I'm trying to get string from BLOB datatype by using
Blob blob = rs.getBlob(cloumnName[i]);
byte[] bdata = blob.getBytes(1, (int) blob.length());
String s = new String(bdata);
It is working fine but when I'm going to convert String
to Blob
and trying to insert into database then nothing inserting into database. I've used below code for converting String to Blob:
String value = (s);
byte[] buff = value.getBytes();
Blob blob = new SerialBlob(buff);
Can anyone help me about to converting of Blob
to String
and String
to Blob
in Java?
How are you setting blob to DB? You should do:
//imagine u have a a prepared statement like:
PreparedStatement ps = conn.prepareStatement("INSERT INTO table VALUES (?)");
String blobString= "This is the string u want to convert to Blob";
oracle.sql.BLOB myBlob = oracle.sql.BLOB.createTemporary(conn, false,oracle.sql.BLOB.DURATION_SESSION);
byte[] buff = blobString.getBytes();
myBlob.putBytes(1,buff);
ps.setBlob(1, myBlob);
ps.executeUpdate();
Use this to convert String to Blob. Where connection is the connection to db object.
String strContent = s;
byte[] byteConent = strContent.getBytes();
Blob blob = connection.createBlob();//Where connection is the connection to db object.
blob.setBytes(1, byteContent);
To convert Blob to String in Java:
byte[] bytes = baos.toByteArray();//Convert into Byte array
String blobString = new String(bytes);//Convert Byte Array into String
try this (a2 is BLOB col)
PreparedStatement ps1 = conn.prepareStatement("update t1 set a2=? where id=1");
Blob blob = conn.createBlob();
blob.setBytes(1, str.getBytes());
ps1.setBlob(1, blob);
ps1.executeUpdate();
it may work even without BLOB, driver will transform types automatically:
ps1.setBytes(1, str.getBytes);
ps1.setString(1, str);
Besides if you work with text CLOB seems to be a more natural col type
And here is my solution, that always works for me
StringBuffer buf = new StringBuffer();
String temp;
BufferedReader bufReader = new BufferedReader(new InputStreamReader(myBlob.getBinaryStream()));
while ((temp=bufReader.readLine())!=null) {
bufappend(temp);
}
Source: Stackoverflow.com