java存图片到mysql数据库

JAY.LIN 收录于 Web Java Java Java

2025-01-24 约 980 字预计阅读 2 分钟

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java存图片到mysql数据库

我们使用mysql数据库的时候基本上都是存字段，很少用到存入图片的，那么如果我们想存图片在我们的数据库中该如何去解决呢？

其实我们的图片存入数据库是以二进制的形式存在数据库里面的，那么我们来看看我们的图片是如何保存并读取的吧

注：本文来自

数据库：

CREATE TABLE photo (

id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,

name VARCHAR(100) COMMENT ‘名称’,

photo blob COMMENT ‘照片’

)

类DBUtil

/**
 * Created by yuehailin on 2017/12/6.
 */
/**
 *
 */

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;


public class DBUtil {
    // 定义数据库连接参数
    public static final String DRIVER_CLASS_NAME = "com.mysql.jdbc.Driver";
    public static final String URL = "jdbc:mysql://localhost:3306/test";
    public static final String USERNAME = "root";
    public static final String PASSWORD = "123";

    // 注册数据库驱动
    static {
        try {
            Class.forName(DRIVER_CLASS_NAME);
        } catch (ClassNotFoundException e) {
            System.out.println("注册失败！");
            e.printStackTrace();
        }
    }

    // 获取连接
    public static Connection getConn() throws SQLException {
        return DriverManager.getConnection(URL, USERNAME, PASSWORD);
    }

    // 关闭连接
    public static void closeConn(Connection conn) {
        if (null != conn) {
            try {
                conn.close();
            } catch (SQLException e) {
                System.out.println("关闭连接失败！");
                e.printStackTrace();
            }
        }
    }
    //测试
    public static void main(String[] args) throws SQLException {
        System.out.println(DBUtil.getConn());
    }

}

类ImageDemo

/**
 * Created by yuehailin on 2017/12/6.
 */
/**
 *
 */

import java.io.FileInputStream;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class ImageDemo {

    // 将图片插入数据库
    public static void readImage2DB() {
        String path = "D:/1.PNG";
        Connection conn = null;
        PreparedStatement ps = null;
        FileInputStream in = null;
        try {
            in = ImageUtil.readImage(path);
            conn = DBUtil.getConn();
            String sql = "insert into photo (id,name,photo)values(?,?,?)";
            ps = conn.prepareStatement(sql);
            ps.setInt(1, 1);
            ps.setString(2, "Tom");
            ps.setBinaryStream(3, in, in.available());
            int count = ps.executeUpdate();
            if (count > 0) {
                System.out.println("插入成功！");
            } else {
                System.out.println("插入失败！");
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            DBUtil.closeConn(conn);
            if (null != ps) {
                try {
                    ps.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
        }

    }

    // 读取数据库中图片
    public static void readDB2Image() {
        String targetPath = "D:/image/1.png";
        Connection conn = null;
        PreparedStatement ps = null;
        ResultSet rs = null;
        try {
            conn = DBUtil.getConn();
            String sql = "select * from photo where id =?";
            ps = conn.prepareStatement(sql);
            ps.setInt(1, 1);
            rs = ps.executeQuery();
            while (rs.next()) {
                InputStream in = rs.getBinaryStream("photo");
                ImageUtil.readBin2Image(in, targetPath);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            DBUtil.closeConn(conn);
            if (rs != null) {
                try {
                    rs.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            if (ps != null) {
                try {
                    ps.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }

        }
    }
    //测试
    public static void main(String[] args) {
       // readImage2DB();
        readDB2Image();
    }
}

类ImageUtil

/**
 * Created by yuehailin on 2017/12/6.
 */
/**
 *
 */


import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;

public class ImageUtil {

    // 读取本地图片获取输入流
    public static FileInputStream readImage(String path) throws IOException {
        return new FileInputStream(new File(path));
    }

    // 读取表中图片获取输出流
    public static void readBin2Image(InputStream in, String targetPath) {
        File file = new File(targetPath);
        String path = targetPath.substring(0, targetPath.lastIndexOf("/"));
        if (!file.exists()) {
            new File(path).mkdir();
        }
        FileOutputStream fos = null;
        try {
            fos = new FileOutputStream(file);
            int len = 0;
            byte[] buf = new byte[1024];
            while ((len = in.read(buf)) != -1) {
                fos.write(buf, 0, len);
            }
            fos.flush();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (null != fos) {
                try {
                    fos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

说明：

1.连接数据库的时候一定要记得导入jar包

2.数据库的相关配置需要设置好

3.需要从本地文件读取一张图片，存入数据库

4.然后从数据库中读取刚刚存入的照片，再存到一个新的目录中