How to update oracle Oracle by using JDBC

Question

Mostly we used and still using the following way, as well as it was recommended by oracle official document.
String empty_string = "need to be updated";
conn = getConnection();
pStmt = conn.prepareStatement("SELECT REFERENCE FROM activity WHERE ID = ? FOR UPDATE");
pStmt.setLong(1, 1);
rset = pStmt.executeQuery();
Clob clob = null;
while (rset.next()) { 
clob = rset.getClob(1);
Writer writer = adapter.getCharacterOutputStream(clob);
writer.write(empty_string);
writer.flush();
writer.close();
pStmt = conn.prepareStatement("update activity set REFERENCE = ? WHERE ID = ?");
pStmt.setClob(1, clob);
pStmt.setLong(2, 1);
pStmt.executeUpdate();
Now I want use the second way as below, to be honest I never used it before so I wonder can it work properly? as it did not require an explicit lock. will it bring potential risk? according your experience if it work well, which did better performance?
1. String toBeUpdated = "need to be updated";
2. StringReader clob = new StringReader(toBeUpdated );
3. pStmt = conn.prepareStatement("update activity set REFERENCE = ? WHERE ID = ?");
4. pStmt.setCharacterStream(1, clob, toBeUpdated.length());
5. pStmt.setLong(2, 1);
6. pStmt.executeUpdate();

Answer 1

Welcome to the vast OTN forums!
If you are asking about jdbc specifically, perhaps the relevant forum is: {forum:id=1050}.
If what you really are asking is something like (without java code and context):
"I used to do Select.. for update, followed by update table .... Can I instead use only update table ... ? When and why would you use one or the other?"
Then this forum might be ok, but the SQL and PL/SQL forum might be even better: {forum:id=75}