Mysql JDBC驱动源码分析(socket的连接创建)三

Socket的连接创建

代码往下调试进入ConnectionImp下的createNewIO()方法

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public synchronized void createNewIO(boolean isForReconnect)throws SQLException {Properties mergedProps  = exposeAsProperties(this.props);if (!getHighAvailability()) {                        //进入该方法connectOneTryOnly(isForReconnect, mergedProps);return;}                       //???connectWithRetries(isForReconnect, mergedProps);}

?private void connectOneTryOnly(boolean isForReconnect,

Properties mergedProps) throws SQLException {Exception connectionNotEstablishedBecause = null;try {//IO创建主要在这个方法里coreConnect(mergedProps);this.connectionId = this.io.getThreadId();this.isClosed = false;// save state from old connectionboolean oldAutoCommit = getAutoCommit();int oldIsolationLevel = this.isolationLevel;boolean oldReadOnly = isReadOnly();String oldCatalog = getCatalog();this.io.setStatementInterceptors(this.statementInterceptors);// Server properties might be different// from previous connection, so initialize// again...initializePropsFromServer();if (isForReconnect) {// Restore state from old connectionsetAutoCommit(oldAutoCommit);if (this.hasIsolationLevels) {setTransactionIsolation(oldIsolationLevel);}setCatalog(oldCatalog);setReadOnly(oldReadOnly);}return;} catch (Exception EEE) {if (this.io != null) {this.io.forceClose();}connectionNotEstablishedBecause = EEE;if (EEE instanceof SQLException) {throw (SQLException)EEE;}SQLException chainedEx = SQLError.createSQLException(Messages.getString("Connection.UnableToConnect"),SQLError.SQL_STATE_UNABLE_TO_CONNECT_TO_DATASOURCE, getExceptionInterceptor());chainedEx.initCause(connectionNotEstablishedBecause);throw chainedEx;}}

?进入coreconnect()方法

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private void coreConnect(Properties mergedProps) throws SQLException,IOException {int newPort = 3306;String newHost = "localhost";String protocol = mergedProps.getProperty(NonRegisteringDriver.PROTOCOL_PROPERTY_KEY);if (protocol != null) {// "new" style URLif ("tcp".equalsIgnoreCase(protocol)) {newHost = normalizeHost(mergedProps.getProperty(NonRegisteringDriver.HOST_PROPERTY_KEY));newPort = parsePortNumber(mergedProps.getProperty(NonRegisteringDriver.PORT_PROPERTY_KEY, "3306"));} else if ("pipe".equalsIgnoreCase(protocol)) {setSocketFactoryClassName(NamedPipeSocketFactory.class.getName());String path = mergedProps.getProperty(NonRegisteringDriver.PATH_PROPERTY_KEY);if (path != null) {mergedProps.setProperty(NamedPipeSocketFactory.NAMED_PIPE_PROP_NAME, path);}} else {// normalize for all unknown protocolsnewHost = normalizeHost(mergedProps.getProperty(NonRegisteringDriver.HOST_PROPERTY_KEY));newPort = parsePortNumber(mergedProps.getProperty(NonRegisteringDriver.PORT_PROPERTY_KEY, "3306"));}} else {String[] parsedHostPortPair = NonRegisteringDriver.parseHostPortPair(this.hostPortPair);newHost = parsedHostPortPair[NonRegisteringDriver.HOST_NAME_INDEX];newHost = normalizeHost(newHost);if (parsedHostPortPair[NonRegisteringDriver.PORT_NUMBER_INDEX] != null) {newPort = parsePortNumber(parsedHostPortPair[NonRegisteringDriver.PORT_NUMBER_INDEX]);}}this.port = newPort;this.host = newHost;              //MysqlIO的创建，用来于服务器进行通信this.io = new MysqlIO(newHost, newPort,mergedProps, getSocketFactoryClassName(),getProxy(), getSocketTimeout(),this.largeRowSizeThreshold.getValueAsInt());     this.io.doHandshake(this.user, this.password,this.database);}

?MysqlIO构造器的创建

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 public MysqlIO(String host, int port, Properties props,        String socketFactoryClassName, MySQLConnection conn,        int socketTimeout, int useBufferRowSizeThreshold) throws IOException, SQLException {        this.connection = conn;                if (this.connection.getEnablePacketDebug()) {            this.packetDebugRingBuffer = new LinkedList();        }        this.traceProtocol = this.connection.getTraceProtocol();                this.useAutoSlowLog = this.connection.getAutoSlowLog();                this.useBufferRowSizeThreshold = useBufferRowSizeThreshold;        this.useDirectRowUnpack = this.connection.getUseDirectRowUnpack();        this.logSlowQueries = this.connection.getLogSlowQueries();        this.reusablePacket = new Buffer(INITIAL_PACKET_SIZE);        this.sendPacket = new Buffer(INITIAL_PACKET_SIZE);        this.port = port;        this.host = host;        this.socketFactoryClassName = socketFactoryClassName;        this.socketFactory = createSocketFactory();        this.exceptionInterceptor = this.connection.getExceptionInterceptor();                try {//创建得到一个socket        this.mysqlConnection = this.socketFactory.connect(this.host,        this.port, props);                if (socketTimeout != 0) {        try {        this.mysqlConnection.setSoTimeout(socketTimeout);        } catch (Exception ex) {        /* Ignore if the platform does not support it */        }        }        this.mysqlConnection = this.socketFactory.beforeHandshake();        if (this.connection.getUseReadAheadInput()) {              //创建input流        this.mysqlInput = new ReadAheadInputStream(this.mysqlConnection.getInputStream(), 16384,        this.connection.getTraceProtocol(),        this.connection.getLog());        } else if (this.connection.useUnbufferedInput()) {        this.mysqlInput = this.mysqlConnection.getInputStream();        } else {        this.mysqlInput = new BufferedInputStream(this.mysqlConnection.getInputStream(),        16384);        }      //创建output流        this.mysqlOutput = new BufferedOutputStream(this.mysqlConnection.getOutputStream(),        16384);        this.isInteractiveClient = this.connection.getInteractiveClient();        this.profileSql = this.connection.getProfileSql();        this.autoGenerateTestcaseScript = this.connection.getAutoGenerateTestcaseScript();        this.needToGrabQueryFromPacket = (this.profileSql ||        this.logSlowQueries ||        this.autoGenerateTestcaseScript);        if (this.connection.getUseNanosForElapsedTime()&& Util.nanoTimeAvailable()) {this.useNanosForElapsedTime = true;this.queryTimingUnits = Messages.getString("Nanoseconds");} else {this.queryTimingUnits = Messages.getString("Milliseconds");}if (this.connection.getLogSlowQueries()) {calculateSlowQueryThreshold();}        } catch (IOException ioEx) {        throw SQLError.createCommunicationsException(this.connection, 0, 0, ioEx, getExceptionInterceptor());        }    }

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