SpringBoot集成Redis，以及MybatisPlus分页、Mapper的使用（二）

概述

上节主要讲解SpringBoot项目框架搭建，这里不再赘述。内容建立在上节基础上，具体详情地址：http://blog.csdn.net/fjekin/article/details/78407153，本篇介绍MybatisPlus分页和Redis的使用。

分页测试（效果图）

笔者用的接口测试工具是谷歌的apizza，也是蛮强大的。减少文档编写工作量。

分页

排序规则，Order.java

package com.jekin.example.entity.page;

/**
 * 数据库排序
 *
 * 
 * @Date 2017年5月31日20:48:41
 */
public enum Order {

    ASC("asc"), DESC("desc");

    private String des;

    Order(String des) {
        this.des = des;
    }

    public String getDes() {
        return des;
    }

    public void setDes(String des) {
        this.des = des;
    }
}

分页结果封装，PageInfoBT.java

package com.jekin.example.entity.page;

import java.util.List;

import com.baomidou.mybatisplus.plugins.Page;

/**
 * 分页结果的封装
 * 
 * @author Jekin
 * @date 2017年10月31日
 */
public class PageInfoBT {

    // 结果集
    private List content;

    // 总数
    private long total;

    public PageInfoBT(Page page) {
        this.content = page.getRecords();
        this.total = page.getTotal();
    }

    public List getContent() {
        return content;
    }

    public void setContent(List content) {
        this.content = content;
    }

    public long getTotal() {
        return total;
    }

    public void setTotal(long total) {
        this.total = total;
    }
}

接口请求默认分页配置，PageFactory.java

package com.jekin.example.factory;

import javax.servlet.http.HttpServletRequest;

import org.apache.commons.lang3.StringUtils;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import com.baomidou.mybatisplus.plugins.Page;
import com.jekin.example.entity.page.Order;

/**
 * 默认分页
 * 
 * @author Jekin
 * @date 2017年10月31日
 */
public class PageFactory {
    public Page defaultPage() {
        HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
        int size = 12;
        int current = 0;
        if (!StringUtils.isEmpty(request.getParameter("size"))) {
            size = Integer.valueOf(request.getParameter("size"));
            current = Integer.valueOf(request.getParameter("page"));
        } else {
            size = 60000;
            current = 0;
        }
        String sort = request.getParameter("sort");
        String order = request.getParameter("order");
        if (StringUtils.isEmpty(sort)) {
            Page page = new Page<>(current, size);
            page.setOpenSort(false);
            return page;
        } else {
            Page page = new Page<>(current, size, sort);
            if (Order.ASC.getDes().equals(order)) {
                page.setAsc(true);
            } else {
                page.setAsc(false);
            }
            return page;
        }
    }
}

使用例子，UserController.java

package com.jekin.example.controller;

import java.util.List;

import javax.annotation.Resource;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import com.baomidou.mybatisplus.plugins.Page;
import com.jekin.example.entity.ResultInfo;
import com.jekin.example.entity.User;
import com.jekin.example.entity.page.PageInfoBT;
import com.jekin.example.factory.PageFactory;
import com.jekin.example.mapper.UserMapper;

/**
 * 分页测试
 * 
 * @author Jekin
 * @date 2017年10月31日
 */
@Controller
@RequestMapping(value = "/redis/user")
public class UserController {

    @Resource
    private UserMapper userMapper;

    @RequestMapping("/list")
    @ResponseBody
    public ResultInfo list(
    ) {
        Page page = new PageFactory().defaultPage();
        List result = userMapper.getUserPage(page,
        page.getOrderByField(), page.isAsc());
        page.setRecords(result);
        ResultInfo resultInfo = new ResultInfo(0, "success");
        resultInfo.setData(new PageInfoBT(page));
        return resultInfo;
    }

}

默认，分页参数可不传，ResultInfo是对结果集的包装。
Dao方法，UserMapper.java

List getUserPage(@Param("page") Page page,
        @Param("orderByField") String orderByField, @Param("isAsc") boolean isAsc);

映射文件，UserMapper.xml

<mapper namespace="com.jekin.example.mapper.UserMapper">
    
    <sql id="Base_Column_List">
        id,type,openid,avatar,account,password,salt,name,birthday,sex,email,phone,roleid,status,createtime,updatetime,balance
    sql>

