展示JDBC存取大型数据对象LOB情形的示范类[Java编程]
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展示JDBC存取ORACLE大型数据对象LOB几种情形的示范类
import java.io.*;
import java.util.*;
import java.sql.*;
public class LobPros
{
/**
* ORACLE驱动程序
*/
private static final String DRIVER = "oracle.jdbc.driver.OracleDriver";
/**
* ORACLE衔接用URL
*/
private static final String URL = "jdbc:oracle:thin:@test2000:1521:orac";
/**
* 用户名
*/
private static final String USER = "user";
/**
* 密码
*/
private static final String PASSWORD = "pswd";
/**
* 数据库衔接
*/
private static Connection conn = null;
/**
* SQL语句对象
*/
private static Statement stmt = null;
/**
* @roseuid 3EDA089E02BC
*/
public LobPros()
{
}
/**
* 往数据库中插入一个新的CLOB对象
*
* @param infile - 数据文件
* @throws java.lang.Exception
* @roseuid 3EDA04A902BC
*/
public static void clobInsert(String infile) throws Exception
{
/* 设定不自动提交 */
boolean defaultCommit = conn.getAutoCommit();
conn.setAutoCommit(false);
try {
/* 插入一个空的CLOB对象 */
stmt.executeUpdate("INSERT INTO TEST_CLOB VALUES (''111'', EMPTY_CLOB())");
/* 查询此CLOB对象并锁定 */
ResultSet rs = stmt.executeQuery("SELECT CLOBCOL FROM TEST_CLOB WHERE ID=''111'' FOR UPDATE");
while (rs.next()) {
/* 取出此CLOB对象 */
oracle.sql.CLOB clob = (oracle.sql.CLOB)rs.getClob("CLOBCOL");
/* 向CLOB对象中写入数据 */
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) {
/* 出错回滚 */
conn.rollback();
throw ex;
}
/* 恢答复提交状况 */
conn.setAutoCommit(defaultCommit);
}
/**
* 改正CLOB对象(是在原CLOB对象底子上举行覆盖式的改正)
*
* @param infile - 数据文件
* @throws java.lang.Exception
* @roseuid 3EDA04B60367
*/
public static void clobModify(String infile) throws Exception
{
/* 设定不自动提交 */
boolean defaultCommit = conn.getAutoCommit();
conn.setAutoCommit(false);
try {
/* 查询CLOB对象并锁定 */
ResultSet rs = stmt.executeQuery("SELECT CLOBCOL FROM TEST_CLOB WHERE ID=''111'' FOR UPDATE");
while (rs.next()) {
/* 获得此CLOB对象 */
oracle.sql.CLOB clob = (oracle.sql.CLOB)rs.getClob("CLOBCOL");
/* 举行覆盖式改正 */
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) {
/* 出错回滚 */
conn.rollback();
throw ex;
}
/* 恢答复提交状况 */
conn.setAutoCommit(defaultCommit);
}
/**
* 替换CLOB对象(将原CLOB对象排除,换成一个全新的CLOB对象)
*
* @param infile - 数据文件
* @throws java.lang.Exception
* @roseuid 3EDA04BF01E1
*/
public static void clobReplace(String infile) throws Exception
{
/* 设定不自动提交 */
boolean defaultCommit = conn.getAutoCommit();
conn.setAutoCommit(false);
try {
/* 清空原CLOB对象 */
stmt.executeUpdate("UPDATE TEST_CLOB SET CLOBCOL=EMPTY_CLOB() WHERE ID=''111''");
/* 查询CLOB对象并锁定 */
ResultSet rs = stmt.executeQuery("SELECT CLOBCOL FROM TEST_CLOB WHERE ID=''111'' FOR UPDATE");
while (rs.next()) {
/* 获得此CLOB对象 */
oracle.sql.CLOB clob = (oracle.sql.CLOB)rs.getClob("CLOBCOL");
/* 更新数据 */
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) {
/* 出错回滚 */
conn.rollback();
throw ex;
}
/* 恢答复提交状况 */
conn.setAutoCommit(defaultCommit);
}
/**
* CLOB对象读取
*
* @param outfile - 输出文件名
* @throws java.lang.Exception
* @roseuid 3EDA04D80116
*/
public static void clobRead(String outfile) throws Exception
{
/* 设定不自动提交 */
boolean defaultCommit = conn.getAutoCommit();
conn.setAutoCommit(false);
try {
/* 查询CLOB对象 */
ResultSet rs = stmt.executeQuery("SELECT * FROM TEST_CLOB WHERE ID=''111''");
while (rs.next()) {
/* 获得CLOB对象 */
oracle.sql.CLOB clob = (oracle.sql.CLOB)rs.getClob("CLOBCOL");
/* 以字符情势输出 */
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;
}
/* 恢答复提交状况 */
conn.setAutoCommit(defaultCommit);
}
/**
* 向数据库中插入一个新的BLOB对象
*
* @param infile - 数据文件
* @throws java.lang.Exception
* @roseuid 3EDA04E300F6
*/
public static void blobInsert(String infile) throws Exception
{
