dubbo 的服务由 ServiceBean 暴露，ServiceBean的层次结构：
ServiceBean 实现了 InitializingBean，InitializingBean 接口的作用不必多说，实现了 InitializingBean 的 bean ，Spring 会在填充 bean 的属性之后调用它的 afterPropertiesSet 方法：
ServiceBean：
public void afterPropertiesSet() throws Exception {
// 判断是否解析过 provider 配置，解析过则不再解析
if (getProvider() == null) {
// 获取所有 ProviderConfig 类型的 bean
Map<String, ProviderConfig> providerConfigMap = applicationContext == null ? null : BeanFactoryUtils.beansOfTypeIncludingAncestors(applicationContext, ProviderConfig.class, false, false);
if (providerConfigMap != null && providerConfigMap.size() > 0) {
// 获取所有 ProtocolConfig 类型的 bean
Map<String, ProtocolConfig> protocolConfigMap = applicationContext == null ? null : BeanFactoryUtils.beansOfTypeIncludingAncestors(applicationContext, ProtocolConfig.class, false, false);
// 向后兼容，判断是否 protocol 为空并且 provider 不为空
if ((protocolConfigMap == null || protocolConfigMap.size() == 0)
&& providerConfigMap.size() > 1) {
List<ProviderConfig> providerConfigs = new ArrayList<ProviderConfig>();
for (ProviderConfig config : providerConfigMap.values()) {
if (config.isDefault() != null && config.isDefault().booleanValue()) {
// 添加默认的 ProviderConfig
providerConfigs.add(config);
}
}
if (providerConfigs.size() > 0) {
// 将 ProviderConfig 转换为 ProtocolConfig 赋值给 protocols 成员属性
setProviders(providerConfigs);
}
} else {
ProviderConfig providerConfig = null;
for (ProviderConfig config : providerConfigMap.values()) {
if (config.isDefault() == null || config.isDefault().booleanValue()) {
// 默认的 ProviderConfig 只能有一个
if (providerConfig != null) {
throw new IllegalStateException("Duplicate provider configs: " + providerConfig + " and " + config);
}
providerConfig = config;
}
}
if (providerConfig != null) {
// 设置 provider 配置
setProvider(providerConfig);
}
}
}
}
// 判断是否解析过 application 配置，解析过则不再解析
if (getApplication() == null
&& (getProvider() == null || getProvider().getApplication() == null)) {
// 获取所有 ApplicationConfig 类型的 bean
Map<String, ApplicationConfig> applicationConfigMap = applicationContext == null ? null : BeanFactoryUtils.beansOfTypeIncludingAncestors(applicationContext, ApplicationConfig.class, false, false);
if (applicationConfigMap != null && applicationConfigMap.size() > 0) {
ApplicationConfig applicationConfig = null;
for (ApplicationConfig config : applicationConfigMap.values()) {
if (config.isDefault() == null || config.isDefault().booleanValue()) {
// 默认的 ApplicationConfig 只能有一个
if (applicationConfig != null) {
throw new IllegalStateException("Duplicate application configs: " + applicationConfig + " and " + config);
}
applicationConfig = config;
}
}
if (applicationConfig != null) {
// 设置 application 配置
setApplication(applicationConfig);
}
}
}
// 判断是否解析过 module 配置，解析过则不再解析
if (getModule() == null
&& (getProvider() == null || getProvider().getModule() == null)) {
// 获取所有 ModuleConfig 类型的 bean
Map<String, ModuleConfig> moduleConfigMap = applicationContext == null ? null : BeanFactoryUtils.beansOfTypeIncludingAncestors(applicationContext, ModuleConfig.class, false, false);
if (moduleConfigMap != null && moduleConfigMap.size() > 0) {
ModuleConfig moduleConfig = null;
for (ModuleConfig config : moduleConfigMap.values()) {
if (config.isDefault() == null || config.isDefault().booleanValue()) {
// 默认的 ModuleConfig 只能有一个
if (moduleConfig != null) {
throw new IllegalStateException("Duplicate module configs: " + moduleConfig + " and " + config);
}
moduleConfig = config;
}
}
if (moduleConfig != null) {
// 设置 module 配置
setModule(moduleConfig);
}
}
}
// 判断是否解析过 registry 配置，解析过则不再解析
