【如何在spring-boot中用application.properties制作config类（）】白日放歌须纵酒，青春作伴好还乡。这篇文章主要讲述如何在spring-boot中用application.properties制作config类？相关的知识，希望能为你提供帮助。
我有两个问题。
首先，我在spring-boot中测试了db连接，如下图所示。
@RunWith(SpringJUnit4ClassRunner.class)
public class OracleConnectionTest {
private static final Logger LOGGER = LoggerFactory.getLogger(OracleConnectionTest.class);
private static final String DRIVER = "oracle.jdbc.driver.OracleDriver";
private static final String URL = "jdbc:oracle:thin:@127.0.0.1:1521:orcl";
private static final String USER = "user1";
private static final String PW = "user1";
@Test
public void testConnection() throws ClassNotFoundException {
Class.forName(DRIVER);
try (Connection connection = DriverManager.getConnection(URL, USER, PW)) {
LOGGER.info(String.valueOf(connection));
} catch (SQLException e) {
LOGGER.error(String.valueOf(e));
}
}
}
但是我想把DB信息分离到application.properties文件(resourcesapplication.properties)中去，所以我需要制作JdbcConfig文件(java Bean)。所以我需要制作JdbcConfig文件(java bean)，如下图所示(含测试代码)。
@Getter
@Setter
@Configuration
@ConfigurationProperties(prefix = "spring.datasource")
public class JdbcConfig {
@Value("${driver-class-name}")
private String driverClassName;
@Value("${url}")
private String url;
@Value("${username}")
private String username;
@Value("${password}")
private String password;
@Override
public String toString() {
return "JdbcConfig[" +
"driverClassName=" + driverClassName
+ ", url=" + url
+ ", username=" + username
+ ", password=" + password
+ "]";
}
}
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = {JdbcConfig.class})
public class OracleConnectionTest {
private static final Logger LOGGER = LoggerFactory.getLogger(OracleConnectionTest.class);
@Autowired
private JdbcConfig jdbcConfig;
@Test
public void testConnection() throws ClassNotFoundException {
LOGGER.info("Test: {}", jdbcConfig.toString());
Class.forName(jdbcConfig.getDriverClassName());
try (Connection connection = DriverManager.getConnection(jdbcConfig.getUrl(), jdbcConfig.getUsername(), jdbcConfig.getPassword())) {
LOGGER.info(String.valueOf(connection));
} catch (SQLException e) {
LOGGER.error(String.valueOf(e));
}
}
}
但是，我遇到了
NullPointerException(JdbcConfig) 运行时 testConnection(). 所以我必须这样修改JdbcConfig类。@Getter
@Setter
@Component
@PropertySource("classpath:application.properties")
public class JdbcConfig {
@Value("${spring.datasource.driver-class-name}")
private String driverClassName;
@Value("${spring.datasource.url}")
private String url;
@Value("${spring.datasource.username}")
private String username;
@Value("${spring.datasource.password}")
private String password;
@Override
public String toString() {
return "JdbcConfig[" +
"driverClassName=" + driverClassName
+ ", url=" + url
+ ", username=" + username
+ ", password=" + password
+ "]";
}
}
我不明白为什么
@Configuration &
@ConfigurationProperties 注解不适用。其次，我以为spring-boot会自动创建
DataSource(javax.sql.DataSource) 通过阅读 application.properties. 例如，我的朋友在没有创建DataSource bean(class)的情况下测试成功。但是我遇到了一个错误，就像下面的错误一样，所以我必须创建DataSource bean。Unsatisfied dependency expressed through field 'ds';
nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'javax.sql.DataSource' available
所以我必须创建DataSource bean。我不知道为什么我朋友的代码不创建bean(DataSource)就能自动运行，而我却不一样。我的代码如下。
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = DataSourceConfig.class)
public class DataSourceTest {
private static final Logger LOGGER = LoggerFactory.getLogger(DataSourceTest.class);
@Autowired
private DataSource ds;
// DataSource &
DriverManagerDataSource@Test
public void testConnection() throws Exception {
try (Connection con = ds.getConnection()) {
LOGGER.info(String.valueOf(con));
} catch (Exception e) {
e.printStackTrace();
}
}
}
@Configuration
@Import(JdbcConfig.class)
public class DataSourceConfig {
private static final Logger LOGGER = LoggerFactory.getLogger(DataSourceConfig.class);
@Bean
public DataSource dataSource(JdbcConfig jdbcConfig) {
LOGGER.debug("Test: {}", jdbcConfig.toString());
DriverManagerDataSource dataSource = new DriverManagerDataSource();
dataSource.setDriverClassName(jdbcConfig.getDriverClassName());
dataSource.setUrl(jdbcConfig.getUrl());
dataSource.setUsername(jdbcConfig.getUsername());
dataSource.setPassword(jdbcConfig.getPassword());
return dataSource;
}
}
谢谢你阅读我的长文。
添加一个属性文件(application.properties)
# JSP
spring.mvc.view.prefix = /WEB-INF/jsp/
spring.mvc.view.suffix = .jsp# language setting
spring.http.encoding.charset = UTF-8
spring.http.encoding.enabled = true
spring.http.encoding.force = true# Database Info
spring.datasource.driver-class-name = oracle.jdbc.driver.OracleDriver
spring.datasource.url = jdbc:oracle:thin:@127.0.0.1:1521:orcl
spring.datasource.username = user1
spring.datasource.password = user1
答案所有你需要的。
@Getter
@Setter
@ConfigurationProperties(prefix = "spring.datasource")
+
@EnableConfigurationProperties(YourPropertiesClass.class) 在任何配置类上如果你使用的是Spring Boot 2.+，那么即使是这个也是多余的。发行说明 更多
需要增加
@ConfigurationPropertiesScan 现在推荐阅读
- 在JavaAndroid中获取开始和结束的一天的纪元第二。
- 在android studio中引用Firestore
- Sqlite表在小米Note 7s上不创建，但在其他手机和Android Studio中的虚拟设备上创建。
- Apple为什么说iPhone应用程序使用MVC（）
- 如何在Android Studio中将Pdf文件转换为文本
- 在Odoo中的Many2Many字段插入请求在android中不起作用
- App爬虫----adb的使用
- pi币可期（区块链，派币），app翻译
- ESP8266环境监测系统+制作手机App在线实时显示