摘要：添加用戶接口類簡(jiǎn)單用戶鏈接數(shù)據(jù)庫(kù)微服務(wù)通過(guò)注解標(biāo)注該類為持久化操作對(duì)象。查找用戶數(shù)據(jù)保存用戶數(shù)據(jù)更新用戶數(shù)據(jù)刪除用戶數(shù)據(jù)這是清除緩存添加緩存配置緩存配置。對(duì)象是否永久有效，一但設(shè)置了，將不起作用。設(shè)置對(duì)象在失效前允許存活時(shí)間單位秒。

-

1、數(shù)據(jù)庫(kù)頻繁的操作也會(huì)影響性能，所以本章節(jié)準(zhǔn)備給訪問(wèn)數(shù)據(jù)庫(kù)前面添加一層緩存操作；
2、雖然說(shuō)緩存框架存在很多且各有各的優(yōu)勢(shì)，本章節(jié)僅僅只是為了測(cè)試緩存的操作實(shí)現(xiàn)，所以就采用了一個(gè)簡(jiǎn)單的緩存框架ehcache；

    4.0.0

    springms-provider-user-mysql-mybatis-mapper-ehcache
    1.0-SNAPSHOT
    jar
    
    
        com.springms.cloud
        springms-spring-cloud
        1.0-SNAPSHOT
    
    
    
        
        
            org.springframework.boot
            spring-boot-starter-data-jpa
        

        
        
            org.springframework.boot
            spring-boot-starter-web
        

        
        
            mysql
            mysql-connector-java
        

        
        
            org.mybatis.spring.boot
            mybatis-spring-boot-starter
            1.3.1
        

        
        
            org.springframework.boot
            spring-boot-starter-cache
        

        
        
            net.sf.ehcache
            ehcache
        
    

server:
  port: 8385
spring:
  application:
    name: springms-provider-user-mysql-mybatis-mapper-ehcache  #全部小寫


#####################################################################################################
# mysql 屬性配置
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://120.77.176.162:3306/hmilyylimh
    username: root
    password: mysqladmin
#  jpa:
#    hibernate:
#      #ddl-auto: create #ddl-auto:設(shè)為create表示每次都重新建表
#      ddl-auto: update #ddl-auto:設(shè)為update表示每次都不會(huì)重新建表
#    show-sql: true
#####################################################################################################

#####################################################################################################
# mybatis mapper xml 配置
mybatis:
  # mybatis.type-aliases-package：指定domain類的基包，即指定其在*Mapper.xml文件中可以使用簡(jiǎn)名來(lái)代替全類名（看后邊的UserMapper.xml介紹）
  type-aliases-package:
  mapper-locations: classpath:mybatis/mapper/*.xml
  config-location: classpath:mybatis/mybatis-config.xml
#####################################################################################################

#####################################################################################################
# 打印日志
logging:
  level:
    root: INFO
    org.hibernate: INFO
    org.hibernate.type.descriptor.sql.BasicBinder: TRACE
    org.hibernate.type.descriptor.sql.BasicExtractor: TRACE
    com.springms: DEBUG
#####################################################################################################

    
        
        
        
        
        
    


    
    
        
    

    
        select * from user
        where id = #{id,jdbcType=BIGINT}
    

    
        select * from user
    

    
        DELETE from user where id = #{id}
    

    
        update user set userName=#{username},name=#{name},age=#{age},balance=#{balance} where id=#{id}
    

package com.springms.cloud.entity;


public class User {

  private Long id;

  private String username;

  private String name;

  private Integer age;

  private String balance;

