🤜🏻 🗞️ 👎🏾 Was ist Spring Framework? Von der Abhängigkeitsinjektion zur Web-MVC 🙅🏼 🕺🏼 🎅🏼

Sie können dieses Handbuch für verschiedene Zwecke verwenden:

Um zu verstehen, was das Spring Framework ist
Funktionsweise der Kernfunktionen: Abhängigkeitsinjektion oder Web-MVC
Dies ist auch eine ausführliche FAQ (Liste mit häufig gestellten Fragen).

Hinweis: Ein Artikel mit ~ 9.000 Wörtern ist auf einem mobilen Gerät wahrscheinlich nicht lesenswert. Setzen Sie ein Lesezeichen und kommen Sie später wieder. Und selbst am Computer ~~essen Sie~~ diesen Elefanten Stück für Stück :-)

Inhalt

Einführung
Grundlagen der Abhängigkeitsinjektion
Spring IOC / Dependency Injection Container
Spring AOP (- )
Spring
Spring Web MVC
Spring Framework
Spring Framework:
:
. .

Spring

Spring, spring.io, , Spring 21 . !

, Spring , , Spring Boot Spring Data.

, : Spring Framework. ?

, Spring Framework . Spring Boot, Spring Data, Spring Batch — Spring.

Spring Framework . , . Spring Boot, , , Spring Framework .
~ 15 , 80% Spring Framework, .

Spring Framework?

:

Spring Framework , (: , , - , RPC, - MVC). Java-.

, ?

, :

, , Spring IOC / Dependency Injection. .

?

, Java , . DAO ( ) . , UserDAO.

public class UserDao {

    public User findById(Integer id) {
        // execute a sql query to find the user
    }
}

UserDAO , .

SQL , UserDAO . Java , , , DataSource. , :

import javax.sql.DataSource;

public class UserDao {

    public User findById(Integer id) throws SQLException {
        try (Connection connection = dataSource.getConnection()) { // (1)
               PreparedStatement selectStatement = connection.prepareStatement("select * from users where id =  ?");
               // use the connection etc.
        }
    }

}

, UserDao ? , DAO SQL-.

new()

, , . , MySQL UserDAO :

import com.mysql.cj.jdbc.MysqlDataSource;

public class UserDao {

    public User findById(Integer id) {
        MysqlDataSource dataSource = new MysqlDataSource(); // (1)
        dataSource.setURL("jdbc:mysql://localhost:3306/myDatabase");
        dataSource.setUser("root");
        dataSource.setPassword("s3cr3t");

        try (Connection connection = dataSource.getConnection()) { // (2)
             PreparedStatement selectStatement = connection.prepareStatement("select * from users where id =  ?");
             // execute the statement..convert the raw jdbc resultset to a user
             return user;
        }
    }
}

MySQL, MysqlDataSource url/username/password .
.

, , , UserDao , findByFirstName.

, . UserDAO , newDataSource.

import com.mysql.cj.jdbc.MysqlDataSource;

public class UserDao {

    public User findById(Integer id) {
        try (Connection connection = newDataSource().getConnection()) { // (1)
               PreparedStatement selectStatement = connection.prepareStatement("select * from users where id =  ?");
               // TODO execute the select , handle exceptions, return the user
        }
    }

    public User findByFirstName(String firstName) {
        try (Connection connection = newDataSource().getConnection()) { // (2)
               PreparedStatement selectStatement = connection.prepareStatement("select * from users where first_name =  ?");
               // TODO execute the select ,  handle exceptions, return the user
        }
    }

    public DataSource newDataSource() {
        MysqlDataSource dataSource = new MysqlDataSource(); // (3)
        dataSource.setUser("root");
        dataSource.setPassword("s3cr3t");
        dataSource.setURL("jdbc:mysql://localhost:3306/myDatabase");
        return dataSource;
    }
}

findById newDataSource().
findByFirstName newDataSource().
, .

, :

, ProductDAO, SQL? ProductDAO DataSource, UserDAO. , DataSource.
SQL. , DataSource - Java- . . , , , . UserDao, , DAO.

