JDBC连接的获取： http://donald-draper.iteye.com/blog/2342011
Mysql负载均衡连接的获取： http://donald-draper.iteye.com/blog/2342089
Mysql主从复制读写分离连接的获取： http://donald-draper.iteye.com/blog/2342108
ConnectionImp创建MysqlIO ： http://donald-draper.iteye.com/blog/2342959
Mysql预编译SQL： http://donald-draper.iteye.com/blog/2342960
MysqlSQL PreparedStatement的查询: http://donald-draper.iteye.com/blog/2343083
MySQL ServerPreparedStatement查询： http://donald-draper.iteye.com/blog/2343124
在前文中，我们讲过statment的查询，今天来看一下批处理，在看批处理之前，statement设值
//设值
public void setString(int parameterIndex, String x)
throws SQLException
{
if(x == null)
{
setNull(parameterIndex, 1);
} else
{
checkClosed();
int stringLength = x.length();
if(connection.isNoBackslashEscapesSet())
{
boolean needsHexEscape = isEscapeNeededForString(x, stringLength);
if(!needsHexEscape)
{
byte parameterAsBytes[] = null;
StringBuffer quotedString = new StringBuffer(x.length() + 2);
quotedString.append('\'');
quotedString.append(x);
quotedString.append('\'');
if(!isLoadDataQuery)
parameterAsBytes = StringUtils.getBytes(quotedString.toString(), charConverter, charEncoding, connection.getServerCharacterEncoding(), connection.parserKnowsUnicode(), getExceptionInterceptor());
else
parameterAsBytes = quotedString.toString().getBytes();
//将String转换为bytes，设值
setInternal(parameterIndex, parameterAsBytes);
} else
{
byte parameterAsBytes[] = null;
if(!isLoadDataQuery)
parameterAsBytes = StringUtils.getBytes(x, charConverter, charEncoding, connection.getServerCharacterEncoding(), connection.parserKnowsUnicode(), getExceptionInterceptor());
else
parameterAsBytes = x.getBytes();
//将String转换为bytes，设值
setBytes(parameterIndex, parameterAsBytes);
}
return;
}
String parameterAsString = x;
boolean needsQuoted = true;
if(isLoadDataQuery || isEscapeNeededForString(x, stringLength))
{
needsQuoted = false;
StringBuffer buf = new StringBuffer((int)((double)x.length() * 1.1000000000000001D));
buf.append('\'');
for(int i = 0; i < stringLength; i++)
{
char c = x.charAt(i);
switch(c)
{
default:
break;
case 0: // '\0'
buf.append('\\');
buf.append('0');
continue;
case 10: // '\n'
buf.append('\\');
buf.append('n');
continue;
case 13: // '\r'
buf.append('\\');
buf.append('r');
continue;
case 92: // '\\'
buf.append('\\');
buf.append('\\');
continue;
case 39: // '\''
buf.append('\\');
buf.append('\'');
continue;
case 34: // '"'
if(usingAnsiMode)
buf.append('\\');
buf.append('"');
continue;
case 26: // '\032'
buf.append('\\');
buf.append('Z');
continue;
case 165:
case 8361:
if(charsetEncoder != null)
{
CharBuffer cbuf = CharBuffer.allocate(1);
ByteBuffer bbuf = ByteBuffer.allocate(1);
cbuf.put(c);
cbuf.position(0);
charsetEncoder.encode(cbuf, bbuf, true);
if(bbuf.get(0) == 92)
buf.append('\\');
}
break;
}
buf.append(c);
}
buf.append('\'');
parameterAsString = buf.toString();
}
byte parameterAsBytes[] = null;
if(!isLoadDataQuery)
{
if(needsQuoted)
parameterAsBytes = StringUtils.getBytesWrapped(parameterAsString, '\'', '\'', charConverter, charEncoding, connection.getServerCharacterEncoding(), connection.parserKnowsUnicode(), getExceptionInterceptor());
else
parameterAsBytes = StringUtils.getBytes(parameterAsString, charConverter, charEncoding, connection.getServerCharacterEncoding(), connection.parserKnowsUnicode(), getExceptionInterceptor());
} else
{
parameterAsBytes = parameterAsString.getBytes();
}
setInternal(parameterIndex, parameterAsBytes);
parameterTypes[(parameterIndex - 1) + getParameterIndexOffset()] = 12;
}
}
我们先看一下Prepare内部变量，再看setInternal方法
//描述PrepareStatement的参数信息，PrepareStatement的变量
private boolean isNull[];参数是否为null private boolean isStream[];//参数是不是流CLOB或BLOB protected int numberOfExecutions; protected String originalSql; protected int parameterCount;//参数数量 protected MysqlParameterMetadata parameterMetaData; private InputStream parameterStreams[];//参数流 private byte parameterValues[][];//参数值 protected int parameterTypes[];//参数类型
现在来看setInternal方法
