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Spring Boot：如何将JDBC数据源配置外部化？

springjdbcspring-boot
12

我有以下工作的Spring Boot控制器代码。 (一些敏感文本已被替换)

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;
        }
    }
}

现在我想将数据源的配置外部化。 也就是说，BasicDataSource类、驱动程序类名和数据源URL应该放置在application.properties中。 我该怎么做呢？

顺便说一下，我是Spring、Spring Boot甚至Java Beans的新手。我只有一些针对移动设备的Java编程经验。我花了几天时间研究Spring Boot环境，但实际上我感到不知所措。 因此，请给我详细的指导和具体的示例。

更新： 当我应用M. Deinum的答案时，运行应用程序时出现以下错误：

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

供参考，build.grade 文件的内容如下（我使用 Gradle），根据 M. Deinum 的建议，我删除了 org.apache.commons.dbcp 的依赖。

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'
}

这是Application.java文件，它是主要的源文件。

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);
    }
}

出现错误时应该怎么做？

更新：根据M. Deinum的建议，当我按照以下方式更改build.gradle文件后，应用程序可以正常运行！

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'
}
2个回答
19

将你的控制器更改为以下内容

@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;
        }
    }
}

在 src/main/resources 目录下添加一个 application.properties 文件，并将以下内容添加进去。

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

只需启动应用程序即可，无需使用xml。Spring Boot将创建DataSource并添加默认的JdbcTemplate实例。

提示：删除对org.apache.commons.dbcp的依赖，Spring Boot将为您提供更新（我认为更好）的Tomcat连接池（尽管它的名称可以完全独立使用）。

谢谢您的回答。但是当我应用它时，出现了一个错误。我已经编辑了问题，包括错误输出。 - zeodtr
我假定你已经添加了所有的依赖项，并将 spring-boot-starter-jdbc 添加为依赖项。同时请移除 spring-jdbc 依赖，因为它将由 spring-boot-starter-jdbc 拉取。另外建议将 Spring Boot 更新到 M6 而不是 M5。 - M. Deinum
1
非常感谢您，您救了我的一天！当我应用了您的两个建议（包括spring-boot-starter-jdbc依赖项和更新到M6版本）时，应用程序就可以工作了。再次感谢您。为了参考，我已经更新了我的问题，包括build.gradle文件的最终（已更正）内容。 - zeodtr
0

我会以更好的方式重新修改您的代码。

首先，由于您正在使用Spring，因此无需在代码中使用new运算符，而可以使用Spring的强大功能即依赖注入。

@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>

另一个建议是将与数据库相关的代码移动到DAO类中，把它放在控制器中是非常糟糕的做法。如果你还想坚持自己的方法，可以使用java.util包中的Properties类。
点击这里查看详细信息。
谢谢您的快速回复。但是我已经了解到，如果使用Spring Boot，则不再需要XML配置文件，而可以使用application.properties文件来覆盖一些默认配置值。那么，我是否仍然需要像您建议的那样使用XML文件呢？ - zeodtr
如果你正在使用Spring，就不能完全消除xml文件。如果你觉得合适的话，请查看更新的答案并接受我的答案。 - Shoaib Chikate
再次感谢，我会仔细研究您的答案。由于我是新手，可能需要一些时间... - zeodtr
5
@ShoaibChikate，这并不正确（甚至是半年前），在使用Spring时，你可以完全消除XML文件。当在Servlet 3.0+环境中运行时，甚至web.xml也不是必需的。 ;) - Jakub Jirutka
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