if ((getRegistries() == null || getRegistries().size() == 0)
&& (getProvider() == null || getProvider().getRegistries() == null || getProvider().getRegistries().size() == 0)
&& (getApplication() == null || getApplication().getRegistries() == null || getApplication().getRegistries().size() == 0)) {
// 获取所有 RegistryConfig 类型的 bean
Map<String, RegistryConfig> registryConfigMap = applicationContext == null ? null : BeanFactoryUtils.beansOfTypeIncludingAncestors(applicationContext, RegistryConfig.class, false, false);
if (registryConfigMap != null && registryConfigMap.size() > 0) {
List<RegistryConfig> registryConfigs = new ArrayList<RegistryConfig>();
for (RegistryConfig config : registryConfigMap.values()) {
if (config.isDefault() == null || config.isDefault().booleanValue()) {
// 添加 RegistryConfig 配置
registryConfigs.add(config);
}
}
if (registryConfigs != null && registryConfigs.size() > 0) {
// 设置 registry 配置
super.setRegistries(registryConfigs);
}
}
}
// 判断是否解析过 monitor 配置，解析过则不再解析
if (getMonitor() == null
&& (getProvider() == null || getProvider().getMonitor() == null)
&& (getApplication() == null || getApplication().getMonitor() == null)) {
// 获取所有 MonitorConfig 类型的 bean
Map<String, MonitorConfig> monitorConfigMap = applicationContext == null ? null : BeanFactoryUtils.beansOfTypeIncludingAncestors(applicationContext, MonitorConfig.class, false, false);
if (monitorConfigMap != null && monitorConfigMap.size() > 0) {
MonitorConfig monitorConfig = null;
for (MonitorConfig config : monitorConfigMap.values()) {
if (config.isDefault() == null || config.isDefault().booleanValue()) {
// 默认的 MonitorConfig 只能有一个
if (monitorConfig != null) {
throw new IllegalStateException("Duplicate monitor configs: " + monitorConfig + " and " + config);
}
monitorConfig = config;
}
}
if (monitorConfig != null) {
// 设置 monitor 配置
setMonitor(monitorConfig);
}
}
}
// 判断是否解析过 protocol 配置，解析过则不再解析
if ((getProtocols() == null || getProtocols().size() == 0)
&& (getProvider() == null || getProvider().getProtocols() == null || getProvider().getProtocols().size() == 0)) {
// 获取所有 ProtocolConfig 类型的bean
Map<String, ProtocolConfig> protocolConfigMap = applicationContext == null ? null : BeanFactoryUtils.beansOfTypeIncludingAncestors(applicationContext, ProtocolConfig.class, false, false);
if (protocolConfigMap != null && protocolConfigMap.size() > 0) {
List<ProtocolConfig> protocolConfigs = new ArrayList<ProtocolConfig>();
for (ProtocolConfig config : protocolConfigMap.values()) {
if (config.isDefault() == null || config.isDefault().booleanValue()) {
// 添加 ProtocolConfig 配置
protocolConfigs.add(config);
}
}
if (protocolConfigs != null && protocolConfigs.size() > 0) {
// 设置 protocol 配置
super.setProtocols(protocolConfigs);
}
}
}
// 判断是否解析过 path 配置，解析过则不再解析
if (getPath() == null || getPath().length() == 0) {
// interface 就是我们配置的 interface
if (beanName != null && beanName.length() > 0
&& getInterface() != null && getInterface().length() > 0
&& beanName.startsWith(getInterface())) {
// 检查 beanName 的格式（长度、正则）并设置为 path
setPath(beanName);
}
}
if (!isDelay()) {
/* 没有设置延迟暴露则直接暴露 */
export();
}
}
ServiceConfig：
public synchronized void export() {
if (provider != null) {
// 确定是否暴露过
if (export == null) {
export = provider.getExport();
}
// 确定是否延迟暴露
if (delay == null) {
delay = provider.getDelay();
}
}
// 暴露过不在暴露
if (export != null && !export) {
return;
}
// 延迟暴露
if (delay != null && delay > 0) {
delayExportExecutor.schedule(new Runnable() {
public void run() {
/* 作为 ScheduledExecutorService 的一个作业进行暴露 */
doExport();
}