  /** 來(lái)自于哪里，默認(rèn)來(lái)自于數(shù)據(jù)庫(kù) */
  private String from = "";

  public Long getId() {
    return this.id;
  }

  public void setId(Long id) {
    this.id = id;
  }

  public String getUsername() {
    return this.username;
  }

  public void setUsername(String username) {
    this.username = username;
  }

  public String getName() {
    return this.name;
  }

  public void setName(String name) {
    this.name = name;
  }

  public Integer getAge() {
    return this.age;
  }

  public void setAge(Integer age) {
    this.age = age;
  }

  public String getBalance() {
    return this.balance;
  }

  public void setBalance(String balance) {
    this.balance = balance;
  }

  public String getFrom() {
    return from;
  }

  public void setFrom(String from) {
    this.from = from;
  }

  @Override
  public String toString() {
    return "User{" +
            "id=" + id +
            ", username="" + username + """ +
            ", name="" + name + """ +
            ", age=" + age +
            ", balance="" + balance + """ +
            ", from="" + from + """ +
            "}";
  }
}

package com.springms.cloud.mapper;

import com.springms.cloud.entity.User;

import java.util.List;

/**
 * 用戶 mybatis 接口文件。
 *
 * @author hmilyylimh
 *
 * @version 0.0.1
 *
 * @date 2017-10-19
 *
 */
public interface IUserMapper {

    User findUserById(Long id);

    List findAllUsers();

    int insertUser(User user);

    int updateUser(User user);

    int deleteUser(Long id);
}

package com.springms.cloud.dao;

import com.springms.cloud.entity.User;

import java.util.List;

/**
 * 簡(jiǎn)單用戶鏈接Mysql數(shù)據(jù)庫(kù)微服務(wù)（通過(guò)@Repository注解標(biāo)注該類為持久化操作對(duì)象）。
 *
 * @author hmilyylimh
 *
 * @version 0.0.1
 *
 * @date 2017-10-19
 *
 */
public interface IUserDao {

    User findUserById(Long id);

    List findAllUsers();

    int insertUser(User user);

    int updateUser(User user);

    int deleteUser(Long id);
}

package com.springms.cloud.dao.impl;

import com.springms.cloud.dao.IUserDao;
import com.springms.cloud.entity.User;
import com.springms.cloud.mapper.IUserMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

import java.util.List;

/**
 * 簡(jiǎn)單用戶鏈接Mysql數(shù)據(jù)庫(kù)微服務(wù)（通過(guò)@Repository注解標(biāo)注該類為持久化操作對(duì)象）。
 *
 * @author hmilyylimh
 *
 * @version 0.0.1
 *
 * @date 2017-10-19
 *
 */
@Repository
public class UserDaoImpl implements IUserDao {

    @Autowired
    private IUserMapper iUserMapper;

    @Override
    public User findUserById(Long id) {
        return iUserMapper.findUserById(id);
    }

    @Override
    public List findAllUsers() {
        return iUserMapper.findAllUsers();
    }

    @Override
    public int insertUser(User user) {
        return iUserMapper.insertUser(user);
    }

    @Override
    public int updateUser(User user) {
        return iUserMapper.updateUser(user);
    }

    @Override
    public int deleteUser(Long id) {
        return iUserMapper.deleteUser(id);
    }
}

package com.springms.cloud.service;

import com.springms.cloud.entity.User;

import java.util.List;

/**
 * 簡(jiǎn)單用戶鏈接Mysql數(shù)據(jù)庫(kù)微服務(wù)（通過(guò)@Service注解標(biāo)注該類為持久化操作對(duì)象）。
 *
 * @author hmilyylimh
 *
 * @version 0.0.1
 *
 * @date 2017-10-19
 *
 */
public interface IUserService {

    User findUserById(Long id);

    List findAllUsers();

    int insertUser(User user);

    int updateUser(User user);

    int deleteUser(Long id);
}

package com.springms.cloud.service.impl;

import com.springms.cloud.dao.IUserDao;
import com.springms.cloud.entity.User;
import com.springms.cloud.service.IUserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cache.annotation.CacheEvict;
import org.springframework.cache.annotation.CachePut;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * 簡(jiǎn)單用戶鏈接Mysql數(shù)據(jù)庫(kù)微服務(wù)（通過(guò)@Service注解標(biāo)注該類為持久化操作對(duì)象）。

