发布于 2016-07-31 10:14:00 | 111 次阅读 | 评论: 0 | 来源: 网友投递

这里有新鲜出炉的Java设计模式,程序狗速度看过来!

Java程序设计语言

java 是一种可以撰写跨平台应用软件的面向对象的程序设计语言,是由Sun Microsystems公司于1995年5月推出的Java程序设计语言和Java平台(即JavaEE(j2ee), JavaME(j2me), JavaSE(j2se))的总称。


之前一直没有做过涉及到图片存储的应用,最近要做的东东涉及到了这个点,就做了一个小的例子算是对图片存储的初试吧

1.创建表:


drop table if exists photo;
CREATE TABLE photo (
    id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(100) COMMENT '名称',
    photo blob COMMENT '照片'
)
ENGINE=InnoDB
DEFAULT CHARSET=utf8
COLLATE=utf8_general_ci;

 图片在MySql中的数据存储格式为blob类型;Blob是一个可以存储二进制文件的容器。

2.编写图片流数据存取的工具类:


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

public class ImageUtil {
    private static File file = null;

    /**
     * 从本地文件读取图像的二进制流
     *
     * @param infile
     * @return
     */
    public static FileInputStream getImageByte(String infile) {
        FileInputStream imageByte = null;
        file = new File(infile);
        try {
            imageByte = new FileInputStream(file);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        return imageByte;
    }

    /**
     * 将图片流读出为图片
     *
     * @param inputStream
     * @param path
     */
    public static void readBlob(InputStream inputStream, String path) {
        try {
            FileOutputStream fileOutputStream = new FileOutputStream(path);
            byte[] buffer = new byte[1024];
            int len = 0;
            while ((len = inputStream.read(buffer)) != -1) {
                fileOutputStream.write(buffer, 0, len);
            }
            inputStream.close();
            fileOutputStream.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }
}

3.将本地文件保存到数据库

  需要添加MySql的数据库驱动--mysql-connector-java-5.1.24-bin.jar


import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;

public class ImageInsert {
    public static void main(String[] args) {
        try {
            Class.forName("com.mysql.jdbc.Driver").newInstance();
        } catch (InstantiationException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        String user = "root";
        String password = "root";
        String url = "jdbc:mysql://localhost:3306/test?characterEncoding=utf-8";
        Connection connection = null;
        try {
            connection = DriverManager.getConnection(url, user, password);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        PreparedStatement preparedStatement = null;
        InputStream inputStream = null;
        inputStream = ImageUtil.getImageByte("D:\\temp\\photo1.png");
        try {
            String sql = "insert into photo(id,name,photo) values(?,?,?)";
            preparedStatement = connection.prepareStatement(sql);
            preparedStatement.setInt(1, 1);
            preparedStatement.setString(2, "朱莉");
            preparedStatement.setBinaryStream(3, inputStream,
                    inputStream.available());
            preparedStatement.execute();
        } catch (SQLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (inputStream != null)
                    inputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                try {
                    if (preparedStatement != null)
                        preparedStatement.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                } finally {
                    try {
                        connection.close();
                    } catch (SQLException e) {
                        e.printStackTrace();
                    }
                }
            }
        }

    }
}


4.从数据库中读取并生成图片

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class ImageGet {     public static void main(String[] args) {         try {             Class.forName("com.mysql.jdbc.Driver").newInstance();         } catch (InstantiationException e) {             e.printStackTrace();         } catch (IllegalAccessException e) {             e.printStackTrace();         } catch (ClassNotFoundException e) {             e.printStackTrace();         }         String user = "root";         String password = "root";         String url = "jdbc:mysql://localhost:3306/test?characterEncoding=utf-8";         Connection connection = null;         try {             connection = DriverManager.getConnection(url, user, password);         } catch (SQLException e) {             e.printStackTrace();         }         Statement statement = null;         ResultSet resultSet = null;         InputStream inputStream = null;         try {             statement = connection.createStatement();             String sql = "select p.photo from photo p where id = 1";             resultSet = statement.executeQuery(sql);             resultSet.next();             inputStream = resultSet.getBinaryStream("photo");             ImageUtil.readBlob(inputStream, "D:\\temp\\photo2.png");         } catch (SQLException e) {             e.printStackTrace();         } finally {             try {                 if (inputStream != null)                     inputStream.close();             } catch (IOException e) {                 e.printStackTrace();             } finally {                 try {                     if (resultSet != null)                         resultSet.close();                 } catch (SQLException e) {                     e.printStackTrace();                 } finally {                     if (statement != null)                         if (statement != null)                             try {                                 statement.close();                             } catch (SQLException e) {                                 e.printStackTrace();                             } finally {                                 if (connection != null)                                     try {                                         connection.close();                                     } catch (SQLException e) {                                         e.printStackTrace();                                     }                             }                 }             }         }

    } }


5.Over!



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