    public void test4(){
       List<String> lists=redisUtils.getRedisTemplete().opsForHash().values("a");
        System.out.println(lists.toString());
        System.out.println(lists.size());
    }
    @Test
    public void test5(){
        redisUtils.getRedisTemplete().opsForHash().delete("a","b");
    }
    @Test
    public void test6(){
        System.out.println(redisUtils.getRedisTemplete().opsForHash().get("a","b3"));
    }
}

Redis中opsForValue()方法的使用介绍：

1、set(K key, V value)
  新增一个字符串类型的值，key是键，value是值。

redisTemplate.opsForValue().set("stringValue","bbb");  
2、get(Object key)
  获取key键对应的值。

String stringValue = redisTemplate.opsForValue().get("key")
3、append(K key, String value)
在原有的值基础上新增字符串到末尾。

redisTemplate.opsForValue().append("key", "appendValue");
String stringValueAppend = redisTemplate.opsForValue().get("key");
System.out.println("通过append(K key, String value)方法修改后的字符串:"+stringValueAppend);  
4、get(K key, long start, long end)
截取key键对应值得字符串，从开始下标位置开始到结束下标的位置(包含结束下标)的字符串。

String cutString = redisTemplate.opsForValue().get("key", 0, 3);  
System.out.println("通过get(K key, long start, long end)方法获取截取的字符串:"+cutString);  
5、getAndSet(K key, V value)
  获取原来key键对应的值并重新赋新值。

String oldAndNewStringValue = redisTemplate.opsForValue().getAndSet("key", "ccc");  
System.out.print("通过getAndSet(K key, V value)方法获取原来的值：" + oldAndNewStringValue );  
String newStringValue = redisTemplate.opsForValue().get("key");  
System.out.println("修改过后的值:"+newStringValue);  
6、setBit(K key, long offset, boolean value)
  key键对应的值value对应的ascii码,在offset的位置(从左向右数)变为value。

redisTemplate.opsForValue().setBit("key",1,false);  
newStringValue = redisTemplate.opsForValue().get("key")+"";  
System.out.println("通过setBit(K key,long offset,boolean value)方法修改过后的值:"+newStringValue);  
 7、getBit(K key, long offset)
  判断指定的位置ASCII码的bit位是否为1。

boolean bitBoolean = redisTemplate.opsForValue().getBit("key",1);  
System.out.println("通过getBit(K key,long offset)方法判断指定bit位的值是:" + bitBoolean);  
8、size(K key)

  获取指定字符串的长度

Long stringValueLength = redisTemplate.opsForValue().size("key");  
System.out.println("通过size(K key)方法获取字符串的长度:"+stringValueLength);  
9、increment(K key, double delta)

  以增量的方式将double值存储在变量中。

double stringValueDouble = redisTemplate.opsForValue().increment("doubleKey",5);   
System.out.println("通过increment(K key, double delta)方法以增量方式存储double值:" + stringValueDouble);  
10、increment(K key, long delta)
  以增量的方式将long值存储在变量中。

double stringValueLong = redisTemplate.opsForValue().increment("longKey",6);   
System.out.println("通过increment(K key, long delta)方法以增量方式存储long值:" + stringValueLong);  
11、setIfAbsent(K key, V value)

  如果键不存在则新增,存在则不改变已经有的值。

boolean absentBoolean = redisTemplate.opsForValue().setIfAbsent("absentKey","fff");  
System.out.println("通过setIfAbsent(K key, V value)方法判断变量值absentValue是否存在:" + absentBoolean);  
if(absentBoolean){  
    String absentValue = redisTemplate.opsForValue().get("absentKey")+"";  
    System.out.print(",不存在，则新增后的值是:"+absentValue);  
    boolean existBoolean = redisTemplate.opsForValue().setIfAbsent("absentKey","eee");  
    System.out.print(",再次调用setIfAbsent(K key, V value)判断absentValue是否存在并重新赋值:" + existBoolean);  
    if(!existBoolean){  
        absentValue = redisTemplate.opsForValue().get("absentKey")+"";  
        System.out.print("如果存在,则重新赋值后的absentValue变量的值是:" + absentValue);  
12、set(K key, V value, long timeout, TimeUnit unit)
  设置变量值的过期时间。

redisTemplate.opsForValue().set("timeOutKey", "timeOut", 5, TimeUnit.SECONDS);  
String timeOutValue = redisTemplate.opsForValue().get("timeOutKey")+"";  
System.out.println("通过set(K key, V value, long timeout, TimeUnit unit)方法设置过期时间，
过期之前获取的数据:"+timeOutValue);  
Thread.sleep(5*1000);  
timeOutValue = redisTemplate.opsForValue().get("timeOutKey")+"";  
System.out.print(",等待10s过后，获取的值:"+timeOutValue);  
13、set(K key, V value, long offset)
  覆盖从指定位置开始的值。

redisTemplate.opsForValue().set("absentKey","dd",1);  
String overrideString = redisTemplate.opsForValue().get("absentKey");  
System.out.println("通过set(K key, V value, long offset)方法覆盖部分的值:"+overrideString);  


14、multiSet(Map<? extends K,? extends V> map)
  设置map集合到redis。

Map valueMap = new HashMap();  
valueMap.put("valueMap1","map1");  
valueMap.put("valueMap2","map2");  
valueMap.put("valueMap3","map3");  
redisTemplate.opsForValue().multiSet(valueMap);  
15、multiGet(Collection<K> keys)
  根据集合取出对应的value值。

//根据List集合取出对应的value值  
List paraList = new ArrayList();  
paraList.add("valueMap1");  
paraList.add("valueMap2");  
paraList.add("valueMap3");  
List<String> valueList = redisTemplate.opsForValue().multiGet(paraList);  
for (String value : valueList){  
    System.out.println("通过multiGet(Collection<K> keys)方法获取map值:" + value);  
}
16、multiSetIfAbsent(Map<? extends K,? extends V> map)
Map valueMap = new HashMap();  
valueMap.put("valueMap1","map1");  
valueMap.put("valueMap2","map2");  
valueMap.put("valueMap3","map3");  
redisTemplate.opsForValue().multiSetIfAbsent(valueMap);