展示JDBC存取ORACLE大型數據對象LOB幾種情況的示范類
import java.io.*;
import java.util.*;
import java.sql.*;
public class LobPros
{
/**
* ORACLE驅動程序
*/
private static final String DRIVER = "oracle.jdbc.driver.OracleDriver";
/**
* ORACLE連接用URL
*/
private static final String URL = "jdbc:oracle:thin:@test2000:1521:orac";
/**
* 用戶名
*/
private static final String USER = "user";
/**
* 密碼
*/
private static final String PASSWORD = "pswd";
/**
* 數據庫連接
*/
private static Connection conn = null;
/**
* SQL語句對象
*/
private static Statement stmt = null;
/**
* @roseuid 3EDA089E02BC
*/
public LobPros()
{
}
/**
* 往數據庫中插入一個新的CLOB對象
*
* @param infile - 數據文件
* @throws java.lang.Exception
* @roseuid 3EDA04A902BC
*/
public static void clobInsert(String infile) throws Exception
{
/* 設定不自動提交 */
boolean defaultCommit = conn.getAutoCommit();
conn.setAutoCommit(false);
try {
/* 插入一個空的CLOB對象 */
stmt.executeUpdate("INSERT INTO TEST_CLOB VALUES (''111'', EMPTY_CLOB())");
/* 查詢此CLOB對象並鎖定 */
ResultSet rs = stmt.executeQuery("SELECT CLOBCOL FROM TEST_CLOB WHERE ID=''111'' FOR UPDATE");
while (rs.next()) {
/* 取出此CLOB對象 */
oracle.sql.CLOB clob = (oracle.sql.CLOB)rs.getClob("CLOBCOL");
/* 向CLOB對象中寫入數據 */
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) {
/* 出錯回滾 */
conn.rollback();
throw ex;
}
/* 恢復原提交狀態 */
conn.setAutoCommit(defaultCommit);
}
/**
* 修改CLOB對象（是在原CLOB對象基礎上進行覆蓋式的修改）
*
* @param infile - 數據文件
* @throws java.lang.Exception
* @roseuid 3EDA04B60367
*/
public static void clobModify(String infile) throws Exception
{
/* 設定不自動提交 */
boolean defaultCommit = conn.getAutoCommit();
conn.setAutoCommit(false);
try {
/* 查詢CLOB對象並鎖定 */
ResultSet rs = stmt.executeQuery("SELECT CLOBCOL FROM TEST_CLOB WHERE ID=''111'' FOR UPDATE");
while (rs.next()) {
/* 獲取此CLOB對象 */
oracle.sql.CLOB clob = (oracle.sql.CLOB)rs.getClob("CLOBCOL");
/* 進行覆蓋式修改 */
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) {
/* 出錯回滾 */
conn.rollback();
throw ex;
}
/* 恢復原提交狀態 */
conn.setAutoCommit(defaultCommit);
}
/**
* 替換CLOB對象（將原CLOB對象清除，換成一個全新的CLOB對象）
*
* @param infile - 數據文件
* @throws java.lang.Exception
* @roseuid 3EDA04BF01E1
*/
public static void clobReplace(String infile) throws Exception
{
/* 設定不自動提交 */
boolean defaultCommit = conn.getAutoCommit();
conn.setAutoCommit(false);
try {
/* 清空原CLOB對象 */
stmt.executeUpdate("UPDATE TEST_CLOB SET CLOBCOL=EMPTY_CLOB() WHERE ID=''111''");
/* 查詢CLOB對象並鎖定 */
ResultSet rs = stmt.executeQuery("SELECT CLOBCOL FROM TEST_CLOB WHERE ID=''111'' FOR UPDATE");
while (rs.next()) {
/* 獲取此CLOB對象 */
oracle.sql.CLOB clob = (oracle.sql.CLOB)rs.getClob("CLOBCOL");
/* 更新數據 */
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) {
/* 出錯回滾 */
conn.rollback();
throw ex;
}
/* 恢復原提交狀態 */
