spring-boot讀取props和yml配置文件

最近微框架spring-boot很火，筆者也跟風學習了一下，廢話很少說，現給出一個讀取配置文件的例子。 首先，須要在pom文件中依賴如下jar包 [html] view plain copy <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，咱們須要一個spring-boot啓動類 [java] view plain copy @SpringBootApplication
@EnableConfigurationProperties({PropsConfig.class,YmlConfig.class})
public class ReadApplication {
public static void main(String[] args) {
SpringApplication.run(ReadApplication.class, args);
}
}
沒錯，@EnableConfigurationProperties註解裏指出的PropsConfig.class,YmlConfig.class分別就是讀取props和yml配置文件的類。接下來，咱們分別進行讀取properties和yml配置文件的具體實現。

1.讀取properties配置文件 在類路徑下放置一個application.properties文件，大體內容以下： [html] view plain copy master.ds.driverClassName=com.mysql.jdbc.Driver
master.ds.url=jdbc:mysql://localhost:3306/test
master.ds.username=root
master.ds.password=root
master.ds.filters=stat
master.ds.maxActive=20
master.ds.initialSize=1
master.ds.maxWait=60000
master.ds.minIdle=10
master.ds.timeBetweenEvictionRunsMillis=60000
master.ds.minEvictableIdleTimeMillis=300000
master.ds.validationQuery=SELECT 'x'
master.ds.testWhileIdle=true
master.ds.testOnBorrow=false
master.ds.testOnReturn=false
master.ds.poolPreparedStatements=true
master.ds.maxOpenPreparedStatements=100
master.ds.removeAbandoned=true
master.ds.removeAbandonedTimeout=1800
master.ds.logAbandoned=true

讀取props配置的類，很簡單，基本就是一個pojo/vo類，在類上加載@ConfigurationProperties註解便可。 [java] view plain copy @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;  
}

}

單元測試類 [java] view plain copy @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);  
      
}

}

能夠看到在控制檯輸出的測試內容： [html] view plain copy driverClassName -> com.mysql.jdbc.Driver
url -> jdbc:mysql://localhost:3306/test
username -> root
password -> root
initialSize -> 1
maxWait -> 60000

2.讀取yml配置文件 在類路徑下放置一個application.yml文件，大體內容以下： [html] view plain copy myProps: #自定義的屬性和值
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

讀取yml配置文件的類。 [java] view plain copy @ConfigurationProperties(prefix="myProps") //application.yml中的myProps下的屬性
public class YmlConfig {
private String simpleProp;
private String[] arrayProps;
private List<Map<String, String>> listProp1 = new ArrayList<>(); //接收prop1裏面的屬性值
private List<String> listProp2 = new ArrayList<>(); //接收prop2裏面的屬性值
private Map<String, String> mapProps = new HashMap<>(); //接收prop1裏面的屬性值

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;    
}

}

單元測試類 [java] view plain copy @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()));    


}

}

能夠看到在控制檯輸出的測試內容： [html] view plain copy 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"}

是否是很神奇，不須要spring的applicationContext.xml文件也能夠順利運行之。