}, delay, TimeUnit.MILLISECONDS);
} else {
/* 暴露 */
doExport();
}
}
ServiceConfig：
protected synchronized void doExport() {
if (unexported) {
throw new IllegalStateException("Already unexported!");
}
// 暴露过直接返回
if (exported) {
return;
}
exported = true;
if (interfaceName == null || interfaceName.length() == 0) {
throw new IllegalStateException("<dubbo:service interface="" /> interface not allow null!");
}
/* 检查默认配置 */
checkDefault();
// 下面为一些配置成员属性的赋值
if (provider != null) {
if (application == null) {
application = provider.getApplication();
}
if (module == null) {
module = provider.getModule();
}
if (registries == null) {
registries = provider.getRegistries();
}
if (monitor == null) {
monitor = provider.getMonitor();
}
if (protocols == null) {
protocols = provider.getProtocols();
}
}
if (module != null) {
if (registries == null) {
registries = module.getRegistries();
}
if (monitor == null) {
monitor = module.getMonitor();
}
}
if (application != null) {
if (registries == null) {
registries = application.getRegistries();
}
if (monitor == null) {
monitor = application.getMonitor();
}
}
// 泛化调用判断
if (ref instanceof GenericService) {
interfaceClass = GenericService.class;
if (StringUtils.isEmpty(generic)) {
generic = Boolean.TRUE.toString();
}
} else {
try {
interfaceClass = Class.forName(interfaceName, true, Thread.currentThread()
.getContextClassLoader());
} catch (ClassNotFoundException e) {
throw new IllegalStateException(e.getMessage(), e);
}
// 检查接口和方法，接口不能为 null 并且必须是 interface，方法必须属于接口
checkInterfaceAndMethods(interfaceClass, methods);
// 检查 ref 配置，不能为 null，并且必须是配置的接口的实现类
checkRef();
generic = Boolean.FALSE.toString();
}
if (local != null) {
if ("true".equals(local)) {
local = interfaceName + "Local";
}
Class<?> localClass;
try {
localClass = ClassHelper.forNameWithThreadContextClassLoader(local);
} catch (ClassNotFoundException e) {
throw new IllegalStateException(e.getMessage(), e);
}
if (!interfaceClass.isAssignableFrom(localClass)) {
throw new IllegalStateException("The local implementation class " + localClass.getName() + " not implement interface " + interfaceName);
}
}
if (stub != null) {
if ("true".equals(stub)) {
stub = interfaceName + "Stub";
}
Class<?> stubClass;
try {
stubClass = ClassHelper.forNameWithThreadContextClassLoader(stub);
} catch (ClassNotFoundException e) {
throw new IllegalStateException(e.getMessage(), e);
}
if (!interfaceClass.isAssignableFrom(stubClass)) {
throw new IllegalStateException("The stub implementation class " + stubClass.getName() + " not implement interface " + interfaceName);
}
}
/* 检查 application 配置 */
checkApplication();
/* 检查 registry 配置 */
checkRegistry();
/* 检查 protocol 配置 */
checkProtocol();
/* 追加 properties 配置 */
appendProperties(this);
/* 检查 stub、mock 配置 */
checkStubAndMock(interfaceClass);
if (path == null || path.length() == 0) {
path = interfaceName;
}
/* 暴露 url */
doExportUrls();
// 构造 ProviderModel，将服务的方法封装成 ProviderMethodModel 保存到集合中，并将集合与方法名称做映射保存
ProviderModel providerModel = new ProviderModel(getUniqueServiceName(), this, ref);
// 获取服务唯一名称，注册到已提供服务列表中
ApplicationModel.initProviderModel(getUniqueServiceName(), providerModel);
}
ServiceConfig：
private void checkDefault() {
if (provider == null) {
provider = new ProviderConfig();
}
/* 追加 properties 配置 */
appendProperties(provider);
}
AbstractConfig：
protected static void appendProperties(AbstractConfig config) {
if (config == null) {
return;
}
// 获取标签名称（config 名称除去 Config 或 Bean 后缀转成小写，例如 ProviderConfig --> provider、ServiceBean --> service），拼接前缀，eg：ProviderConfig --> dubbo.provider.