protected final void setInternal(int paramIndex, byte val[])
throws SQLException
{
if(isClosed)
{
throw SQLError.createSQLException(Messages.getString("PreparedStatement.48"), "S1009", getExceptionInterceptor());
} else
{
int parameterIndexOffset = getParameterIndexOffset();
checkBounds(paramIndex, parameterIndexOffset);
//paramIndex对应的参数是不是流
isStream[(paramIndex - 1) + parameterIndexOffset] = false;
//paramIndex对应的参数是不是null
isNull[(paramIndex - 1) + parameterIndexOffset] = false;
//paramIndex对应的参数流
parameterStreams[(paramIndex - 1) + parameterIndexOffset] = null;
//paramIndex对应的参数值
parameterValues[(paramIndex - 1) + parameterIndexOffset] = val;
return;
}
}
public void setBytes(int parameterIndex, byte x[])
throws SQLException
{
setBytes(parameterIndex, x, true, true);
if(x != null)
parameterTypes[(parameterIndex - 1) + getParameterIndexOffset()] = -2;
}
protected void setBytes(int parameterIndex, byte x[], boolean checkForIntroducer, boolean escapeForMBChars)
throws SQLException
{
if(x == null)
{
setNull(parameterIndex, -2);
} else
{
String connectionEncoding = connection.getEncoding();
if(connection.isNoBackslashEscapesSet() || escapeForMBChars && connection.getUseUnicode() && connectionEncoding != null && CharsetMapping.isMultibyteCharset(connectionEncoding))
{
ByteArrayOutputStream bOut = new ByteArrayOutputStream(x.length * 2 + 3);
bOut.write(120);
bOut.write(39);
for(int i = 0; i < x.length; i++)
{
int lowBits = (x[i] & 255) / 16;
int highBits = (x[i] & 255) % 16;
bOut.write(HEX_DIGITS[lowBits]);
bOut.write(HEX_DIGITS[highBits]);
}
bOut.write(39);
setInternal(parameterIndex, bOut.toByteArray());
return;
}
int numBytes = x.length;
int pad = 2;
boolean needsIntroducer = checkForIntroducer && connection.versionMeetsMinimum(4, 1, 0);
if(needsIntroducer)
pad += 7;
ByteArrayOutputStream bOut = new ByteArrayOutputStream(numBytes + pad);
if(needsIntroducer)
{
bOut.write(95);
bOut.write(98);
bOut.write(105);
bOut.write(110);
bOut.write(97);
bOut.write(114);
bOut.write(121);
}
bOut.write(39);
for(int i = 0; i < numBytes; i++)
{
byte b = x[i];
switch(b)
{
case 0: // '\0'
bOut.write(92);
bOut.write(48);
break;
case 10: // '\n'
bOut.write(92);
bOut.write(110);
break;
case 13: // '\r'
bOut.write(92);
bOut.write(114);
break;
case 92: // '\\'
bOut.write(92);
bOut.write(92);
break;
case 39: // '\''
bOut.write(92);
bOut.write(39);
break;
case 34: // '"'
bOut.write(92);
bOut.write(34);
break;
case 26: // '\032'
bOut.write(92);
bOut.write(90);
break;
default:
bOut.write(b);
break;
}
}
bOut.write(39);
//最后还是委托给setInternal
setInternal(parameterIndex, bOut.toByteArray());
}
}
从上面可以看出，preparestatment设值，就是将值是否为null，是否是流，参数值，参数流信息放到statement
的isNull，isStream，parameterStreams，parameterValues中。
//添加到批处理
public void addBatch()
throws SQLException
{
if(batchedArgs == null)
batchedArgs = new ArrayList();
for(int i = 0; i < parameterValues.length; i++)
checkAllParametersSet(parameterValues[i], parameterStreams[i], i);
batchedArgs.add(new BatchParams(parameterValues, parameterStreams, isStream, streamLengths, isNull));
}
//批参数
class BatchParams
{
boolean isNull[];
boolean isStream[];
InputStream parameterStreams[];
byte parameterStrings[][];
int streamLengths[];
BatchParams(byte strings[][], InputStream streams[], boolean isStreamFlags[], int lengths[], boolean isNullFlags[])
{
isNull = null;
isStream = null;
parameterStreams = null;
parameterStrings = (byte[][])null;
streamLengths = null;
parameterStrings = new byte[strings.length][];
parameterStreams = new InputStream[streams.length];
isStream = new boolean[isStreamFlags.length];
streamLengths = new int[lengths.length];
isNull = new boolean[isNullFlags.length];
System.arraycopy(strings, 0, parameterStrings, 0, strings.length);
System.arraycopy(streams, 0, parameterStreams, 0, streams.length);
System.arraycopy(isStreamFlags, 0, isStream, 0, isStreamFlags.length);
System.arraycopy(lengths, 0, streamLengths, 0, lengths.length);
