Java+MySql圖片數(shù)據(jù)保存與讀取的具體實(shí)例

2019-11-26 16:03:19

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1.創(chuàng)建表：

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

　圖片在MySql中的數(shù)據(jù)存儲(chǔ)格式為blob類型;Blob是一個(gè)可以存儲(chǔ)二進(jìn)制文件的容器。

2.編寫圖片流數(shù)據(jù)存取的工具類:

復(fù)制代碼代碼如下:

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;

    /**
     * 從本地文件讀取圖像的二進(jìn)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;
    }

    /**
     * 將圖片流讀出為圖片
     *
     * @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.將本地文件保存到數(shù)據(jù)庫

　　需要添加MySql的數(shù)據(jù)庫驅(qū)動(dòng)--mysql-connector-java-5.1.24-bin.jar

復(fù)制代碼代碼如下:

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.從數(shù)據(jù)庫中讀取并生成圖片

復(fù)制代碼代碼如下:

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();
                                    }
                            }
                }
            }
        }