, Application, :

import com.mysql.cj.jdbc.MysqlDataSource;

public enum Application {

    INSTANCE;

    private DataSource dataSource;

    public DataSource dataSource() {
        if (dataSource == null) {
            MysqlDataSource dataSource = new MysqlDataSource();
            dataSource.setUser("root");
            dataSource.setPassword("s3cr3t");
            dataSource.setURL("jdbc:mysql://localhost:3306/myDatabase");
            this.dataSource = dataSource;
        }
        return dataSource;
    }
}

UserDAO :

import com.yourpackage.Application;

public class UserDao {
    public User findById(Integer id) {
        try (Connection connection = Application.INSTANCE.dataSource().getConnection()) { // (1)
               PreparedStatement selectStatement = connection.prepareStatement("select * from users where id =  ?");
               // TODO execute the select etc.
        }
    }

    public User findByFirstName(String firstName) {
        try (Connection connection = Application.INSTANCE.dataSource().getConnection()) { // (2)
               PreparedStatement selectStatement = connection.prepareStatement("select * from users where first_name =  ?");
               // TODO execute the select etc.
        }
    }
}

UserDAO DataSource, Application . DAO.
( , INSTANCE), DataSource.

UserDAO , , → Application.INSTANCE.dataSource().
, , Application.java, . / ..

(IoC, Inversion of Control)

, UserDAO ? , Application.INSTANCE.dataSource(), UserDAO (-) , , , / / ?

, (Inversion of Control).

, UserDAO, .

import javax.sql.DataSource;

public class UserDao {

    private DataSource dataSource;

    private UserDao(DataSource dataSource) { // (1)
        this.dataSource = dataSource;
    }

    public User findById(Integer id) {
        try (Connection connection = dataSource.getConnection()) { // (2)
               PreparedStatement selectStatement = connection.prepareStatement("select * from users where id =  ?");
               // TODO execute the select etc.
        }
    }

    public User findByFirstName(String firstName) {
        try (Connection connection = dataSource.getConnection()) { // (2)
               PreparedStatement selectStatement = connection.prepareStatement("select * from users where first_name =  ?");
               // TODO execute the select etc.
        }
    }
}

, UserDao , .
findByX .

UserDao . , , . , « ( ) , ».

, . «new UserService()», UserDao(dataSource).

public class MyApplication {

    public static void main(String[] args) {
        UserDao userDao = new UserDao(Application.INSTANCE.dataSource());
        User user1 = userDao.findById(1);
        User user2 = userDao.findById(2);
        // etc ...
    }
}

, , , , UserDAO , , DataSource .

, - , UserDAO DataSource, , ? : DataSource UserDao?

- , Spring.

Spring IOC / Dependency Injection

, Spring Framework , (. ). , .

ApplicationContext? ?

, (: ), ApplicationContext Spring.

, ( UserDao DataSource , , ):

import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import javax.sql.DataSource;

public class MyApplication {

    public static void main(String[] args) {
        ApplicationContext ctx = new AnnotationConfigApplicationContext(someConfigClass); // (1)

        UserDao userDao = ctx.getBean(UserDao.class); // (2)
        User user1 = userDao.findById(1);
        User user2 = userDao.findById(2);

        DataSource dataSource = ctx.getBean(DataSource.class); // (3)
        // etc ...
    }
}

Spring ApplicationContext. , , .
ApplicationContext UserDao, DataSource.
ApplicationContext , , UserDao.

, ? , , , ApplicationContext !

ApplicationContextConfiguration? ApplicationContexts .

someConfigClass AnnotationConfigApplicationContext. :

import org.springframework.context.annotation.AnnotationConfigApplicationContext;
public class MyApplication {

    public static void main(String[] args) {
        ApplicationContext ctx = new AnnotationConfigApplicationContext(someConfigClass); // (1)
        // ...
    }
}

, ApplicationContext, , :

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class MyApplicationContextConfiguration {  // (1)

    @Bean
    public DataSource dataSource() {  // (2)
        MysqlDataSource dataSource = new MysqlDataSource();
        dataSource.setUser("root");
        dataSource.setPassword("s3cr3t");
        dataSource.setURL("jdbc:mysql://localhost:3306/myDatabase");
        return dataSource;
    }

    @Bean
    public UserDao userDao() { // (3)
        return new UserDao(dataSource());
    }

}

ApplicationContext, @Configuration, Application.java .
, DataSource @Bean Spring.
, UserDao UserDao, bean- dataSource.

