/*
* Method to check to see if a connection is still usable
*
* @param conn - the connection to check
* @return True if the connection is still usable
*/
protected boolean pingConnection(PooledConnection conn) { // 用连接做个查询，测试一个
boolean result = true;
try {
result = !conn.getRealConnection().isClosed();
} catch (SQLException e) {
if (log.isDebugEnabled()) {
log.debug("Connection " + conn.getRealHashCode() + " is BAD: " + e.getMessage());
}
result = false;
}
if (result) {
if (poolPingEnabled) {
if (poolPingConnectionsNotUsedFor >= 0
&& conn.getTimeElapsedSinceLastUse() > poolPingConnectionsNotUsedFor) {
try {
if (log.isDebugEnabled()) {
log.debug("Testing connection " + conn.getRealHashCode() + " ...");
}
Connection realConn = conn.getRealConnection(); // 取出真连接
Statement statement = realConn.createStatement();
ResultSet rs = statement.executeQuery(poolPingQuery); // 测试一个
rs.close();
statement.close();
if (!realConn.getAutoCommit()) {
realConn.rollback();
}
result = true;
if (log.isDebugEnabled()) {
log.debug("Connection " + conn.getRealHashCode() + " is GOOD!");
}
} catch (Exception e) {
log.warn("Execution of ping query '" + poolPingQuery + "' failed: " + e.getMessage());
try {
conn.getRealConnection().close();
} catch (Exception e2) {
// ignore
}
result = false;
if (log.isDebugEnabled()) {
log.debug("Connection " + conn.getRealHashCode() + " is BAD: " + e.getMessage());
}
}
}
}
}
return result;
}
private static Object crateProxy(
Class<?> type,
Callback callback,
List<Class<?>> constructorArgTypes,
List<Object> constructorArgs) {
Enhancer enhancer = new Enhancer();
enhancer.setCallback(callback);
enhancer.setSuperclass(type);
try {
type.getDeclaredMethod(WRITE_REPLACE_METHOD);
// ObjectOutputStream will call writeReplace of objects returned by writeReplace
log.debug(
WRITE_REPLACE_METHOD
+ " method was found on bean "
+ type
+ ", make sure it returns this");
} catch (NoSuchMethodException e) {
enhancer.setInterfaces(new Class[] {WriteReplaceInterface.class});
} catch (SecurityException e) {
// nothing to do here
}
Object enhanced = null;
if (constructorArgTypes.isEmpty()) {
enhanced = enhancer.create();
} else {
Class<?>[] typesArray = constructorArgTypes.toArray(new Class[constructorArgTypes.size()]);
Object[] valuesArray = constructorArgs.toArray(new Object[constructorArgs.size()]);
enhanced = enhancer.create(typesArray, valuesArray);
}
return enhanced;
}
protected void pushConnection(PooledConnection conn) throws SQLException { // 关闭一个连接，其实是放回pool
synchronized (state) { // 加锁
state.activeConnections.remove(conn); // 从活动list移出
if (conn.isValid()) { // conn是有效的
if (state.idleConnections.size() < poolMaximumIdleConnections
&& conn.getConnectionTypeCode() == expectedConnectionTypeCode) {
state.accumulatedCheckoutTime += conn.getCheckoutTime();
if (!conn.getRealConnection().getAutoCommit()) { // 不是自动提交的话
conn.getRealConnection().rollback(); // 回滚
}
PooledConnection newConn =
new PooledConnection(conn.getRealConnection(), this); // 新建一个连接，用原来的真连接
state.idleConnections.add(newConn); // 加入空闲list
newConn.setCreatedTimestamp(conn.getCreatedTimestamp());
newConn.setLastUsedTimestamp(conn.getLastUsedTimestamp());
conn.invalidate(); // 老连接标记为无效
if (log.isDebugEnabled()) {
log.debug("Returned connection " + newConn.getRealHashCode() + " to pool.");
}
state.notifyAll(); // 唤醒popConnection中等待连接的线程可以来抢state的锁
} else {
state.accumulatedCheckoutTime += conn.getCheckoutTime();
if (!conn.getRealConnection().getAutoCommit()) {
conn.getRealConnection().rollback(); // 回滚
}
conn.getRealConnection().close(); // 关闭
if (log.isDebugEnabled()) {
log.debug("Closed connection " + conn.getRealHashCode() + ".");
}
conn.invalidate();
}
} else {
if (log.isDebugEnabled()) {
log.debug(
"A bad connection ("
+ conn.getRealHashCode()
+ ") attempted to return to the pool, discarding connection.");
}
