学记：spring boot使用官网推荐以外的其他数据源druid

　　虽然spring boot提供了4种数据源的配置，但是如果要使用其他的数据源怎么办？例如，有人就是喜欢druid可以监控的强大功能，有些人项目的需要使用c3p0，那么，我们就没办法了吗？我们就要编程式新建一个数据源了吗？不用了！spring boot 1.4.1.RELEASE为我们提供了简洁的方式使用自己想要的数据源。

　　网上也有其他数据源的配置方法，但是都是编程式新建一个数据源，太繁琐了。我在这里记录一下官网的做法：

1、Configure a DataSource

官网介绍：http://docs.spring.io/spring-boot/docs/current-SNAPSHOT/reference/htmlsingle/#howto-configure-a-datasource

@Configuration
@EnableConfigurationProperties(DataSourceProperties.class)
public class DruidConfiguration {

    @Bean
    @ConfigurationProperties(prefix="spring.datasource.druid")
    public DataSource dataSource(DataSourceProperties properties) {
        return properties.initializeDataSourceBuilder()
                // additional customizations
                .build();
    }
}

说明：@ConfigurationProperties(prefix="spring.datasource.druid")，前缀可以自己随意。

2、配置文件

spring:
    datasource:
        name: test
        url: jdbc:mysql://localhost:3306/test
        username: root
        password: root
        # 使用druid数据源
        type: com.alibaba.druid.pool.DruidDataSource
        driver-class-name: com.mysql.jdbc.Driver
        druid:
          filters: stat,wall,log4j
          maxActive: 20
          initialSize: 1
          maxWait: 60000
          minIdle: 1
          timeBetweenEvictionRunsMillis: 60000
          minEvictableIdleTimeMillis: 300000
          validationQuery: SELECT 1 FROM DUAL
          testWhileIdle: true
          testOnBorrow: false
          testOnReturn: false
          poolPreparedStatements: true
          maxOpenPreparedStatements: 20

　　以上步骤就配置好druid了，在验证druid的配置属性是否有成功注入的时候，可以注入DataSource，断点观察DataSource的属性validationQuery是否和你写的一样。

3、配置提示

有强迫症可以看看，这个是配置提示的功能，不是必要项。

添加依赖：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-configuration-processor</artifactId>
    <optional>true</optional>
</dependency>

在resources下新建META-INF，在建一个additional-spring-configuration-metadata.json文件

{
  "properties": [
    {
      "name": "spring.datasource.druid.maxActive",
      "type": "java.lang.String",
      "description": "Description for spring.datasource.druid.maxActive."
    },
    {
      "name": "spring.datasource.druid.initialSize",
      "type": "java.lang.String",
      "description": "Description for spring.datasource.druid.initialSize."
    },
    {
      "name": "spring.datasource.druid.filters",
      "type": "java.lang.String",
      "description": "Description for spring.datasource.druid.filters."
    },
    {
      "name": "spring.datasource.druid.maxWait",
      "type": "java.lang.String",
      "description": "Description for spring.datasource.druid.maxWait."
    },
    {
      "name": "spring.datasource.druid.minIdle",
      "type": "java.lang.String",
      "description": "Description for spring.datasource.druid.minIdle."
    },
    {
      "name": "spring.datasource.druid.timeBetweenEvictionRunsMillis",
      "type": "java.lang.String",
      "description": "Description for spring.datasource.druid.timeBetweenEvictionRunsMillis."
    },
    {
      "name": "spring.datasource.druid.minEvictableIdleTimeMillis",
      "type": "java.lang.String",
      "description": "Description for spring.datasource.druid.minEvictableIdleTimeMillis."
    },
    {
      "name": "spring.datasource.druid.validationQuery",
      "type": "java.lang.String",
      "description": "Description for spring.datasource.druid.validationQuery."
    },
    {
      "name": "spring.datasource.druid.testWhileIdle",
      "type": "java.lang.String",
      "description": "Description for spring.datasource.druid.testWhileIdle."
    },
    {
      "name": "spring.datasource.druid.testOnBorrow",
      "type": "java.lang.String",
      "description": "Description for spring.datasource.druid.testOnBorrow."
    },
    {
      "name": "spring.datasource.druid.testOnReturn",
      "type": "java.lang.String",
      "description": "Description for spring.datasource.druid.testOnReturn."
    },
    {
      "name": "spring.datasource.druid.poolPreparedStatements",
      "type": "java.lang.String",
      "description": "Description for spring.datasource.druid.poolPreparedStatements."
    },
    {
      "name": "spring.datasource.druid.maxOpenPreparedStatements",
      "type": "java.lang.String",
      "description": "Description for spring.datasource.druid.maxOpenPreparedStatements."
    }
  ]
}

这样在使用druid的时候IDEA就会出现提示了。

注意：如果没有出现提示，可以断点数据源，观察相应的配置就行了(大概):)

 4、druid监控

网上有很多例子，这个就不多说了。

/**
     * 注册一个StatViewServlet
     * @return
     */
    @Bean
    public ServletRegistrationBean druidStatViewServle(){
        //org.springframework.boot.context.embedded.ServletRegistrationBean提供类的进行注册.
        ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean(new StatViewServlet(),"/druid/*");

        //添加初始化参数：initParams

        //白名单：
        //servletRegistrationBean.addInitParameter("allow","127.0.0.1");
        //IP黑名单 (存在共同时，deny优先于allow) : 如果满足deny的话提示:Sorry, you are not permitted to view this page.
        //servletRegistrationBean.addInitParameter("deny","192.168.1.73");
        //登录查看信息的账号密码.
        //servletRegistrationBean.addInitParameter("loginUsername","admin2");
        //servletRegistrationBean.addInitParameter("loginPassword","123456");
        //是否能够重置数据.
        servletRegistrationBean.addInitParameter("resetEnable","false");
        return servletRegistrationBean;
    }

    /**
     * 注册一个：filterRegistrationBean
     * @return
     */
    @Bean
    public FilterRegistrationBean druidStatFilter(){

        FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean(new WebStatFilter());

        //添加过滤规则.
        filterRegistrationBean.addUrlPatterns("/*");

        //添加不需要忽略的格式信息.
        filterRegistrationBean.addInitParameter("exclusions","*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*");
        return filterRegistrationBean;
    }

怎么使用可以看druid官网。