Spring.

import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;

public class MyApplication {

    public static void main(String[] args) {
        ApplicationContext ctx = new AnnotationConfigApplicationContext(MyApplicationContextConfiguration.class);
        UserDao userDao = ctx.getBean(UserDao.class);
        // User user1 = userDao.findById(1);
        // User user2 = userDao.findById(1);
        DataSource dataSource = ctx.getBean(DataSource.class);
    }
}

, Spring AnnotationConfigApplicationContext , .

AnnotationConfigApplicationContext? ApplicationContext?

Spring ApplicationContext, , XML, Java . ApplicationContext.

MyApplicationContextConfiguration . Java, Spring. ConfigApplicationContext.

ApplicationContext XML, ClassPathXmlApplicationContext.

, Spring , .

`@Bean`? Spring Bean?

ApplicationContext . , , UserDao, , DataSource.

, , bean-. : ( Spring) , .

: Spring?

Spring bean scope?

DAO Spring? , bean scope ( ).

Spring singleton: DAO ?
Spring prototype: DAO ?
, : HttpRequest? HttpSession? WebSocket?

, , .

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Scope;
import org.springframework.context.annotation.Configuration;

@Configuration
public class MyApplicationContextConfiguration {

    @Bean
    @Scope("singleton")
    // @Scope("prototype") etc.
    public DataSource dataSource() {
        MysqlDataSource dataSource = new MysqlDataSource();
        dataSource.setUser("root");
        dataSource.setPassword("s3cr3t");
        dataSource.setURL("jdbc:mysql://localhost:3306/myDatabase");
        return dataSource;
    }
}

(scope annotation) , Spring. , , :

Scope("singleton") → , .. .
Scope("prototype") → , - , Spring . ( , , ).
Scope("session") → HTTP .
..

: Spring bean-, bean- (, , , websocket ..).

, ApplicationContexts, Beans & Scopes, , UserDAO DataSource.

Spring Java Config?

bean- ApplicationContext @Bean Java.

, Spring Java Config, XML, Spring. , :

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class MyApplicationContextConfiguration {

    @Bean
    public DataSource dataSource() {
        MysqlDataSource dataSource = new MysqlDataSource();
        dataSource.setUser("root");
        dataSource.setPassword("s3cr3t");
        dataSource.setURL("jdbc:mysql://localhost:3306/myDatabase");
        return dataSource;
    }

    @Bean
    public UserDao userDao() { // (1)
        return new UserDao(dataSource());
    }

}

: UserDao() dataSource()? Spring ?

@ComponentScan.

`@ComponentScan`?

, , — @ComponentScan.

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

@Configuration
@ComponentScan  // (1)
public class MyApplicationContextConfiguration {

    @Bean
    public DataSource dataSource() {
        MysqlDataSource dataSource = new MysqlDataSource();
        dataSource.setUser("root");
        dataSource.setPassword("s3cr3t");
        dataSource.setURL("jdbc:mysql://localhost:3306/myDatabase");
        return dataSource;
    }

    // (2)

    // no more UserDao @Bean method!
}

@ComponentScan.
, UserDAO !

, @ComponentScan, Spring: Java , , Spring Bean!

, , MyApplicationContextConfiguration com.marcobehler, Spring , , com.marcobehler Spring.

Spring , - Spring? : , @Component.

`@Component` `@Autowired`?

@Component UserDAO.

import javax.sql.DataSource;
import org.springframework.stereotype.Component;

@Component
public class UserDao {

    private DataSource dataSource;

    private UserDao(DataSource dataSource) { // (1)
        this.dataSource = dataSource;
    }
}

Spring, @Bean, : , , @Component @ComponentScan, Spring, , !

( , @Controller, @Service @Repository, , , , @Component!).

. Spring , DataSource, @Bean, UserDAO DataSource?