state.badConnectionCount++;
}
}
}
protected void pushConnection(PooledConnection conn) throws SQLException {
synchronized (state) {
state.activeConnections.remove(conn);
if (conn.isValid()) {
if (state.idleConnections.size() < poolMaximumIdleConnections
&& conn.getConnectionTypeCode() == expectedConnectionTypeCode) {
state.accumulatedCheckoutTime += conn.getCheckoutTime();
if (!conn.getRealConnection().getAutoCommit()) {
conn.getRealConnection().rollback();
}
PooledConnection newConn = new PooledConnection(conn.getRealConnection(), this);
state.idleConnections.add(newConn);
newConn.setCreatedTimestamp(conn.getCreatedTimestamp());
newConn.setLastUsedTimestamp(conn.getLastUsedTimestamp());
conn.invalidate();
if (log.isDebugEnabled()) {
log.debug("Returned connection " + newConn.getRealHashCode() + " to pool.");
}
state.notifyAll();
} else {
state.accumulatedCheckoutTime += conn.getCheckoutTime();
if (!conn.getRealConnection().getAutoCommit()) {
conn.getRealConnection().rollback();
}
conn.getRealConnection().close();
if (log.isDebugEnabled()) {
log.debug("Closed connection " + conn.getRealHashCode() + ".");
}
conn.invalidate();
}
} else {
if (log.isDebugEnabled()) {
log.debug(
"A bad connection ("
+ conn.getRealHashCode()
+ ") attempted to return to the pool, discarding connection.");
}
state.badConnectionCount++;
}
}
}
public void close(boolean forceRollback) {
try {
try {
rollback(forceRollback);
} finally {
if (transaction != null) transaction.close();
}
} catch (SQLException e) {
// Ignore. There's nothing that can be done at this point.
log.debug("Unexpected exception on closing transaction. Cause: " + e);
} finally {
transaction = null;
deferredLoads = null;
localCache = null;
localOutputParameterCache = null;
batchResults = null;
closed = true;
}
}
/*
* Closes all active and idle connections in the pool
*/
public void forceCloseAll() { // 关闭pool里的所有连接，两个list中的连接都移除且关闭
synchronized (state) {
expectedConnectionTypeCode =
assembleConnectionTypeCode(
dataSource.getUrl(), dataSource.getUsername(), dataSource.getPassword());
for (int i = state.activeConnections.size(); i > 0; i--) { // 遍历活动连接list
try {
PooledConnection conn = state.activeConnections.remove(i - 1); // 从活动连接list移出
conn.invalidate(); // PooledConnection的valid设为false
Connection realConn = conn.getRealConnection(); // 获取真conn (java.sql.Connection)
if (!realConn.getAutoCommit()) { // 不是自动提交的话
realConn.rollback(); // 回滚
}
realConn.close();
} catch (Exception e) {
// ignore
}
}
for (int i = state.idleConnections.size(); i > 0; i--) { // 简历空闲连接list
try {
PooledConnection conn = state.idleConnections.remove(i - 1);
conn.invalidate();
Connection realConn = conn.getRealConnection();
if (!realConn.getAutoCommit()) {
realConn.rollback();
}
realConn.close();
} catch (Exception e) {
// ignore
}
}
}
if (log.isDebugEnabled()) {
log.debug("PooledDataSource forcefully closed/removed all connections.");
}
}
/*
* Closes all active and idle connections in the pool
*/
public void forceCloseAll() {
synchronized (state) {
expectedConnectionTypeCode =
assembleConnectionTypeCode(
dataSource.getUrl(), dataSource.getUsername(), dataSource.getPassword());
for (int i = state.activeConnections.size(); i > 0; i--) {
try {
PooledConnection conn = (PooledConnection) state.activeConnections.remove(i - 1);
conn.invalidate();
Connection realConn = conn.getRealConnection();
if (!realConn.getAutoCommit()) {
realConn.rollback();
}
realConn.close();
} catch (Exception e) {
// ignore
}
}
for (int i = state.idleConnections.size(); i > 0; i--) {
try {
PooledConnection conn = (PooledConnection) state.idleConnections.remove(i - 1);
conn.invalidate();
Connection realConn = conn.getRealConnection();
if (!realConn.getAutoCommit()) {
realConn.rollback();
}
realConn.close();
} catch (Exception e) {
// ignore
}
}
}
if (log.isDebugEnabled()) {
