Debug SourceCode - shi-yuan/dynamic-datasource-spring-boot-starter GitHub Wiki

1. 开启动态数据源的debug日志。

logging:
  level:
    com.baomidou.dynamic: debug

检查日志输出是否正确。

2. 断点调试DynamicDataSourceAnnotationInterceptor。

public class DynamicDataSourceAnnotationInterceptor implements MethodInterceptor {

    /**
     * SPEL参数标识
     */
    private static final String DYNAMIC_PREFIX = "#";

    @Setter
    private DsProcessor dsProcessor;

    private DynamicDataSourceClassResolver dynamicDataSourceClassResolver = new DynamicDataSourceClassResolver();

    @Override
    public Object invoke(MethodInvocation invocation) throws Throwable {
        try {
            //这里把获取到的数据源标识如master存入本地线程
            DynamicDataSourceContextHolder.push(determineDatasource(invocation));
            return invocation.proceed();
        } finally {
            DynamicDataSourceContextHolder.poll();
        }
    }

    private String determineDatasource(MethodInvocation invocation) throws Throwable {
        //此处打断点
        //获得DS注解的方法
       ● Method method = invocation.getMethod();
        //获得方法上的DS注解。
        Class<?> declaringClass = dynamicDataSourceClassResolver.targetClass(invocation);
        DS ds = method.isAnnotationPresent(DS.class) ? method.getAnnotation(DS.class)
                : AnnotationUtils.findAnnotation(declaringClass, DS.class);
        //获得DS注解的内容
        String key = ds.value();
        //如果DS注解内容是以#开头解析动态最终值否则直接返回
        return (!key.isEmpty() && key.startsWith(DYNAMIC_PREFIX)) ? dsProcessor.determineDatasource(invocation, key) : key;
    }
}

3. 断点调试DynamicRoutingDataSource。

public class DynamicRoutingDataSource extends AbstractRoutingDataSource {


    private static final String UNDERLINE = "_";
    @Setter
    protected DynamicDataSourceProvider provider;
    @Setter
    protected Class<? extends DynamicDataSourceStrategy> strategy;
    @Setter
    protected String primary;
    protected boolean p6spy;
    /**
     * 所有数据库
     */
    private Map<String, DataSource> dataSourceMap = new LinkedHashMap<>();
    /**
     * 分组数据库
     */
    private Map<String, DynamicGroupDataSource> groupDataSources = new ConcurrentHashMap<>();

    @Override
    public DataSource determineDataSource() {
        //从本地线程获取key解析最终真实的数据源
       ●  return getDataSource(DynamicDataSourceContextHolder.peek());
    }

    private DataSource determinePrimaryDataSource() {
        log.debug("从默认数据源中返回数据");
        return groupDataSources.containsKey(primary) ? groupDataSources.get(primary).determineDataSource() : dataSourceMap.get(primary);
    }


    /**
     * 获取数据源
     *
     * @param ds 数据源名称
     * @return 数据源
     */
    public DataSource getDataSource(String ds) {
        if (StringUtils.isEmpty(ds)) {
            return determinePrimaryDataSource();
        } else if (!groupDataSources.isEmpty() && groupDataSources.containsKey(ds)) {
            log.debug("从 {} 组数据源中返回数据源", ds);
            return groupDataSources.get(ds).determineDataSource();
        } else if (dataSourceMap.containsKey(ds)) {
            log.debug("从 {} 单数据源中返回数据源", ds);
            return dataSourceMap.get(ds);
        }
        return determinePrimaryDataSource();
    }
}