2018-07-03

package com.syjh.utils;

import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.TimeUnit;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.data.redis.core.RedisTemplate;

import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;
import com.syjh.common.exception.BusinessException;
import com.syjh.consts.Const;
import com.syjh.entity.User;
import com.syjh.utils.ajax.JsonUtil;
import com.syjh.utils.ajax.Result;

public class RedisUtil {

private static Logger LOGGER = LoggerFactory.getLogger(RedisUtil.class);
@SuppressWarnings("unchecked")
public static RedisTemplate<String, String> redisTemplate = SpringContextHolder.getBean(RedisTemplate.class);

// private static int DEFAULT_EXPIRE_MIN = 1;

public static void set(String key, String value) {
    set(key, value, Const.DEFAULT_EXPIRE_TIME);
}

public static void setFalsenum(String key,String value) {
    set(key,value,Const.DEFAULT_TOKEN_EXPIRE_TIME);
}

public static void set(String key, String value, int expire_min) {
    redisTemplate.opsForValue().set(key, value, expire_min, TimeUnit.SECONDS);
}

public static void setObject(String key, Object value) {
    setObject(key, value, Const.DEFAULT_EXPIRE_TIME);
}
public static void setLockValue(String key, Object value) {
    String str = JsonUtil.parse(value);
    redisTemplate.opsForValue().set(key, str,Const.DEFAULT_TOKEN_EXPIRE_TIME,TimeUnit.SECONDS);
}

public static void setObject(String key, Object value, int expire_min) {
    String str = JsonUtil.parse(value);
    redisTemplate.opsForValue().set(key, str, expire_min, TimeUnit.SECONDS);
}

public static void delete(String key) {
    redisTemplate.delete(key);
}

public static String get(String key) {
    return redisTemplate.opsForValue().get(key);
}

public static void deleteKeys(String key) {
    Set<String> keys = redisTemplate.keys(key);
    redisTemplate.delete(keys);
}

public static User getMiniappsUser(String token) {
    if (token == null) {
        return null;
    }
    User user = RedisUtil.getObject(Const.MINIAPPS_CUSTOMER_TOKEN + token, User.class);
    // 检查过期时间
    if (user != null) {
        long expireTime = user.getExpireTime().getTime() - System.currentTimeMillis();
        if (expireTime < Const.DEFAULT_TOKEN_REFRESH_TIME) {
            redisTemplate.expire(token, Const.DEFAULT_TOKEN_EXPIRE_TIME, TimeUnit.SECONDS);
        }
    }
    return user;
}

public static void setCustomerUser(String token, User user) {
    if (user == null) {
        throw new BusinessException(Result.authFail("请重新登录"));
    }
    user.setPassword(null);
    user.setExpireTime(new Date(System.currentTimeMillis() + Const.DEFAULT_TOKEN_EXPIRE_TIME));
    RedisUtil.setObject(Const.MINIAPPS_CUSTOMER_TOKEN + token, user, Const.DEFAULT_TOKEN_EXPIRE_TIME);
}

public static <T> T getObject(String key, Class<T> clazz) {
    String str = redisTemplate.opsForValue().get(key);
    if (str != null) {
        T res = null;
        Gson gson = new Gson();
        res = gson.fromJson(str, clazz);
        return res;
    }
    return null;
}

public static <T> List<T> getList(String key, Class<T> clazz){
    String str = redisTemplate.opsForValue().get(key);
    if (str != null) {
        Gson gson = new Gson();
        Type type = new TypeToken<ArrayList<T>>() {}.getType();
        ArrayList<T> sList=gson.fromJson(str, type);
        return sList;
    }
    return null;
}

/*
 * 判断是否存在
 */
public static boolean hasKey(String key){  
    try {  
        return redisTemplate.hasKey(key);  
    } catch (Exception e) {  
        e.printStackTrace();  
        return false;  
    }  
}

/*
 * 获取过期时间
 */
public static long getExpire(String key){  
    return redisTemplate.getExpire(key,TimeUnit.SECONDS);  
}  

}

使用Redis作缓存数据库，将对像转换成json字符串后存入redis数据库，然后取出相应的值，取出值后再将其转化成对像，使用的是gson类的fromJson(str, clazz)方法，这个方法只能将字符串转化成对像，不能将字符串转化成数组，如果字符串是一个json数组的话就会出错是，于是就要使用gson的fromJson(str, type)方法，就能正确转换。 image.png