log.debug("PooledDataSource forcefully closed/removed all connections.");
}
}
protected void printQueryId(String queryId) {
if (log.isDebugEnabled()) {
log.debug("\t QueryId \t : " + queryId);
}
}
private PooledConnection popConnection(String username, String password)
throws SQLException { // 获取一个连接
boolean countedWait = false;
PooledConnection conn = null;
long t = System.currentTimeMillis();
int localBadConnectionCount = 0;
while (conn == null) {
synchronized (state) {
if (!state.idleConnections.isEmpty()) { // pool里还有空闲连接
// Pool has available connection
conn = state.idleConnections.remove(0); // 从空闲list移出一个conn，用做新连接
if (log.isDebugEnabled()) {
log.debug("Checked out connection " + conn.getRealHashCode() + " from pool.");
}
} else { // pool里没有空闲连接了
// Pool does not have available connection
if (state.activeConnections.size() < poolMaximumActiveConnections) { // 活动list没有满
// Can create new connection
conn = new PooledConnection(dataSource.getConnection(), this); // 新建一个PooledConnection
if (log.isDebugEnabled()) {
log.debug("Created connection " + conn.getRealHashCode() + ".");
}
} else { // 活动list已经满了，无法创建新连接
// Cannot create new connection
PooledConnection oldestActiveConnection = state.activeConnections.get(0); // 获取最早开始活动的连接
long longestCheckoutTime =
oldestActiveConnection.getCheckoutTime(); // 获得最老的活动连接的checkout时间
if (longestCheckoutTime > poolMaximumCheckoutTime) { // 如果checkout时间大于最大值
// Can claim overdue connection
state.claimedOverdueConnectionCount++; // 过期连接计数++
state.accumulatedCheckoutTimeOfOverdueConnections +=
longestCheckoutTime; // 累加过期连接的checkout时间
state.accumulatedCheckoutTime += longestCheckoutTime; // 累加checkout时间
state.activeConnections.remove(oldestActiveConnection); // 从活动list移出最老的活动连接，留出空位来啦
if (!oldestActiveConnection.getRealConnection().getAutoCommit()) {
oldestActiveConnection.getRealConnection().rollback(); // 回滚
}
conn =
new PooledConnection(
oldestActiveConnection.getRealConnection(), this); // 新建连接，用最老连接的真连接
oldestActiveConnection.invalidate(); // 最老连接标记无效
if (log.isDebugEnabled()) {
log.debug("Claimed overdue connection " + conn.getRealHashCode() + ".");
}
} else { // 如果checkout时间并没有超过最大值，必须等待
// Must wait
try {
if (!countedWait) { // countedWait原来是false
state.hadToWaitCount++; // 必须等待的计数++
countedWait = true; // countedWait变为true
}
if (log.isDebugEnabled()) {
log.debug(
"Waiting as long as " + poolTimeToWait + " milliseconds for connection.");
}
long wt = System.currentTimeMillis();
state.wait(
poolTimeToWait); // 等poolTimeToWait微秒，pushConnection移出一个连接时会notifyAll来唤醒wait的线程
state.accumulatedWaitTime += System.currentTimeMillis() - wt;
} catch (InterruptedException e) {
break;
}
}
}
}
if (conn != null) { // conn非空，确实建出来了
if (conn.isValid()) { // conn有效
if (!conn.getRealConnection().getAutoCommit()) {
conn.getRealConnection().rollback(); // 这里回滚是干啥？ hama
}
conn.setConnectionTypeCode(
assembleConnectionTypeCode(dataSource.getUrl(), username, password));
conn.setCheckoutTimestamp(System.currentTimeMillis());
conn.setLastUsedTimestamp(System.currentTimeMillis());
state.activeConnections.add(conn); // 加入活动list
state.requestCount++;
state.accumulatedRequestTime += System.currentTimeMillis() - t;
} else { // conn无效
if (log.isDebugEnabled()) {
log.debug(
"A bad connection ("
+ conn.getRealHashCode()
+ ") was returned from the pool, getting another connection.");
}
state.badConnectionCount++;
localBadConnectionCount++;
conn = null;
if (localBadConnectionCount > (poolMaximumIdleConnections + 3)) {
if (log.isDebugEnabled()) {
log.debug("PooledDataSource: Could not get a good connection to the database.");
}
throw new SQLException(
"PooledDataSource: Could not get a good connection to the database.");
}
}
}
}
} // 到这里while结束
if (conn == null) { // 出现了奇葩的Unknown错吧
if (log.isDebugEnabled()) {
log.debug(
"PooledDataSource: Unknown severe error condition. The connection pool returned a null connection.");