conn.setAutoCommit(defaultCommit);
}
/**
* CLOB對象讀取
*
* @param outfile - 輸出文件名
* @throws java.lang.Exception
* @roseuid 3EDA04D80116
*/
public static void clobRead(String outfile) throws Exception
{
/* 設定不自動提交 */
boolean defaultCommit = conn.getAutoCommit();
conn.setAutoCommit(false);
try {
/* 查詢CLOB對象 */
ResultSet rs = stmt.executeQuery("SELECT * FROM TEST_CLOB WHERE ID=''111''");
while (rs.next()) {
/* 獲取CLOB對象 */
oracle.sql.CLOB clob = (oracle.sql.CLOB)rs.getClob("CLOBCOL");
/* 以字符形式輸出 */
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;
}
/* 恢復原提交狀態 */
conn.setAutoCommit(defaultCommit);
}
/**
* 向數據庫中插入一個新的BLOB對象
*
* @param infile - 數據文件
* @throws java.lang.Exception
* @roseuid 3EDA04E300F6
*/
public static void blobInsert(String infile) throws Exception
{
/* 設定不自動提交 */
boolean defaultCommit = conn.getAutoCommit();
conn.setAutoCommit(false);
try {
/* 插入一個空的BLOB對象 */
stmt.executeUpdate("INSERT INTO TEST_BLOB VALUES (''222'', EMPTY_BLOB())");
/* 查詢此BLOB對象並鎖定 */
ResultSet rs = stmt.executeQuery("SELECT BLOBCOL FROM TEST_BLOB WHERE ID=''222'' FOR UPDATE");
while (rs.next()) {
/* 取出此BLOB對象 */
oracle.sql.BLOB blob = (oracle.sql.BLOB)rs.getBlob("BLOBCOL");
/* 向BLOB對象中寫入數據 */
BufferedOutputStream out = new BufferedOutputStream(blob.getBinaryOutputStream());
BufferedInputStream in = new BufferedInputStream(new FileInputStream(infile));
int c;
while ((c=in.read())!=-1) {
out.write(c);
}
in.close();
out.close();
}
/* 正式提交 */
conn.commit();
} catch (Exception ex) {
/* 出錯回滾 */
conn.rollback();
throw ex;
}
/* 恢復原提交狀態 */
conn.setAutoCommit(defaultCommit);
}
/**
* 修改BLOB對象（是在原BLOB對象基礎上進行覆蓋式的修改）
*
* @param infile - 數據文件
* @throws java.lang.Exception
* @roseuid 3EDA04E90106
*/
public static void blobModify(String infile) throws Exception
{
/* 設定不自動提交 */
boolean defaultCommit = conn.getAutoCommit();
conn.setAutoCommit(false);
try {
/* 查詢BLOB對象並鎖定 */
ResultSet rs = stmt.executeQuery("SELECT BLOBCOL FROM TEST_BLOB WHERE ID=''222'' FOR UPDATE");
while (rs.next()) {
/* 取出此BLOB對象 */
oracle.sql.BLOB blob = (oracle.sql.BLOB)rs.getBlob("BLOBCOL");
/* 向BLOB對象中寫入數據 */
BufferedOutputStream out = new BufferedOutputStream(blob.getBinaryOutputStream());
BufferedInputStream in = new BufferedInputStream(new FileInputStream(infile));
int c;
while ((c=in.read())!=-1) {
out.write(c);
}
in.close();
out.close();
}
/* 正式提交 */
conn.commit();
} catch (Exception ex) {
/* 出錯回滾 */
conn.rollback();
throw ex;
}
/* 恢復原提交狀態 */
conn.setAutoCommit(defaultCommit);
}
/**
* 替換BLOB對象（將原BLOB對象清除，換成一個全新的BLOB對象）
*
* @param infile - 數據文件
* @throws java.lang.Exception
* @roseuid 3EDA0505000C
*/
public static void blobReplace(String infile) throws Exception
{
/* 設定不自動提交 */
boolean defaultCommit = conn.getAutoCommit();