 *
 * 
注意：CACHE_KEY、CACHE_NAME_B 的單引號(hào)不能少，否則會(huì)報(bào)錯(cuò)，被識(shí)別是一個(gè)對(duì)象。
 *
 * 
value 指的是 ehcache.xml 中的緩存策略空間；key 指的是緩存的標(biāo)識(shí)
 *
 * @author hmilyylimh
 *
 * @version 0.0.1
 *
 * @date 2017-10-19
 *
 */
@Service
public class UserServiceImpl implements IUserService {

    private static final String CACHE_KEY = ""user"";
    private static final String CACHE_NAME_B = "cache-b";

    //* @Cacheable : Spring在每次執(zhí)行前都會(huì)檢查Cache中是否存在相同key的緩存元素，如果存在就不再執(zhí)行該方法，而是直接從緩存中獲取結(jié)果進(jìn)行返回，否則才會(huì)執(zhí)行并將返回結(jié)果存入指定的緩存中。
    //* @CacheEvict : 清除緩存。
    //* @CachePut : @CachePut也可以聲明一個(gè)方法支持緩存功能。使用@CachePut標(biāo)注的方法在執(zhí)行前不會(huì)去檢查緩存中是否存在之前執(zhí)行過(guò)的結(jié)果，而是每次都會(huì)執(zhí)行該方法，并將執(zhí)行結(jié)果以鍵值對(duì)的形式存入指定的緩存中。

    @Autowired
    IUserDao iUserDao;

    /**
     * 查找用戶數(shù)據(jù)
     *
     * @param id
     * @return
     */
    @Cacheable(value=CACHE_NAME_B, key=""user_"+#id")
    @Override
    public User findUserById(Long id) {
        return iUserDao.findUserById(id);
    }

    @Override
    public List findAllUsers() {
        return iUserDao.findAllUsers();
    }

    /**
     * 保存用戶數(shù)據(jù)
     *
     * @param user
     * @return
     */
    @CacheEvict(value=CACHE_NAME_B, key=CACHE_KEY)
    @Override
    public int insertUser(User user) {
        return iUserDao.insertUser(user);
    }

    /**
     * 更新用戶數(shù)據(jù)
     *
     * @param user
     * @return
     */
    @CachePut(value = CACHE_NAME_B, key = ""user_"+#user.id")
    @Override
    public int updateUser(User user) {
        return iUserDao.updateUser(user);
    }

    /**
     * 刪除用戶數(shù)據(jù)
     *
     * @param id
     * @return
     */
    @CacheEvict(value = CACHE_NAME_B, key = ""user_" + #id") //這是清除緩存
    @Override
    public int deleteUser(Long id) {
        return iUserDao.deleteUser(id);
    }
}

package com.springms.cloud.config;

import org.springframework.cache.annotation.EnableCaching;
import org.springframework.cache.ehcache.EhCacheCacheManager;  
import org.springframework.cache.ehcache.EhCacheManagerFactoryBean;  
import org.springframework.context.annotation.Bean;  
import org.springframework.context.annotation.Configuration;  
import org.springframework.core.io.ClassPathResource;  

/**
 * 緩存配置。
 *
 * @author hmilyylimh
 *
 * @version 0.0.1
 *
 * @date 2017-10-19
 *
 */
@Configuration  
@EnableCaching//標(biāo)注啟動(dòng)緩存.  
public class CacheConfiguration {  
     
    /** 
     * ehcache 主要的管理器
     *
     * @param bean 
     * @return 
     */  
    @Bean  
    public EhCacheCacheManager ehCacheCacheManager(EhCacheManagerFactoryBean bean){
       System.out.println("CacheConfiguration.ehCacheCacheManager()");  
       return new EhCacheCacheManager(bean.getObject());  
    }  
     
