spring-boot读取props和yml配置文件

最近微框架spring-boot很火，笔者也跟风学习了一下，废话不多说，现给出一个读取配置文件的例子。
首先，需要在pom文件中依赖以下jar包

    <dependencies>        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-web</artifactId>        </dependency>                <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-test</artifactId>            <scope>test</scope>        </dependency>    </dependencies>

其次，我们需要一个spring-boot启动类

@SpringBootApplication@EnableConfigurationProperties({PropsConfig.class,YmlConfig.class}) public class ReadApplication {    public static void main(String[] args) {        SpringApplication.run(ReadApplication.class, args);    }}

没错，@EnableConfigurationProperties注解里指出的PropsConfig.class,YmlConfig.class分别就是读取props和yml配置文件的类。接下来，我们分别进行读取properties和yml配置文件的具体实现。

1.读取properties配置文件
在类路径下放置一个application.properties文件，大致内容如下：

master.ds.driverClassName=com.mysql.jdbc.Drivermaster.ds.url=jdbc:mysql://localhost:3306/testmaster.ds.username=rootmaster.ds.password=rootmaster.ds.filters=statmaster.ds.maxActive=20master.ds.initialSize=1master.ds.maxWait=60000master.ds.minIdle=10master.ds.timeBetweenEvictionRunsMillis=60000master.ds.minEvictableIdleTimeMillis=300000master.ds.validationQuery=SELECT 'x'master.ds.testWhileIdle=truemaster.ds.testOnBorrow=falsemaster.ds.testOnReturn=falsemaster.ds.poolPreparedStatements=truemaster.ds.maxOpenPreparedStatements=100master.ds.removeAbandoned=truemaster.ds.removeAbandonedTimeout=1800master.ds.logAbandoned=true

读取props配置的类，很简单，基本就是一个pojo/vo类，在类上加载@ConfigurationProperties注解即可。

@ConfigurationProperties(prefix = "master.ds",locations = "classpath:application.properties")public class PropsConfig {    private String driverClassName;    private String url;    private String username;    private String password;    private String filters;    private String maxActive;    private String initialSize;    private String maxWait;            public String getDriverClassName() {        return driverClassName;    }    public void setDriverClassName(String driverClassName) {        this.driverClassName = driverClassName;    }    public String getUrl() {        return url;    }    public void setUrl(String url) {        this.url = url;    }    public String getUsername() {        return username;    }    public void setUsername(String username) {        this.username = username;    }    public String getPassword() {        return password;    }    public void setPassword(String password) {        this.password = password;    }    public String getFilters() {        return filters;    }    public void setFilters(String filters) {        this.filters = filters;    }    public String getMaxActive() {        return maxActive;    }    public void setMaxActive(String maxActive) {        this.maxActive = maxActive;    }    public String getInitialSize() {        return initialSize;    }    public void setInitialSize(String initialSize) {        this.initialSize = initialSize;    }    public String getMaxWait() {        return maxWait;    }    public void setMaxWait(String maxWait) {        this.maxWait = maxWait;    }}

单元测试类

@RunWith(SpringJUnit4ClassRunner.class)@SpringBootTest(classes = ReadApplication.class)public class ReadApplicationPropsTests {    @Autowired    private PropsConfig propsConfig;        @Test    public void testDisplayPropsValue() {        String driverClassName = propsConfig.getDriverClassName();        String url = propsConfig.getUrl();        String username = propsConfig.getUsername();        String password = propsConfig.getPassword();                String filters = propsConfig.getFilters();        String maxActive = propsConfig.getMaxActive();        String initialSize = propsConfig.getInitialSize();        String maxWait = propsConfig.getMaxWait();                        System.out.println("driverClassName -> " + driverClassName);        System.out.println("url -> " + url);        System.out.println("username -> " + username);        System.out.println("password -> " + password);                System.out.println("initialSize -> " + initialSize);        System.out.println("maxWait -> " + maxWait);            }}

可以看到在控制台输出的测试内容：

driverClassName -> com.mysql.jdbc.Driverurl -> jdbc:mysql://localhost:3306/testusername -> rootpassword -> rootinitialSize -> 1maxWait -> 60000

2.读取yml配置文件
在类路径下放置一个application.yml文件，大致内容如下：

myProps: #自定义的属性和值  simpleProp: simplePropValue  arrayProps: 1,2,3,4,5  listProp1:    - name: abc      value: abcValue    - name: efg      value: efgValue  listProp2:    - config2Value1    - config2Vavlue2  mapProps:    key1: value1    key2: value2

读取yml配置文件的类。

@ConfigurationProperties(prefix="myProps") //application.yml中的myProps下的属性  public class YmlConfig {    private String simpleProp;      private String[] arrayProps;      private List<Map<String, String>> listProp1 = new ArrayList<>(); //接收prop1里面的属性值      private List<String> listProp2 = new ArrayList<>(); //接收prop2里面的属性值      private Map<String, String> mapProps = new HashMap<>(); //接收prop1里面的属性值            public String getSimpleProp() {          return simpleProp;      }            public void setSimpleProp(String simpleProp) {          this.simpleProp = simpleProp;      }            public List<Map<String, String>> getListProp1() {          return listProp1;      }      public List<String> getListProp2() {          return listProp2;      }        public String[] getArrayProps() {          return arrayProps;      }        public void setArrayProps(String[] arrayProps) {          this.arrayProps = arrayProps;      }        public Map<String, String> getMapProps() {          return mapProps;      }        public void setMapProps(Map<String, String> mapProps) {          this.mapProps = mapProps;      } }

单元测试类

@RunWith(SpringJUnit4ClassRunner.class)@SpringBootTest(classes = ReadApplication.class)public class ReadApplicationYmlTests {    @Autowired    private YmlConfig ymlConfig;        @Test    public void testDisplayYmlValue() throws JsonProcessingException {        System.out.println("simpleProp: " + ymlConfig.getSimpleProp());                  ObjectMapper objectMapper = new ObjectMapper();        System.out.println("arrayProps: " + objectMapper.writeValueAsString(ymlConfig.getArrayProps()));          System.out.println("listProp1: " + objectMapper.writeValueAsString(ymlConfig.getListProp1()));          System.out.println("listProp2: " + objectMapper.writeValueAsString(ymlConfig.getListProp2()));          System.out.println("mapProps: " + objectMapper.writeValueAsString(ymlConfig.getMapProps()));    }}

可以看到在控制台输出的测试内容：

simpleProp: simplePropValuearrayProps: ["1","2","3","4","5"]listProp1: [{"name":"abc","value":"abcValue"},{"name":"efg","value":"efgValue"}]listProp2: ["config2Value1","config2Vavlue2"]mapProps: {"key1":"value1","key2":"value2"}