System.arraycopy(isNullFlags, 0, isNull, 0, isNullFlags.length);
}
}
//批处理sql
public synchronized void addBatch(String sql)
throws SQLException
{
batchHasPlainStatements = true;
//委托给父类StatementImpl
super.addBatch(sql);
}
//StatementImpl
public synchronized void addBatch(String sql)
throws SQLException
{
if(batchedArgs == null)
batchedArgs = new ArrayList();
if(sql != null)
batchedArgs.add(sql);
}
//批执行
public int[] executeBatch()
throws SQLException
{
checkClosed();
if(connection.isReadOnly())
throw new SQLException(Messages.getString("PreparedStatement.25") + Messages.getString("PreparedStatement.26"), "S1009");
//获取互斥锁
Object obj = connection.getMutex();
JVM INSTR monitorenter ;
if(batchedArgs == null || batchedArgs.size() == 0)
return new int[0];
int batchTimeout;
batchTimeout = timeoutInMillis;
timeoutInMillis = 0;
resetCancelledState();
int ai[];
clearWarnings();
if(batchHasPlainStatements || !connection.getRewriteBatchedStatements())
break MISSING_BLOCK_LABEL_195;
if(!canRewriteAsMultiValueInsertAtSqlLevel())
break MISSING_BLOCK_LABEL_141;
//执行批插入
ai = executeBatchedInserts(batchTimeout);
clearBatch();
obj;
JVM INSTR monitorexit ;
return ai;
if(!connection.versionMeetsMinimum(4, 1, 0) || batchHasPlainStatements || batchedArgs == null || batchedArgs.size() <= 3)
break MISSING_BLOCK_LABEL_195;
//执行批PrepareStatment
ai = executePreparedBatchAsMultiStatement(batchTimeout);
clearBatch();
}
来看一下，批量插入
protected int[] executeBatchedInserts(int batchTimeout)
throws SQLException
{
Connection locallyScopedConn;
//批量大小
int numBatchedArgs;
//每批的大小
int numValuesPerBatch;
//batch处理statement
java.sql.PreparedStatement batchedStatement;
//batch参数index
int batchedParamIndex;
int updateCountRunningTotal;
int batchCounter;
//延时statement任务
StatementImpl.CancelTask timeoutTask;
SQLException sqlEx;
int updateCounts[];
String valuesClause = getValuesClause();
//连接
locallyScopedConn = connection;
if(valuesClause == null)
return executeBatchSerially(batchTimeout);
//批量大小
numBatchedArgs = batchedArgs.size();
if(retrieveGeneratedKeys)
batchedGeneratedKeys = new ArrayList(numBatchedArgs);
//计算每批的大小
numValuesPerBatch = computeBatchSize(numBatchedArgs);
if(numBatchedArgs < numValuesPerBatch)
numValuesPerBatch = numBatchedArgs;
batchedStatement = null;
batchedParamIndex = 1;
updateCountRunningTotal = 0;
int numberToExecuteAsMultiValue = 0;
batchCounter = 0;
timeoutTask = null;
sqlEx = null;
updateCounts = new int[numBatchedArgs];
for(int i = 0; i < batchedArgs.size(); i++)
updateCounts[i] = 1;
batchedStatement = prepareBatchedInsertSQL((ConnectionImpl)locallyScopedConn, numValuesPerBatch);
if(connection.getEnableQueryTimeouts() && batchTimeout != 0 && connection.versionMeetsMinimum(5, 0, 0))
{
timeoutTask = new StatementImpl.CancelTask(this, (StatementImpl)batchedStatement);
ConnectionImpl.getCancelTimer().schedule(timeoutTask, batchTimeout);
}
int numberToExecuteAsMultiValue;
if(numBatchedArgs < numValuesPerBatch)
numberToExecuteAsMultiValue = numBatchedArgs;
else
numberToExecuteAsMultiValue = numBatchedArgs / numValuesPerBatch;
int numberArgsToExecute = numberToExecuteAsMultiValue * numValuesPerBatch;
for(int i = 0; i < numberArgsToExecute; i++)
{
if(i != 0 && i % numValuesPerBatch == 0)
{
try
{
updateCountRunningTotal += batchedStatement.executeUpdate();
}
catch(SQLException ex)
{
sqlEx = handleExceptionForBatch(batchCounter - 1, numValuesPerBatch, updateCounts, ex);
}
getBatchedGeneratedKeys(batchedStatement);
batchedStatement.clearParameters();
batchedParamIndex = 1;
}
batchedParamIndex = setOneBatchedParameterSet(batchedStatement, batchedParamIndex, batchedArgs.get(batchCounter++));
}
try
{
updateCountRunningTotal += batchedStatement.executeUpdate();
}
catch(SQLException ex)
{
sqlEx = handleExceptionForBatch(batchCounter - 1, numValuesPerBatch, updateCounts, ex);
}
getBatchedGeneratedKeys(batchedStatement);
numValuesPerBatch = numBatchedArgs - batchCounter;
int ai[];
//分批次，执行更新