String prefix = "dubbo." + getTagName(config.getClass()) + ".";
Method[] methods = config.getClass().getMethods();
for (Method method : methods) {
try {
String name = method.getName();
// 判断 setter 方法访问修饰符为 public 并且参数只有一个且是基本类型（包括包装类型、String 和 Object）
if (name.length() > 3 && name.startsWith("set") && Modifier.isPublic(method.getModifiers())
&& method.getParameterTypes().length == 1 && isPrimitive(method.getParameterTypes()[0])) {
// 将 setter 驼峰命名去掉 set 后转成.连接的命名，如 setDumpDirectory --> dump.directory
String property = StringUtils.camelToSplitName(name.substring(3, 4).toLowerCase() + name.substring(4), ".");
String value = null;
if (config.getId() != null && config.getId().length() > 0) {
// 如果 id 属性不为空，携带 id 拼接 key 尝试从系统属性中获取相关配置
String pn = prefix + config.getId() + "." + property;
value = System.getProperty(pn);
if (!StringUtils.isBlank(value)) {
logger.info("Use System Property " + pn + " to config dubbo");
}
}
if (value == null || value.length() == 0) {
// 如果 id 属性为空，不带 id 拼接 key 尝试从系统属性中获取相关配置
String pn = prefix + property;
value = System.getProperty(pn);
if (!StringUtils.isBlank(value)) {
logger.info("Use System Property " + pn + " to config dubbo");
}
}
if (value == null || value.length() == 0) {
Method getter;
try {
// 如果从系统属性中没有获取到配置，则尝试获取响应 getter 方法
getter = config.getClass().getMethod("get" + name.substring(3), new Class<?>[0]);
} catch (NoSuchMethodException e) {
try {
// boolean 类型的属性的 getter 方法可能以 is 开头
getter = config.getClass().getMethod("is" + name.substring(3), new Class<?>[0]);
} catch (NoSuchMethodException e2) {
getter = null;
}
}
if (getter != null) {
// 判断调用 getter 方法的返回值是否为 null
if (getter.invoke(config, new Object[0]) == null) {
if (config.getId() != null && config.getId().length() > 0) {
/* 如果 id 属性不为空，携带 id 拼接 key 尝试获取相关配置 */
value = ConfigUtils.getProperty(prefix + config.getId() + "." + property);
}
if (value == null || value.length() == 0) {
/* 如果 value 为空，不带 id 拼接 key 尝试获取相关配置 */
value = ConfigUtils.getProperty(prefix + property);
}
if (value == null || value.length() == 0) {
// 从预制的 key 映射中获取 key
String legacyKey = legacyProperties.get(prefix + property);
if (legacyKey != null && legacyKey.length() > 0) {
/* 尝试获取配置并转换（dubbo.service.max.retry.providers 和dubbo.service.allow.no.provider 两个配置需要转换） */
value = convertLegacyValue(legacyKey, ConfigUtils.getProperty(legacyKey));
}
}
}
}
}
if (value != null && value.length() > 0) {
// 如果到这里 value 不为空，则调用 setter 方法为属性赋值
method.invoke(config, new Object[]{convertPrimitive(method.getParameterTypes()[0], value)});
}
}
} catch (Exception e) {
logger.error(e.getMessage(), e);
}
}
}
ConfigUtils：
public static String getProperty(String key) {
/* 获取配置 */
return getProperty(key, null);
}
ConfigUtils：
public static String getProperty(String key, String defaultValue) {
String value = System.getProperty(key);
if (value != null && value.length() > 0) {
return value;
}
/* 获取 properties 配置 */
Properties properties = getProperties();
/* 将$和${}表达式替换为对应配置 */
return replaceProperty(properties.getProperty(key, defaultValue), (Map) properties);
}
ConfigUtils：
public static String replaceProperty(String expression, Map<String, String> params) {
// 表达式不含$忽略
if (expression == null || expression.length() == 0 || expression.indexOf('$') < 0) {
return expression;
}
// 正则为$s*{?s*([._0-9a-zA-Z]+)s*}?