    /*
     * 據(jù)shared與否的設(shè)置,
     * Spring分別通過(guò)CacheManager.create()
     * 或new CacheManager()方式來(lái)創(chuàng)建一個(gè)ehcache基地.
     *
     * 也說(shuō)是說(shuō)通過(guò)這個(gè)來(lái)設(shè)置cache的基地是這里的Spring獨(dú)用,還是跟別的(如hibernate的Ehcache共享)
     *
     */
    @Bean
    public EhCacheManagerFactoryBean ehCacheManagerFactoryBean(){
    System.out.println("CacheConfiguration.ehCacheManagerFactoryBean()");
    EhCacheManagerFactoryBean cacheManagerFactoryBean = new EhCacheManagerFactoryBean ();
    cacheManagerFactoryBean.setConfigLocation (new ClassPathResource("ehcache.xml"));
    cacheManagerFactoryBean.setShared(true);
    return cacheManagerFactoryBean;
    }
} 

package com.springms.cloud.controller;

import com.springms.cloud.entity.User;
import com.springms.cloud.service.IUserService;
import org.hibernate.cache.CacheException;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;

/**
 * 用戶微服務(wù)Controller。
 *
 * @author hmilyylimh
 *
 * @version 0.0.1
 *
 * @date 2017-10-19
 *
 */
@RestController
public class ProviderUserMysqlMybatisMapperEhCacheController {

    private static final org.slf4j.Logger Logger = LoggerFactory.getLogger(ProviderUserMysqlMybatisMapperEhCacheController.class);

    @Autowired
    private IUserService iUserService;

    @GetMapping("/user/{id}")
    public User findUserById(@PathVariable Long id) {
        return this.iUserService.findUserById(id);
    }

    @GetMapping("/user/list")
    public List findUserList() {
        return this.iUserService.findAllUsers();
    }

    /**
     * 添加一個(gè)student,使用postMapping接收post請(qǐng)求
     *
     * http://localhost:8330/simple/addUser?username=user11&age=11&balance=11
     *
     * @return
     */
    @PostMapping("/user/addUser")
    public User addUser(@RequestParam(value = "username", required=false) String username, @RequestParam(value = "age", required=false) Integer age, @RequestParam(value = "balance", required=false) String balance){
        User user=new User();

        user.setUsername(username);
        user.setName(username);
        user.setAge(age);
        user.setBalance(balance);

        int result = iUserService.insertUser(user);
        if(result > 0){
            return user;
        }

        user.setId(0L);
        user.setName(null);
        user.setUsername(null);
        user.setBalance(null);
        return user;
    }

    @GetMapping("/user/ehcache")
    public String ehcache() {
        Logger.info("===========  進(jìn)行Encache緩存測(cè)試");

        List allUsers = iUserService.findAllUsers();
        User lastUser = allUsers.get(allUsers.size() - 1);
        String lastUserUsername = lastUser.getUsername();
        String indexString = lastUserUsername.substring(4);

        Logger.info("===========  ====生成第一個(gè)用戶====");
        User user1 = new User();
        //生成第一個(gè)用戶的唯一標(biāo)識(shí)符 UUID
        user1.setName("user" + (Integer.parseInt(indexString) + 1));
        user1.setUsername(user1.getName());
        user1.setAge(1000);
        user1.setBalance("1000");
        if (iUserService.insertUser(user1) == 0){
            throw new CacheException("用戶對(duì)象插入數(shù)據(jù)庫(kù)失敗");
        }

        allUsers = iUserService.findAllUsers();
        lastUser = allUsers.get(allUsers.size() - 1);
        Long lastUserId = lastUser.getId();

        //第一次查詢
        Logger.info("===========  第一次查詢");
        Logger.info("===========  第一次查詢結(jié)果: {}", iUserService.findUserById(lastUserId));
        //通過(guò)緩存查詢
        Logger.info("===========  通過(guò)緩存第 1 次查詢");
        Logger.info("===========  通過(guò)緩存第 1 次查詢結(jié)果: {}", iUserService.findUserById(lastUserId));
        Logger.info("===========  通過(guò)緩存第 2 次查詢");
        Logger.info("===========  通過(guò)緩存第 2 次查詢結(jié)果: {}", iUserService.findUserById(lastUserId));
        Logger.info("===========  通過(guò)緩存第 3 次查詢");
        Logger.info("===========  通過(guò)緩存第 3 次查詢結(jié)果: {}", iUserService.findUserById(lastUserId));

