java+mysql实现保存图片到数据库，以及读取数据库存储的图片

一：建表

二：获取数据库连接

1：导入mysql的驱动jar包，mysql-connector-java-5.1.8-bin.jar

2：写代码连接数据库，如下：

 /**
  *
  */
 package com.hlcui.file;

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

 /**
  * @author Administrator
  *
  */
 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 = "root";

     // 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());
     }

 }

三：封装读取图片的流

 /**
  *
  */
 package com.hlcui.file;

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

 /**
  * @author Administrator
  *
  */
 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();
                 }
             }
         }
     }
 }

四：实现图片（本地、数据库互相传输）

 /**
  *
  */
 package com.hlcui.file;

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

 /**
  * @author Administrator 测试写入数据库以及从数据库中读取
  */
 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();
     }
 }

以上代码均已经验证！