HikariBase的作用
HikariBase是HikariPool的父类，提供了Connection的一些基本属性，和对Connection的操作，如创建、关闭、查询是否活跃等。
PoolBase构造函数
- 设置各种属性
- 初始化DataSource，依次使用的方式：
- 用户set到HikariConfig中的DataSource实例
- HikariConfig中的
DataSourceClassName - HikariConfig中的
jdbcUrl
PoolBase(final HikariConfig config) {
this.config = config;
this.networkTimeout = UNINITIALIZED;
this.catalog = config.getCatalog();
this.isReadOnly = config.isReadOnly();
this.isAutoCommit = config.isAutoCommit();
this.transactionIsolation = UtilityElf.getTransactionIsolation(config.getTransactionIsolation());
this.isQueryTimeoutSupported = UNINITIALIZED;
this.isNetworkTimeoutSupported = UNINITIALIZED;
this.isUseJdbc4Validation = config.getConnectionTestQuery() == null;
this.isIsolateInternalQueries = config.isIsolateInternalQueries();
this.poolName = config.getPoolName();
this.connectionTimeout = config.getConnectionTimeout();
this.validationTimeout = config.getValidationTimeout();
this.lastConnectionFailure = new AtomicReference<>();
initializeDataSource();
}
/**
* Create/initialize the underlying DataSource.
*
* @return a DataSource instance
*/
private void initializeDataSource() {
final String jdbcUrl = config.getJdbcUrl();
final String username = config.getUsername();
final String password = config.getPassword();
final String dsClassName = config.getDataSourceClassName();
final String driverClassName = config.getDriverClassName();
final Properties dataSourceProperties = config.getDataSourceProperties();
//新建DataSource实例顺序：
// 1. HikariConfig中的DataSource；
// 2. HikariConfig中的DataSourceClassName；
// 3. HikariConfig中的jdbcUrl
DataSource dataSource = config.getDataSource();
if (dsClassName != null && dataSource == null) {
dataSource = createInstance(dsClassName, DataSource.class);
PropertyElf.setTargetFromProperties(dataSource, dataSourceProperties);
} else if (jdbcUrl != null && dataSource == null) {
dataSource = new DriverDataSource(jdbcUrl, driverClassName, dataSourceProperties, username, password);
}
if (dataSource != null) {
setLoginTimeout(dataSource);
createNetworkTimeoutExecutor(dataSource, dsClassName, jdbcUrl);
}
this.dataSource = dataSource;
}
获取链接
- 根据userName和password创建Connection
- 创建Connection时使用MySQL Driver提供的方法
- 设置Connection的属性，并测试testSql
- 若创建失败，则close掉
/**
* Obtain connection from data source.
*
* @return a Connection connection
*/
Connection newConnection() throws Exception {
Connection connection = null;
try {
String username = config.getUsername();
String password = config.getPassword();
//新建Connection，若设置了userName，则使用DriverDataSource获取Connection
//HikariCp中有两个DataSource实现类：HikariDataSource和DriverDataSource；其中HikariDataSource只支持不带参数的getConnection()
connection = (username == null) ? dataSource.getConnection() : dataSource.getConnection(username, password);
if (connection == null) {
throw new SQLTransientConnectionException("DataSource returned null unexpectedly");
}
//设置默认属性、测试Connection等
setupConnection(connection);
lastConnectionFailure.set(null);
return connection;
} catch (Exception e) {
if (connection != null) {
//若异常，则Close该Connection
quietlyCloseConnection(connection, "(Failed to create/setup connection)");
} else if (getLastConnectionFailure() == null) {
LOGGER.debug("{} - Failed to create/setup connection: {}", poolName, e.getMessage());
}
lastConnectionFailure.set(e);
throw e;
}
}
/**
* Setup a connection initial state.