, : @Autowired. , .

import javax.sql.DataSource;
import org.springframework.stereotype.Component;
import org.springframework.beans.factory.annotation.Autowired;

@Component
public class UserDao {

    private DataSource dataSource;

    private UserDao(@Autowired DataSource dataSource) {
        this.dataSource = dataSource;
    }
}

Spring , bean- UserDAO:

UserDAO @Component → Spring
UserDAO @Autowired → Spring , @Bean
Spring , NoSuchBeanDefinition .

Autowired

- . Spring ( 4.2) @Autowired, .

Spring , @Autowired . .

@Component
public class UserDao {

    private DataSource dataSource;

    private UserDao(DataSource dataSource) {
        this.dataSource = dataSource;
    }
}

@Autowired ? , @Autowired , .

— — .

Field Injection? Setter Injection?

, Spring .

import javax.sql.DataSource;
import org.springframework.stereotype.Component;
import org.springframework.beans.factory.annotation.Autowired;

@Component
public class UserDao {

    @Autowired
    private DataSource dataSource;

}

, Spring .

import javax.sql.DataSource;
import org.springframework.stereotype.Component;
import org.springframework.beans.factory.annotation.Autowired;

@Component
public class UserDao {

    private DataSource dataSource;

    @Autowired
    public void setDataSource(DataSource dataSource) {
        this.dataSource = dataSource;
    }

}

(, ) , : Spring Bean. , , .

, , , , .

, , (setter) .

, . , .
: 80% , 10% 10%.
Spring : / . : .

Spring IoC

, Spring.

, , ApplicationContexts, Beans, , .

, Spring, .

Spring AOP (- )

, , Spring. ApplicationContextConfiguration:

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class MyApplicationContextConfiguration {

    @Bean
    public UserService userService() { // (1)
        return new UserService();
    }
}

, UserService — , .

Spring:

Spring , @Bean, , Spring , UserService.

Spring - , UserService. ? ?

Spring

Spring @Bean , ( ) UserService, .

- - UserService, , .

, Spring - Cglib, - (, - JDK): Cglib - . ( , .)

Spring ?

Spring . , , - (: AOP) .

AOP — Spring @Transactional.

Spring `@Transactional`

UserService :

import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.Transactional;

@Component
public class UserService {

    @Transactional           // (2)
    public User activateUser(Integer id) {  // (1)
        // execute some sql
        // send an event
        // send an email
    }
}

activUser, SQL-, , , .
@Transactional Spring, / . Spring .

: Spring UserService applicationContext, UserService. , .

, UserService, . , - , , UserService.

ContextConfiguration.

@Configuration
@EnableTransactionManagement // (1)
public class MyApplicationContextConfiguration {

    @Bean
    public UserService userService() { // (2)
        return new UserService();
    }
}

, Spring: , @Transactional, Cglib .
Spring UserService . Cglib- , , UserService, UserService .

, Spring . - Spring : , — . , , .

Spring Cglib?

AOP Spring. , AspectJ, -. AspectJ .

: Spring AOP AspectJ?

Spring AOP

, - , , Spring AOP, @Transactional Spring Security, @Secured. AOP, .

, , @Transactional Spring, @Transactional.

Spring

. , Spring. Spring.

, Java HTTP FTP. URL Java .

, ? , - ( , packaged.jar).

, , , , , (URL-, , ).

: Spring. .

import org.springframework.core.io.Resource;

public class MyApplication {

    public static void main(String[] args) {
            ApplicationContext ctx = new AnnotationConfigApplicationContext(someConfigClass); // (1)

            Resource aClasspathTemplate = ctx.getResource("classpath:somePackage/application.properties"); // (2)

            Resource aFileTemplate = ctx.getResource("file:///someDirectory/application.properties"); // (3)

            Resource anHttpTemplate = ctx.getResource("https://marcobehler.com/application.properties"); // (4)

            Resource depends = ctx.getResource("myhost.com/resource/path/myTemplate.txt"); // (5)

            Resource s3Resources = ctx.getResource("s3://myBucket/myFile.txt"); // (6)
    }
}

, ApplicationContext .
getResource() applicationContext , classpath:, Spring application classpath.
getResource() , file:, Spring .
getResource() , https: ( http), Spring .
, , . .
Spring Framework, , Spring Cloud, s3://.