    <resultMap id="BaseResultMap" type="User">
        <id column="id" property="id" />
        <result column="type" property="type" />
        <result column="openid" property="openid" />
        <result column="avatar" property="avatar" />
        <result column="account" property="account" />
        <result column="password" property="password" />
        <result column="salt" property="salt" />
        <result column="name" property="name" />
        <result column="birthday" property="birthday" />
        <result column="sex" property="sex" />
        <result column="email" property="email" />
        <result column="phone" property="phone" />
        <result column="roleid" property="roleid" />
        <result column="status" property="status" />
        <result column="createtime" property="createtime" />
        <result column="updatetime" property="updatetime" />
        <result column="balance" property="balance" />
    resultMap>

    <select id="getUserPage" resultType="User">
        select <include refid="Base_Column_List" /> from user where 1 = 1
        <choose>
            <when test="orderByField != null and orderByField !=''">
                <choose>
                    <when test="isAsc == true">
                        order by ${orderByField} ASC
                    when>
                    <otherwise>
                        order by ${orderByField} DESC
                    otherwise>
                choose>
            when>
            <otherwise>
                order by id DESC
            otherwise>
        choose>
    select>

mapper>

以上重点是PageFactory类，笔者在MP分页辅助类Page上又一次包装，通过HttpServletRequest获取接口参数做初始化工作。关于MP更多内容，可以查看官网地址，笔者建议直接查看源码，里面都有中文注释，比官网介绍的更详细。

Redis缓存

引入jar包，配置地址等参数（上节有写，不赘述）。序列和反序列化，FastJson2JsonRedisSerializer.java

package com.jekin.example.config;

import java.nio.charset.Charset;

import org.springframework.data.redis.serializer.RedisSerializer;
import org.springframework.data.redis.serializer.SerializationException;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.serializer.SerializerFeature;

/**
 * Redis序列化和反序列化，以对象形式存储
 * 
 * It is recommended that
 * implementations are designed to handle null objects/empty arrays on serialization and deserialization side.
 * @author Jekin
 * @date 2017年10月31日
 */
public class FastJson2JsonRedisSerializer<T> implements RedisSerializer<T> {

    public static final Charset DEFAULT_CHARSET = Charset.forName("UTF-8");

    private Class clazz;

    public FastJson2JsonRedisSerializer(Class clazz) {
        super();
        this.clazz = clazz;
    }

    public byte[] serialize(T t) throws SerializationException {
        if (t == null) {
            return new byte[0];
        }
        return JSON.toJSONString(t, SerializerFeature.WriteClassName).getBytes(DEFAULT_CHARSET);
    }

    public T deserialize(byte[] bytes) throws SerializationException {
        if (bytes == null || bytes.length <= 0) {
            return null;
        }
        String str = new String(bytes, DEFAULT_CHARSET);

        return (T) JSON.parseObject(str, clazz);
    }

}

注解方式实例化，RedisConfig.java

package com.jekin.example.config;

import java.lang.reflect.Method;

import org.springframework.cache.CacheManager;
import org.springframework.cache.annotation.CachingConfigurerSupport;
import org.springframework.cache.annotation.EnableCaching;
import org.springframework.cache.interceptor.KeyGenerator;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.cache.RedisCacheManager;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.serializer.RedisSerializer;

@Configuration
@EnableCaching
public class RedisConfig extends CachingConfigurerSupport {
    /**
     * 使用@Cacheable注解，修改key的生成策略
     * 
     * @return
     */
    @Bean
    public KeyGenerator keyGenerator() {
        return new KeyGenerator() {
            @Override
            public Object generate(Object target, Method method, Object... params) {
                StringBuilder sb = new StringBuilder();
                sb.append(target.getClass().getName());
                sb.append(method.getName());
                for (Object obj : params) {
                    sb.append(obj.toString());
                }
                return sb.toString();
            }
        };
    }

    /**
     * 管理缓存
     */
    @SuppressWarnings("rawtypes")
    @Bean
    public CacheManager cacheManager(RedisTemplate redisTemplate) {
        RedisCacheManager rcm = new RedisCacheManager(redisTemplate);
        return rcm;
    }

    @Bean
    @SuppressWarnings("rawtypes")
    public RedisSerializer fastJson2JsonRedisSerializer() {
        return new FastJson2JsonRedisSerializer