if(numValuesPerBatch > 0)
{
batchedStatement = prepareBatchedInsertSQL((ConnectionImpl)locallyScopedConn, numValuesPerBatch);
if(timeoutTask != null)
timeoutTask.toCancel = (StatementImpl)batchedStatement;
for(batchedParamIndex = 1; batchCounter < numBatchedArgs; batchedParamIndex = setOneBatchedParameterSet(batchedStatement, batchedParamIndex, batchedArgs.get(batchCounter++)));
try
{
//更新
updateCountRunningTotal += batchedStatement.executeUpdate();
}
catch(SQLException ex)
{
sqlEx = handleExceptionForBatch(batchCounter - 1, numValuesPerBatch, updateCounts, ex);
}
getBatchedGeneratedKeys(batchedStatement);
}
ai = updateCounts;
if(batchedStatement != null)
batchedStatement.close();
return ai;
}
在看执行更新
public int executeUpdate()
throws SQLException
{
return executeUpdate(true, false);
}
protected int executeUpdate(boolean clearBatchedGeneratedKeysAndWarnings, boolean isBatch)
throws SQLException
{
if(clearBatchedGeneratedKeysAndWarnings)
{
clearWarnings();
batchedGeneratedKeys = null;
}
return executeUpdate(parameterValues, parameterStreams, isStream, streamLengths, isNull, isBatch);
}
//执行更新
protected int executeUpdate(byte batchedParameterStrings[][], InputStream batchedParameterStreams[], boolean batchedIsStream[], int batchedStreamLengths[], boolean batchedIsNull[], boolean isReallyBatch)
throws SQLException
{
checkClosed();
ConnectionImpl locallyScopedConn = connection;
if(locallyScopedConn.isReadOnly())
throw SQLError.createSQLException(Messages.getString("PreparedStatement.34") + Messages.getString("PreparedStatement.35"), "S1009", getExceptionInterceptor());
if(firstCharOfStmt == 'S' && isSelectQuery())
throw SQLError.createSQLException(Messages.getString("PreparedStatement.37"), "01S03", getExceptionInterceptor());
if(results != null && !locallyScopedConn.getHoldResultsOpenOverStatementClose())
results.realClose(false);
//返回结果
ResultSetInternalMethods rs = null;
synchronized(locallyScopedConn.getMutex())
{
//填充更新包
Buffer sendPacket = fillSendPacket(batchedParameterStrings, batchedParameterStreams, batchedIsStream, batchedStreamLengths);
String oldCatalog = null;
if(!locallyScopedConn.getCatalog().equals(currentCatalog))
{
oldCatalog = locallyScopedConn.getCatalog();
locallyScopedConn.setCatalog(currentCatalog);
}
if(locallyScopedConn.useMaxRows())
executeSimpleNonQuery(locallyScopedConn, "SET OPTION SQL_SELECT_LIMIT=DEFAULT");
boolean oldInfoMsgState = false;
if(retrieveGeneratedKeys)
{
oldInfoMsgState = locallyScopedConn.isReadInfoMsgEnabled();
locallyScopedConn.setReadInfoMsgEnabled(true);
}
//内部执行更新，这个我们在前面，看过，今天再看一下，只看关键
rs = executeInternal(-1, sendPacket, false, false, null, isReallyBatch);
if(retrieveGeneratedKeys)
{
locallyScopedConn.setReadInfoMsgEnabled(oldInfoMsgState);
rs.setFirstCharOfQuery(firstCharOfStmt);
}
if(oldCatalog != null)
locallyScopedConn.setCatalog(oldCatalog);
}
results = rs;
updateCount = rs.getUpdateCount();
if(containsOnDuplicateKeyUpdateInSQL() && compensateForOnDuplicateKeyUpdate && (updateCount == 2L || updateCount == 0L))
updateCount = 1L;
int truncatedUpdateCount = 0;
if(updateCount > 2147483647L)
truncatedUpdateCount = 2147483647;
else
truncatedUpdateCount = (int)updateCount;
lastInsertId = rs.getUpdateID();
return truncatedUpdateCount;
}
//执行更新
protected ResultSetInternalMethods executeInternal(int maxRowsToRetrieve, Buffer sendPacket, boolean createStreamingResultSet, boolean queryIsSelectOnly, Field metadataFromCache[], boolean isBatch)
throws SQLException
{
ConnectionImpl locallyScopedConnection;
resetCancelledState();
locallyScopedConnection = connection;
numberOfExecutions++;
if(!doPingInstead)
break MISSING_BLOCK_LABEL_36;
doPingInstead();
return results;
StatementImpl.CancelTask timeoutTask = null;
ResultSetInternalMethods rs;
if(locallyScopedConnection.getEnableQueryTimeouts() && timeoutInMillis != 0 && locallyScopedConnection.versionMeetsMinimum(5, 0, 0))
{
timeoutTask = new StatementImpl.CancelTask(this, this);
