mqttAsyncClientnewMqttAsyncClient(ssl://my-example. com:2345,CLIENT_ID,newMemoryPersistence());在 Android 开发重执行上述代码出现如下错误信息java.lang.IllegalArgumentException: Cant parse string to URI ssl://my-example. com:2345问题原因URI 字符串错误异常是 IllegalArgumentException而不是 MqttException源码如下publicMqttAsyncClient(StringserverURI,StringclientId,MqttClientPersistencepersistence)throwsMqttException{this(serverURI,clientId,persistence,null,null);}publicMqttAsyncClient(StringserverURI,StringclientId,MqttClientPersistencepersistence,MqttPingSenderpingSender,ScheduledExecutorServiceexecutorService)throwsMqttException{finalStringmethodNameMqttAsyncClient;log.setResourceName(clientId);if(clientId!null){// Verify that the client ID is not too long// Encode it ourselves to checkByteArrayOutputStreambaosnewByteArrayOutputStream();DataOutputStreamdosnewDataOutputStream(baos);MqttDataTypes.encodeUTF8(dos,clientId);// Remove the two size bytes.if(dos.size()-265535){thrownewIllegalArgumentException(ClientId longer than 65535 characters);}}else{clientId;}mqttConnectionnewMqttConnectionState(clientId);NetworkModuleService.validateURI(serverURI);this.serverURIserverURI;this.mqttSession.setClientId(clientId);this.persistencepersistence;if(this.persistencenull){this.persistencenewMemoryPersistence();}this.executorServiceexecutorService;this.pingSenderpingSender;if(this.pingSendernull){this.pingSendernewTimerPingSender(this.executorService);}// TRACE 101init ClientID{0} ServerURI{1} PersistenceType{2}log.fine(CLASS_NAME,methodName,101,newObject[]{clientId,serverURI,persistence});this.persistence.open(clientId);this.commsnewClientComms(this,this.persistence,this.pingSender,this.executorService,this.mqttSession,this.mqttConnection);this.persistence.close();this.topicsnewHashtableString,MqttTopic();}publicstaticvoidvalidateURI(StringbrokerUri)throwsIllegalArgumentException{try{URIurinewURI(brokerUri);Stringschemeuri.getScheme();if(schemenull||scheme.isEmpty()){thrownewIllegalArgumentException(missing scheme in broker URI: brokerUri);}schemescheme.toLowerCase();synchronized(FACTORY_SERVICE_LOADER){for(NetworkModuleFactoryfactory:FACTORY_SERVICE_LOADER){if(factory.getSupportedUriSchemes().contains(scheme)){factory.validateURI(uri);return;}}}thrownewIllegalArgumentException(no NetworkModule installed for scheme \scheme\ of URI \brokerUri\);}catch(URISyntaxExceptione){thrownewIllegalArgumentException(Cant parse string to URI \brokerUri\,e);}}处理策略确保 URI 字符串格式正确需要同时捕获 MqttException 和 IllegalArgumentException或者可以捕获更通用的 Exceptiontry{mqttAsyncClientnewMqttAsyncClient(ssl://my-example.com:2345,CLIENT_ID,newMemoryPersistence());}catch(IllegalArgumentExceptione){...}catch(MqttExceptione){...}