        Logger.info("===========  ====準(zhǔn)備修改數(shù)據(jù)====");
        User user2 = new User();
        user2.setName(lastUser.getName());
        user2.setUsername(lastUser.getUsername());
        user2.setAge(lastUser.getAge() + 1000);
        user2.setBalance(String.valueOf(user2.getAge()));
        user2.setId(lastUserId);
        try {
            int result = iUserService.updateUser(user2);
            Logger.info("===========  ==== 修改數(shù)據(jù) == {} ==", (result > 0? "成功":"失敗"));
        } catch (CacheException e){
            e.printStackTrace();
        }

        Logger.info("===========  ====修改后再次查詢數(shù)據(jù)");
        Object resultObj = iUserService.findUserById(lastUser.getId());
        Logger.info("===========  ====修改后再次查詢數(shù)據(jù)結(jié)果: {}", resultObj);
        return "success";
    }
}

package com.springms.cloud;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cache.annotation.EnableCaching;

/**
 * 鏈接Mysql數(shù)據(jù)庫(kù)簡(jiǎn)單的集成Mybatis、ehcache框架采用MapperXml訪問(wèn)數(shù)據(jù)庫(kù)。
 *
 * 簡(jiǎn)單用戶鏈接Mysql數(shù)據(jù)庫(kù)微服務(wù)（通過(guò) mybatis 鏈接 mysql 并用 MapperXml 編寫數(shù)據(jù)訪問(wèn)，并且通過(guò) EhCache 緩存來(lái)訪問(wèn)）。
 *
 * @author hmilyylimh
 *
 * @version 0.0.1
 *
 * @date 2017-10-19
 *
 */
@SpringBootApplication
@MapperScan("com.springms.cloud.mapper.**")
@EnableCaching
public class MsProviderUserMysqlMybatisMapperEhCacheApplication {

    public static void main(String[] args) {
        SpringApplication.run(MsProviderUserMysqlMybatisMapperEhCacheApplication.class, args);
        System.out.println("【【【【【【 鏈接MysqlMybatisMapperEhCache數(shù)據(jù)庫(kù)微服務(wù) 】】】】】】已啟動(dòng).");
    }
}

/****************************************************************************************
 注意：Mybatis 需要加上 entity 等注解才可以使用，不然啟動(dòng)都會(huì)報(bào)錯(cuò)；
 @MapperScan("com.springms.cloud.mapper.**") 或者在每個(gè) Mapper 接口文件上添加 @Mapper 也可以；

 一、簡(jiǎn)單用戶鏈接Mysql數(shù)據(jù)庫(kù)微服務(wù)（通過(guò) mybatis 鏈接 mysql 并用 MapperXml 編寫數(shù)據(jù)訪問(wèn)，并且通過(guò) EhCache 緩存來(lái)訪問(wèn)）：

 1、啟動(dòng) springms-provider-user-mysql-mybatis-mapper-ehcache 模塊服務(wù)，啟動(dòng)1個(gè)端口；
 2、在瀏覽器輸入地址 http://localhost:8385/user/10 可以看到用戶ID=10的信息成功的被打印出來(lái)；

 3、使用 IDEA 自帶工具 Test Restful WebService 發(fā)送 HTTP POST 請(qǐng)求,并添加 username、age、balance三個(gè)參數(shù)，然后執(zhí)行請(qǐng)求，并去 mysql 數(shù)據(jù)庫(kù)查看數(shù)據(jù)是否存在，正常情況下 mysql 數(shù)據(jù)庫(kù)剛剛插入的數(shù)據(jù)成功了:
 4、使用 REST Client 執(zhí)行 "/user/ehcache" 接口，也正常將 mysql 數(shù)據(jù)庫(kù)中所有的用戶信息打印出來(lái)了，并且打印的信息如下：