Matcher matcher = VARIABLE_PATTERN.matcher(expression);
StringBuffer sb = new StringBuffer();
while (matcher.find()) {
String key = matcher.group(1);
// 首先尝试从系统属性中获取
String value = System.getProperty(key);
if (value == null && params != null) {
// 没有再尝试从 properties 中获取
value = params.get(key);
}
if (value == null) {
value = "";
}
// 替换表达式为配置值
matcher.appendReplacement(sb, Matcher.quoteReplacement(value));
}
matcher.appendTail(sb);
return sb.toString();
}
AbstractInterfaceConfig：
protected void checkApplication() {
// 向后兼容
if (application == null) {
// 没有 application 配置则尝试从系统属性中获取
String applicationName = ConfigUtils.getProperty("dubbo.application.name");
if (applicationName != null && applicationName.length() > 0) {
application = new ApplicationConfig();
}
}
// 没有配置 <dubbo:application/> 并且系统属性中也没有，则抛出异常
if (application == null) {
throw new IllegalStateException(
"No such application config! Please add <dubbo:application name="..." /> to your spring config.");
}
// 追加配置
appendProperties(application);
// 如果配置了 shutdown wait，设置到系统属性中
String wait = ConfigUtils.getProperty(Constants.SHUTDOWN_WAIT_KEY);
if (wait != null && wait.trim().length() > 0) {
System.setProperty(Constants.SHUTDOWN_WAIT_KEY, wait.trim());
} else {
wait = ConfigUtils.getProperty(Constants.SHUTDOWN_WAIT_SECONDS_KEY);
if (wait != null && wait.trim().length() > 0) {
System.setProperty(Constants.SHUTDOWN_WAIT_SECONDS_KEY, wait.trim());
}
}
}
AbstractInterfaceConfig：
protected void checkRegistry() {
// 向后兼容
if (registries == null || registries.size() == 0) {
// 获取 registry 配置
String address = ConfigUtils.getProperty("dubbo.registry.address");
if (address != null && address.length() > 0) {
registries = new ArrayList<RegistryConfig>();
String[] as = address.split("\s*[|]+\s*");
for (String a : as) {
RegistryConfig registryConfig = new RegistryConfig();
registryConfig.setAddress(a);
// 有相关配置，增加到集合中
registries.add(registryConfig);
}
}
}
// registry 不能为空
if ((registries == null || registries.size() == 0)) {
throw new IllegalStateException((getClass().getSimpleName().startsWith("Reference")
? "No such any registry to refer service in consumer "
: "No such any registry to export service in provider ")
+ NetUtils.getLocalHost()
+ " use dubbo version "
+ Version.getVersion()
+ ", Please add <dubbo:registry address="..." /> to your spring config. If you want unregister, please set <dubbo:service registry="N/A" />");
}
for (RegistryConfig registryConfig : registries) {
// 追加配置
appendProperties(registryConfig);
}
}
ServiceConfig：
private void checkProtocol() {
if ((protocols == null || protocols.size() == 0)
&& provider != null) {
setProtocols(provider.getProtocols());
}
// 向后兼容
if (protocols == null || protocols.size() == 0) {
setProtocol(new ProtocolConfig());
}
for (ProtocolConfig protocolConfig : protocols) {
if (StringUtils.isEmpty(protocolConfig.getName())) {
protocolConfig.setName("dubbo");
}
// 追加配置
appendProperties(protocolConfig);
}
}
AbstractInterfaceConfig：
protected void checkStubAndMock(Class<?> interfaceClass) {
if (ConfigUtils.isNotEmpty(local)) {
// 缺省类名，即：接口名 + Local 后缀
Class<?> localClass = ConfigUtils.isDefault(local) ? ReflectUtils.forName(interfaceClass.getName() + "Local") : ReflectUtils.forName(local);
// 必须实现服务接口
if (!interfaceClass.isAssignableFrom(localClass)) {
throw new IllegalStateException("The local implementation class " + localClass.getName() + " not implement interface " + interfaceClass.getName());
}
try {
// 构造函数必须允许传入服务对象
