access externalize application.properties in Tomcat for Spring boot application?

Question

i have spring boot application.

i am trying to access application.properties file from tomcat location.

i followed this link : How to externalize application.properties in Tomcat webserver for Spring?

MortgageLoanApiApplication

package com.Mortgage.MortgageLoanAPI;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class MortgageLoanApiApplication {

    public static void main(String[] args) {
        System.setProperty("spring.config.name", "application");
        SpringApplication.run(MortgageLoanApiApplication.class, args);
    }

}

ServletInitializer

package com.Mortgage.MortgageLoanAPI;

import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;

public class ServletInitializer extends SpringBootServletInitializer {

    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
        return application.sources(MortgageLoanApiApplication.class).properties("spring.config.name: application");
    }

}

C:\Program Files\Apache Software Foundation\Apache Tomcat 8.0.9\bin\setenv.sh

export spring_config_location=C:/Program Files/Apache Software Foundation/Apache Tomcat 8.0.9/conf/

C:\Program Files\Apache Software Foundation\Apache Tomcat 8.0.9\conf\application.properties

spring.datasource.url=jdbc:mysql://localhost:3306/mortgage_loan
spring.datasource.driverClassName=com.mysql.cj.jdbc.Driver
spring.datasource.username=root
spring.datasource.password=root

But when i am running the application or build the application. it is showing error, because it's not finding the db connection.

2019-03-04 10:53:28.318  INFO 2872 --- [           main] ConditionEvaluationReportLoggingListener : 

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2019-03-04 10:53:28.325 ERROR 2872 --- [           main] o.s.b.d.LoggingFailureAnalysisReporter   : 

***************************
APPLICATION FAILED TO START
***************************

Description:

Failed to configure a DataSource: 'url' attribute is not specified and no embedded datasource could be configured.

Reason: Failed to determine a suitable driver class


Action:

Consider the following:
    If you want an embedded database (H2, HSQL or Derby), please put it on the classpath.
    If you have database settings to be loaded from a particular profile you may need to activate it (no profiles are currently active).

Let me know how to fix this.Or If there is any other way to access properties file from tomcat location using spring boot.

Answer 1

Please add -

spring.autoconfigure.exclude=org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration

or

Use annotation above class -

@EnableAutoConfiguration(exclude={DataSourceAutoConfiguration.class})

https://docs.spring.io/spring-boot/docs/current/reference/html/using-boot-auto-configuration.html

Answer 2

To access application.properties file from tomcat directory. then we need to follow below steps

Need to add plugin in pom.xml. which means it'll ignore the workspace application.properties file after deployment

<!-- Added the below plugin to not include the application.properties inside the war -->
<plugin>
    <artifactId>maven-war-plugin</artifactId>
    <version>2.6</version>
    <configuration>
        <failOnMissingWebXml>false</failOnMissingWebXml>
        <packagingExcludes>
            **/application.properties/
        </packagingExcludes>
    </configuration>
</plugin>

Need to copy the application.properties file to tomcat directory lib location. then we need to change the ServletInitializer.java file.

"classpath:mortgage-api/" means we need to create a folder with name mortgage-api in tomcat lib folder and will copy application.properties file to this location. check the code comment.

import java.util.Properties;

import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;

public class ServletInitializer extends SpringBootServletInitializer {

    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
        return application.sources(MortgageLoanApiApplication.class).properties(loadproperties());
    }

    /**
     * Added this method to load properties from the classpath while intializing the server app
     * location of the properties file should be inside tomcat directory:
     *    lib/mortgage-api/application.properties
     * @return
     */
    private Properties loadproperties() {
          Properties props = new Properties();
          props.put("spring.config.location", "classpath:mortgage-api/");
          return props;
       }

}

then mvn clean, then build war file mvn install