}
throw new SQLException(
"PooledDataSource: Unknown severe error condition. The connection pool returned a null connection.");
}
return conn;
}
private PooledConnection popConnection(String username, String password) throws SQLException {
boolean countedWait = false;
PooledConnection conn = null;
long t = System.currentTimeMillis();
int localBadConnectionCount = 0;
while (conn == null) {
synchronized (state) {
if (state.idleConnections.size() > 0) {
// Pool has available connection
conn = (PooledConnection) state.idleConnections.remove(0);
if (log.isDebugEnabled()) {
log.debug("Checked out connection " + conn.getRealHashCode() + " from pool.");
}
} else {
// Pool does not have available connection
if (state.activeConnections.size() < poolMaximumActiveConnections) {
// Can create new connection
conn = new PooledConnection(dataSource.getConnection(), this);
@SuppressWarnings("unused")
// used in logging, if enabled
Connection realConn = conn.getRealConnection();
if (log.isDebugEnabled()) {
log.debug("Created connection " + conn.getRealHashCode() + ".");
}
} else {
// Cannot create new connection
PooledConnection oldestActiveConnection =
(PooledConnection) state.activeConnections.get(0);
long longestCheckoutTime = oldestActiveConnection.getCheckoutTime();
if (longestCheckoutTime > poolMaximumCheckoutTime) {
// Can claim overdue connection
state.claimedOverdueConnectionCount++;
state.accumulatedCheckoutTimeOfOverdueConnections += longestCheckoutTime;
state.accumulatedCheckoutTime += longestCheckoutTime;
state.activeConnections.remove(oldestActiveConnection);
if (!oldestActiveConnection.getRealConnection().getAutoCommit()) {
oldestActiveConnection.getRealConnection().rollback();
}
conn = new PooledConnection(oldestActiveConnection.getRealConnection(), this);
oldestActiveConnection.invalidate();
if (log.isDebugEnabled()) {
log.debug("Claimed overdue connection " + conn.getRealHashCode() + ".");
}
} else {
// Must wait
try {
if (!countedWait) {
state.hadToWaitCount++;
countedWait = true;
}
if (log.isDebugEnabled()) {
log.debug(
"Waiting as long as " + poolTimeToWait + " milliseconds for connection.");
}
long wt = System.currentTimeMillis();
state.wait(poolTimeToWait);
state.accumulatedWaitTime += System.currentTimeMillis() - wt;
} catch (InterruptedException e) {
break;
}
}
}
}
if (conn != null) {
if (conn.isValid()) {
if (!conn.getRealConnection().getAutoCommit()) {
conn.getRealConnection().rollback();
}
conn.setConnectionTypeCode(
assembleConnectionTypeCode(dataSource.getUrl(), username, password));
conn.setCheckoutTimestamp(System.currentTimeMillis());
conn.setLastUsedTimestamp(System.currentTimeMillis());
state.activeConnections.add(conn);
state.requestCount++;
state.accumulatedRequestTime += System.currentTimeMillis() - t;
} else {
if (log.isDebugEnabled()) {
log.debug(
"A bad connection ("
+ conn.getRealHashCode()
+ ") was returned from the pool, getting another connection.");
}
state.badConnectionCount++;
localBadConnectionCount++;
conn = null;
if (localBadConnectionCount > (poolMaximumIdleConnections + 3)) {
if (log.isDebugEnabled()) {
log.debug("PooledDataSource: Could not get a good connection to the database.");
}
throw new SQLException(
"PooledDataSource: Could not get a good connection to the database.");
}
}
}
}
}
if (conn == null) {
if (log.isDebugEnabled()) {
log.debug(
"PooledDataSource: Unknown severe error condition. The connection pool returned a null connection.");
}
throw new SQLException(
"PooledDataSource: Unknown severe error condition. The connection pool returned a null connection.");
}
return conn;
}
/**
* Build a {@code SqlSessionFactory} instance.
*
* <p>The default implementation uses the standard MyBatis {@code XMLConfigBuilder} API to build a
* {@code SqlSessionFactory} instance based on an Reader.