, Spring . :

public interface Resource extends InputStreamSource {

    boolean exists();

    String getFilename();

    File getFile() throws IOException;

    InputStream getInputStream() throws IOException;

    // ... other methods commented out
}

, :

?
?
File.
(InputStream).

, , , , .

, , Spring: Properties.

Spring Environment?

— (properties), , , ..

.properties, :

classpath, , .
, , .
.

Spring environment.

import org.springframework.core.env.Environment;
public class MyApplication {

    public static void main(String[] args) {
           ApplicationContext ctx = new AnnotationConfigApplicationContext(someConfigClass);
           Environment env = ctx.getEnvironment(); // (1)
           String databaseUrl = env.getProperty("database.url"); // (2)
           boolean containsPassword = env.containsProperty("database.password");
           // etc
    }
}

applicationContext (environment) Spring .
(environment), , , , .

environment?

Spring `@PropertySources`?

, Spring . :

/mydir/application.properties
classpath:/application-default.properties

(. , «dev» «production», ).

- Spring MVC ServletConfig/Context, JNDI JVM. , , .

, @PropertySources :

import org.springframework.context.annotation.PropertySources;
import org.springframework.context.annotation.PropertySource;

@Configuration
@PropertySources(
        {@PropertySource("classpath:/com/${my.placeholder:default/path}/app.properties"),
         @PropertySource("file://myFolder/app-production.properties")})
public class MyApplicationContextConfiguration {
    // your beans
}

, Spring . .

@PropertySource Spring Spring: , : http://, file://, classpath: ..,

@PropertySources — , , , ? , .

Spring `@Value`

bean-, , @Autowired. @Value.

import org.springframework.stereotype.Component;
import org.springframework.beans.factory.annotation.Value;

@Component
public class PaymentService {

    @Value("${paypal.password}")  // (1)
    private String paypalPassword;

     public PaymentService(@Value("${paypal.url}") String paypalUrl) { // (2)
         this.paypalUrl = paypalUrl;
    }
}

@Value ...
.

. , @Value, Spring () — , .

Spring Web MVC

Spring Web MVC, Spring MVC, - Spring. , , - -. , Spring Boot.

MVC?

MVC, Model-View-Controller , .

HTML-, , , MVC Spring:

Model () , -. HTML, Java (, ), .
View () HTML-, HTML-, . , , , .
Controller () @Controller, HTTP- /account , HTTP- Java, Java HTML.

, Spring, HTTP-, (/account), HTML-, , .

- JSON XML.

, , - -- Java: API Java ( Spring MVC). ).

HttpServlet

MVC: -, HTTP Java, , , HttpServlets ( : , , ). HTTP-, HTTP-.

, Tomcat Jetty. , , URL - . "/*", HTTP- .

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class MyServlet extends HttpServlet { // (1)

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) { // (2)
        if (request.getRequestURI().startsWith("/account")) {
            String userId = request.getParameter("userId");
            // return <html> or {json} or <xml> for an account get request
        } else if (request.getRequestURI().startsWith("/status")) {
            // return <html> or {json} or <xml> for a health status get request
        } // etc
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) { // (3)
        // return <html> or {json} or <xml> for a post request, like a form submission
    }
}

Java HttpServlet.
doGet(), Http GET. "/" GET. , «/status», «/info», «/account» doGet.
doPost() POST Http. "/" POST. , «/register», «/submit-form», «/password-recovery» doPost().

— , , MVC, .

, MyServlet () HTTP- , URI , , requestParameters .

, Spring . DispatcherServlet.

DispatcherServlet?

Uber- Spring MVC Spring , DispatcherServlet.

DispatcherServlet, HTTP-, Java Controller.

, HTML / JSON / XML, , . ( , DispatcherServlet ).

, .

Spring HTTP .
.
() ( Java ).

Controller .

Controller

, Controller , /account.

/account HTML- , , , ..

