操作大文本数据存储在数据库中 mysql中有个lob

/*

create table t2(

id int primary key,

content longtext

);

*/

//插入大文本数据

@Test

public void testTextWrite() throws Exception{

Connection conn = JdbcUtil.getConnection();

PreparedStatement stmt = conn.prepareStatement("insert into t2 (id,content) values (?,?)");

stmt.setInt(1, 1);

File file = new File("src/jpm.txt");

Reader reader = new FileReader(file);

stmt.setCharacterStream(2, reader, (int)file.length());//MySQL驱动对于setCharacterStream（int,Reader,long)根本没有实现

stmt.executeUpdate();

JdbcUtil.release(null, stmt, conn);

}

//取出大文本数据

@Test

public void testTextRead() throws Exception{

Connection conn = JdbcUtil.getConnection();

PreparedStatement stmt = conn.prepareStatement("select * from t2 where id=1");

ResultSet rs = stmt.executeQuery();

if(rs.next()){

Reader r = rs.getCharacterStream("content");

//写到磁盘上

Writer w = new FileWriter("d:/jpm.txt");

char c[] = new char[1024];

int len = -1;

while((len=r.read(c))!=-1){

w.write(c, 0, len);

}

r.close();

w.close();

}

JdbcUtil.release(rs, stmt, conn);

}

/*

create table t3(

id int primary key,

content longblob

);

*/

//插入大二进制数据

@Test

public void testBlobWrite() throws Exception{

Connection conn = JdbcUtil.getConnection();

PreparedStatement stmt = conn.prepareStatement("insert into t3 (id,content) values (?,?)");

stmt.setInt(1, 1);

InputStream in = new FileInputStream("src/19.jpg");

stmt.setBinaryStream(2, in, in.available());

stmt.executeUpdate();

JdbcUtil.release(null, stmt, conn);

}

//取出大二进制数据

@Test

public void testBlobRead() throws Exception{

Connection conn = JdbcUtil.getConnection();

PreparedStatement stmt = conn.prepareStatement("select * from t3 where id=1");

ResultSet rs = stmt.executeQuery();

if(rs.next()){

InputStream in = rs.getBinaryStream("content");

//写到磁盘上

OutputStream out = new FileOutputStream("d:/a.jpg");

byte b[] = new byte[1024];

int len = -1;

while((len=in.read(b))!=-1){

out.write(b, 0, len);

}

in.close();

out.close();

}

JdbcUtil.release(rs, stmt, conn);

}