The core technical principles of the Java class library in the Spring framework
The core technical principle of the Java class library in the Spring framework
Spring is an open source Java application development framework. Its main goal is to simplify enterprise -level application development.The Spring framework uses the core technical principles of the Java library to integrate it into its own architecture.This article will introduce the core technical principles of the Java library in the Spring framework and provide some Java code examples.
1. Dependency injection
Dependent injection is one of the core technologies of the Spring framework.It injects the dependency into the object by automatically, avoiding the dependency relationship between manual management objects.The reflection mechanism in the Java class library is one of the key technologies to achieve injecting.
Example code:
public class UserService {
private UserRepository userRepository;
public void setUserRepository(UserRepository userRepository) {
this.userRepository = userRepository;
}
// ...
}
public class UserRepository {
// ...
}
public class MyApp {
public static void main(String[] args) {
// Create objects
UserService userService = new UserService();
UserRepository userRepository = new UserRepository();
// Set up dependencies
userService.setUserRepository(userRepository);
// ...
}
}
2. AOP(Aspect-Oriented Programming)
Facing surface programming (AOP) is another core technology of the Spring framework.It dynamically woven some horizontal sectaries (such as log records, transaction management, etc.) to different modules of the application during runtime, thereby achieving horizontal attention separation.The dynamic proxy in the Java class library is an important technology for AOP.
Example code:
public interface UserService {
void saveUser(User user);
}
public class UserServiceImpl implements UserService {
public void saveUser(User user) {
// Save user information
}
}
public class LoggingAspect {
public void beforeSaveUser() {
// Record log
}
}
public class MyApp {
public static void main(String[] args) {
// Create objects
UserService userService = new UserServiceImpl();
// Create cutting objects
LoggingAspect loggingAspect = new LoggingAspect();
// Create proxy objects
UserServiceProxy userServiceProxy = new UserServiceProxy(userService, loggingAspect);
// The method of calling the proxy object
userServiceProxy.saveUser(new User());
// ...
}
}
3. Programming interface
The Spring framework encourages interface programming, which is an important principle of the Java class library.Through interface programming, the pine coupling module interaction can be achieved, and the testability and maintenance of the code can be improved.
Example code:
public interface UserService {
void saveUser(User user);
}
public class UserServiceImpl implements UserService {
public void saveUser(User user) {
// Save user information
}
}
public class MyApp {
public static void main(String[] args) {
// Create interface objects
UserService userService = new UserServiceImpl();
// Call method
userService.saveUser(new User());
// ...
}
}
Summarize:
The Spring framework uses the core technology of the Java library, such as dependency injection, AOP, and interface -oriented programming, providing a simple and flexible way to build an enterprise -level application.Developers can use these technologies to achieve scalable, maintenance and test -available code.Therefore, in -depth understanding of the core technical principles of the Java library in the Spring framework is critical to develop high -quality applications.
