用java讀取具有數據庫

Question

的Oracle BFILE數據類型的文件，我有一個包含位置對外部文件系統中的文件的表。 用於包含文件位置的列的數據類型是BFILE。

如何讀取使用Java數據庫這樣的文件？

Answer 1

你好，請閱讀下面的帖子和this Link將有助於

此示例演示了Oracle JDBC BFILE的支持。它示出了填充BFILES的表，並且包括用於傾倒BFILE的內容的實用程序。有關BFILE的信息。

/* 
* This sample demonstrate basic File support 
*/ 

import java.sql.*; 
import java.io.*; 
import java.util.*; 

//including this import makes the code easier to read 

import oracle.jdbc.driver.*; 

// needed for new BFILE class 

import oracle.sql.*; 

public class FileExample{ 

public static void main (String args [])throws Exception{ 
// Register the Oracle JDBC driver 
DriverManager.registerDriver(new oracle.jdbc.driver.OracleDriver()); 

// Connect to the database 
// You can put a database name after the @ sign in the connection URL. 
// 
// The sample creates a DIRECTORY and you have to be connected as 
// "system" to be able to run the test. 
// I you can't connect as "system" have your system manager 
// create the directory for you, grant you the rights to it, and 
// remove the portion of this program that drops and creates the directory. 
Connection conn = 
    DriverManager.getConnection ("jdbc:oracle:oci8:@", "system", "manager"); 

// It's faster when auto commit is off 
conn.setAutoCommit (false); 

// Create a Statement 
Statement stmt = conn.createStatement(); 

try 
{ 
    stmt.execute ("drop directory TEST_DIR"); 
} 
catch (SQLException e) 
{ 
    // An error is raised if the directory does not exist. Just ignore it. 
} 
stmt.execute ("create directory TEST_DIR as '/tmp/filetest'"); 

try 
{ 
    stmt.execute ("drop table test_dir_table"); 
} 
catch (SQLException e) 
{ 
    // An error is raised if the table does not exist. Just ignore it. 
} 

// Create and populate a table with files 
// The files file1 and file2 must exist in the directory TEST_DIR created 
// above as symbolic name for /private/local/filetest. 
stmt.execute ("create table test_dir_table (x varchar2 (30), b bfile)"); 
stmt.execute ("insert into test_dir_table values 
       ('one', bfilename ('TEST_DIR', 'file1'))"); 
stmt.execute ("insert into test_dir_table values 
       ('two', bfilename ('TEST_DIR', 'file2'))"); 

// Select the file from the table 
ResultSet rset = stmt.executeQuery ("select * from test_dir_table"); 
while (rset.next()) 
{ 
    String x = rset.getString (1); 
    BFILE bfile = ((OracleResultSet)rset).getBFILE (2); 
    System.out.println (x + " " + bfile); 

    // Dump the file contents 
    dumpBfile (conn, bfile); 
} 

// Close all resources 
rset.close(); 
stmt.close(); 
conn.close();} 

// Utility function to dump the contents of a Bfile 

static void dumpBfile (Connection conn, BFILE bfile) throws Exception{ 

System.out.println ("Dumping file " + bfile.getName()); 

System.out.println ("File exists: " + bfile.fileExists()); 

System.out.println ("File open: " + bfile.isFileOpen()); 

System.out.println ("Opening File: "); 

bfile.openFile(); 

System.out.println ("File open: " + bfile.isFileOpen()); 

long length = bfile.length(); 
System.out.println ("File length: " + length); 

int chunk = 10; 

InputStream instream = bfile.getBinaryStream(); 

// Create temporary buffer for read 
byte[] buffer = new byte[chunk]; 

// Fetch data 
while ((length = instream.read(buffer)) != -1) 
{ 
    System.out.print("Read " + length + " bytes: "); 

    for (int i=0; i<length; i++) 
    System.out.print(buffer[i]+" "); 
    System.out.println(); 
} 

// Close input stream 
instream.close(); 

// close file handler 
bfile.closeFile();}} 

Answer 2

使用下面的鏈接

https://docs.oracle.com/cd/A97335_02/apps.102/a83724/oralob3.htm#1059336

在那裏，你會發現這樣的

OraclePreparedStatement ops = (OraclePreparedStatement)conn.prepareStatement 
         ("INSERT INTO my_bfile_table VALUES (?,?)"); 
ops.setString(1,"one"); 
ops.setBFILE(2, bfile); 
ops.execute(); 

許多例子