Spring Boot: How to externalize JDBC datasource configuration? - spring

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).

Answer 2

I will remodify your code in better approach.
Firstly no need of using new operator in your code as you are using Spring so you can use the powerful feature of Spring i.e Dependency Injection.
#RestController
public class DetailReportController
{ #Required
private JdbcTemplate jt;
//setter for the same
#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;
}
}
}
application-context.xml
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
<property name="driverClassName" value="${jdbc.driverClassName}"/>
<property name="url" value="${jdbc.url}"/>
<property name="username" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
<property name="maxActive" value="100"/>
<property name="maxIdle" value="30"/>
<property name="maxWait" value="16000"/>
<property name="minIdle" value="0"/>
</bean>
<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="location">
<value>database.properties</value>
</property>
</bean>
<bean id="jt" class="org.springframework.jdbc.core.JdbcTemplate;">
<property name="dataSource" ref="dataSource"/>
</bean>
<bean id="detailReportController" class="your class">
<property name="jt" ref="jt"/>
</bean>
Another suggestion that you can move your code related to database in DAO classes,its very bad practice to have the same in Controller.Else if you want to stick to your approach use Properties class of java.util package
See here