【MySql】文件内容写入数据库和从数据库写入文件
//写入文件到数据库static void insert() throws Exception{String sql ="insert into news (info) values (?)";Connection conn=JdbcUtilSingle.getConnection();PreparedStatement pst=conn.prepareStatement(sql);File file = new File("src/jdbc/test/day01/Jdbc01.java");//这里不能用字节流，需要用字符流//InputStream inputstream = new BufferedInputStream(new FileInputStream(file));Reader reader = new BufferedReader(new FileReader(file));//这里也不能再用setBinaryStream了//setBinaryStream(1, inputstream,(long)file.length());pst.setCharacterStream(1, reader, (int)file.length());int i = pst.executeUpdate();System.out.println(i);JdbcUtilSingle.free(null, pst, conn);}//读出数据库信息写入文件static void write() throws Exception{String sql="select * from news ";Connection conn=JdbcUtilSingle.getConnection();PreparedStatement pst=conn.prepareStatement(sql);ResultSet rs=pst.executeQuery();File file = new File("output.java");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);Reader reader = rs.getCharacterStream(1);//OutputStream out = new BufferedOutputStream(new FileOutputStream(file));Writer writer = new BufferedWriter(new FileWriter(file));//这里也要换成字符数组//byte buff[]= new byte[1024];char buff[]=new char[1034];//寫入文件for(int i=0;(i=reader.read(buff))>0;){writer.write(buff, 0, i);}}JdbcUtilSingle.free(rs, pst, conn);}?