Spring Boot: How to externalize JDBC datasource configuration?

Question

I have following Spring Boot controller code that works. (Some sensitive text was replaced)

package com.sample.server;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;

import org.apache.commons.dbcp.BasicDataSource;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.bind.annotation.RequestMapping;

@RestController
public class DetailReportController
{
    @RequestMapping(value="/report/detail", method=RequestMethod.GET)
    public List<UFGroup> detailReport()
    {
        BasicDataSource dataSource = new BasicDataSource();
        dataSource.setDriverClassName("net.sourceforge.jtds.jdbc.Driver");
        dataSource.setUrl("jdbc:jtds:sqlserver://111.11.11.11/DataBaseName;user=sa;password=password");

        JdbcTemplate jt = new JdbcTemplate(dataSource);

        List<UFGroup> results = jt.query(
            "select NID, SCode, SName from UFGroup",
            new RowMapper<UFGroup>()
            {
                @Override
                public UFGroup mapRow(ResultSet rs, int rowNum) throws SQLException
                {
                    return new UFGroup(rs.getInt("NID"), rs.getString("SCode"),
                            rs.getString("SName"));
                }
            });

        return results;
    }

    private static class UFGroup
    {
        public int nid;
        public String scode;
        public String sname;

        public UFGroup(int nid, String scode, String sname)
        {
            this.nid = nid;
            this.scode = scode;
            this.sname = sname;
        }
    }
}

Now I want to externalize the configuration of the datasource. That is, BasicDataSource class, driver class name, datasource URL should be placed into application.properties. How can I do that?

BTW, I am a newbie of Spring, Spring Boot and even Java Beans. All I have is some Java programming experience, mainly for mobile devices. I've spent a few days to study Spring Boot environment, but I was literally overwhelmed. So please, give me the exact instruction with concrete example.

UPDATE: when I applied the answer of M. Deinum, following error occured when I ran the application:

2013-11-18 19:37:54.789  INFO 6868 --- [           main] com.logicplant.uflow.server.Application  : Starting Application on zeo-PC with PID 6868 (C:\Projects\uFlow\Dev\Server\Spring\uFlowServer\build\libs\uFlowServer-1.0.0.jar started by zeo)
2013-11-18 19:37:54.830  INFO 6868 --- [           main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@7f83698f: startup date [Mon Nov 18 19:37:54 KST 2013]; root of context hierarchy
2013-11-18 19:37:55.931  INFO 6868 --- [           main] o.apache.catalina.core.StandardService   : Starting service Tomcat
2013-11-18 19:37:55.932  INFO 6868 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/7.0.42
2013-11-18 19:37:56.009  INFO 6868 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2013-11-18 19:37:56.010  INFO 6868 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 1183 ms
2013-11-18 19:37:56.165  INFO 6868 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring FrameworkServlet 'dispatcherServlet'
2013-11-18 19:37:56.165  INFO 6868 --- [ost-startStop-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization started
2013-11-18 19:37:56.242  INFO 6868 --- [ost-startStop-1] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2013-11-18 19:37:56.388  INFO 6868 --- [ost-startStop-1] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/report/detail],methods=[GET],params=[],headers=[],consumes=[],produces=[],custom=[]}" onto public java.util.List<com.logicplant.uflow.server.DetailReportController$UFGroup> com.logicplant.uflow.server.DetailReportController.detailReport()
2013-11-18 19:37:56.438  INFO 6868 --- [ost-startStop-1] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2013-11-18 19:37:56.439  INFO 6868 --- [ost-startStop-1] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2013-11-18 19:37:56.788  INFO 6868 --- [ost-startStop-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization completed in 622 ms
2013-11-18 19:37:56.881  INFO 6868 --- [           main] o.apache.catalina.core.StandardService   : Stopping service Tomcat
java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:53)
    at java.lang.Thread.run(Unknown Source)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'detailReportController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.springframework.jdbc.core.JdbcTemplate com.logicplant.uflow.server.DetailReportController.jt; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.springframework.jdbc.core.JdbcTemplate] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:292)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1139)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:299)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:295)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:195)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:665)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:760)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:482)
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:509)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:278)
    at com.logicplant.uflow.server.Application.main(Application.java:17)
    ... 6 more
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.springframework.jdbc.core.JdbcTemplate com.logicplant.uflow.server.DetailReportController.jt; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.springframework.jdbc.core.JdbcTemplate] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:505)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:289)
    ... 20 more
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.springframework.jdbc.core.JdbcTemplate] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1051)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:919)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:820)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:477)
    ... 22 more