*
* @param connection a Connection
* @throws SQLException thrown from driver
*/
private void setupConnection(final Connection connection) throws ConnectionSetupException
{
try {
//初始化Connection时使用validationTimeout
if (networkTimeout == UNINITIALIZED) {
networkTimeout = getAndSetNetworkTimeout(connection, validationTimeout);
}
else {
setNetworkTimeout(connection, validationTimeout);
}
//设置属性
connection.setReadOnly(isReadOnly);
connection.setAutoCommit(isAutoCommit);
//执行connectionTestQuery，测试链接是否可用
checkDriverSupport(connection);
if (transactionIsolation != defaultTransactionIsolation) {
connection.setTransactionIsolation(transactionIsolation);
}
if (catalog != null) {
connection.setCatalog(catalog);
}
//执行connectionInitSql（若存在）
executeSql(connection, config.getConnectionInitSql(), true);
//将networkTimeout设置回去
setNetworkTimeout(connection, networkTimeout);
}
catch (SQLException e) {
throw new ConnectionSetupException(e);
}
}
关闭链接
- 关闭Connection中的Statements
- 停止Connection中的内存泄漏检测任务
- 若有执行中的sql，全部rollback
- reset属性：
readonly、autocommit等 - 将该Connection放回连接池(
ConcurrentBag)
public final void close() throws SQLException
{
//关闭Connection中的Statements，这些Statements保存在FastList中
//Closing statements can cause connection eviction, so this must run before the conditional below
closeStatements();
if (delegate != ClosedConnection.CLOSED_CONNECTION) {
//停止内存泄露检测任务
leakTask.cancel();
try {
//isCommitStateDirty执行insert、update等时会将isCommitStateDirty设置为true
//commit或rollback后设置为true
if (isCommitStateDirty && !isAutoCommit) {
delegate.rollback();
lastAccess = clockSource.currentTime();
LOGGER.debug("{} - Executed rollback on connection {} due to dirty commit state on close().", poolEntry.getPoolName(), delegate);
}
if (dirtyBits != 0) {
//dirtyBits用二进制表示Connection中的某几个属性是否被设置了true
// static final int DIRTY_BIT_READONLY = 0b00001; 是否readonly
// static final int DIRTY_BIT_AUTOCOMMIT = 0b00010; 是否自动提交
// static final int DIRTY_BIT_ISOLATION = 0b00100; 是否设置了隔离级别
// static final int DIRTY_BIT_CATALOG = 0b01000; 是否设置了catalog
// static final int DIRTY_BIT_NETTIMEOUT = 0b10000; 是否设置了networkTimeout
poolEntry.resetConnectionState(this, dirtyBits);
lastAccess = clockSource.currentTime();
}
delegate.clearWarnings();
}
catch (SQLException e) {
// when connections are aborted, exceptions are often thrown that should not reach the application
if (!poolEntry.isMarkedEvicted()) {
throw checkException(e);
}
}
finally {
delegate = ClosedConnection.CLOSED_CONNECTION;
//将链接放回连接池，底层为connectionBag.requite
poolEntry.recycle(lastAccess);
}
}
}
链接是否活跃
- 如果没有设置
connectionTestQuery，则通过Connection的isValid测试 - 如果设置了
connectionTestQuery，则执行该sql，没有异常则说明链接是活跃的
boolean isConnectionAlive(final Connection connection)
{
try {
try {
//没有设置connectionTestQuery，则isUseJdbc4Validation为true
if (isUseJdbc4Validation) {
return connection.isValid((int) MILLISECONDS.toSeconds(Math.max(1000L, validationTimeout)));
}
setNetworkTimeout(connection, validationTimeout);
try (Statement statement = connection.createStatement()) {
if (isNetworkTimeoutSupported != TRUE) {
setQueryTimeout(statement, (int) MILLISECONDS.toSeconds(Math.max(1000L, validationTimeout)));
}
//执行connectionTestQuery，没有异常则说明Connection是活跃的
statement.execute(config.getConnectionTestQuery());
}
}
finally {
if (isIsolateInternalQueries && !isAutoCommit) {
connection.rollback();
}
}
setNetworkTimeout(connection, networkTimeout);
return true;
}
catch (SQLException e) {
lastConnectionFailure.set(e);
LOGGER.warn("{} - Failed to validate connection {} ({})", poolName, connection, e.getMessage());
return false;
}
}
github求star：github.com/caychan/CCo…