//连接定时任务执行器Timer，等待timeoutInMillis毫秒后，执行查询定时任务timeoutTask
ConnectionImpl.getCancelTimer().schedule(timeoutTask, timeoutInMillis);
}
//执行查询，并返回结果集
rs = locallyScopedConnection.execSQL(this, null, maxRowsToRetrieve, sendPacket, resultSetType, resultSetConcurrency, createStreamingResultSet, currentCatalog, metadataFromCache, isBatch);
if(timeoutTask != null)
{
timeoutTask.cancel();
if(timeoutTask.caughtWhileCancelling != null)
throw timeoutTask.caughtWhileCancelling;
timeoutTask = null;
}
synchronized(cancelTimeoutMutex)
{
if(wasCancelled)
{
SQLException cause = null;
if(wasCancelledByTimeout)
cause = new MySQLTimeoutException();
else
cause = new MySQLStatementCancelledException();
resetCancelledState();
throw cause;
}
}
if(timeoutTask != null)
timeoutTask.cancel();
break MISSING_BLOCK_LABEL_242;
Exception exception1;
exception1;
if(timeoutTask != null)
timeoutTask.cancel();
throw exception1;
return rs;
NullPointerException npe;
npe;
checkClosed();
throw npe;
}
我们来看一下这一段都做了些什么？
if(locallyScopedConnection.getEnableQueryTimeouts() && timeoutInMillis != 0 && locallyScopedConnection.versionMeetsMinimum(5, 0, 0))
{
timeoutTask = new StatementImpl.CancelTask(this, this);
//连接定时任务执行器Timer，等待timeoutInMillis毫秒后，执行查询定时任务timeoutTask
ConnectionImpl.getCancelTimer().schedule(timeoutTask, timeoutInMillis);
}
//StatementImpl
public class StatementImpl
implements com.mysql.jdbc.Statement
{
class CancelTask extends TimerTask
{
public void run()
{
Thread cancelThread = new Thread() {
public void run()
{
com.mysql.jdbc.Connection cancelConn = null;
Statement cancelStmt = null;
try
{
synchronized(cancelTimeoutMutex)
{
//复制connection
cancelConn = connection.duplicate();
//创建Statement
cancelStmt = cancelConn.createStatement();
cancelStmt.execute("KILL QUERY " + connectionId);
toCancel.wasCancelled = true;
toCancel.wasCancelledByTimeout = true;
}
}
catch(SQLException sqlEx)
{
caughtWhileCancelling = sqlEx;
}
catch(NullPointerException npe) { }
finally
{
if(cancelStmt != null)
try
{
cancelStmt.close();
}
catch(SQLException sqlEx)
{
throw new RuntimeException(sqlEx.toString());
}
if(cancelConn != null)
try
{
cancelConn.close();
}
catch(SQLException sqlEx)
{
throw new RuntimeException(sqlEx.toString());
}
}
}
};
cancelThread.start();
}
long connectionId;
SQLException caughtWhileCancelling;
StatementImpl toCancel;
CancelTask(StatementImpl cancellee)
throws SQLException
{
connectionId = 0L;
caughtWhileCancelling = null;
connectionId = connection.getIO().getThreadId();
toCancel = cancellee;
}
}
}
//创建Statement
cancelStmt = cancelConn.createStatement();
//ConnectionImpl
public Statement createStatement()
throws SQLException
{
return createStatement(1003, 1007);
}
public Statement createStatement(int resultSetType, int resultSetConcurrency)
throws SQLException
{
checkClosed();
StatementImpl stmt = new StatementImpl(this, database);
stmt.setResultSetType(resultSetType);
stmt.setResultSetConcurrency(resultSetConcurrency);
return stmt;
}
//连接定时任务执行器Timer，等待timeoutInMillis毫秒后，执行查询定时任务timeoutTask
ConnectionImpl.getCancelTimer().schedule(timeoutTask, timeoutInMillis);
//ConnectionImpl
protected static Timer getCancelTimer()
{
//private static Timer cancelTimer;
return cancelTimer;
}
从上面这一段可以看出，如果延时查询的话，就创建StatementImpl.CancelTask（TimeTask）定时任务，
并有ConnectionImpl的cancelTimer（Timer）去调度。
回到executeInternal方法，
来看执行查询，返回结果集，这个时调用ConnectionImpl的execSQL
//ConnectionImpl
ResultSetInternalMethods execSQL(StatementImpl callingStatement, String sql, int maxRows, Buffer packet, int resultSetType, int resultSetConcurrency, boolean streamResults,
String catalog, Field cachedMetadata[], boolean isBatch)
throws SQLException
{
Object obj = mutex;
JVM INSTR monitorenter ;
long queryStartTime;
int endOfQueryPacketPosition;
queryStartTime = 0L;
endOfQueryPacketPosition = 0;
if(packet != null)
endOfQueryPacketPosition = packet.getPosition();
if(getGatherPerformanceMetrics())
queryStartTime = System.currentTimeMillis();
