处理BLOB
oracle LOB
LOB(Large Objects大对象)，用来存储大量的二进制和文本数据的一种数据类型
内部LOB
BLOB(二进制数据)
CLOB(单字节字母数据)
NCLOB(多字节字符数据)
外部LOB
插入BLOB类型的数据必须使用PreparedStatement。
因为BLOB类型的数据时无法使用字符串拼写的。
调用setBlob(int index,InputStream inputStream)
@Test
public void test4(){
Connection conn = null;
PreparedStatement preparedStatement = null;
ResultSet resultSet = null;
String sql = "insert into student values(?,?,?,?)";
try {
conn = Methods.getConnection();
preparedStatement = conn.prepareStatement(sql);
preparedStatement.setObject(1,"5");
preparedStatement.setString(2,"yang5");
preparedStatement.setString(3,"1235");
InputStream inputStream = new FileInputStream("boy.png");
preparedStatement.setBlob(4,inputStream);
preparedStatement.executeUpdate();
inputStream.close();
} catch (Exception e) {
e.printStackTrace();
} finally {
Methods.release(preparedStatement,conn,resultSet);
}
}
读取blob数据：
1.使用getBlob方法读取Blob对象
2.调用Blob的getBinaryStream()方法得到输入流，在使用IO操作即可。
@Test
public void test5(){
Connection conn = null;
PreparedStatement preparedStatement = null;
ResultSet resultSet = null;
String sql = "select picture from student where id =5";
try {
conn = Methods.getConnection();
preparedStatement = conn.prepareStatement(sql);
resultSet = preparedStatement.executeQuery();
if(resultSet.next()){
Blob picture = resultSet.getBlob(1);
InputStream in = picture.getBinaryStream();
OutputStream os = new FileOutputStream("boy1.png");
byte[] buffer = new byte[1024];
int len = 0;
while((len= in.read(buffer))!=-1){
os.write(buffer,0,len);
}
os.close();
in.close();
}
} catch (Exception e) {
e.printStackTrace();
} finally {
Methods.release(preparedStatement,conn,resultSet);
}
}
原文：https://www.cnblogs.com/yangHS/p/10832890.html