 5、在瀏覽器輸入地址 http://localhost:8385/user/ehcache 可以看到如下信息被打印出來(lái)；

 2017-10-19 17:48:54.561  INFO 2736 --- [nio-8385-exec-1] erMysqlMybatisMapperXmlEhCacheController : ===========  進(jìn)行Encache緩存測(cè)試
 2017-10-19 17:48:54.610 DEBUG 2736 --- [nio-8385-exec-1] c.i.c.mapper.IUserMapper.findAllUsers    : ==>  Preparing: select * from user
 2017-10-19 17:48:54.629 DEBUG 2736 --- [nio-8385-exec-1] c.i.c.mapper.IUserMapper.findAllUsers    : ==> Parameters:
 2017-10-19 17:48:54.657 DEBUG 2736 --- [nio-8385-exec-1] c.i.c.mapper.IUserMapper.findAllUsers    : <==      Total: 65
 2017-10-19 17:48:54.658  INFO 2736 --- [nio-8385-exec-1] erMysqlMybatisMapperXmlEhCacheController : ===========  ====生成第一個(gè)用戶====
 2017-10-19 17:48:54.661 DEBUG 2736 --- [nio-8385-exec-1] c.i.cloud.mapper.IUserMapper.insertUser  : ==>  Preparing: INSERT INTO user ( username, name, age, balance ) VALUES ( ?, ?, ?, ? )
 2017-10-19 17:48:54.662 DEBUG 2736 --- [nio-8385-exec-1] c.i.cloud.mapper.IUserMapper.insertUser  : ==> Parameters: user66(String), user66(String), 1000(Integer), 1000(String)
 2017-10-19 17:48:54.678 DEBUG 2736 --- [nio-8385-exec-1] c.i.cloud.mapper.IUserMapper.insertUser  : <==    Updates: 1
 2017-10-19 17:48:54.691 DEBUG 2736 --- [nio-8385-exec-1] c.i.c.mapper.IUserMapper.findAllUsers    : ==>  Preparing: select * from user
 2017-10-19 17:48:54.692 DEBUG 2736 --- [nio-8385-exec-1] c.i.c.mapper.IUserMapper.findAllUsers    : ==> Parameters:
 2017-10-19 17:48:54.707 DEBUG 2736 --- [nio-8385-exec-1] c.i.c.mapper.IUserMapper.findAllUsers    : <==      Total: 66
 2017-10-19 17:48:54.708  INFO 2736 --- [nio-8385-exec-1] erMysqlMybatisMapperXmlEhCacheController : ===========  第一次查詢
 2017-10-19 17:48:54.714 DEBUG 2736 --- [nio-8385-exec-1] c.i.c.mapper.IUserMapper.findUserById    : ==>  Preparing: select * from user where id = ?
 2017-10-19 17:48:54.714 DEBUG 2736 --- [nio-8385-exec-1] c.i.c.mapper.IUserMapper.findUserById    : ==> Parameters: 147(Long)
 2017-10-19 17:48:54.721 DEBUG 2736 --- [nio-8385-exec-1] c.i.c.mapper.IUserMapper.findUserById    : <==      Total: 1
 2017-10-19 17:48:54.722  INFO 2736 --- [nio-8385-exec-1] erMysqlMybatisMapperXmlEhCacheController : ===========  第一次查詢結(jié)果: User{id=147, username="user66", name="user66", age=1000, balance="1000", from=""}
 2017-10-19 17:48:54.722  INFO 2736 --- [nio-8385-exec-1] erMysqlMybatisMapperXmlEhCacheController : ===========  通過(guò)緩存第 1 次查詢
