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Some more updates...

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Fri Feb 17 15:11:00 GMT 2001 peter@retep.org.uk
        - Reduced the object overhead in PreparedStatement by reusing the same
          StringBuffer object throughout. Similarly SimpleDateStamp's are alse
          reused in a thread save manner.
        - Implemented in PreparedStatement: setNull(), setDate/Time/Timestamp
          using Calendar, setBlob(), setCharacterStream()
        - Clob's are now implemented in ResultSet & PreparedStatement!
        - Implemented a lot of DatabaseMetaData & ResultSetMetaData methods.
          We have about 18 unimplemented methods left in JDBC2 at the current
          time.
This commit is contained in:
Peter Mount
2001-02-16 16:45:01 +00:00
parent 016f0eed24
commit cdbd27cb23
7 changed files with 348 additions and 124 deletions
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220
src/interfaces/jdbc/org/postgresql/jdbc2/PreparedStatement.java
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@ -36,6 +36,14 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
String[] inStrings;
Connection connection;
// Some performance caches
private StringBuffer sbuf = new StringBuffer();
// We use ThreadLocal for SimpleDateFormat's because they are not that
// thread safe, so each calling thread has its own object.
private ThreadLocal tl_df = new ThreadLocal(); // setDate() SimpleDateFormat
private ThreadLocal tl_tsdf = new ThreadLocal(); // setTimestamp() SimpleDateFormat
/**
* Constructor for the PreparedStatement class.
* Split the SQL statement into segments - separated by the arguments.
@ -78,6 +86,16 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
templateStrings[i] = (String)v.elementAt(i);
}
/**
* New in 7.1 - overides Statement.close() to dispose of a few local objects
*/
public void close() throws SQLException {
// free the ThreadLocal caches
tl_df.set(null);
super.close();
}
/**
* A Prepared SQL query is executed and its ResultSet is returned
*
@ -87,18 +105,7 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
*/
public java.sql.ResultSet executeQuery() throws SQLException
{
StringBuffer s = new StringBuffer();
int i;
for (i = 0 ; i < inStrings.length ; ++i)
{
if (inStrings[i] == null)
throw new PSQLException("postgresql.prep.param",new Integer(i + 1));
s.append (templateStrings[i]);
s.append (inStrings[i]);
}
s.append(templateStrings[inStrings.length]);
return super.executeQuery(s.toString()); // in Statement class
return super.executeQuery(compileQuery()); // in Statement class
}
/**
@ -112,19 +119,28 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
*/
public int executeUpdate() throws SQLException
{
StringBuffer s = new StringBuffer();
return super.executeUpdate(compileQuery()); // in Statement class
}
/**
* Helper - this compiles the SQL query from the various parameters
* This is identical to toString() except it throws an exception if a
* parameter is unused.
*/
private synchronized String compileQuery() throws SQLException
{
sbuf.setLength(0);
int i;
for (i = 0 ; i < inStrings.length ; ++i)
{
if (inStrings[i] == null)
throw new PSQLException("postgresql.prep.param",new Integer(i + 1));
s.append (templateStrings[i]);
s.append (inStrings[i]);
sbuf.append (templateStrings[i]).append (inStrings[i]);
}
s.append(templateStrings[inStrings.length]);
return super.executeUpdate(s.toString()); // in Statement class
}
sbuf.append(templateStrings[inStrings.length]);
return sbuf.toString();
}
/**
* Set a parameter to SQL NULL
@ -262,19 +278,23 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
if(x==null)
set(parameterIndex,"null");
else {
StringBuffer b = new StringBuffer();
int i;
// use the shared buffer object. Should never clash but this makes
// us thread safe!
synchronized(sbuf) {
sbuf.setLength(0);
int i;
b.append('\'');
for (i = 0 ; i < x.length() ; ++i)
{
char c = x.charAt(i);
if (c == '\\' || c == '\'')
b.append((char)'\\');
b.append(c);
}
b.append('\'');
set(parameterIndex, b.toString());
sbuf.append('\'');
for (i = 0 ; i < x.length() ; ++i)
{
char c = x.charAt(i);
if (c == '\\' || c == '\'')
sbuf.append((char)'\\');
sbuf.append(c);
}
sbuf.append('\'');
set(parameterIndex, sbuf.toString());
}
}
}
@ -312,7 +332,11 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
*/
public void setDate(int parameterIndex, java.sql.Date x) throws SQLException
{
SimpleDateFormat df = new SimpleDateFormat("''yyyy-MM-dd''");
SimpleDateFormat df = (SimpleDateFormat) tl_df.get();
if(df==null) {
df = new SimpleDateFormat("''yyyy-MM-dd''");
tl_df.set(df);
}
set(parameterIndex, df.format(x));
@ -351,11 +375,19 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
*/
public void setTimestamp(int parameterIndex, Timestamp x) throws SQLException
{
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
SimpleDateFormat df = (SimpleDateFormat) tl_tsdf.get();
if(df==null) {
df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
tl_tsdf.set(df);
}
df.setTimeZone(TimeZone.getTimeZone("GMT"));
StringBuffer strBuf = new StringBuffer("'");
strBuf.append(df.format(x)).append('.').append(x.getNanos()/10000000).append("+00'");
set(parameterIndex, strBuf.toString());
// Use the shared StringBuffer
synchronized(sbuf) {
sbuf.setLength(0);
sbuf.append("'").append(df.format(x)).append('.').append(x.getNanos()/10000000).append("+00'");
set(parameterIndex, sbuf.toString());
}
// The above works, but so does the following. I'm leaving the above in, but this seems
// to be identical. Pays to read the docs ;-)
@ -575,38 +607,31 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
*/
public boolean execute() throws SQLException
{
StringBuffer s = new StringBuffer();
int i;
for (i = 0 ; i < inStrings.length ; ++i)
{
if (inStrings[i] == null)
throw new PSQLException("postgresql.prep.param",new Integer(i + 1));
s.append (templateStrings[i]);
s.append (inStrings[i]);
}
s.append(templateStrings[inStrings.length]);
return super.execute(s.toString()); // in Statement class
return super.execute(compileQuery()); // in Statement class
}
/**
* Returns the SQL statement with the current template values
* substituted.
