storage.java

JSP聊天系统

package org.ehotsoft.yekki.sql;

import java.sql.ResultSet;
import java.sql.Statement;
import java.sql.Connection;
import java.sql.SQLException;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;

import org.ehotsoft.yekki.upload.Upload;
import org.ehotsoft.yekki.upload.File;
import org.ehotsoft.yekki.upload.UploadException;
import org.ehotsoft.yekki.sql.ConnectionManager;

import oracle.jdbc.OracleResultSet;
import oracle.sql.BLOB;

public class Storage {
	
	//刚插入的数据如何得到其ID号？
	public static int upload( Upload upload, int moduleId )
		throws UploadException {
		
		SQLFacade facade = new SQLFacade();

		Connection cnn = null;
		Statement stmt = null;
		ResultSet rst = null;
		OracleResultSet oracleRst = null;
		File file = upload.getFiles().getFile( 0 );
		int id = -1;
		
		try {

			cnn = facade.getConnection();
			cnn.setAutoCommit( false );
			stmt = cnn.createStatement( ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_UPDATABLE  );
			StringBuffer sql = new StringBuffer();
			
			sql.append( "select seq_storage.nextval from dual" );

			rst = facade.executeQuery( sql.toString() );

			rst.next();

			id = rst.getInt( 1 );
			
			sql = new StringBuffer();
			
			sql.append( "insert into tbl_storage_file( id, file_type, file_name, file_ext, file_size, module_id, content ) values(" )
				.append( id )
				.append( ",'" )
				.append( file.getContentType() )
				.append( "','" )
				.append( file.getFileName() )
				.append( "','" )
				.append( file.getFileExt() )
				.append( "'," )
				.append( file.getSize() )
				.append( "," )
				.append( moduleId )
				.append( ", EMPTY_BLOB() )" );

			stmt.executeUpdate( sql.toString() );

			sql = new StringBuffer( "select content from tbl_storage_file where id=" ).append( id ).append( " for update" );
			oracleRst = ( OracleResultSet )stmt.executeQuery( sql.toString() );
			
			oracleRst.next();
			
			BLOB blob = ( BLOB )oracleRst.getBlob( 1 );
			OutputStream out = blob.getBinaryOutputStream();
			out.write( file.getBinaryData(), file.getStartData(), file.getSize() );

			out.flush();
			out.close();
			
			cnn.commit();
			cnn.setAutoCommit( true );
		}
		catch ( Exception e ) {
			
			try {

				cnn.rollback();
			}
			catch ( SQLException se ) {
				
				se.printStackTrace();
			}
			
			e.printStackTrace();
			throw new UploadException( e.getMessage() );
		}
		finally {
			
			try {
				cnn.setAutoCommit( true );
			}
			catch ( SQLException e ) {
				
				e.printStackTrace();
			}
		}

		return id;
	}
	
	public static int dropById( int id )
		throws SQLException {
		
		String sql = "delete from tbl_storage_file where id=" + id;
		SQLFacade facade = new SQLFacade();
		int retCount = facade.executeUpdate( sql );
		
		facade.close();

		return retCount;
	}

	public static void dump( HttpServletResponse response, int id )
		throws SQLException, IOException {
		
		SQLFacade facade = new SQLFacade();
		String sql = "select * from tbl_storage_file where id=" + id;
		ResultSet rst = facade.executeQuery( sql );
		
		if ( rst.next() ) {
			
			String fileType = rst.getString( "file_type" );
			
			if ( fileType.equals( "document" ) ) {
				
				fileType = " text/html";
			}

			response.setContentType( fileType + "; charset=GB2312" );
			
			if ( !( fileType.equals( " text/html" ) || fileType.equals( " image/gif" ) || fileType.equals( " image/pjpeg" ) || fileType.equals( " text/plain" ) ) ) {
				
				response.setHeader( "Content-disposition", "attachment; filename=" + rst.getString( "file_name" ) );
			}

			ServletOutputStream out = response.getOutputStream();
			
			int len = 0;
			
			InputStream in = rst.getBinaryStream( "content" );
			byte[] bytes = new byte[ 4096 * 10 ];

			while ( ( len = in.read( bytes ) ) != -1 ) {
				
				out.write( bytes, 0, len );
				out.flush();
			}

			in.close();
			out.close();
		}

		facade.close();
	}
}