JavaSE中对Blob数据的处理例子一

JavaSE中对Blob数据的处理例子一

2011-01-04 17:35

下面是从数据库中取出blob数据写入到文件中去的操作。 import java.io.File; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.sql.Blob; import java.sql.Connection; import java.sql.DriverManager; importjava.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class GetBlob {     static {        String driverName = "oracle.jdbc.driver.OracleDriver";        try {            Class.forName(driverName);        } catch (ClassNotFoundException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }     }     public static Connection getConnection() {        Connection conn = null;        String username = "*****";        String password = "*****";        String url = "jdbc:oracle:thin:@****:1521:****";        try {            conn = DriverManager.getConnection(url, username, password);        } catch (SQLException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }        return conn;     }     public static void saveBlob(Blob b) throws IOException, SQLException {        System.out.println("blob=" + b);        InputStream in = b.getBinaryStream(); // 建立输出流        // FileInputStream in =(FileInputStream)b.getBinaryStream();        FileOutputStream file = new FileOutputStream("d:\\多多.txt");        int len = (int) b.length();        byte[] buffer = new byte[len]; // 建立缓冲区        while ((len = in.read(buffer)) != -1) {            file.write(buffer, 0, len);        }        file.close();        in.close();     }     public static void main(String[] args) {        Connection conn = getConnection();        Statement stmt = null;        try {        stmt = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,                   ResultSet.CONCUR_READ_ONLY);            ResultSet rs =                 stmt.executeQuery("SELECT CONTENT FROM AT_FILEUPLOAD WHERE FILE_ID=6243");            if (rs.next()) {               Blob blob = rs.getBlob("content");               // 把blob形式的内容存到文件中去               try {                   System.out.println("saveBlob");                   saveBlob(blob);               } catch (IOException e) {                   // TODO Auto-generated catch block                   e.printStackTrace();               }            }            rs.close();            stmt.close();            conn.close();        } catch (SQLException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }     } }