1. Overview of global configuration files
The global configuration file can modify some default configuration values. Spring Boot uses an application.properties or application.yaml file as a global configuration file, which is stored in the src/main/resource directory or /config in the class path, and the resource directory is generally selected.
2. Application.properties configuration file
(1) Create Spring Boot’s Web project PropertiesDemo
Create a project using Spring Initializr
After setting the project metadata, click next to enter the next step to add Web and DevTools dependencies
Click the [Create] button to complete the project initialization
Set the project encoding to utf8, click Apply and then Cancel after setting
(2) Add relevant configuration in the application properties file
Click on the resource directory to view the application property configuration file
1. Configure server port number and web virtual path
Configure in the application.properties file
# Set the service port number server.port=8888 # Set the web virtual path server.servlet.context-path=/lzy
Start the application and view the console
2. Configuration and use of object types
(1) Create Pet class
Create a bean subpackage in net.wtt.boot, and create a Pet class in the subpackage
package net.wtt.boot.bean;
public class Pet {<!-- -->
private String type; // type
private String name; // name
public String getType() {<!-- -->
return type;
}
public void setType(String type) {<!-- -->
this.type = type;
}
public String getName() {<!-- -->
return name;
}
public void setName(String name) {<!-- -->
this.name = name;
}
@Override
public String toString() {<!-- -->
return "Pet{" +
"type='" + type + '\'' +
", name='" + name + '\'' +
'}';
}
}
(2) Create Person class
Create the Person class in the net.wtt.boot.bean package
package net.wtt.boot.bean;
import java.util.List;
import java.util.Map;
public class Person {<!-- -->
private int id; // number
private String name; // name
private List<String> hobby; // hobby;
private Map<String, String> family; // family members
private Pet pet; // pet
public int getId() {<!-- -->
return id;
}
public void setId(int id) {<!-- -->
this.id = id;
}
public String getName() {<!-- -->
return name;
}
public void setName(String name) {<!-- -->
this.name = name;
}
public List<String> getHobby() {<!-- -->
return hobby;
}
public void setHobby(List<String> hobby) {<!-- -->
this. hobby = hobby;
}
public Map<String, String> getFamily() {<!-- -->
return family;
}
public void setFamily(Map<String, String> family) {<!-- -->
this. family = family;
}
public Pet getPet() {<!-- -->
return pet;
}
public void setPet(Pet pet) {<!-- -->
this. pet = pet;
}
@Override
public String toString() {<!-- -->
return "Person{" +
"id=" + id +
", name='" + name + '\'' +
", hobby=" + hobby +
", family=" + family +
", pet=" + pet +
'}';
}
}
(3) Configure the object in the application property file
# configuration object person.id=1 person.name=Zhang Sanfeng person.hobby=travel,food,music person.family.father=Zhang Yunguang person.family.mother=Wu Wenyan person.family.grandpa=Zhang Hongyu person.famliy.grandma=Tang Yuxin person.family.son=Zhang Junbao person.family.daughter=Zhang Xiaomin person.pet.type=Teddy person.pet.name=Rarity
Configure Person object properties
(4) Add annotations to the Person class
Add the annotation @Component and hand it over to Spring for management
Add annotation @ConfigurationProperties(prefix = “person”)
Note: With the @ConfigurationProperties annotation method, the set method must be used to automatically inject corresponding values for all properties of the Person class, including simple types and complex types
(5) Add annotations to the Pet class
Add the annotation @Component and hand it over to Spring for management
Add annotation @ConfigurationProperties(prefix = “person.pet”) – you don’t need to add
(6) Obtain an instance of the Person class from the Spring container and output it
Implement the interface ApplicationContextAware and implement its abstract method setApplicationContext
Declare the ApplicationContext object and initialize it in setApplicationContext
Create a test method testPerson(), get an instance of the Person class from the Spring container and output
Run the test method testPerson() to view the results
View test class PropertiesDemoApplicationTests code
package net.wtt.boot;
import net.wtt.boot.bean.Person;
import org.junit.jupiter.api.Test;
import org.springframework.beans.BeansException;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
@SpringBootTest
class PropertiesDemoApplicationTests implements ApplicationContextAware {<!-- -->
private ApplicationContext context; //application container
@Test
void contextLoads() {<!-- -->
}
@Override
public void setApplicationContext(ApplicationContext applicationContext)
throws BeansException{<!-- -->
context=applicationContext;
}
@Test
public void testPerson(){<!-- -->
//Get the Person object from the application container by name
Person person=(Person) context. getBean("person");
//Output the Person object
System.out.println(person);
}
}
(7) Obtain an instance of the Pet class from the Spring container and output it
View the annotations of the Pet class, annotations with configuration properties @ConfigurationProperties(prefix = “person.pet”)
Add the test method testPet() in the test class
Run the test method testPet() to view the results
Comment out the annotation @ConfigurationProperties(prefix = “person.pet”) of the configuration property of the Pet class
Run the test method testPet() again, and check the results to find that the pet’s properties are not injected
Modify application.properties to configure pet objects
As you can see, the properties of the pet object are still not injected. Let’s change the property annotation method and use the @Value annotation method.
Add the value annotation @Valu to the properties of the Pet class
Run the test method testPet() again to see the result
3. Application.yaml configuration file
1. Backup application.properties file
The file is renamed application.back, which means that this file does not work
2. Create the application.yaml file in the resoures directory
Create the application.yaml file
Configure container properties
Configure person object properties
Configure pet object properties
View the contents of the application.yaml file
#configure server
server:
port: 8888
servlet:
context-path: /lzy
#Configure the person object
person:
id: 1
name: Zhang Sanfeng
hobby:
travel
gourmet food
music
family: {<!-- -->
father: Zhang Yunguang,
mother: Wu Wenyan,
grandpa: Zhang Hongyu,
grandma: Tang Yuxin,
son: Zhang Junbao,
daughter: Zhang Xiaomin
}
pet:
type: teddy dog
name: Rarity
#Configure the pet object
pet:
type: teddy dog
name: Rarity
3. Run the test method testPerson() and view the results
4. Run the test method testPet() and view the results
4. Comparison of two configuration files
1. application.properties configuration file
Using XML syntax, key-value pairs: key=value, no hierarchy
If there are Chinese characters in the value, it must be converted into unicode, otherwise there will be garbled characters
2. application.yaml configuration file
Using YAML syntax, key-value pairs: key: value (there is a space between the colon and the value), with a hierarchical structure
There are Chinese characters in the allowable value, and there is no need to convert them into unicode, and there will be no garbled characters