ReflectUtils.findConstructor(localClass, interfaceClass);
} catch (NoSuchMethodException e) {
throw new IllegalStateException("No such constructor "public " + localClass.getSimpleName() + "(" + interfaceClass.getName() + ")" in local implementation class " + localClass.getName());
}
}
if (ConfigUtils.isNotEmpty(stub)) {
// 缺省类名，即：接口名 + Stub 后缀
Class<?> localClass = ConfigUtils.isDefault(stub) ? ReflectUtils.forName(interfaceClass.getName() + "Stub") : ReflectUtils.forName(stub);
// 必须实现服务接口
if (!interfaceClass.isAssignableFrom(localClass)) {
throw new IllegalStateException("The local implementation class " + localClass.getName() + " not implement interface " + interfaceClass.getName());
}
try {
// 构造函数必须允许传入服务对象
ReflectUtils.findConstructor(localClass, interfaceClass);
} catch (NoSuchMethodException e) {
throw new IllegalStateException("No such constructor "public " + localClass.getSimpleName() + "(" + interfaceClass.getName() + ")" in local implementation class " + localClass.getName());
}
}
if (ConfigUtils.isNotEmpty(mock)) {
if (mock.startsWith(Constants.RETURN_PREFIX)) {
String value = mock.substring(Constants.RETURN_PREFIX.length());
try {
// 如果是 return 作为前缀，则解析mock的值（值可以为 empty、null、true、false、json 字符串等）
MockInvoker.parseMockValue(value);
} catch (Exception e) {
throw new IllegalStateException("Illegal mock json value in <dubbo:service ... mock="" + mock + "" />");
}
} else {
// 缺省类名，即：接口名 + Mock 后缀
Class<?> mockClass = ConfigUtils.isDefault(mock) ? ReflectUtils.forName(interfaceClass.getName() + "Mock") : ReflectUtils.forName(mock);
// 必须实现服务接口
if (!interfaceClass.isAssignableFrom(mockClass)) {
throw new IllegalStateException("The mock implementation class " + mockClass.getName() + " not implement interface " + interfaceClass.getName());
}
try {
// 需要有无参构造函数
mockClass.getConstructor(new Class<?>[0]);
} catch (NoSuchMethodException e) {
throw new IllegalStateException("No such empty constructor "public " + mockClass.getSimpleName() + "()" in mock implementation class " + mockClass.getName());
}
}
}
}
ServiceConfig：
private void doExportUrls() {
/* 加载注册中心配置 */
List<URL> registryURLs = loadRegistries(true);
for (ProtocolConfig protocolConfig : protocols) {
/* 为每个协议暴露服务 */
doExportUrlsFor1Protocol(protocolConfig, registryURLs);
}
}
AbstractInterfaceConfig：
protected List<URL> loadRegistries(boolean provider) {
/* 检查 registry 配置 */
checkRegistry();
List<URL> registryList = new ArrayList<URL>();
if (registries != null && registries.size() > 0) {
for (RegistryConfig config : registries) {
String address = config.getAddress();
if (address == null || address.length() == 0) {
// 0.0.0.0
address = Constants.ANYHOST_VALUE;
}
// 获取系统属性的注册中心地址配置
String sysaddress = System.getProperty("dubbo.registry.address");
if (sysaddress != null && sysaddress.length() > 0) {
address = sysaddress;
}
if (address != null && address.length() > 0
&& !RegistryConfig.NO_AVAILABLE.equalsIgnoreCase(address)) {
Map<String, String> map = new HashMap<String, String>();
/* 追加参数 */
appendParameters(map, application);
/* 追加参数 */
appendParameters(map, config);
map.put("path", RegistryService.class.getName());
map.put("dubbo", Version.getVersion());
map.put(Constants.TIMESTAMP_KEY, String.valueOf(System.currentTimeMillis()));
if (ConfigUtils.getPid() > 0) {
// 尝试通过 java API 获取进程 id 并记录
map.put(Constants.PID_KEY, String.valueOf(ConfigUtils.getPid()));
}
if (!map.containsKey("protocol")) {
// 判断是否有 remote 扩展，这里涉及到 dubbo SPI 的内容，我们会用单独的文章进行分析
