【0】README

0.1）本文翻译自 http://harmeetsingh13.blogspot.jp/2013/03/insert-and-retrieve-images-from-mysql.html

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【1】正文如下：

段1）演示 从数据库表中插入和查询出图片。大多数情况下，图片数据都存储在数据库外部的一些文件夹下，而将其路径存储到数据库。但是在一些场景下，我们需要将图片以二进制数据格式存储到数据库。

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【2】代码示例

2.1）向数据库插入图片

import java.sql.*;
import java.io.*;
public class InsertImagesMysql{public static void main(String[] args){System.out.println("Insert Image Example!");String driverName = "com.mysql.jdbc.Driver";String url = "jdbc:mysql://localhost:3306/";String dbName = "test";String userName = "root";String password = "root";Connection con = null;try{Class.forName(driverName);con = DriverManager.getConnection(url+dbName,userName,password);Statement st = con.createStatement();File imgfile = new File("pic.jpg");FileInputStream fin = new FileInputStream(imgfile);PreparedStatement pre =con.prepareStatement("insert into Image values(?,?,?)");pre.setString(1,"test");pre.setInt(2,3);pre.setBinaryStream(3,(InputStream)fin,(int)imgfile.length());pre.executeUpdate();System.out.println("Successfully inserted the file into the database!");pre.close();con.close(); }catch (Exception e1){System.out.println(e1.getMessage());}}
}

2.2）从数据库查询图片并保存到本地

import java.sql.*;
import java.io.*;
public class RetriveImagesMysql{public static void main(String[] args){System.out.println("Retrive Image Example!");String driverName = "com.mysql.jdbc.Driver";String url = "jdbc:mysql://localhost:3306/";String dbName = "test";String userName = "root";String password = "root";Connection con = null;try{Class.forName(driverName);con = DriverManager.getConnection(url+dbName,userName,password);Statement stmt = con.createStatement();ResultSet rs = stmt.executeQuery("select image from image");int i = 0;while (rs.next()) {InputStream in = rs.getBinaryStream(1);OutputStream f = new FileOutputStream(new File("test"+i+".jpg"));i++;int c = 0;while ((c = in.read()) > -1) {f.write(c);}f.close();in.close();}}catch(Exception ex){System.out.println(ex.getMessage());}}
}