lastQueryFinishedTime = 0L;
if(!failedOver || !autoCommit || isBatch || !shouldFallBack() || executingFailoverReconnect)
break MISSING_BLOCK_LABEL_151;
executingFailoverReconnect = true;
//创建MysqlIO，这个我们在前面ServerPrepareStatement中讲过
createNewIO(true);
String connectedHost = io.getHost();
if(connectedHost != null && hostList.get(0).equals(connectedHost))
{
failedOver = false;
queriesIssuedFailedOver = 0L;
setReadOnlyInternal(false);
}
if((getHighAvailability() || failedOver) && (autoCommit || getAutoReconnectForPools()) && needsPing && !isBatch)
try
{
pingInternal(false, 0);
needsPing = false;
}
catch(Exception Ex)
{
createNewIO(true);
}
ResultSetInternalMethods resultsetinternalmethods1;
if(packet != null)
break MISSING_BLOCK_LABEL_267;
String encoding = null;
if(getUseUnicode())
encoding = getEncoding();
//关键在这一句MysqlIO执行查询
resultsetinternalmethods1 = io.sqlQueryDirect(callingStatement, sql, encoding, null, maxRows, resultSetType, resultSetConcurrency, streamResults, catalog, cachedMetadata);
return resultsetinternalmethods1;
ResultSetInternalMethods resultsetinternalmethods;
try
{
resultsetinternalmethods = io.sqlQueryDirect(callingStatement, null, null, packet, maxRows, resultSetType, resultSetConcurrency, streamResults, catalog, cachedMetadata);
}
return resultsetinternalmethods;
}
来看MysqlIO执行查询
//MysqlIO
final ResultSetInternalMethods sqlQueryDirect(StatementImpl callingStatement, String query, String characterEncoding, Buffer queryPacket, int maxRows, int resultSetType, int resultSetConcurrency,
boolean streamResults, String catalog, Field cachedMetadata[])
throws Exception
{
statementExecutionDepth++;
//返回结果集
ResultSetInternalMethods resultsetinternalmethods;
if(statementInterceptors == null)
break MISSING_BLOCK_LABEL_47;
//拦截器处理
ResultSetInternalMethods interceptedResults = invokeStatementInterceptorsPre(query, callingStatement);
if(interceptedResults == null)
break MISSING_BLOCK_LABEL_47;
resultsetinternalmethods = interceptedResults;
statementExecutionDepth--;
return resultsetinternalmethods;
ResultSetInternalMethods resultsetinternalmethods1;
long queryStartTime = 0L;
long queryEndTime = 0L;
if(query != null)
{
int packLength = 5 + query.length() * 2 + 2;
String statementComment = connection.getStatementComment();
byte commentAsBytes[] = null;
if(statementComment != null)
{
commentAsBytes = StringUtils.getBytes(statementComment, null, characterEncoding, connection.getServerCharacterEncoding(), connection.parserKnowsUnicode(), getExceptionInterceptor());
packLength += commentAsBytes.length;
packLength += 6;
}
if(sendPacket == null)
sendPacket = new Buffer(packLength);
else
sendPacket.clear();
sendPacket.writeByte((byte)3);
if(commentAsBytes != null)
{
//将注释添加的查询包中
sendPacket.writeBytesNoNull(Constants.SLASH_STAR_SPACE_AS_BYTES);
sendPacket.writeBytesNoNull(commentAsBytes);
sendPacket.writeBytesNoNull(Constants.SPACE_STAR_SLASH_SPACE_AS_BYTES);
}
if(characterEncoding != null)
{
//如果有编码信息，则将查询编码后，组装到包中
if(platformDbCharsetMatches)
sendPacket.writeStringNoNull(query, characterEncoding, connection.getServerCharacterEncoding(), connection.parserKnowsUnicode(), connection);
else
if(StringUtils.startsWithIgnoreCaseAndWs(query, "LOAD DATA"))
sendPacket.writeBytesNoNull(query.getBytes());
else
sendPacket.writeStringNoNull(query, characterEncoding, connection.getServerCharacterEncoding(), connection.parserKnowsUnicode(), connection);
} else
{
sendPacket.writeStringNoNull(query);
}
queryPacket = sendPacket;
}
byte queryBuf[] = null;
int oldPacketPosition = 0;
if(needToGrabQueryFromPacket)
{
queryBuf = queryPacket.getByteBuffer();
oldPacketPosition = queryPacket.getPosition();
queryStartTime = getCurrentTimeNanosOrMillis();
}
if(autoGenerateTestcaseScript)
{
String testcaseQuery = null;
if(query != null)
testcaseQuery = query;
else
testcaseQuery = new String(queryBuf, 5, oldPacketPosition - 5);
StringBuffer debugBuf = new StringBuffer(testcaseQuery.length() + 32);
