运行时环境
整个Spring5框架的代码基于Java8,运行时兼容JDK9,许多不建议使用的类和方法在代码库中删除
Spring5.0框架自带了通用的日志封装
在src下新建
<?xml version="1.0" encoding="UTF-8"?>
<!--日志级别以及优先级排序: OFF > FATAL > ERROR > WARN > INFO > DEBUG > TRACE > ALL -->
<!--Configuration后面的status用于设置log4j2自身内部的信息输出,可以不设置,当设置成trace时,可以看到log4j2内部各种详细输出-->
<configuration status="INFO">
<!--先定义所有的appender-->
<appenders>
<!--输出日志信息到控制台-->
<console name="Console" target="SYSTEM_OUT">
<!--控制日志输出的格式-->
<PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
</console>
</appenders>
<!--然后定义logger,只有定义了logger并引入的appender,appender才会生效-->
<!--root:用于指定项目的根日志,如果没有单独指定Logger,则会使用root作为默认的日志输出-->
<loggers>
<root level="info">
<appender-ref ref="Console"/>
</root>
</loggers>
</configuration>
package com.dance.spring.learn.testdemo;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class TestLog {
public static final Logger log = LoggerFactory.getLogger(TestLog.class);
public static void main(String[] args) {
log.info("test logger.....");
}
}
2021-12-12 17:17:17.551 [main] INFO com.dance.spring.learn.testdemo.TestLog - test logger.....
Spring5框架核心容器支持@Nullable注解
返回值可以为空
方法参数可以为空
属性值可以为空
我不是很理解,感觉这个@Nullable没啥用,应为本来就是可以为空的,但是在我看了一篇文章后,才发现也挺好用的
https://www.cnblogs.com/zhilili/p/12202079.html
就是这个大大写的,对于一些入参来说,可以很好的标识,该字段是否可以为空,有助于减少空指针异常等代码的编写,别人看的时候也很容易理解
函数式风格创建对象,交给Spring容器进行管理
@Test
public void testGenericApplicationContext() {
//1 创建 GenericApplicationContext 对象
GenericApplicationContext context = new GenericApplicationContext();
//2 调用 context 的方法对象注册
context.refresh();
context.registerBean("user1", User.class, User::new);
//3 获取在 spring 注册的对象
User user = context.getBean("user1",User.class);
System.out.println(user);
}
User{userId='null', userName='null', ustatus='null'}
package com.dance.spring.learn.testdemo;
import com.dance.spring.learn.jdbc.config.SpringJdbcConfig;
import com.dance.spring.learn.jdbc.service.UserService;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
@RunWith(SpringJUnit4ClassRunner.class)
// 使用value 指定xml也可以使用classes指定配置类
@ContextConfiguration(classes = SpringJdbcConfig.class)
public class JTest4 {
@Autowired
private UserService userService;
@Test
public void test(){
userService.accountMoney();
}
}
十二月 12, 2021 5:43:57 下午 org.springframework.test.context.support.AbstractTestContextBootstrapper getDefaultTestExecutionListenerClassNames
信息: Loaded default TestExecutionListener class names from location [META-INF/spring.factories]: [org.springframework.test.context.web.ServletTestExecutionListener, org.springframework.test.context.support.DirtiesContextBeforeModesTestExecutionListener, org.springframework.test.context.support.DependencyInjectionTestExecutionListener, org.springframework.test.context.support.DirtiesContextTestExecutionListener, org.springframework.test.context.transaction.TransactionalTestExecutionListener, org.springframework.test.context.jdbc.SqlScriptsTestExecutionListener, org.springframework.test.context.event.EventPublishingTestExecutionListener]
十二月 12, 2021 5:43:57 下午 org.springframework.test.context.support.AbstractTestContextBootstrapper getTestExecutionListeners
信息: Using TestExecutionListeners: [org.springframework.test.context.support.DirtiesContextBeforeModesTestExecutionListener@4b952a2d, org.springframework.test.context.support.DependencyInjectionTestExecutionListener@3159c4b8, org.springframework.test.context.support.DirtiesContextTestExecutionListener@73846619, org.springframework.test.context.transaction.TransactionalTestExecutionListener@4bec1f0c, org.springframework.test.context.jdbc.SqlScriptsTestExecutionListener@29ca901e, org.springframework.test.context.event.EventPublishingTestExecutionListener@5649fd9b]
2021-12-12 17:43:58.847 [main] INFO com.alibaba.druid.pool.DruidDataSource - {dataSource-1} inited
转账完成,flower 账户支出100元
package com.dance.spring.learn.testdemo;
import com.dance.spring.learn.jdbc.config.SpringJdbcConfig;
import com.dance.spring.learn.jdbc.service.UserService;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit.jupiter.SpringExtension;
@ExtendWith(SpringExtension.class)
@ContextConfiguration(classes = SpringJdbcConfig.class)
public class JTest5 {
@Autowired
private UserService userService;
@Test
public void test(){
userService.accountMoney();
}
}
2021-12-12 17:49:28.230 [main] INFO com.alibaba.druid.pool.DruidDataSource - {dataSource-1} inited
转账完成,flower 账户支出100元
使用一个注解替换两个注解
//@ExtendWith(SpringExtension.class)
//@ContextConfiguration(classes = SpringJdbcConfig.class)
@SpringJUnitConfig(classes = SpringJdbcConfig.class)
执行结果也是一样的