java io之图片存取

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：

 1 /**
 2  * 
 3 */  4 package com.hlcui.file;  5  6 import java.sql.Connection;  7 import java.sql.DriverManager;  8 import java.sql.SQLException;  9 10 /** 11  * @author Administrator 12  * 13 */ 14 public class DBUtil { 15 // 定义数据库连接参数 16 public static final String DRIVER_CLASS_NAME = "com.mysql.jdbc.Driver"; 17 public static final String URL = "jdbc:mysql://localhost:3306/test"; 18 public static final String USERNAME = "root"; 19 public static final String PASSWORD = "root"; 20 21 // 注册数据库驱动 22 static { 23 try { 24  Class.forName(DRIVER_CLASS_NAME); 25 } catch (ClassNotFoundException e) { 26 System.out.println("注册失败！"); 27  e.printStackTrace(); 28  } 29  } 30 31 // 获取连接 32 public static Connection getConn() throws SQLException { 33 return DriverManager.getConnection(URL, USERNAME, PASSWORD); 34  } 35 36 // 关闭连接 37 public static void closeConn(Connection conn) { 38 if (null != conn) { 39 try { 40  conn.close(); 41 } catch (SQLException e) { 42 System.out.println("关闭连接失败！"); 43  e.printStackTrace(); 44  } 45  } 46  } 47 //测试 48 public static void main(String[] args) throws SQLException { 49 System.out.println(DBUtil.getConn()); 50  } 51 52 }

三：封装读取图片的流

 1 /**
 2  * 
 3  */  4 package com.hlcui.file;  5  6 import java.io.File;  7 import java.io.FileInputStream;  8 import java.io.FileOutputStream;  9 import java.io.IOException; 10 import java.io.InputStream; 11 12 /** 13  * @author Administrator 14  * 15 */ 16 public class ImageUtil { 17 18 // 读取本地图片获取输入流 19 public static FileInputStream readImage(String path) throws IOException { 20 return new FileInputStream(new File(path)); 21  } 22 23 // 读取表中图片获取输出流 24 public static void readBin2Image(InputStream in, String targetPath) { 25 File file = new File(targetPath); 26 String path = targetPath.substring(0, targetPath.lastIndexOf("/")); 27 if (!file.exists()) { 28 new File(path).mkdir(); 29  } 30 FileOutputStream fos = null; 31 try { 32 fos = new FileOutputStream(file); 33 int len = 0; 34 byte[] buf = new byte[1024]; 35 while ((len = in.read(buf)) != -1) { 36 fos.write(buf, 0, len); 37  } 38  fos.flush(); 39 } catch (Exception e) { 40  e.printStackTrace(); 41 } finally { 42 if (null != fos) { 43 try { 44  fos.close(); 45 } catch (IOException e) { 46  e.printStackTrace(); 47  } 48  } 49  } 50  } 51 }

四：实现图片（本地、数据库互相传输）

 1 /**
 2  * 
 3  */  4 package com.hlcui.file;  5  6 import java.io.FileInputStream;  7 import java.io.InputStream;  8 import java.sql.Connection;  9 import java.sql.PreparedStatement; 10 import java.sql.ResultSet; 11 import java.sql.SQLException; 12 13 /** 14  * @author Administrator 测试写入数据库以及从数据库中读取 15 */ 16 public class ImageDemo { 17 18 // 将图片插入数据库 19 public static void readImage2DB() { 20 String path = "D:/1.png"; 21 Connection conn = null; 22 PreparedStatement ps = null; 23 FileInputStream in = null; 24 try { 25 in = ImageUtil.readImage(path); 26 conn = DBUtil.getConn(); 27 String sql = "insert into photo (id,name,photo)values(?,?,?)"; 28 ps = conn.prepareStatement(sql); 29 ps.setInt(1, 1); 30 ps.setString(2, "Tom"); 31 ps.setBinaryStream(3, in, in.available()); 32 int count = ps.executeUpdate(); 33 if (count > 0) { 34 System.out.println("插入成功！"); 35 } else { 36 System.out.println("插入失败！"); 37  } 38 } catch (Exception e) { 39  e.printStackTrace(); 40 } finally { 41  DBUtil.closeConn(conn); 42 if (null != ps) { 43 try { 44  ps.close(); 45 } catch (SQLException e) { 46  e.printStackTrace(); 47  } 48  } 49  } 50 51  } 52 53 // 读取数据库中图片 54 public static void readDB2Image() { 55 String targetPath = "D:/image/1.png"; 56 Connection conn = null; 57 PreparedStatement ps = null; 58 ResultSet rs = null; 59 try { 60 conn = DBUtil.getConn(); 61 String sql = "select * from photo where id =?"; 62 ps = conn.prepareStatement(sql); 63 ps.setInt(1, 1); 64 rs = ps.executeQuery(); 65 while (rs.next()) { 66 InputStream in = rs.getBinaryStream("photo"); 67  ImageUtil.readBin2Image(in, targetPath); 68  } 69 } catch (Exception e) { 70  e.printStackTrace(); 71 } finally { 72  DBUtil.closeConn(conn); 73 if (rs != null) { 74 try { 75  rs.close(); 76 } catch (SQLException e) { 77  e.printStackTrace(); 78  } 79  } 80 if (ps != null) { 81 try { 82 ps.close(); 83 } catch (SQLException e) { 84 e.printStackTrace(); 85 } 86 } 87 88 } 89 } 90 //测试 91 public static void main(String[] args) { 92 //readImage2DB(); 93 readDB2Image(); 94 } 95 }