详解SpringBoot注解读取配置文件的方式

一、@Value读取application.properties配置文件中的值

application.properties配置文件

fileName=configName

PropertiesConfig类文件

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

@Component
public class PropertiesConfig {
 //通过@Value注解读取fileName的值
 @Value("${fileName}")
 private String fileName;

public String getFileName() {
   return fileName;
 }

public void setFileName(String fileName) {
   this.fileName = fileName;
 }
}

测试

import com.model.PropertiesConfig;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest
public class PropertiesConfigTest {
 @Autowired
 private PropertiesConfig propertiesConfig;
 @Test
 public void test(){
   System.out.println(propertiesConfig.getFileName());//结果输出：configName
   assert "configName".equals(propertiesConfig.getFileName());
 }
}

二、@ConfigurationProperties读取多个application.properties配置文件中的值

application.properties文件

database.username=root
database.password=root

DatabaseConfig类文件

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

@Component
@ConfigurationProperties("database")
public class DatabaseConfig {
 private String userName;
 private String passWord;

public String getUserName() {
   return userName;
 }

public void setUserName(String userName) {
   this.userName = userName;
 }

public String getPassWord() {
   return passWord;
 }

public void setPassWord(String passWord) {
   this.passWord = passWord;
 }
}

测试

import com.model.DatabaseConfig;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest
public class DatabaseConfigTest {
 @Autowired
 private DatabaseConfig databaseConfig;
 @Test
 public void test(){
   System.out.println("username = " + databaseConfig.getUserName() +", password = "+databaseConfig.getPassWord());//结果输出：username = root, password = root
   assert "root".equals(databaseConfig.getUserName());
   assert "root".equals(databaseConfig.getPassWord());
 }
}

三、@PropertySource读取任意配置文件

新建property-source.properties配置文件

fileName=configName
database.username=root
database.password=root

PropertySourceConfig类文件

import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.PropertySource;
import org.springframework.stereotype.Component;

@Component
@PropertySource(value = {"classpath:property-source.properties"})
@ConfigurationProperties("database")
public class PropertySourceConfig {
 @Value("${fileName}")
 private String fileName;
 private String userName;
 private String passWord;

public String getFileName() {
   return fileName;
 }

public void setFileName(String fileName) {
   this.fileName = fileName;
 }

public String getUserName() {
   return userName;
 }

public void setUserName(String userName) {
   this.userName = userName;
 }

public String getPassWord() {
   return passWord;
 }

public void setPassWord(String passWord) {
   this.passWord = passWord;
 }
}

测试

import com.model.PropertySourceConfig;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest
public class PropertySourceConfigTest {

@Autowired
 private PropertySourceConfig propertySourceConfig;

@Test
 public void test(){
   assert "configName".equals(propertySourceConfig.getFileName());
   System.out.println("fileName = " + propertySourceConfig.getFileName());//结果输出：configName
   assert "root".equals(propertySourceConfig.getUserName());
   System.out.println(propertySourceConfig.getUserName());//结果输出：root
   assert "root".equals(propertySourceConfig.getPassWord());
   System.out.println(propertySourceConfig.getPassWord());//结果输出：root
 }
}

完整代码链接：read-config-file项目地址

来源：https://juejin.cn/post/6927101340178972686