*
* @return SqlSessionFactory
* @throws IOException if loading the config file failed
*/
protected SqlSessionFactory buildSqlSessionFactory() throws IOException {
Configuration configuration;
XMLConfigBuilder xmlConfigBuilder = null;
if (this.configLocation != null) {
xmlConfigBuilder =
new XMLConfigBuilder(
this.configLocation.getInputStream(), null, this.configurationProperties);
configuration = xmlConfigBuilder.getConfiguration();
} else {
if (logger.isDebugEnabled()) {
logger.debug(
"Property 'configLocation' not specified, using default MyBatis Configuration");
}
configuration = new Configuration();
configuration.setVariables(this.configurationProperties);
}
if (this.objectFactory != null) {
configuration.setObjectFactory(this.objectFactory);
}
if (this.objectWrapperFactory != null) {
configuration.setObjectWrapperFactory(this.objectWrapperFactory);
}
if (hasLength(this.typeAliasesPackage)) {
String[] typeAliasPackageArray =
tokenizeToStringArray(
this.typeAliasesPackage, ConfigurableApplicationContext.CONFIG_LOCATION_DELIMITERS);
for (String packageToScan : typeAliasPackageArray) {
configuration
.getTypeAliasRegistry()
.registerAliases(
packageToScan, typeAliasesSuperType == null ? Object.class : typeAliasesSuperType);
if (logger.isDebugEnabled()) {
logger.debug("Scanned package: '" + packageToScan + "' for aliases");
}
}
}
if (!isEmpty(this.typeAliases)) {
for (Class<?> typeAlias : this.typeAliases) {
configuration.getTypeAliasRegistry().registerAlias(typeAlias);
if (logger.isDebugEnabled()) {
logger.debug("Registered type alias: '" + typeAlias + "'");
}
}
}
if (!isEmpty(this.plugins)) {
for (Interceptor plugin : this.plugins) {
configuration.addInterceptor(plugin);
if (logger.isDebugEnabled()) {
logger.debug("Registered plugin: '" + plugin + "'");
}
}
}
if (hasLength(this.typeHandlersPackage)) {
String[] typeHandlersPackageArray =
tokenizeToStringArray(
this.typeHandlersPackage, ConfigurableApplicationContext.CONFIG_LOCATION_DELIMITERS);
for (String packageToScan : typeHandlersPackageArray) {
configuration.getTypeHandlerRegistry().register(packageToScan);
if (logger.isDebugEnabled()) {
logger.debug("Scanned package: '" + packageToScan + "' for type handlers");
}
}
}
if (!isEmpty(this.typeHandlers)) {
for (TypeHandler<?> typeHandler : this.typeHandlers) {
configuration.getTypeHandlerRegistry().register(typeHandler);
if (logger.isDebugEnabled()) {
logger.debug("Registered type handler: '" + typeHandler + "'");
}
}
}
if (xmlConfigBuilder != null) {
try {
xmlConfigBuilder.parse();
if (logger.isDebugEnabled()) {
logger.debug("Parsed configuration file: '" + this.configLocation + "'");
}
} catch (Exception ex) {
throw new NestedIOException("Failed to parse config resource: " + this.configLocation, ex);
} finally {
ErrorContext.instance().reset();
}
}
if (this.transactionFactory == null) {
this.transactionFactory = new SpringManagedTransactionFactory();
}
Environment environment =
new Environment(this.environment, this.transactionFactory, this.dataSource);
configuration.setEnvironment(environment);
if (this.databaseIdProvider != null) {
try {
configuration.setDatabaseId(this.databaseIdProvider.getDatabaseId(this.dataSource));
} catch (SQLException e) {
throw new NestedIOException("Failed getting a databaseId", e);
}
}
// TODO 增加location 获取加载xml的路径，也可配置
String location = null;
if (!isEmpty(this.mapperLocations)) {
for (Resource mapperLocation : this.mapperLocations) {
if (location == null) {
location = mapperLocation.toString();
}
if (mapperLocation == null) {
continue;
}
try {
XMLMapperBuilder xmlMapperBuilder =
new XMLMapperBuilder(
mapperLocation.getInputStream(),
configuration,
mapperLocation.toString(),
configuration.getSqlFragments());
xmlMapperBuilder.parse();
} catch (Exception e) {
e.printStackTrace(); // 出现错误抛出异常
throw new NestedIOException(
"Failed to parse mapping resource: '" + mapperLocation + "'", e);
} finally {
ErrorContext.instance().reset();
}
if (logger.isDebugEnabled()) {
logger.debug("Parsed mapper file: '" + mapperLocation + "'");
}
}
} else {
if (logger.isDebugEnabled()) {
logger.debug("Property 'mapperLocations' was not specified or no matching resources found");
}
}
// TODO 编译sqlsession时，启动定时器
new org.apache.ibatis.thread.Runnable(location, configuration).run();
return this.sqlSessionFactoryBuilder.build(configuration);
}