使用Leopard Cache

使用Leopard Cache
学习如何使用Leopard Cache。
本指南将引导您使用Leopard Cache操作缓存。
How to complete this guide
你可以从头开始并完成每一个步骤,或者您可以绕过你已经熟悉的基本设置步骤。无论哪种方式,你最终都可以得到可工作的代码。
1、配置maven依赖
在dao模块的pom.xml加入

    <dependencies>
        [...]
        <dependency>
            <groupId>io.leopard</groupId>
            <artifactId>leopard-data</artifactId>
            <version>0.0.1-SNAPSHOT</version>
        </dependency>
        [...]
    </dependencies>
    <repositories>
        <repository>
            <id>leopard-snapshots</id>
            <name>Leopard Snapshots</name>
            <url>http://leopard.io/nexus/content/repositories/snapshots/</url>
        </repository>
    </repositories>

2、配置spring
src/main/resources/applicationContext-dao.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" <span style='font-weight:bold;color:#ff0000'>xmlns:leopard="http://www.leopard.io/schema/leopard"</span>
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
	<span style='font-weight:bold;color:#ff0000'>http://www.leopard.io/schema/leopard http://www.leopard.io/schema/leopard.xsd</span>">

	<leopard:component-scan base-package="io.leopard.guides" />

	<leopard:jdbc id="jdbc" host="112.126.75.27" database="example" user="example" password="leopard" />
	<leopard:redis id="redis" server="112.126.75.27:6311" />

</beans>

3、创建UserDao接口，用到缓存必须实现IGet接口.
此处为了展现更多接口直接实现了IDelete接口
创建src/main/java/io/leopard/guides/dao/UserDao.java

package io.leopard.guides.dao;

import io.leopard.data4j.cache.api.uid.IDelete;
import io.leopard.guides.model.User;

import java.util.Date;

public interface UserDao extends IDelete<User, Long> {

	@Override
	public boolean add(User user);

	@Override
	User get(Long uid);

	@Override
	boolean delete(Long uid, long opuid, Date lmodify);

}

4、创建UserDao接口Mysql实现
创建src/main/java/io/leopard/guides/dao/mysql/UserDaoMysqlImpl.java

package io.leopard.guides.dao.mysql;

import io.leopard.data4j.jdbc.Jdbc;
import io.leopard.data4j.jdbc.builder.InsertBuilder;
import io.leopard.guides.dao.UserDao;
import io.leopard.guides.model.User;

import java.util.Date;

import javax.annotation.Resource;

import org.springframework.stereotype.Repository;

@Repository
public class UserDaoMysqlImpl implements UserDao {

	@Resource
	private Jdbc jdbc;

	@Override
	public boolean add(User user) {
		InsertBuilder builder = new InsertBuilder("user");
		builder.setLong("uid", user.getUid());
		builder.setString("nickname", user.getNickname());
		builder.setDate("posttime", user.getPosttime());
		return this.jdbc.insertForBoolean(builder);
	}

	@Override
	public User get(Long uid) {
		String sql = "select * from user where uid=?;";
		return jdbc.query(sql, User.class, uid);
	}

	@Override
	public boolean delete(Long uid, long opuid, Date lmodify) {
		String sql = "delete from user where uid=?;";
		return jdbc.updateForBoolean(sql, uid);
	}

}

5、创建UserDao接口Redis实现
创建src/main/java/io/leopard/guides/dao/redis/UserDaoRedisImpl.java

package io.leopard.guides.dao.redis;

import io.leopard.burrow.lang.Json;
import io.leopard.burrow.util.NumberUtil;
import io.leopard.data4j.redis.Redis;
import io.leopard.guides.dao.UserDao;
import io.leopard.guides.model.User;

import java.util.Date;

import javax.annotation.Resource;

import org.springframework.stereotype.Repository;

@Repository
public class UserDaoRedisImpl implements UserDao {

	@Resource
	private Redis redis;

	@Override
	public boolean add(User user) {
		String key = this.getKey(user.getUid());
		redis.set(key, Json.toJson(user));
		return true;
	}

	@Override
	public User get(Long uid) {
		String key = this.getKey(uid);
		String json = redis.get(key);
		return Json.toObject(json, User.class);
	}

	@Override
	public boolean delete(Long uid, long opuid, Date lmodify) {
		String key = this.getKey(uid);
		Long result = redis.del(key);
		return NumberUtil.toBool(result);
	}

	protected String getKey(long uid) {
		return "user:" + uid;
	}

}

6、创建UserDao接口Cache实现
创建src/main/java/io/leopard/guides/dao/cache/UserDaoCacheImpl.java

package io.leopard.guides.dao.cache;

import io.leopard.data4j.cache.CacheLoader;
import io.leopard.guides.dao.UserDao;
import io.leopard.guides.model.User;

import java.util.Date;

import javax.annotation.Resource;

import org.springframework.stereotype.Repository;

@Repository
public class UserDaoCacheImpl implements UserDao {

	@Resource
	private UserDao userDaoMysqlImpl;

	@Resource
	private UserDao userDaoRedisImpl;

	@Override
	public boolean add(User user) {
		return userDaoMysqlImpl.add(user);
	}

	@Override
	public User get(Long uid) {
		// 先到userDaoRedisImpl.get方法查，有数据直接返回
		// 如果redis实现没有数据，就到userDaoMysqlImpl.get方法查询数据。如果有数据将数据传给userDaoRedisImpl.add方法保存并返回。如果mysql实现也没有数据则返回null.
		return CacheLoader.get(userDaoRedisImpl, userDaoMysqlImpl, uid);
	}

	@Override
	public boolean delete(Long uid, long opuid, Date lmodify) {
		userDaoRedisImpl.delete(uid, opuid, lmodify);
		return this.userDaoMysqlImpl.delete(uid, opuid, lmodify);
	}

}

7、在UserService使用UserDao接口
创建src/main/java/io/leopard/guides/service/UserService.java

package io.leopard.guides.service;

import io.leopard.guides.dao.UserDao;
import io.leopard.guides.model.User;

import java.util.Date;

import javax.annotation.Resource;

import org.springframework.stereotype.Service;

@Service
public class UserService {

	@Resource
	// 当有xxxDaoCacheImpl存在时，Leopard自动为它增加了@Primary注解
	// 这里会自动注入userDaoCacheImpl.
	private UserDao userDao;

	public boolean add(User user) {
		return this.userDao.add(user);
	}

	public User get(long uid) {
		return this.userDao.get(uid);
	}

	public boolean delete(long uid) {
		return this.userDao.delete(uid, 0, new Date());
	}
}

8、编写UserService测试代码
创建src/test/java/io/leopard/guides/service/UserServiceTest.java

package io.leopard.guides.service;

import io.leopard.guides.model.User;
import io.leopard.test.IntegrationTests;

import java.util.Date;

import org.junit.Assert;
import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;

public class UserServiceTest extends IntegrationTests {

	@Autowired
	private UserService userService;

	@Test
	public void get() {
		this.userService.delete(1);// 先删除记录
		{
			User user = new User();
			user.setUid(1);
			user.setNickname("Leopard");
			user.setPosttime(new Date());
			userService.add(user);
		}
		{
			User user = userService.get(1);
			Assert.assertNotNull(user);
			Assert.assertEquals("Leopard", user.getNickname());
		}

	}

}

总结
恭喜你！您已经可以配置使用Leopard Cache，虽然功能比较简单，你可以在这个基础上扩展出你的业务系统，祝您好运。

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