java - 如何使用 java 从 oracle blob 检索 zip 文件？

Question

我有一个存储在 Oracle 数据库表中的 zip 文件，该文件由三个不同的 xml 文件组成。我想做的就是在我的本地文件系统中获取这个 zip 文件。为了检索这个 zip 文件，我编写了下面的 java 代码:

package com.pack.IOT;

import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class Test2 {

    public static Connection con;
    public static PreparedStatement stmt;

    public static void main(String[] args) {

        try {
            Class.forName("oracle.jdbc.driver.OracleDriver");           
            con = DriverManager.getConnection(url,uname,pwd);           
            stmt=con.prepareStatement("select * from FileStore");

            ResultSet rs=stmt.executeQuery();
            while (rs.next()) {
                InputStream is = rs.getBinaryStream(3);
                convert(is);
            }

        } catch (Exception e) {
            e.printStackTrace();
        }

        finally {
            try {
                stmt.close();
                con.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
}

    }

    private static void convert(InputStream is) {

        FileOutputStream outputStream = null;
        File file = new File("C:\\Users\\nshaik\\Desktop\\IOTZip.zip");
        try {
        outputStream = new FileOutputStream(file);
        BufferedInputStream bis = new BufferedInputStream(is);
        ByteArrayOutputStream buf = new ByteArrayOutputStream();
        int result;

        result = bis.read();

        while (result != -1) {
            buf.write((byte) result);
            result = bis.read();
        }           
        outputStream.write(buf.toByteArray());
        System.out.println("File write success....");
        } 
        catch (IOException e) {
            e.printStackTrace();
        }
        finally {
        try {
            outputStream.close();
        }
        catch (Exception e) {
            e.printStackTrace();
        }
    }
  }
}

代码运行良好，但我看到错误“存档意外结束”，并且此 zip 文件应包含三个不同的文件，但我只看到一个文件，且其大小为零。

我不确定我做错了什么，非常感谢任何人的帮助。

Answer 1

下面是满足上述要求的工作代码，

package com.pack.IOT;

import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class Test2 {

    public static Connection con;
    public static PreparedStatement stmt;

    public static void main(String[] args) {

        try {
            Class.forName("oracle.jdbc.driver.OracleDriver");           
            con = DriverManager.getConnection(url,uname,pwd);           
            stmt=con.prepareStatement("select * from FileStore");

            ResultSet rs=stmt.executeQuery();
            while (rs.next()) {
                InputStream is = rs.getBinaryStream(3);
                convert(is);
            }

        } catch (Exception e) {
            e.printStackTrace();
        }

        finally {
            try {
                stmt.close();
                con.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
}

    }

    private static void convert(InputStream is) {

        FileOutputStream outputStream = null;
        File file = new File("C:\\Users\\nshaik\\Desktop\\IOTZip.zip");
        try {
        outputStream = new FileOutputStream(file);
        BufferedInputStream bis = new BufferedInputStream(is);
        ByteArrayOutputStream buf = new ByteArrayOutputStream();
        int result;

        result = bis.read();

        while (result != -1) {
            buf.write((byte) result);
            result = bis.read();
        }           
        outputStream.write(buf.toByteArray());
        System.out.println("File write success....");
        } 
        catch (IOException e) {
            e.printStackTrace();
        }
        finally {
        try {
            outputStream.close();
        }
        catch (Exception e) {
            e.printStackTrace();
        }
    }
  }
}