/* 设定不自动提交 */
boolean defaultCommit = conn.getAutoCommit();
conn.setAutoCommit(false);
try {
/* 插入一个空的BLOB对象 */
stmt.executeUpdate("INSERT INTO TEST_BLOB VALUES (''222'', EMPTY_BLOB())");
/* 查询此BLOB对象并锁定 */
ResultSet rs = stmt.executeQuery("SELECT BLOBCOL FROM TEST_BLOB WHERE ID=''222'' FOR UPDATE");
while (rs.next()) {
/* 取出此BLOB对象 */
oracle.sql.BLOB blob = (oracle.sql.BLOB)rs.getBlob("BLOBCOL");
/* 向BLOB对象中写入数据 */
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) {
/* 出错回滚 */
conn.rollback();
throw ex;
}
/* 恢答复提交状况 */
conn.setAutoCommit(defaultCommit);
}
/**
* 改正BLOB对象(是在原BLOB对象底子上举行覆盖式的改正)
*
* @param infile - 数据文件
* @throws java.lang.Exception
* @roseuid 3EDA04E90106
*/
public static void blobModify(String infile) throws Exception
{
/* 设定不自动提交 */
boolean defaultCommit = conn.getAutoCommit();
conn.setAutoCommit(false);
try {
/* 查询BLOB对象并锁定 */
ResultSet rs = stmt.executeQuery("SELECT BLOBCOL FROM TEST_BLOB WHERE ID=''222'' FOR UPDATE");
while (rs.next()) {
/* 取出此BLOB对象 */
oracle.sql.BLOB blob = (oracle.sql.BLOB)rs.getBlob("BLOBCOL");
/* 向BLOB对象中写入数据 */
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) {
/* 出错回滚 */
conn.rollback();
throw ex;
}
/* 恢答复提交状况 */
conn.setAutoCommit(defaultCommit);
}
/**
* 替换BLOB对象(将原BLOB对象排除,换成一个全新的BLOB对象)
*
* @param infile - 数据文件
* @throws java.lang.Exception
* @roseuid 3EDA0505000C
*/
public static void blobReplace(String infile) throws Exception
{
/* 设定不自动提交 */
boolean defaultCommit = conn.getAutoCommit();
conn.setAutoCommit(false);
try {
/* 清空原BLOB对象 */
stmt.executeUpdate("UPDATE TEST_BLOB SET BLOBCOL=EMPTY_BLOB() WHERE ID=''222''");
/* 查询此BLOB对象并锁定 */
ResultSet rs = stmt.executeQuery("SELECT BLOBCOL FROM TEST_BLOB WHERE ID=''222'' FOR UPDATE");
while (rs.next()) {
/* 取出此BLOB对象 */
oracle.sql.BLOB blob = (oracle.sql.BLOB)rs.getBlob("BLOBCOL");
/* 向BLOB对象中写入数据 */
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) {
/* 出错回滚 */
conn.rollback();
throw ex;
}
/* 恢答复提交状况 */
conn.setAutoCommit(defaultCommit);
}
/**
* BLOB对象读取
*
* @param outfile - 输出文件名
* @throws java.lang.Exception
* @roseuid 3EDA050B003B
*/
public static void blobRead(String outfile) throws Exception
{
/* 设定不自动提交 */
boolean defaultCommit = conn.getAutoCommit();
conn.setAutoCommit(false);
try {
/* 查询BLOB对象 */
ResultSet rs = stmt.executeQuery("SELECT BLOBCOL FROM TEST_BLOB WHERE ID=''222''");
while (rs.next()) {
/* 取出此BLOB对象 */
oracle.sql.BLOB blob = (oracle.sql.BLOB)rs.getBlob("BLOBCOL");
/* 以二进制情势输出 */
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) {
/* 出错回滚 */
conn.rollback();
throw ex;
}
/* 恢答复提交状况 */
conn.setAutoCommit(defaultCommit);
}
/**
* 成立测试用表格
* @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 - 号令行参数
* @throws java.lang.Exception
* @roseuid 3EDA052002AC
*/
public static void main(String[] args) throws Exception
{
/* 装载驱动,成立数据库衔接 */
Class.forName(DRIVER);
conn = DriverManager.getConnection(URL,USER,PASSWORD);
stmt = conn.createStatement();
/* 成立测试表格 */
createTables();
/* CLOB对象插入测试 */
clobInsert("c:/clobInsert.txt");
clobRead("c:/clobInsert.out");
/* CLOB对象改正测试 */
clobModify("c:/clobModify.txt");
clobRead("c:/clobModify.out");
/* CLOB对象替换测试 */
clobReplace("c:/clobReplace.txt");
clobRead("c:/clobReplace.out");
/* BLOB对象插入测试 */
blobInsert("c:/blobInsert.doc");
blobRead("c:/blobInsert.out");
/* BLOB对象改正测试 */
blobModify("c:/blobModify.doc");
blobRead("c:/blobModify.out");
/* BLOB对象替换测试 */
blobReplace("c:/blobReplace.doc");
blobRead("c:/bolbReplace.out");
/* 关闭资源退出 */
conn.close();
System.exit(0);
}
}
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