To further my studies in this program, to learn about it through this program.

.com.shousidaima.truede.
					   -
                       -controller.
                         -HelloController.java
                       -dao.
                         -.impl.
                         	-HelloDaoJDBCImpl.java
                         -HelloDao.java
                       -entity.
                       	 -Hello.java
                       -service.
                       	 -HelloService.java
                         -impl.
    						-HeloServiceImpl.java
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The details are as follows:

com.shousidaima.truede.HelloDao.java:

package com.shousidaima.truede.dao;


import com.shousidaima.truede.entity.Hello;

// Data access layer
public interface HelloDao {

    Hello getHello(int code,String msg);

}
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com.shousidaima.truede.HelloJDBCImpl.java

We use Java classes to simulate JDBC linking; We usually use Mybatis to bind dao.

package com.shousidaima.truede.dao.Impl;

import com.shousidaima.truede.dao.HelloDao;
import com.shousidaima.truede.entity.Hello;
import org.springframework.stereotype.Repository;

@Repository
public class HelloJDBCImpl implements HelloDao {

    @Override
    public Hello getHello(int code, String msg) {
        Hello hello = new Hello();
        hello.setCode(code);
        hello.setMsg(msg);
        returnhello; }}Copy the code

com.shousidaima.truede.Hello.java

package com.shousidaima.truede.entity;

public class Hello {

    private String msg;

    private int code;

    public String getMsg(a) {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }

    public int getCode(a) {
        return code;
    }

    public void setCode(int code) {
        this.code = code;
    }

    @Override
    public String toString(a) {
        return "Hello{" +
                "msg='" + msg + '\' ' +
                ", code=" + code +
                '} '; }}Copy the code

com.shousidaima.truede.HelloService.java

package com.shousidaima.truede.service;

import com.shousidaima.truede.entity.Hello;



public interface HelloService {

    Hello getHello(int code, String msg);

}
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com.shousidaima.truede.HelloServiceImpl.java

package com.shousidaima.truede.service.impl;

import com.shousidaima.truede.dao.HelloDao;
import com.shousidaima.truede.entity.Hello;
import com.shousidaima.truede.service.HelloService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;


@Service
public class HelloServiceImpl implements HelloService {

    @Autowired
    HelloDao helloDao;

    @Override
    public Hello getHello(int code, String msg) {
        returnhelloDao.getHello(code,msg); }}Copy the code

@Repository
public class HelloJDBCImpl implements HelloDao {}@Service
public class HelloServiceImpl implements HelloService {}Copy the code

You can see that both classes have annotations in their headers, @repository and @service.

@repository: code that identifies this class as a data access layer; @service: identifies this class as business layer code;

In fact, there is no essential difference between the two, the code is the same, only the annotation name is different:

The purpose of doing this is also to distinguish for the class what type of class object your class is.

The point is that both classes have the @Component annotation, which is one of the ways Spring uses to inject Bena.

Back to the HelloController.java object:

@Controller
@RequestMapping(value = "hello")
public class HelloController {

    @RequestMapping(value = "getHello",method = RequestMethod.GET)
    @ResponseBody
    public String getHello(a){
        return "HelloController hello."; }}Copy the code

The source code for the @Controller annotation is as follows:

Surprisingly, the source code for @Repository and @Service is the same as the source code for @Repository and @Service, again to identify what type this class is. Adding @Controller indicates that this is a Java class at the control layer, so when accessed, the object is accessed (and, of course, processed).

Singletons should be managed: (1) unified resource classes; (2) Use the same object N times;

In Spring, or SpringBoot, or Mybatis, or some spring-related open source framework, IOC (dependency injection, also known as BeanFactory managed objects) is basically a must.

(1) For example, we set server.port=8081

The parameters actually passed are received by the ServerProperties.java file and managed. When SpringBoot is started, it takes the serverProperties.java parameter port.

Serverproperties.java source code is as follows:

@ConfigurationProperties( prefix = "server", ignoreUnknownFields = true )
public class ServerProperties {
    private Integer port;
    privateInetAddress address; . }Copy the code

(2) For example: configuration file data in a framework I open source is hosted this way

It is convenient to configure some information using a configuration file.

Most open source frameworks are used in the framework I develop.

My unified entry: swaggerPluginconfig.java a piece of code

/** * Spring IOC unified management object */
@Configuration
public class SwaggerPluginConfig {

	// Get the information at the beginning of swagger-plugin from the configuration file
    @ConfigurationProperties(prefix = "swagger-plugin")
    @Bean(name = "swaggerPluginConfigBean")
    public SwaggerPluginConfigBean getSwaggerPluginConfigBean(a){
        return newSwaggerPluginConfigBean(); }}Copy the code

So the project using my framework needs to be in the configuration file (application.yml) :

# swagger configuration
swagger-plugin:
    Configure the Controller layer to scan
    scan:
        path: com.springbootswagger1.controller
    Whether to enable the debug mode of swagger-Plugin framework
    debug: true
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So I can get it directly in the framework:

  @Autowired
  private SwaggerPluginConfigBean swaggerPluginConfigBean;
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Call directly when using:

try{... }catch (CannotCompileException e) {
    If the debug mode is enabled, the log will be printed
    if(swaggerPluginConfigBean.isDebug()){
        logger.warn("Can't find 1:"+e.getMessage()); }}catch (NotFoundException e) {
    if(swaggerPluginConfigBean.isDebug()){
        logger.warn("Can't find 2:"+e.getMessage()); }}Copy the code

That is the benefit of the IOC.

In order to give readers a better reading experience, hereby separate to write, pay attention to me, see the next article.

In order to give readers a better reading experience, hereby separate to write, pay attention to me, see the next article.