oracle-操作lob文件（举例Blob）

一.写入BLOB



1.先在blob中插入empty_blob()



2.获得对刚刚插入记录的引用

BLOB blob = (BLOB) rs.getBlob("你的blob字段名称");

3.写入

OutputStream out = blob.getBinaryOutputStream();

out.write(ENCYPWD);//注意这里

二.读出BLOB



1.blob  = rs.getBlob("你的blob字段名称");

、

2.InputStream is = blob.getBinaryStream();

int length = (int) blob.length();

byte[] buffer = new byte[length];

is.read(buffer);

is.close();



3.你有了is就随便处理了

比如说输出到一个文件

FileOutputStream fo = new FileOutputStream(filename);//数据到的文件名

fo.write(buffer);

fo.close();

一、BLOB操作

1、入库

（1）JDBC方式

 

    //通过JDBC获得数据库连接

    Class.forName("oracle.jdbc.driver.OracleDriver");

    Connection con = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:testdb", "test", "test");

    con.setAutoCommit(false);

    Statement st = con.createStatement();

    //插入一个空对象empty_blob()

    st.executeUpdate("insert into TESTBLOB (ID, NAME, BLOBATTR) values (1, "thename", empty_blob())");

    //锁定数据行进行更新，注意“for update”语句

    ResultSet rs = st.executeQuery("select BLOBATTR from TESTBLOB where ID=1 for update");

    if (rs.next())

    {

        //得到java.sql.Blob对象后强制转换为oracle.sql.BLOB

        oracle.sql.BLOB blob = (oracle.sql.BLOB) rs.getBlob("BLOBATTR");

        OutputStream outStream = blob.getBinaryOutputStream();

        //data是传入的byte数组，定义：byte[] data

        outStream.write(data, 0, data.length);

    }

    outStream.flush();

    outStream.close();

    con.commit();

    con.close(); 


 2、出库

    //获得数据库连接

    Connection con = ConnectionFactory.getConnection();

    con.setAutoCommit(false);

    Statement st = con.createStatement();

    //不需要“for update”

    ResultSet rs = st.executeQuery("select BLOBATTR from TESTBLOB where ID=1");

    if (rs.next())

    {

        java.sql.Blob blob = rs.getBlob("BLOBATTR");

        InputStream inStream = blob.getBinaryStream();

        //data是读出并需要返回的数据，类型是byte[]

        data = new byte[input.available()];

        inStream.read(data);

        inStream.close();

    }

    inStream.close();

    con.commit();

    con.close();