For reference, the content of build.grade file (I use Gradle) is as follows: (following M. Deinum's suggestion, I removed the dependency for org.apache.commons.dbcp.)

buildscript {
    repositories {
        maven { url "http://repo.spring.io/libs-snapshot" }
        mavenLocal()
    }
    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:0.5.0.M5")
    }
}

apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'idea'
apply plugin: 'spring-boot'

jar {
    baseName = 'uFlowServer'
    version = '1.0.0'
}

repositories {
    mavenCentral()
    maven { url "http://repo.spring.io/libs-snapshot" }
}

dependencies {
    compile("org.springframework.boot:spring-boot-starter-web:0.5.0.M5")
    compile("com.fasterxml.jackson.core:jackson-databind")
    compile("org.springframework:spring-jdbc:4.0.0.M3")
    runtime("net.sourceforge.jtds:jtds:1.3.1")
    testCompile("junit:junit:4.11")
}

task wrapper(type: Wrapper) {
    gradleVersion = '1.8'
}

And this is Application.java file, which is the main source file.

package com.sample.server;

import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.SpringApplication;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

@Configuration
@EnableAutoConfiguration
@ComponentScan
public class Application
{
    public static void main(String args[])
    {
        SpringApplication app = new SpringApplication(Application.class);
        app.setShowBanner(false);
        app.run(args);
    }
}

What can be done for the error?

UPDATE: As M. Deinum suggested, when I changed build.gradle file as follows, the application worked!

buildscript {
    repositories {
        maven { url "http://repo.spring.io/libs-snapshot" }
        mavenLocal()
    }
    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:0.5.0.M6")
    }
}

apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'idea'
apply plugin: 'spring-boot'

jar {
    baseName = 'uFlowServer'
    version = '1.0.0'
}

repositories {
    mavenCentral()
    maven { url "http://repo.spring.io/libs-snapshot" }
}

dependencies {
    compile("org.springframework.boot:spring-boot-starter-web:0.5.0.M6")
    compile("org.springframework.boot:spring-boot-starter-jdbc:0.5.0.M6")
    compile("com.fasterxml.jackson.core:jackson-databind")
    runtime("net.sourceforge.jtds:jtds:1.3.1")
    testCompile("junit:junit:4.11")
}

task wrapper(type: Wrapper) {
    gradleVersion = '1.8'
}

Answer 1

Change your controller to the following

@RestController
public class DetailReportController {

    @Autowired
    private JdbcTemplate jt;

    @RequestMapping(value="/report/detail", method=RequestMethod.GET)
    public List<UFGroup> detailReport() {
        List<UFGroup> results = jt.query(
            "select NID, SCode, SName from UFGroup",
            new RowMapper<UFGroup>(){
                @Override
                public UFGroup mapRow(ResultSet rs, int rowNum) throws SQLException {
                    return new UFGroup(rs.getInt("NID"), rs.getString("SCode"), rs.getString("SName"));
                }
            });
        return results;
    }

    private static class UFGroup
    {
        public int nid;
        public String scode;
        public String sname;

        public UFGroup(int nid, String scode, String sname)
        {
            this.nid = nid;
            this.scode = scode;
            this.sname = sname;
        }
    }
}

In src/main/resources add an application.properties with the following

spring.datasource.driverClassName=net.sourceforge.jtds.jdbc.Driver
spring.datasource.url=jdbc:jtds:sqlserver://111.11.11.11/DataBaseName
spring.datasource.username=sa
spring.datasource.password=password

And simply start your application. No xml needed. Spring boot will create the DataSource and will add a default JdbcTemplate instance.

Tip: Remove the dependency for org.apache.commons.dbcp spring-boot will give you the newer (and IMHO better) tomcat connection pool (which despite the name can be used entirely on its own).