oracle中读写blob字段的问题

3、替?CLOB?像（?原CLOB?像清除，?成一?全新的CLOB?像）

public static void clobReplace(String infile) throws Exception

{

/* ?定不自?提交 */

boolean defaultCommit = conn.getAutoCommit();

conn.setAutoCommit(false);

try {

/* 清空原CLOB?像 */

stmt.executeUpdate("UPDATE TEST_CLOB SET CLOBCOL=EMPTY_CLOB() WHERE ID='111'");

/* 查?CLOB?象??定 */

ResultSet rs = stmt.executeQuery("SELECT CLOBCOL FROM TEST_CLOB WHERE ID='111' FOR UPDATE");

while (rs.next()) {

/* ?取此CLOB?像 */

oracle.sql.CLOB clob = (oracle.sql.CLOB)rs.getClob("CLOBCOL");

/* 更新?? */

BufferedWriter out = new BufferedWriter(clob.getCharacterOutputStream());

BufferedReader in = new BufferedReader(new FileReader(infile));

int c;

while ((c=in.read())!=-1) {

out.write(c);

}

in.close();

out.close();

}

/* 正式提交 */

conn.commit();

} catch (Exception ex) {

/* 出?回? */

conn.rollback();

throw ex;

}

/* 恢?原提交?? */

conn.setAutoCommit(defaultCommit);

}

4、CLOB?像?取

public static void clobRead(String outfile) throws Exception

{

/* ?定不自?提交 */

boolean defaultCommit = conn.getAutoCommit();

conn.setAutoCommit(false);

try {

/* 查?CLOB?像 */

ResultSet rs = stmt.executeQuery("SELECT * FROM TEST_CLOB WHERE ID='111'");

while (rs.next()) {

/* ?取CLOB?像 */

oracle.sql.CLOB clob = (oracle.sql.CLOB)rs.getClob("CLOBCOL");

/* 以字符形式?出 */

BufferedReader in = new BufferedReader(clob.getCharacterStream());

BufferedWriter out = new BufferedWriter(new FileWriter(outfile));

int c;

while ((c=in.read())!=-1) {

out.write(c);

}

out.close();

in.close();

}

} catch (Exception ex) {

conn.rollback();

throw ex;

}

/* 恢?原提交?? */

conn.setAutoCommit(defaultCommit);

}

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