【MySql】数据库写入图片和读出图片

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//写入图片到数据库
static void insert() throws Exception
{
String sql ="insert into pics (pic) values (?)";
Connection conn=JdbcUtilSingle.getConnection();
PreparedStatement pst=conn.prepareStatement(sql);
File file = new File("p_large_CuRa_47110000afc8121a.jpg");
InputStream inputstream = new BufferedInputStream(new FileInputStream(file));
pst.setBinaryStream(1, inputstream, (int)file.length());//说明：这里一定要转化为int，否则会报错，length()返回值为long类型的
//setBinaryStream(1, inputstream,(long)file.length());
int i = pst.executeUpdate();
System.out.println(i);
JdbcUtilSingle.free(null, pst, conn);
}
//读出图片信息
static void write() throws Exception
{
String sql="select * from pics ";
Connection conn=JdbcUtilSingle.getConnection();
PreparedStatement pst=conn.prepareStatement(sql);
ResultSet rs=pst.executeQuery();
File file = new File("mypic.jpg");
while(rs.next())
{
//Blob blob = rs.getBlob(1);
//InputStream in = blob.getBinaryStream();
//上面兩行的作用和下面這行相同
InputStream in = rs.getBinaryStream(1);
OutputStream out = new BufferedOutputStream(new FileOutputStream(file));
byte buff[]= new byte[1024];
//寫入文件
for(int i=0;(i=in.read(buff))>0;)
{
out.write(buff, 0, i);
}
}
JdbcUtilSingle.free(rs, pst, conn);