if (ExtensionLoader.getExtensionLoader(RegistryFactory.class).hasExtension("remote")) {
map.put("protocol", "remote");
} else {
map.put("protocol", "dubbo");
}
}
/* 解析 URL */
List<URL> urls = UrlUtils.parseURLs(address, map);
for (URL url : urls) {
url = url.addParameter(Constants.REGISTRY_KEY, url.getProtocol());
url = url.setProtocol(Constants.REGISTRY_PROTOCOL);
if ((provider && url.getParameter(Constants.REGISTER_KEY, true))
|| (!provider && url.getParameter(Constants.SUBSCRIBE_KEY, true))) {
// 添加注册中心地址
registryList.add(url);
}
}
}
}
}
return registryList;
}
AbstractConfig：
protected static void appendParameters(Map<String, String> parameters, Object config) {
/* 追加参数 */
appendParameters(parameters, config, null);
}
AbstractConfig：
protected static void appendParameters(Map<String, String> parameters, Object config, String prefix) {
if (config == null) {
return;
}
Method[] methods = config.getClass().getMethods();
for (Method method : methods) {
try {
String name = method.getName();
// getter 方法，过滤掉 getClass 方法，public 修饰符并且没有参数并且返回值为基本类型（包括 String、包装类和 Object）
if ((name.startsWith("get") || name.startsWith("is"))
&& !"getClass".equals(name)
&& Modifier.isPublic(method.getModifiers())
&& method.getParameterTypes().length == 0
&& isPrimitive(method.getReturnType())) {
Parameter parameter = method.getAnnotation(Parameter.class);
// 忽略返回值类型为 Object 或注解 excluded 属性设置为 true 的 getter 方法
if (method.getReturnType() == Object.class || parameter != null && parameter.excluded()) {
continue;
}
int i = name.startsWith("get") ? 3 : 2;
// 将 getter 驼峰命名去掉 get 或 is 后转成.连接的命名，如 getDumpDirectory --> dump.directory
String prop = StringUtils.camelToSplitName(name.substring(i, i + 1).toLowerCase() + name.substring(i + 1), ".");
String key;
// 确定 key 的值，注解的 key 属性值优先
if (parameter != null && parameter.key() != null && parameter.key().length() > 0) {
key = parameter.key();
} else {
key = prop;
}
// 执行 getter 方法获取返回值
Object value = method.invoke(config, new Object[0]);
String str = String.valueOf(value).trim();
if (value != null && str.length() > 0) {
if (parameter != null && parameter.escaped()) {
// URL 编码
str = URL.encode(str);
}
if (parameter != null && parameter.append()) {
// 注解设置了追加属性，则追加前缀
String pre = (String) parameters.get(Constants.DEFAULT_KEY + "." + key);
if (pre != null && pre.length() > 0) {
str = pre + "," + str;
}
pre = (String) parameters.get(key);
if (pre != null && pre.length() > 0) {
str = pre + "," + str;
}
}
if (prefix != null && prefix.length() > 0) {
key = prefix + "." + key;
}
// 设置参数映射
parameters.put(key, str);
} else if (parameter != null && parameter.required()) {
throw new IllegalStateException(config.getClass().getSimpleName() + "." + key + " == null");
}
// getParameters 方法
} else if ("getParameters".equals(name)
&& Modifier.isPublic(method.getModifiers())
&& method.getParameterTypes().length == 0
&& method.getReturnType() == Map.class) {
// 执行方法获取返回值
Map<String, String> map = (Map<String, String>) method.invoke(config, new Object[0]);
if (map != null && map.size() > 0) {
String pre = (prefix != null && prefix.length() > 0 ? prefix + "." : "");
for (Map.Entry<String, String> entry : map.entrySet()) {
// 将 key 的-替换为.并追加指定的前缀，重新设置参数映射
parameters.put(pre + entry.getKey().replace('-', '.'), entry.getValue());
}
}
}
} catch (Exception e) {
throw new IllegalStateException(e.getMessage(), e);
}
}
}
UrlUtils：
public static List<URL> parseURLs(String address, Map<String, String> defaults) {
if (address == null || address.length() == 0) {
