JDBC存取二进制文件示例

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PutFile.java
import java.io.File;
import java.io.FileInputStream;
import java.sql.*;
 
 
public class PutFile {
 
 
    public static void main(String args[]) {
 
 
        Connection conn = null;
        PreparedStatement psmd = null;
        String sql = null;
 
 
        try {
            conn = ConnUtil.getConn();
            File file = new File("F:\\1.jpg");// 要转换的文件 
            FileInputStream inputStream = new FileInputStream(file);// 将文件按二进制存储在一个字段内
            // CREATE TABLE images (imgname text, img bytea);
            sql = " insert into images values(?,?)";
            psmd = conn.prepareStatement(sql);
            psmd.setString(1, file.getName());
            psmd.setBinaryStream(2, inputStream, (int) file.length());          
            int rs = psmd.executeUpdate();
 
 
            if (rs < 0) {
                System.out.println("存入数据失败！！！");
            } else {
                System.out.println("存入数据成功！！！");
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        if (psmd != null) {
            try {
                psmd.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
}
GetFile.java
import java.io.FileOutputStream;
import java.io.OutputStream;
import java.sql.*;
 
public class GetFile {
 
    public static void main(String args[]) {
 
        Connection conn = null;
        PreparedStatement psmd = null;
        String sql = null;
        OutputStream out = null;
 
        try {
            conn = ConnUtil.getConn();
            // CREATE TABLE images (imgname text, img bytea);
            sql = " SELECT img FROM images WHERE imgname = ?";
            psmd = conn.prepareStatement(sql);
            psmd.setString(1, "1.jpg");
            ResultSet rs = psmd.executeQuery();
            while(rs.next()) {
                byte[] imgBytes = rs.getBytes(1);
                // 实例化OutputStream对象，在f盘创建一个图片文件
                out = new FileOutputStream("f:\\2.jpg");
                // 将文件输出，内容则为byte数组里面的数据
                out.write(imgBytes);
                out.flush();
                System.out.println("获取数据成功！！！");        
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
 
        if (psmd != null) {
            try {
                psmd.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
 
}
ConnUtil.java
 
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
 
public class ConnUtil {
 
    public static Connection getConn() {
        Connection conn = null;
        try {
            Class.forName("com.scistor.swift.jdbc.Driver"); // 驱动
            String url = "jdbc:swift://192.168.8.103:2345/swfit"; // 连接数据库的url
            try {
                conn = DriverManager.getConnection(url, "super", "111111"); // super 为数据库用户名，111111为密码
            } catch (SQLException e) {
                e.printStackTrace();
            }
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
 
        return conn;
    }
 
}