spring启动自动加载数据

有时我们需要在项目启动时就要加载一些数据到缓存中(spring缓存或第三方缓存)，spring在启动时加载数据有两种方式*（我所知道的，如果还有别的方式欢迎告知，嘿嘿）：实现InitializingBean和实现BeanPostProcessor

第一种：实现InitializingBean

这种方式比较简单，写一个service实现InitializingBean并在spring配置文件中配置一下，启动时就会加载数据

public class InternationalServiceImpl implements InitializingBean{

	@Override
	public void afterPropertiesSet() throws Exception {
		
		System.err.println("重启开始加载数据。。。");
		
	}

}

 

配置文件：

<bean id = "internationalService" class="com.taotao.manage.service.InternationalServiceImpl"></bean>

 测试例子：

public class LoadTest {
	
	private PBSTrackManagerPostProcessor pbsTrackManagerPostProcessor;
	
	@Before
    public void setUp() throws Exception {
        ApplicationContext context = new ClassPathXmlApplicationContext(new String[]{"spring/applicationContext.xml"});
        this.pbsTrackManagerPostProcessor = context.getBean(PBSTrackManagerPostProcessor.class);
    }
	
	@Test
    public void testQueryOrderByOrderNumber() {
        System.out.println("开始加载");
    }
}

 

结果：

重启开始加载数据。。。

 

第二种：实现BeanPostProcessor

数据层（这里写的比较简单）：

public class Country implements Serializable{

	private static final long serialVersionUID = 4014709713611499131L;
	private String Province;
	private String city;
	public String getProvince() {
		return Province;
	}
	public void setProvince(String province) {
		Province = province;
	}
	public String getCity() {
		return city;
	}
	public void setCity(String city) {
		this.city = city;
	}
	@Override
	public String toString() {
		return "Country [Province=" + Province + ", city=" + city + "]";
	}
	
	
}

 service层：

@Service
public class CountryServiceImpl implements CountryService{

	@Override
	public List<Country> getAllCountry() {
		List<Country> countries = new ArrayList<Country>();
		for(int i = 0;i <10;i++){
			Country country = new Country();
			country.setCity("北京"+i);
			country.setProvince("上海"+i);
			countries.add(country);
		}
		return countries;
	}

}

 再写一个service来调用这个service

public class StartOnLoadService {

	public static Map<String, List<Country>> map = new HashMap<String, List<Country>>();
	
	@Autowired
	private CountryService countryService;
	
	public void loadAllCountries(){
		
		List<Country> list = countryService.getAllCountry();
		
		map.put("countryMap", list);
		
		System.out.println(map);
	}
}

 然后写一个processor来加载这个service

public class PBSTrackManagerPostProcessor implements BeanPostProcessor{

	@Override
	public Object postProcessAfterInitialization(Object obj, String arg1)
			throws BeansException {
		
		if(obj instanceof StartOnLoadService){
			((StartOnLoadService)obj).loadAllCountries();
		}
		
		return obj;
	}

	@Override
	public Object postProcessBeforeInitialization(Object arg0, String arg1)
			throws BeansException {
		// TODO Auto-generated method stub
		return arg0;
	}

}

 最后写配置文件：

<bean id="startOnLoadService" class="com.taotao.manage.controller.StartOnLoadService"></bean>
	
<bean id="pbsTrackManagerPostProcessor" class="com.taotao.manage.controller.PBSTrackManagerPostProcessor">
</bean>

 测试例子：

public class LoadTest {
	
	private PBSTrackManagerPostProcessor pbsTrackManagerPostProcessor;
	
	@Before
    public void setUp() throws Exception {
        ApplicationContext context = new ClassPathXmlApplicationContext(new String[]{"spring/applicationContext.xml"});
        this.pbsTrackManagerPostProcessor = context.getBean(PBSTrackManagerPostProcessor.class);
    }
	
	@Test
    public void testQueryOrderByOrderNumber() {
        System.out.println("开始加载");
    }
}

 结果：

{countryMap=[Country [Province=上海0, city=北京0], Country [Province=上海1, city=北京1], Country [Province=上海2, city=北京2],。。。｝

我觉得那个countryService可以不用写，当时就那么写了。大家可以尝试下

新手，不足指出请指教！