* NB: This is identical to compileQuery() except instead of throwing
* SQLException if a parameter is null, it places ? instead.
*/
public String toString() {
StringBuffer s = new StringBuffer();
synchronized(sbuf) {
sbuf.setLength(0);
int i;
for (i = 0 ; i < inStrings.length ; ++i)
{
if (inStrings[i] == null)
s.append( '?' );
sbuf.append( '?' );
else
s.append (templateStrings[i]);
s.append (inStrings[i]);
sbuf.append (templateStrings[i]);
sbuf.append (inStrings[i]);
}
s.append(templateStrings[inStrings.length]);
return s.toString();
sbuf.append(templateStrings[inStrings.length]);
return sbuf.toString();
}
}
// **************************************************************
@ -631,14 +656,26 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
// ** JDBC 2 Extensions **
/**
* This parses the query and adds it to the current batch
*/
public void addBatch() throws SQLException
{
throw org.postgresql.Driver.notImplemented();
super.addBatch(compileQuery());
}
/**
* Not sure what this one does, so I'm saying this returns the MetaData for
* the last ResultSet returned!
*/
public java.sql.ResultSetMetaData getMetaData() throws SQLException
{
throw org.postgresql.Driver.notImplemented();
java.sql.ResultSet rs = getResultSet();
if(rs!=null)
return rs.getMetaData();
// Does anyone really know what this method does?
return null;
}
public void setArray(int i,Array x) throws SQLException
@ -646,24 +683,59 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
throw org.postgresql.Driver.notImplemented();
}
/**
* Sets a Blob - basically its similar to setBinaryStream()
*/
public void setBlob(int i,Blob x) throws SQLException
{
throw org.postgresql.Driver.notImplemented();
setBinaryStream(i,x.getBinaryStream(),(int)x.length());
}
/**
* This is similar to setBinaryStream except it uses a Reader instead of
* InputStream.
*/
public void setCharacterStream(int i,java.io.Reader x,int length) throws SQLException
{
throw org.postgresql.Driver.notImplemented();
LargeObjectManager lom = connection.getLargeObjectAPI();
int oid = lom.create();
LargeObject lob = lom.open(oid);
OutputStream los = lob.getOutputStream();
try {
// could be buffered, but then the OutputStream returned by LargeObject
// is buffered internally anyhow, so there would be no performance
// boost gained, if anything it would be worse!
int c=x.read();
int p=0;
while(c>-1 && p<length) {
los.write(c);
c=x.read();
p++;
}
los.close();
} catch(IOException se) {
throw new PSQLException("postgresql.prep.is",se);
}
// lob is closed by the stream so don't call lob.close()
setInt(i,oid);
}
/**
* New in 7.1
*/
public void setClob(int i,Clob x) throws SQLException
{
throw org.postgresql.Driver.notImplemented();
setBinaryStream(i,x.getAsciiStream(),(int)x.length());
}
/**
* At least this works as in PostgreSQL null represents anything null ;-)
*
* New in 7,1
*/
public void setNull(int i,int t,String s) throws SQLException
{
throw org.postgresql.Driver.notImplemented();
setNull(i,t);
}
public void setRef(int i,Ref x) throws SQLException
@ -671,19 +743,43 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
throw org.postgresql.Driver.notImplemented();
}
/**
* New in 7,1
*/
public void setDate(int i,java.sql.Date d,java.util.Calendar cal) throws SQLException
{
throw org.postgresql.Driver.notImplemented();
if(cal==null)
setDate(i,d);
else {
cal.setTime(d);
setDate(i,new java.sql.Date(cal.getTime().getTime()));
}
}
/**
* New in 7,1
*/
public void setTime(int i,Time t,java.util.Calendar cal) throws SQLException
{
throw org.postgresql.Driver.notImplemented();
if(cal==null)
setTime(i,t);
else {
cal.setTime(t);
setTime(i,new java.sql.Time(cal.getTime().getTime()));
}
}
/**
* New in 7,1
*/
public void setTimestamp(int i,Timestamp t,java.util.Calendar cal) throws SQLException
{
throw org.postgresql.Driver.notImplemented();
if(cal==null)
setTimestamp(i,t);
else {
cal.setTime(t);
setTimestamp(i,new java.sql.Timestamp(cal.getTime().getTime()));
}
}
}