conn.setAutoCommit(false);
try {
/* 清空原BLOB對象 */
stmt.executeUpdate("UPDATE TEST_BLOB SET BLOBCOL=EMPTY_BLOB() WHERE ID=''222''");
/* 查詢此BLOB對象並鎖定 */
ResultSet rs = stmt.executeQuery("SELECT BLOBCOL FROM TEST_BLOB WHERE ID=''222'' FOR UPDATE");
while (rs.next()) {
/* 取出此BLOB對象 */
oracle.sql.BLOB blob = (oracle.sql.BLOB)rs.getBlob("BLOBCOL");
/* 向BLOB對象中寫入數據 */
BufferedOutputStream out = new BufferedOutputStream(blob.getBinaryOutputStream());
BufferedInputStream in = new BufferedInputStream(new FileInputStream(infile));
int c;
while ((c=in.read())!=-1) {
out.write(c);
}
in.close();
out.close();
}
/* 正式提交 */
conn.commit();
} catch (Exception ex) {
/* 出錯回滾 */
conn.rollback();
throw ex;
}
/* 恢復原提交狀態 */
conn.setAutoCommit(defaultCommit);
}
/**
* BLOB對象讀取
*
* @param outfile - 輸出文件名
* @throws java.lang.Exception
* @roseuid 3EDA050B003B
*/
public static void blobRead(String outfile) throws Exception
{
/* 設定不自動提交 */
boolean defaultCommit = conn.getAutoCommit();
conn.setAutoCommit(false);
try {
/* 查詢BLOB對象 */
ResultSet rs = stmt.executeQuery("SELECT BLOBCOL FROM TEST_BLOB WHERE ID=''222''");
while (rs.next()) {
/* 取出此BLOB對象 */
oracle.sql.BLOB blob = (oracle.sql.BLOB)rs.getBlob("BLOBCOL");
/* 以二進制形式輸出 */
BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream(outfile));
BufferedInputStream in = new BufferedInputStream(blob.getBinaryStream());
int c;
while ((c=in.read())!=-1) {
out.write(c);
}
in.close();
out.close();
}
/* 正式提交 */
conn.commit();
} catch (Exception ex) {
/* 出錯回滾 */
conn.rollback();
throw ex;
}
/* 恢復原提交狀態 */
conn.setAutoCommit(defaultCommit);
}
/**
* 建立測試用表格
* @throws Exception
*/
public static void createTables() throws Exception {
try {
stmt.executeUpdate("CREATE TABLE TEST_CLOB ( ID NUMBER(3), CLOBCOL CLOB)");
stmt.executeUpdate("CREATE TABLE TEST_BLOB ( ID NUMBER(3), BLOBCOL BLOB)");
} catch (Exception ex) {
}
}
/**
* @param args - 命令行參數
* @throws java.lang.Exception
* @roseuid 3EDA052002AC
*/
public static void main(String[] args) throws Exception
{
/* 裝載驅動,建立數據庫連接 */
Class.forName(DRIVER);
conn = DriverManager.getConnection(URL,USER,PASSWORD);
stmt = conn.createStatement();
/* 建立測試表格 */
createTables();
/* CLOB對象插入測試 */
clobInsert("c:/clobInsert.txt");
clobRead("c:/clobInsert.out");
/* CLOB對象修改測試 */
clobModify("c:/clobModify.txt");
clobRead("c:/clobModify.out");
/* CLOB對象替換測試 */
clobReplace("c:/clobReplace.txt");
clobRead("c:/clobReplace.out");
/* BLOB對象插入測試 */
blobInsert("c:/blobInsert.doc");
blobRead("c:/blobInsert.out");
/* BLOB對象修改測試 */
blobModify("c:/blobModify.doc");
blobRead("c:/blobModify.out");
/* BLOB對象替換測試 */
blobReplace("c:/blobReplace.doc");
blobRead("c:/bolbReplace.out");
/* 關閉資源退出 */
conn.close();
System.exit(0);
}
}
