redis的初步使用（一）
阿新 • • 發佈：2018-12-19
以法院專案查詢公告為例
步驟一：在application.yml中新增redis資訊
spring: datasource: driver-class-name: com.mysql.jdbc.Driver url: jdbc:mysql:///ggt username: root password: root type: com.alibaba.druid.pool.DruidDataSource redis: host: 10.9.251.200 port: 8100 password: redis001 jedis: pool: max-active: 1024 max-idle: 100 min-idle: 10 pagehelper: helper-dialect: mysql params: count=countsql reasonable: true support-methods-arguments: true
步驟二：:新增配置檔案類，在伺服器啟動的時候建立JedisPool物件
package com.qf.fayuan.config; import org.springframework.beans.factory.annotation.Value; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import redis.clients.jedis.Jedis; import redis.clients.jedis.JedisPool; import redis.clients.jedis.JedisPoolConfig; @Configuration public class RedisConfig { @Value(value = ("${spring.redis.host}")) private String host; @Value(value = ("${spring.redis.port}")) private int port; @Value(value =("${spring.redis.password}") ) private String password; @Bean public JedisPool jedisPool(JedisPoolConfig jedisPoolConfig){ JedisPool jedisPool = new JedisPool(jedisPoolConfig,host,port,5000,password); return jedisPool; } @Bean public JedisPoolConfig jedisPoolConfig(){ JedisPoolConfig jedisPoolConfig = new JedisPoolConfig(); jedisPoolConfig.setMaxTotal(1024); jedisPoolConfig.setMaxIdle(100); jedisPoolConfig.setMinIdle(10); return jedisPoolConfig; } }
步驟三：配置工具類，如果快取中沒有，將資料新增入
package com.qf.fayuan.utils; import redis.clients.jedis.Jedis; import java.beans.PropertyDescriptor; import java.lang.reflect.Field; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; public class RedisUtils { public static void hSet(int key, Object object, Jedis jedis){ //獲取類的位元組碼物件 Class<?> aClass = object.getClass(); //獲得類中的所有屬性 Field[] declaredFields = aClass.getDeclaredFields(); for (Field field : declaredFields) { String fieldName = field.getName(); try { //獲取屬性的get/set 方法 PropertyDescriptor propertyDescriptor = new PropertyDescriptor(fieldName, aClass); //獲取get方法 Method readMethod = propertyDescriptor.getReadMethod(); if (readMethod != null) { //得到屬性的值 Object result = readMethod.invoke(object); if (result != null) { //向快取中新增資料 jedis.hset(key + "noticeinfo", fieldName, result.toString()); } } } catch (Exception e) { e.printStackTrace(); } } } }
第四部分：service部分
/**
* 通過查詢id獲得公告的資訊，這裡使用快取來提高效率
* @param id 公告資訊的id
* @return
*/
@Override
public ResultBean getNoticeInfo(int id) {
Jedis jedis = null;
try {
jedis = jedisPool.getResource();
//從快取中讀取，判斷快取中是否含有資料
Map<String, String> stringMap = jedis.hgetAll(id + "noticeinfo");
if (stringMap == null || stringMap.isEmpty()) {
//設定防止穿透,判斷資料庫中是否含有該項資料，沒有的話就不用去查詢資料庫了
Boolean fangchuantou_notice = jedis.sismember("fangchuantou_notice", String.valueOf(id));
if (fangchuantou_notice) {
Notice notice = noticeMapper.getNoticeInfo(id);
if (notice != null) {
//將資料新增到快取中
RedisUtils.hSet(id, notice, jedis);
//設定資料在快取中的儲存時間，單位是 秒
jedis.expire(id + "noticeinfo", 1800);
return ResultBean.setOk(notice);
}
}
}else {
return ResultBean.setOk(stringMap);
}
}catch(Exception e){
e.printStackTrace();
throw e;
}finally{
if (jedis != null) {
jedis.close();
}
}
return ResultBean.setError(ErrorCodeInterface.XIUGAIMIMASHIBAI,"查詢失敗",null);
}
第五部分：為了防止穿透，在伺服器啟動的時候就遍歷資料庫，將所有的key值便利出來
package com.qf.fayuan.config;
import com.qf.fayuan.mapper.NoticeMapper;
import com.qf.fayuan.notice.pojo.Notice;
import io.swagger.models.auth.In;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import javax.annotation.PostConstruct;
import java.util.List;
@Configuration
public class GetAllRedisConfig {
@Autowired
private JedisPool jedisPool;
@Autowired
private NoticeMapper noticeMapper;
@PostConstruct
public void init(){
Jedis jedis = jedisPool.getResource();
List<Integer> list = noticeMapper.getAllNoticeKey();
// String[] arr = list.toArray(new String[list.size()]);
String[] arr = new String[list.size()];
for (int i = 0; i < list.size(); i++) {
arr[i] = list.get(i).toString();
}
jedis.sadd("fangchuantou_notice",arr);
jedis.close();
}
}
第六部分：在使用者執行其他操作時（增刪改查），要實時更新防穿透列表
@Service
public class NoticeServiceImpl implements NoticeService {
@Autowired
private NoticeMapper noticeMapper;
@Autowired
private JedisPool jedisPool;
@Override
public void addNotice(Notice notice) {
noticeMapper.addNotice(notice);
//比如新增資料的時候，更新放穿透列表
Jedis jedis = jedisPool.getResource();
jedis.sadd("fangchuantou_notice",notice.getId()+"");
jedis.close();
}
上面注意的是，新增資料後如何獲取物件的id 要將selectkey 放在sql插入語句後面
<insert id="addNotice">
insert into rw_notice(number, user_id, notice_type_id, court_id, case_num,show_area, about_mobile, about_identify_num, about_name, name_id, create_time, update_time, img,status, trade_no, pub_time, pub_days) values (#{number},#{user_id},#{notice_type_id},#{court_id},#{case_num},#{show_area},#{about_mobile},#{about_identify_num},#{about_name},#{name_id},#{create_time},#{update_time},#{img},#{status},#{trade_no},#{pub_time},#{pub_days})
<selectKey resultType="int" keyProperty="id" order="AFTER">
select LAST_INSERT_ID() as value
</selectKey>
</insert>