connection.generateConnectionCommentBlock(debugBuf);
debugBuf.append(testcaseQuery);
debugBuf.append(';');
connection.dumpTestcaseQuery(debugBuf.toString());
}
//MysqlIO发送查询包到Server，获取返回结果
Buffer resultPacket = sendCommand(3, null, queryPacket, false, null, 0);
long fetchBeginTime = 0L;
long fetchEndTime = 0L;
String profileQueryToLog = null;
boolean queryWasSlow = false;
if(profileSql || logSlowQueries)
{
queryEndTime = System.currentTimeMillis();
boolean shouldExtractQuery = false;
if(profileSql)
shouldExtractQuery = true;
else
if(logSlowQueries)
{
long queryTime = queryEndTime - queryStartTime;
boolean logSlow = false;
if(useAutoSlowLog)
{
logSlow = queryTime > (long)connection.getSlowQueryThresholdMillis();
} else
{
logSlow = connection.isAbonormallyLongQuery(queryTime);
connection.reportQueryTime(queryTime);
}
if(logSlow)
{
shouldExtractQuery = true;
queryWasSlow = true;
}
}
if(shouldExtractQuery)
{
boolean truncated = false;
int extractPosition = oldPacketPosition;
if(oldPacketPosition > connection.getMaxQuerySizeToLog())
{
extractPosition = connection.getMaxQuerySizeToLog() + 5;
truncated = true;
}
profileQueryToLog = new String(queryBuf, 5, extractPosition - 5);
if(truncated)
profileQueryToLog = profileQueryToLog + Messages.getString("MysqlIO.25");
}
fetchBeginTime = queryEndTime;
}
//从中resultPacket，获取返回结果
ResultSetInternalMethods rs = readAllResults(callingStatement, maxRows, resultSetType, resultSetConcurrency, streamResults, catalog, resultPacket, false, -1L, cachedMetadata);
if(queryWasSlow && !serverQueryWasSlow)
{
StringBuffer mesgBuf = new StringBuffer(48 + profileQueryToLog.length());
mesgBuf.append(Messages.getString("MysqlIO.SlowQuery", new Object[] {
new Long(slowQueryThreshold), queryTimingUnits, new Long(queryEndTime - queryStartTime)
}));
mesgBuf.append(profileQueryToLog);
ProfilerEventHandler eventSink = ProfilerEventHandlerFactory.getInstance(connection);
eventSink.consumeEvent(new ProfilerEvent((byte)6, "", catalog, connection.getId(), callingStatement == null ? 999 : callingStatement.getId(), ((ResultSetImpl)rs).resultId, System.currentTimeMillis(), (int)(queryEndTime - queryStartTime), queryTimingUnits, null, new Throwable(), mesgBuf.toString()));
if(connection.getExplainSlowQueries())
if(oldPacketPosition < 1048576)
explainSlowQuery(queryPacket.getBytes(5, oldPacketPosition - 5), profileQueryToLog);
else
connection.getLog().logWarn(Messages.getString("MysqlIO.28") + 1048576 + Messages.getString("MysqlIO.29"));
}
if(logSlowQueries)
{
ProfilerEventHandler eventSink = ProfilerEventHandlerFactory.getInstance(connection);
if(queryBadIndexUsed)
eventSink.consumeEvent(new ProfilerEvent((byte)6, "", catalog, connection.getId(), callingStatement == null ? 999 : callingStatement.getId(), ((ResultSetImpl)rs).resultId, System.currentTimeMillis(), queryEndTime - queryStartTime, queryTimingUnits, null, new Throwable(), Messages.getString("MysqlIO.33") + profileQueryToLog));
if(queryNoIndexUsed)
eventSink.consumeEvent(new ProfilerEvent((byte)6, "", catalog, connection.getId(), callingStatement == null ? 999 : callingStatement.getId(), ((ResultSetImpl)rs).resultId, System.currentTimeMillis(), queryEndTime - queryStartTime, queryTimingUnits, null, new Throwable(), Messages.getString("MysqlIO.35") + profileQueryToLog));
if(serverQueryWasSlow)
eventSink.consumeEvent(new ProfilerEvent((byte)6, "", catalog, connection.getId(), callingStatement == null ? 999 : callingStatement.getId(), ((ResultSetImpl)rs).resultId, System.currentTimeMillis(), queryEndTime - queryStartTime, queryTimingUnits, null, new Throwable(), Messages.getString("MysqlIO.ServerSlowQuery") + profileQueryToLog));
}
if(profileSql)
{
fetchEndTime = getCurrentTimeNanosOrMillis();
ProfilerEventHandler eventSink = ProfilerEventHandlerFactory.getInstance(connection);