 2017-10-19 17:48:54.723  INFO 2736 --- [nio-8385-exec-1] erMysqlMybatisMapperXmlEhCacheController : ===========  通過(guò)緩存第 1 次查詢結(jié)果: User{id=147, username="user66", name="user66", age=1000, balance="1000", from=""}
 2017-10-19 17:48:54.723  INFO 2736 --- [nio-8385-exec-1] erMysqlMybatisMapperXmlEhCacheController : ===========  通過(guò)緩存第 2 次查詢
 2017-10-19 17:48:54.724  INFO 2736 --- [nio-8385-exec-1] erMysqlMybatisMapperXmlEhCacheController : ===========  通過(guò)緩存第 2 次查詢結(jié)果: User{id=147, username="user66", name="user66", age=1000, balance="1000", from=""}
 2017-10-19 17:48:54.724  INFO 2736 --- [nio-8385-exec-1] erMysqlMybatisMapperXmlEhCacheController : ===========  通過(guò)緩存第 3 次查詢
 2017-10-19 17:48:54.724  INFO 2736 --- [nio-8385-exec-1] erMysqlMybatisMapperXmlEhCacheController : ===========  通過(guò)緩存第 3 次查詢結(jié)果: User{id=147, username="user66", name="user66", age=1000, balance="1000", from=""}
 2017-10-19 17:48:54.724  INFO 2736 --- [nio-8385-exec-1] erMysqlMybatisMapperXmlEhCacheController : ===========  ====準(zhǔn)備修改數(shù)據(jù)====
 2017-10-19 17:48:54.725 DEBUG 2736 --- [nio-8385-exec-1] c.i.cloud.mapper.IUserMapper.updateUser  : ==>  Preparing: update user set userName=?,name=?,age=?,balance=? where id=?
 2017-10-19 17:48:54.725 DEBUG 2736 --- [nio-8385-exec-1] c.i.cloud.mapper.IUserMapper.updateUser  : ==> Parameters: user66(String), user66(String), 2000(Integer), 2000(String), 147(Long)
 2017-10-19 17:48:54.738 DEBUG 2736 --- [nio-8385-exec-1] c.i.cloud.mapper.IUserMapper.updateUser  : <==    Updates: 1
 2017-10-19 17:48:54.747  INFO 2736 --- [nio-8385-exec-1] erMysqlMybatisMapperXmlEhCacheController : ===========  ==== 修改數(shù)據(jù) == 成功 ==
 2017-10-19 17:48:54.747  INFO 2736 --- [nio-8385-exec-1] erMysqlMybatisMapperXmlEhCacheController : ===========  ====修改后再次查詢數(shù)據(jù)
 2017-10-19 17:48:54.747 DEBUG 2736 --- [nio-8385-exec-1] c.i.c.mapper.IUserMapper.findUserById    : ==>  Preparing: select * from user where id = ?
 2017-10-19 17:48:54.747 DEBUG 2736 --- [nio-8385-exec-1] c.i.c.mapper.IUserMapper.findUserById    : ==> Parameters: 147(Long)
 2017-10-19 17:48:54.747 DEBUG 2736 --- [nio-8385-exec-1] c.i.c.mapper.IUserMapper.findUserById    : <==      Total: 1
 2017-10-19 17:48:54.747  INFO 2736 --- [nio-8385-exec-1] erMysqlMybatisMapperXmlEhCacheController : ===========  ====修改后再次查詢數(shù)據(jù)結(jié)果: User{id=147, username="user66", name="user66", age=2000, balance="2000", from=""}

