jdbc 3.0

1.将Blob、Clob类型数据保存到数据库

import java.io.File;
import java.io.FileInputStream;
import java.io.FileReader;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;


public class Test4 {
    /**
     * 将图片、文本保存在数据库
     * Blob、Clob
     * @author 容杰龙
     */
    public static void main(String[] args) {
        try {
            Class.forName("com.mysql.jdbc.Driver");
            String url="jdbc:mysql://localhost:3306/rjl";
            String user="rjl";
            String password="123";
            Connection conn = DriverManager.getConnection(url, user, password);
            String sql1="insert into pic(img,msg) values(?,?)";
            
            File file=new File("C:/Users/Rong/Desktop/qq.png");
            FileInputStream inputStream = new FileInputStream(file);
            
            FileReader reader = new FileReader("C:/Users/Rong/Desktop/msg.txt");
            
            PreparedStatement ps = conn.prepareStatement(sql1);
            //字节流-二进制图像
            ps.setBlob(1, inputStream);
            //字符流
            ps.setClob(2, reader);
            int count = ps.executeUpdate();
            if (count>0) {
                System.out.println("添加成功！");
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

    }

}

2.从数据库表里读取Blob、Clob类型数据

package com.rong.web;

import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.InputStream;
import java.io.Reader;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

public class Test5 {


    /**
     * 读取MySQL数据库Blob、Clob类型的数据到硬盘
     * @author 容杰龙
     */
    public static void main(String[] args) {
        try {
            Class.forName("com.mysql.jdbc.Driver");
            String url="jdbc:mysql://localhost:3306/rjl?user=root&password=123123";
            Connection conn = DriverManager.getConnection(url);
            String sql="select * from pic where id=?";
            PreparedStatement ps = conn.prepareStatement(sql);
            ps.setInt(1, 1);
            ResultSet rs = ps.executeQuery();
            while(rs.next()){
                //获取字节输入流
                InputStream inputStream = rs.getAsciiStream("img");
                //获取字符输入流
                Reader reader = rs.getCharacterStream("msg");
                byte[] bytes=new byte[1024];
                char[] chars=new char[1024];
                int len=0;
                //创建文件输出流，设置文件存储的硬盘位置
                FileOutputStream fos = new FileOutputStream("C:/Users/Administrator/Desktop/jdbc.png");
                FileWriter fw = new FileWriter("C:/Users/Administrator/Desktop/jdbc.txt");
                //字节输出
                while ((len=inputStream.read(bytes))!=-1) {
                    fos.write(bytes, 0, len);
                }
                fos.close();
                inputStream.close();
                len=0;
                //字符输出
                while ((len=reader.read(chars))!=-1) {
                    fw.write(chars, 0, len);
                }
                fw.close();
                reader.close();
                
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

    }

}

package com.rong.web;

import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.InputStream;
import java.io.Reader;
import java.sql.Blob;
import java.sql.Clob;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

public class Test6 {

    /**
     * 读取MySQL数据库Blob、Clob类型的数据到硬盘
     * @author 容杰龙
     */
    public static void main(String[] args) {
        try {
            Class.forName("com.mysql.jdbc.Driver");
            String url="jdbc:mysql://localhost:3306/rjl?user=root&password=123123";
            Connection conn = DriverManager.getConnection(url);
            String sql="select * from pic where id=?";
            PreparedStatement ps = conn.prepareStatement(sql);
            ps.setInt(1, 1);
            ResultSet rs = ps.executeQuery();
            while(rs.next()){
                //获取blob对象
                Blob blob = rs.getBlob("img");
                //获取二进制字节输入流
                InputStream binaryStream = blob.getBinaryStream();
                //////////////////////////////////////////////////
                
                //获取clob对象
                Clob clob = rs.getClob("msg");
                //获取字符输入流
                Reader characterStream = clob.getCharacterStream();
                
                byte[] bytes=new byte[1024];
                char[] chars=new char[1024];
                int len=0;
                //创建文件输出流，设置文件存储的硬盘位置
                FileOutputStream fos = new FileOutputStream("C:/Users/Administrator/Desktop/jdbc.png");
                FileWriter fw = new FileWriter("C:/Users/Administrator/Desktop/jdbc.txt");
                //字节输出
                /////////////////////////////////
//                byte[] bs = rs.getBytes("img");
//                fos.write(bs);
                ////////////////////////////////////
                while ((len=binaryStream.read(bytes))!=-1) {
                    fos.write(bytes, 0, len);
                }
                fos.close();
                binaryStream.close();
                len=0;
                //字符输出
                while ((len=characterStream.read(chars))!=-1) {
                    fw.write(chars, 0, len);
                }
                fw.close();
                characterStream.close();
                
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

    }

}