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！