 總結(jié)：可以看出查詢過(guò)一次后，就不會(huì)再查詢數(shù)據(jù)庫(kù)了，所以第二次、第三次都會(huì)去查找緩存的數(shù)據(jù)；
 ****************************************************************************************/



/****************************************************************************************
 Ehcache 相關(guān)資料：

 diskStore：為緩存路徑，ehcache分為內(nèi)存和磁盤兩級(jí)，此屬性定義磁盤的緩存位置。
 defaultCache：默認(rèn)緩存策略，當(dāng)ehcache找不到定義的緩存時(shí)，則使用這個(gè)緩存策略。只能定義一個(gè)。
 name:緩存名稱。
 maxElementsInMemory:緩存最大數(shù)目
 maxElementsOnDisk：硬盤最大緩存?zhèn)€數(shù)。
 eternal:對(duì)象是否永久有效，一但設(shè)置了，timeout將不起作用。
 overflowToDisk:是否保存到磁盤，當(dāng)系統(tǒng)當(dāng)機(jī)時(shí)
 timeToIdleSeconds:設(shè)置對(duì)象在失效前的允許閑置時(shí)間（單位：秒）。僅當(dāng)eternal=false對(duì)象不是永久有效時(shí)使用，可選屬性，默認(rèn)值是0，也就是可閑置時(shí)間無(wú)窮大。
 timeToLiveSeconds:設(shè)置對(duì)象在失效前允許存活時(shí)間（單位：秒）。最大時(shí)間介于創(chuàng)建時(shí)間和失效時(shí)間之間。僅當(dāng)eternal=false對(duì)象不是永久有效時(shí)使用，默認(rèn)是0.，也就是對(duì)象存活時(shí)間無(wú)窮大。
 diskPersistent：是否緩存虛擬機(jī)重啟期數(shù)據(jù) Whether the disk store persists between restarts of the Virtual Machine. The default value is false.diskSpoolBufferSizeMB：這個(gè)參數(shù)設(shè)置DiskStore（磁盤緩存）的緩存區(qū)大小。默認(rèn)是30MB。每個(gè)Cache都應(yīng)該有自己的一個(gè)緩沖區(qū)。
 diskExpiryThreadIntervalSeconds：磁盤失效線程運(yùn)行時(shí)間間隔，默認(rèn)是120秒。
 memoryStoreEvictionPolicy：當(dāng)達(dá)到maxElementsInMemory限制時(shí)，Ehcache將會(huì)根據(jù)指定的策略去清理內(nèi)存。默認(rèn)策略是LRU（最近最少使用）。你可以設(shè)置為FIFO（先進(jìn)先出）或是LFU（較少使用）。
 clearOnFlush：內(nèi)存數(shù)量最大時(shí)是否清除。
 memoryStoreEvictionPolicy:可選策略有：LRU（最近最少使用，默認(rèn)策略）、FIFO（先進(jìn)先出）、LFU（最少訪問(wèn)次數(shù)）。


 FIFO，first in first out，先進(jìn)先出。
 LFU， Less Frequently Used，一直以來(lái)最少被使用的。如上面所講，緩存的元素有一個(gè)hit屬性，hit值最小的將會(huì)被清出緩存。
 LRU，Least Recently Used，最近最少使用的，緩存的元素有一個(gè)時(shí)間戳，當(dāng)緩存容量滿了，而又需要騰出地方來(lái)緩存新的元素的時(shí)候，那么現(xiàn)有緩存元素中時(shí)間戳離當(dāng)前時(shí)間最遠(yuǎn)的元素將被清出緩存。


 一般情況下，我們?cè)赟ercive層進(jìn)行對(duì)緩存的操作。先介紹 Ehcache 在 Spring 中的注解：在支持 Spring Cache 的環(huán)境下，
 * @Cacheable : Spring在每次執(zhí)行前都會(huì)檢查Cache中是否存在相同key的緩存元素，如果存在就不再執(zhí)行該方法，而是直接從緩存中獲取結(jié)果進(jìn)行返回，否則才會(huì)執(zhí)行并將返回結(jié)果存入指定的緩存中。
 * @CacheEvict : 清除緩存。
 * @CachePut : @CachePut也可以聲明一個(gè)方法支持緩存功能。使用@CachePut標(biāo)注的方法在執(zhí)行前不會(huì)去檢查緩存中是否存在之前執(zhí)行過(guò)的結(jié)果，而是每次都會(huì)執(zhí)行該方法，并將執(zhí)行結(jié)果以鍵值對(duì)的形式存入指定的緩存中。
 * 這三個(gè)方法中都有兩個(gè)主要的屬性：value 指的是 ehcache.xml 中的緩存策略空間；key 指的是緩存的標(biāo)識(shí)，同時(shí)可以用 # 來(lái)引用參數(shù)。
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