JDBC - PS - 增删改 - 图片blob

两个例子

从电脑端存图片到数据库
从数据库查图片

package com.atguigu5.blob;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Blob;
import java.sql.Connection;
import java.sql.Date;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import org.junit.Test;
import com.atguigu3.bean.Customer;
import com.atguigu3.util.JDBCUtils;
/**
 * 
 * @Description 测试使用PreparedStatement操作Blob类型的数据
 * @author shkstart  Email:shkstart@126.com
 * @version 
 * @date 下午4:08:58
 *
 */
public class BlobTest {
    //向数据表customers中插入Blob类型的字段
    @Test
    public void testInsert() throws Exception{
        Connection conn = JDBCUtils.getConnection();
        String sql = "insert into customers(name,email,birth,photo)values(?,?,?,?)";
        PreparedStatement ps = conn.prepareStatement(sql);
        ps.setObject(1,"袁浩");
        ps.setObject(2, "yuan@qq.com");
        ps.setObject(3,"1992-09-08");
        FileInputStream is = new FileInputStream(new File("girl.jpg"));
        ps.setBlob(4, is);
        ps.execute();
        JDBCUtils.closeResource(conn, ps);
    }
    //查询数据表customers中Blob类型的字段
    @Test
    public void testQuery(){
        Connection conn = null;
        PreparedStatement ps = null;
        InputStream is = null;
        FileOutputStream fos = null;
        ResultSet rs = null;
        try {
            conn = JDBCUtils.getConnection();
            String sql = "select id,name,email,birth,photo from customers where id = ?";
            ps = conn.prepareStatement(sql);
            ps.setInt(1, 21);
            rs = ps.executeQuery();
            if(rs.next()){
    //            方式一：
    //            int id = rs.getInt(1);
    //            String name = rs.getString(2);
    //            String email = rs.getString(3);
    //            Date birth = rs.getDate(4);
                //方式二：
                int id = rs.getInt("id");
                String name = rs.getString("name");
                String email = rs.getString("email");
                Date birth = rs.getDate("birth");
                Customer cust = new Customer(id, name, email, birth);
                System.out.println(cust);
                //将Blob类型的字段下载下来，以文件的方式保存在本地
                Blob photo = rs.getBlob("photo");
                is = photo.getBinaryStream();
                fos = new FileOutputStream("zhangyuhao.jpg");
                byte[] buffer = new byte[1024];
                int len;
                while((len = is.read(buffer)) != -1){
                    fos.write(buffer, 0, len);
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }finally{
            try {
                if(is != null)
                    is.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
            try {
                if(fos != null)
                    fos.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
            JDBCUtils.closeResource(conn, ps, rs);
        }
    }
}