Spring Framework Tutorial (7): Spring5 commonly used new features

1. Integrated log framework: spring5 integrates Log4j2

  Spring5 comes with a common logging framework, but it can also integrate other logging frameworks. Taking Log4j2 as an example, the integration process is as follows:

• Introduce the relevant jar package:

  log4j-api-2.11.2.jar、log4j-core-2.11.2.jar、log4j-slf4j-impl-2.11.2.jar、slf4j-api-1.7.30.jar。

• Create a log4j.xml configuration file in the src directory:

<?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>

  After this configuration, the corresponding information will be output on the console when running the program.

• You can also create a special log class to perform some operations:

	package com.wang;
	
	import org.slf4j.Logger;
	import org.slf4j.LoggerFactory;
	
	public class UserLog {
    
    
	    private static final Logger log= LoggerFactory.getLogger(UserLog.class);
	
	    public static void main(String[] arg){
    
    
	        log.info("hello log4j2");
	        log.warn("hello log4j2");
	    }
	}

2.@Nullable annotation

  @Nullable annotation can be used on methods (allowing to return a null value), attributes (attribute values ​​can be empty), and parameters (parameter values ​​can be empty).

3. Functional Registration Object

  I wrote a method in the test class to demonstrate this process:

	//函数式风格创建对象，交给spring管理
    @Test
    public void testFunction(){
    
    
        //1创建GenericApplicationContext对象
        GenericApplicationContext context=new GenericApplicationContext();
        //2注册对象
        context.refresh();
        context.registerBean(User.class,()->new User());
        //3获取对象
        User user=(User)context.getBean("com.wang.entity.User");
        System.out.println(user);
    }

4. Integrate the JUnit unit testing framework

(1)Integrate JUnit4

• Introduce the jar package: spring-test-5.2.6.RELEASE.jar
• Introduce JUnit4 dependency: when proceeding to the next step, add according to IDEA prompts when using annotations
• Create a test class and complete it through annotations:

package com.wang.test;
import com.wang.entity.Person;
import com.wang.service.PersonService;
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)//单元测试框架
@ContextConfiguration("classpath:bean.xml")//加载配置文件
public class JTest4 {
    
    
    @Autowired
    private PersonService personService;

    @Test
    public void test1(){
    
    
        Person p1=new Person();Person p2=new Person();
        p1.setPerson_id("1");p2.setPerson_id("2");
        personService.transfer(p1,p2,100);
    }
}

(2)Integrate JUnit5

• Introduce the jar package: spring-test-5.2.6.RELEASE.jar
• Introduce JUnit5 dependency: when proceeding to the next step, add it according to IDEA prompts when using annotations.
• Create a test class and complete it through annotations:

package com.wang.test;

import com.wang.entity.Person;
import com.wang.service.PersonService;
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("classpath:bean.xml")
//上面两个注解可用这一个注解代替@SpringJUnitConfig(locations="classpath:bean.xml")
public class JTest5 {
    
    
    @Autowired
    private PersonService personService;

    @Test
    public void test1(){
    
    
        Person p1=new Person();Person p2=new Person();
        p1.setPerson_id("1");p2.setPerson_id("2");
        personService.transfer(p1,p2,100);
    }
}