在简单的 java 程序中下载 zip 文件中的 blob 数据

Question

我无法使用以下代码下载文件，因为我有多种类型的扩展可供下载，并且我想压缩所有文件并下载。如果我运行下面的代码，它会说文件已损坏。请有人帮忙解决这个问题吗？import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import java.sql.Blob;import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;public class JdbcReadFile {    private static final int BUFFER_SIZE = 4096;    public static void main(String[] args) {        String url = "jdbc:oracle:thin:@xxx:xxxx:xxx";        String user = "xxx";        String password = "xxx";        String filePath = "C:/abc.vsd";        try {            Connection conn = DriverManager.getConnection(url, user, password);            String sql = "SELECT DOC_BO FROM table fetch first 10 rows only";            PreparedStatement statement = conn.prepareStatement(sql);            ResultSet result = statement.executeQuery();            if (result.next()) {                Blob blob = result.getBlob("DOC_BO");                InputStream inputStream = blob.getBinaryStream();                OutputStream outputStream = new FileOutputStream(filePath);                int bytesRead = -1;                byte[] buffer = new byte[BUFFER_SIZE];                while ((bytesRead = inputStream.read(buffer)) != -1) {                    outputStream.write(buffer, 0, bytesRead);                }                inputStream.close();                outputStream.close();                System.out.println("File saved");            }            conn.close();        } catch (SQLException ex) {            ex.printStackTrace();        } catch (IOException ex) {            ex.printStackTrace();        }    }}

Answer 1

为此不需要前端。使用以下代码解决了问题。

公共类 BlobDataExtract { 静态 ZipOutputStream zos = null; 静态字符串 url = "jdbc:oracle:thin:@主机名:1521:SID";

public static void main(String[] args) throws ClassNotFoundException, SQLException, IOException {

    Class.forName("oracle.jdbc.driver.OracleDriver");

    Connection conn = DriverManager.getConnection(url, "user", "password");

    String sql = "select Blob_Data,ORIG_NM from table";

    PreparedStatement stmt = conn.prepareStatement(sql);

    ResultSet rs = stmt.executeQuery();

    byte[] docBlob = null;

    String filename = null;

    FileOutputStream fos = new FileOutputStream("C:/Users/test.zip");

    zos = new ZipOutputStream(fos);

    while (rs.next()) {

        docBlob = rs.getBytes("Blob_Data");

        filename = rs.getString("ORIG_NM");

        try {

            zos.putNextEntry(new ZipEntry(filename));

            zos.write(docBlob, 0, docBlob.length);

        } catch (FileNotFoundException ex) {

            System.err.println("A file does not exist: " + ex);

        } catch (IOException ex) {

            System.err.println("I/O error: " + ex);

        }

        zos.closeEntry();

    }

}

}