如何将文本以BLOB类型存入数据库并取出
BLOB类型的使用
java完整代码
import java.io.*;
import java.sql.*;
public class test {
static public void save() throws SQLException{
Connection conn = DB.getConn(); //连接个人数据库
try {
File file = new File("g:\1.txt"); //要转换的文件的所在路径
FileInputStream inputStream = new FileInputStream(file);
String sql="insert into save_image(image) values(?)";//存入数据库的SQL语句在执行的时候一定要用prepareStatement
PreparedStatement statement = conn.prepareStatement(sql);
statement.setBinaryStream(1, inputStream,(int)file.length());
statement.executeUpdate();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
}
static public void readerJpg() throws SQLException{
Connection conn = DB.getConn();
String sqlString = "select image from save_image where id=0";//从数据库中读出要还原文件的二进制码，这里我读的是个人数据库id为0的文件
File file = new File("E:\1.txt"); //本地生成的文件
if(!file.exists()){
try {
file.createNewFile();
} catch (Exception e) {
e.printStackTrace();
}
}
try {
byte[] Buffer = new byte[1024*5]; //根据文本大小给出字节数组
PreparedStatement statement=conn.prepareStatement(sqlString);
ResultSet resultSet = statement.executeQuery();
if(resultSet.next()){
FileOutputStream outputStream = new FileOutputStream(file);
InputStream iStream = resultSet.getBinaryStream("image"); //去字段用getBinaryStream()
int size=0;
while((size=iStream.read(Buffer))!=-1){
System.out.println(size);
outputStream.write(Buffer,0,size);
System.out.println(new String(Buffer));
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
try {
save();
} catch (SQLException e) {
e.printStackTrace();
}
try {
readerJpg();
} catch (SQLException e) {
e.printStackTrace();
}
}
}