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;

/**
*  A class that responds to /account requests.
*  Think of Netflix's account page, where you want to see your username/password/subscription info
*/
@Controller // (1)
public class AccountController {

    @GetMapping("/account/{userId}")
    public String account(@PathVariable Integer userId) { // (2)
        // TODO retrieve name, address, subscription information
        return "templates/account"; // (3)
    }
}

, , .

AccountController, @Controller. Spring: HTTP- , DispatcherServlet .

Java-, account(). , @GetMapping. DispatcherServlet, , /account/{userId}, . , dispatcherServlet {userId}, !

Java account. , (HTML-). .

HTML (view) Spring Web MVC

Spring MVC , HTML. , , HTML- , , Velocity Freemarker. Spring .

, ():
classpath:/templates/account.vm

<html>
  <body>
    Hello $user.name, this is your account!
    <!-- list subscriptions etc -->
  </body>
</html>

HTML-, , $user.name. ? . .

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;

@Controller
public class AccountController {

    @GetMapping("/account/{userId}")
    public String account(Model model, @PathVariable Integer userId) { // (1)
        // TODO validate user id
        model.addAttribute("user", userDao.findById(userId)); // (2)
        return "templates/account"; // (3)
    }
}

Spring "Model" . , , , .. .
Spring map (), .
, view, , .

, Spring MVC !

JSON / XML () Spring Web MVC

- HTML, XML JSON. , Spring MVC .

, , Jackson, , Controller , Spring: , Java XML / JSON, , .

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
public class HealthController {

    @GetMapping("/health")
    @ResponseBody // (1)
    public HealthStatus health() {
        return new HealthStatus(); // (2)
    }
}

@ResponseBody , Spring, Java- HealthStatus HttpResponse (, XML JSON).
Java- , .

Spring , XML, JSON - ?

(content negotiation) Spring MVC

, , , Spring MVC, Spring MVC.

Accept, «Accept: application/json» «Accept: application/xml». " ", XML JSON.
URL , /health.json /health.xml. Spring MVC .
, /health?Format = json. Spring MVC .

Spring : @ResponseBody, «JSON». , , JSON? , , HealthStatus JSON. .

, .

HTTP- Spring?

Spring MVC , HTTP — .

, JSON, XML HTTP (Multipart) Fileupload, Spring Java.

HTTP- Spring MVC?

Spring MVC HttpServletResponse — .

HTML, JSON, XML WebSocket. , Java .

Spring MVC?

Spring MVC , , -.

, RequestParams, , , ViewHandlers, RootContexts, , , . , .

: Spring Boot
Spring Boot, , @RestController, , , Spring Boot.

, Spring Boot ( ), , , Spring MVC. :

// some other annotations left out
@Controller
@ResponseBody
public @interface RestController {

}

, Spring MVC @RestController — , Spring MVC @Controller Spring MVC @ResponseBody — , - Spring Boot.

: Spring MVC

Spring MVC — MVC, HTML / JSON / XML - -. Spring, .

: Java-, , , Http- , .

Spring Framework

IoC Spring, Spring Web MVC Spring. . ?

Spring Framework?

Spring Framework , . 20 Spring spring.io. , Spring.

, ?

, , Spring , Java. JDK, . Spring Framework .

: Java API , , , . .

Spring API- Java Mail API, , , , Spring.

import org.springframework.core.io.FileSystemResource;
import org.springframework.mail.javamail.JavaMailSender;
import org.springframework.mail.javamail.MimeMessageHelper;

public class SpringMailSender {

    @Autowired
    private JavaMailSender mailSender; // (1)

    public void sendInvoice(User user, File pdf) throws Exception {
        MimeMessage mimeMessage = mailSender.createMimeMessage();

        MimeMessageHelper helper = new MimeMessageHelper(mimeMessage, true); // (2)

        helper.setTo("john@rambo.com");
        helper.setText("Check out your new invoice!");
        FileSystemResource file = new FileSystemResource(pdf);
        helper.addAttachment("invoice.pdf", file);

        mailSender.send(mimeMessage);
    }
}

, (URL, , ), MailSender, Spring, , .
Spring , MimeMessageHelper, , , , .