eventSink.consumeEvent(new ProfilerEvent((byte)3, "", catalog, connection.getId(), callingStatement == null ? 999 : callingStatement.getId(), ((ResultSetImpl)rs).resultId, System.currentTimeMillis(), queryEndTime - queryStartTime, queryTimingUnits, null, new Throwable(), profileQueryToLog));
eventSink.consumeEvent(new ProfilerEvent((byte)5, "", catalog, connection.getId(), callingStatement == null ? 999 : callingStatement.getId(), ((ResultSetImpl)rs).resultId, System.currentTimeMillis(), fetchEndTime - fetchBeginTime, queryTimingUnits, null, new Throwable(), null));
}
if(hadWarnings)
scanForAndThrowDataTruncation();
if(statementInterceptors != null)
{
ResultSetInternalMethods interceptedResults = invokeStatementInterceptorsPost(query, callingStatement, rs);
if(interceptedResults != null)
rs = interceptedResults;
}
resultsetinternalmethods1 = rs;
statementExecutionDepth--;
return resultsetinternalmethods1;
}
//从缓冲区，去除结果集
ResultSetImpl readAllResults(StatementImpl callingStatement, int maxRows, int resultSetType, int resultSetConcurrency, boolean streamResults, String catalog, Buffer resultPacket,
boolean isBinaryEncoded, long preSentColumnCount, Field metadataFromCache[])
throws SQLException
{
resultPacket.setPosition(resultPacket.getPosition() - 1);
ResultSetImpl topLevelResultSet = readResultsForQueryOrUpdate(callingStatement, maxRows, resultSetType, resultSetConcurrency, streamResults, catalog, resultPacket, isBinaryEncoded, preSentColumnCount, metadataFromCache);
ResultSetImpl currentResultSet = topLevelResultSet;
boolean checkForMoreResults = (clientParam & 131072L) != 0L;
boolean serverHasMoreResults = (serverStatus & 8) != 0;
if(serverHasMoreResults && streamResults)
{
if(topLevelResultSet.getUpdateCount() != -1L)
tackOnMoreStreamingResults(topLevelResultSet);
reclaimLargeReusablePacket();
return topLevelResultSet;
}
for(boolean moreRowSetsExist = checkForMoreResults & serverHasMoreResults; moreRowSetsExist; moreRowSetsExist = (serverStatus & 8) != 0)
{
Buffer fieldPacket = checkErrorPacket();
fieldPacket.setPosition(0);
//读取结果集
ResultSetImpl newResultSet = readResultsForQueryOrUpdate(callingStatement, maxRows, resultSetType, resultSetConcurrency, streamResults, catalog, fieldPacket, isBinaryEncoded, preSentColumnCount, metadataFromCache);
currentResultSet.setNextResultSet(newResultSet);
currentResultSet = newResultSet;
}
if(!streamResults)
clearInputStream();
reclaimLargeReusablePacket();
return topLevelResultSet;
}
从上面可以看出，批处理就是将PrepareStatment的参数信息，是不是流，是否为null，参数值，参数流封装成BatchParams，添加到batchedArgs List中，执行批处理是将batchedArgs里的参数分批次通过MysqlIO发送给Server。
//清空批信息
public synchronized void clearBatch()
throws SQLException
{
batchHasPlainStatements = false;
super.clearBatch();
}
//StatementImpl
public synchronized void clearBatch()
throws SQLException
{
if(batchedArgs != null)
//清空参数List
batchedArgs.clear();
}
//清除参数
public synchronized void clearParameters()
throws SQLException
{
checkClosed();
for(int i = 0; i < parameterValues.length; i++)
{
//重置statement，参数值，参数流，参数类型，是否为null，是否是流描述信息
parameterValues[i] = null;
parameterStreams[i] = null;
isStream[i] = false;
isNull[i] = false;
parameterTypes[i] = 0;
}
}
//关闭Statement
public synchronized void close()
throws SQLException
{
//委托给realClose
realClose(true, true);
}
//关闭Statement
protected void realClose(boolean calledExplicitly, boolean closeOpenResults)
throws SQLException
{
if(useUsageAdvisor && numberOfExecutions <= 1)
{
String message = Messages.getString("PreparedStatement.43");
eventSink.consumeEvent(new ProfilerEvent((byte)0, "", currentCatalog, connectionId, getId(), -1, System.currentTimeMillis(), 0L, Constants.MILLIS_I18N, null, pointOfOrigin, message));
}
super.realClose(calledExplicitly, closeOpenResults);
dbmd = null;
originalSql = null;
staticSqlStrings = (byte[][])null;
parameterValues = (byte[][])null;
parameterStreams = null;
isStream = null;
streamLengths = null;
isNull = null;
streamConvertBuf = null;
parameterTypes = null;
}
从realClose方法来看，关闭Statement，就是清空参数类型，参数流，参数值，sql，databaseMetaData等信息。