return null;
}
// 分割地址
String[] addresses = Constants.REGISTRY_SPLIT_PATTERN.split(address);
if (addresses == null || addresses.length == 0) {
return null;
}
List<URL> registries = new ArrayList<URL>();
for (String addr : addresses) {
registries.add(parseURL(addr, defaults));
}
return registries;
}
UrlUtils：
public static URL parseURL(String address, Map<String, String> defaults) {
if (address == null || address.length() == 0) {
return null;
}
String url;
if (address.indexOf(":// ") >= 0) {
url = address;
} else {
String[] addresses = Constants.COMMA_SPLIT_PATTERN.split(address);
url = addresses[0];
if (addresses.length > 1) {
StringBuilder backup = new StringBuilder();
for (int i = 1; i < addresses.length; i++) {
if (i > 1) {
backup.append(",");
}
backup.append(addresses[i]);
}
// 设置 backup，如192.168.1.1,192.168.1.2 --> 192.168.1.1?backup=192.168.1.2
url += "?" + Constants.BACKUP_KEY + "=" + backup.toString();
}
}
String defaultProtocol = defaults == null ? null : defaults.get("protocol");
if (defaultProtocol == null || defaultProtocol.length() == 0) {
// 默认协议为 dubbo
defaultProtocol = "dubbo";
}
// 获取一些默认配置
String defaultUsername = defaults == null ? null : defaults.get("username");
String defaultPassword = defaults == null ? null : defaults.get("password");
int defaultPort = StringUtils.parseInteger(defaults == null ? null : defaults.get("port"));
String defaultPath = defaults == null ? null : defaults.get("path");
Map<String, String> defaultParameters = defaults == null ? null : new HashMap<String, String>(defaults);
if (defaultParameters != null) {
defaultParameters.remove("protocol");
defaultParameters.remove("username");
defaultParameters.remove("password");
defaultParameters.remove("host");
defaultParameters.remove("port");
defaultParameters.remove("path");
}
// 将 url 解析成 URL 对象
URL u = URL.valueOf(url);
boolean changed = false;
String protocol = u.getProtocol();
String username = u.getUsername();
String password = u.getPassword();
String host = u.getHost();
int port = u.getPort();
String path = u.getPath();
Map<String, String> parameters = new HashMap<String, String>(u.getParameters());
// 判断几个属性的值是否为空，如果为空赋为默认值
if ((protocol == null || protocol.length() == 0) && defaultProtocol != null && defaultProtocol.length() > 0) {
changed = true;
protocol = defaultProtocol;
}
if ((username == null || username.length() == 0) && defaultUsername != null && defaultUsername.length() > 0) {
changed = true;
username = defaultUsername;
}
if ((password == null || password.length() == 0) && defaultPassword != null && defaultPassword.length() > 0) {
changed = true;
password = defaultPassword;
}
if (port <= 0) {
if (defaultPort > 0) {
changed = true;
port = defaultPort;
} else {
changed = true;
port = 9090;
}
}
if (path == null || path.length() == 0) {
if (defaultPath != null && defaultPath.length() > 0) {
changed = true;
path = defaultPath;
}
}
if (defaultParameters != null && defaultParameters.size() > 0) {
for (Map.Entry<String, String> entry : defaultParameters.entrySet()) {
String key = entry.getKey();
String defaultValue = entry.getValue();
if (defaultValue != null && defaultValue.length() > 0) {
String value = parameters.get(key);
if (value == null || value.length() == 0) {
changed = true;
parameters.put(key, defaultValue);
}
}
}
}
if (changed) {
// 如果属性值有改变，则用新的属性值构建新的 URL 对象
u = new URL(protocol, username, password, host, port, path, parameters);
}
return u;
}
到这里，整个 dubbo provider 初始化的源码分析就完成了。