, , Spring Framework , «» Java, , , API Spring.

Spring Framework?

, , Spring. , . .

Spring’s Data Access: Spring Data (JPA / JDBC). Springs @Transactional, JDBC ORM (, Hibernate).
Spring Integration : , JMS AMQP, . .
Spring Expression Language (SpEL): , DSL Regex / / Spring Bean. .
Spring. -.
Spring. () Spring , , Spring, REST.

Spring Framework: FAQ

Spring ?

Spring :

Spring Boot, Spring . , Spring Boot 2.2.x, Spring 5.2.x ( ).
Spring , , . Spring 5.2.3.RELEASE, Spring.
Spring , Spring, ( EOL ) — Spring (. ).

Spring 4.x-5.x, , , Spring 3.x ( : 2009).

Spring? ?

, Spring:

, Spring ~ 17 , 3-4 . , .

, Spring 4.3 2016 2020 .
Spring 5.0 5.1 2020 , Spring 5.2, 2019 .

. EOL() ( ) Spring, 5.2, 31 2020 .

, Spring?

, , Spring. spring-context. , Spring.

Maven Gradle, (. : Spring ?) — .jar .

<!-- Maven -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context</artifactId>
    <version>5.2.3.RELEASE</version>
</dependency>

// Gradle
compile group: 'org.springframework', name: 'spring-context', version: '5.2.3.RELEASE'

Spring ( Spring JDBC JMS) .

Spring, Maven artifactIds . :

<!-- Maven -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
    <version>5.2.3.RELEASE</version>
</dependency>

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-jdbc</artifactId>
    <version>5.2.3.RELEASE</version>
</dependency>

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(Hinweis: Fragen Sie mich nicht, wie ich zu diesen Vergleichen gekommen bin;))

Das ist alles für heute. Wenn Sie Fragen oder Anregungen haben, schreiben Sie mir an marco@marcobehler.com oder hinterlassen Sie unten einen Kommentar. Praktische Übungen finden Sie im Spring Framework-Tutorial .

Danke fürs Lesen. Auf Wiedersehen.

Danksagung

Vielen Dank:

Patricio Moschcovich, der diesen Artikel hervorragend gelesen und auf einige kleine Fehler hingewiesen hat.
Maciej Walkowiak für den Hinweis, dass @RestControllerer immer Teil von Spring MVC war, nicht von Spring Boot.
(Dank an den Autor des Originalartikels - ca. Transl.)

Was ist Spring Framework? Von der Abhängigkeitsinjektion zur Web-MVC

Inhalt

Spring

Spring Framework?

:

, :

?

new()

(IoC, Inversion of Control)

Spring IOC / Dependency Injection

ApplicationContext? ?

ApplicationContextConfiguration? ApplicationContexts .

AnnotationConfigApplicationContext? ApplicationContext?

@Bean? Spring Bean?

Spring bean scope?

Spring Java Config?

@ComponentScan?

@Component @Autowired?

Autowired

Field Injection? Setter Injection?

Spring IoC

Spring AOP (- )

Spring

Spring ?

Spring @Transactional

Spring Cglib?

Spring AOP

Spring

Spring Environment?

Spring @PropertySources?

Spring @Value

Spring Web MVC

MVC?

HttpServlet

DispatcherServlet?

Controller

HTML (view) Spring Web MVC

JSON / XML () Spring Web MVC

(content negotiation) Spring MVC

HTTP- Spring?

HTTP- Spring MVC?

Spring MVC?

: Spring MVC

Spring Framework

Spring Framework?

Spring Framework?

Spring Framework: FAQ

Spring ?

Spring? ?

, Spring?

Spring?

20 Spring.io? -?

Spring Spring Boot?

Spring AOP AspectJ?

Spring Spring Batch?

Spring Spring Web MVC?

Spring Struts?

? Spring XML Java ?

? ?

Spring?

Danksagung

More articles:

`@Bean`? Spring Bean?

`@ComponentScan`?

`@Component` `@Autowired`?

Spring `@Transactional`

Spring `@PropertySources`?

Spring `@Value`