先说一下没有注解的 先给出实体类: public class City { private int city_id; private String city_name; public int getCity_id() { return city_id; } public void setCity_id(int city_id) { this.city_id = city_id; } public String getCity_name() { return city_name; } public
spring中开启事务管理需要在xml配置文件中配置,springboot中采取java config的配置方式. 核心是@EnableTransactionManager注解,该注解即为开启事务管理器. @Configuration @EnableTransactionManagement public class TransactionConfiguration { @Bean @Qualifier("transactionManager") public PlatformTran
1.ThreadLocal该类提供了线程局部变量 2.分析原理: ThreadLocal内部有一个Map.Map的key是当前线程对象,value是一个Object对象. 模拟该类: public class ThreadLocal<T>{ private Map<Runnable,T> map = new HashMap<Runnable,T>(); public void set(T t){ map.put(Thread.currentThread(),t); //