使用 spring boot 配置和加载多个属性

Question

I was trying to configure properties using spring boot. I will be packaging the project as a jar file and need to be able to change the value configured in the properties(outside the jar) as required and the location of the properties file should be relative to the jar file. The following sample code demonstrates how I did this using java libraries :

Properties properties = new Properties();
String path = System.getProperty("user.dir")+"/config/linuxScripts.properties";

try(FileInputStream fis = new FileInputStream(path)) {
    prop.load(fis);
}catch (Exception e) {
    e.printStackTrace();
}

Now that I want to configure multiple properties that are located outside the jar file. I have used @PropertySource annotation and I was able to fetch the properties using Environment class provided by spring boot. Unfortunately, I cannot use System.getProperty("user.dir") to set the path value when using @PropertySource annotation. I need to set the path of the properties file as relative to the application and not configured in the system environment variable. Is there a way to workaround the issue and get the user directory?

I have tried using PropertySourcesPlaceholderConfigurer in the configuration class. As it seems like I wont be able to get the properties using Environment class in this case.

Answer 1

So the solution is based on fact that we may extend classpath by specifying items in manifest file. So we need to

1) Leave properties file in /src/main/resources.

2) Exclude it from a final jar

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-jar-plugin</artifactId>
    <version>2.4</version>
    <configuration>
                    <excludes>
                        <exclude>**/*.properties</exclude>
                    </excludes>
                    <archive>
                        <manifest>
                            <mainClass>com.blabla.daemon.MainListener</mainClass>
                            <classpathPrefix>lib/</classpathPrefix>
                            <addClasspath>true</addClasspath>
                        </manifest>
                        <manifestEntries>
                            <Class-Path>conf/</Class-Path>
                        </manifestEntries>
                    </archive>
                </configuration>
            </plugin>

3) Make a folder conf outside the jar

4) Copy there properties file from resources folder with maven

<plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-resources-plugin</artifactId>
                <version>2.3</version>
                <executions>
                    <execution>
                        <id>copy-resources</id>
                        <phase>install</phase>
                        <goals>
                            <goal>copy-resources</goal>
                        </goals>
                        <configuration>
                            <outputDirectory>${basedir}/target/conf</outputDirectory>
                            <resources>
                                <resource>
                                    <directory>src/main/resources</directory>
                                    <includes>
                                        <include>**/*.properties</include>
                                    </includes>
                                </resource>
                            </resources>
                        </configuration>
                    </execution>
                </executions>
            </plugin>

5) Specify manifest file that points to the conf folder (a part of step 1 -see there)

<archive>
    <manifest>
      <mainClass>com.blabla.daemon.MainListener</mainClass>
      <classpathPrefix>lib/</classpathPrefix>
         <addClasspath>true</addClasspath>
     </manifest>
     <manifestEntries>
       <Class-Path>conf/</Class-Path>
     </manifestEntries>
  </archive>