关于#java#的问题：nested exception is java.lang.IllegalStateException

Question

@Configuration
@MapperScan(basePackages = "com.isafety.project.master.dao", sqlSessionFactoryRef = "masterNewSqlSessionFactory")
public class MasterNewDataSourceConfig {

@Primary // 表示这个数据源是默认数据源, 这个注解必须要加，因为不加的话spring将分不清楚那个为主数据源（默认数据源）
@Bean(name = "masterNewDataSource")
@ConfigurationProperties(prefix = "spring.datasource.master")////读取application.yml中的配置参数映射成为一个对象
public DataSource dataSource() {
    return DataSourceBuilder.create().build();
}

@Primary
@Bean(name = "masterNewSqlSessionFactory")
public MybatisSqlSessionFactoryBean basicSqlSessionFactory(@Qualifier("masterNewDataSource") DataSource basicDataSource) throws Exception {
    MybatisSqlSessionFactoryBean factoryBean = new MybatisSqlSessionFactoryBean();
    factoryBean.setDataSource(basicDataSource);
    factoryBean.setTypeAliasesPackage("com.isafety.project.master.**.domain");
    factoryBean.setVfs(SpringBootVFS.class);
    factoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:/mapper/master/*Mapper.xml"));
    return factoryBean;
}

@Primary
@Bean(name = "masterNewSqlSessionTemplate")
public SqlSessionTemplate testSqlSessionTemplate(@Qualifier("masterNewSqlSessionFactory") SqlSessionFactory sqlSessionFactory) {
    return new SqlSessionTemplate(sqlSessionFactory);
}

Application run failed
org.springframework.boot.context.properties.ConfigurationPropertiesBindException: Error creating bean with name 'masterNewDataSource': Could not bind properties to 'DataSource' : prefix=spring.datasource.master, ignoreInvalidFields=false, ignoreUnknownFields=true; nested exception is java.lang.IllegalStateException: org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@38029349 has been closed already

我配置了两个数据源，启动的时候出现这个问题，请帮我分析一下这是什么问题

Answer 1

这就需要自己debug了，ConfigurationPropertiesBindingPostProcessor这个类实现的绑定过程