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一、大文本存取:
我们有一本约10M的小说,现存入数据库:
代码如下:以junit测试的方式给出
package com.dzq.lob; import java.io.File; import java.io.FileReader; import java.io.FileWriter; import java.io.Reader; import java.io.Writer; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import org.junit.Test; import com.dzq.util.JDBCUtils; public class TextDemo1 { @Test public void addText(){ Connection conn=null; PreparedStatement ps=null; ResultSet rs=null; String sql="insert into textdemo values (null,?,?)"; try{ conn=JDBCUtils.getConn(); ps=conn.prepareStatement(sql); ps.setString(1, "钢铁是怎样炼成的.txt"); File file=new File("1.txt"); ps.setCharacterStream(2, new FileReader(file),(int)file.length()); ps.executeUpdate(); }catch(Exception e){ e.printStackTrace(); }finally{ JDBCUtils.close(rs, ps, conn); } } @Test public void findText(){ Connection conn=null; PreparedStatement ps=null; ResultSet rs=null; String sql="select * from textdemo where id=?"; try{ conn=JDBCUtils.getConn(); ps=conn.prepareStatement(sql); ps.setInt(1, 5); rs=ps.executeQuery(); while (rs.next()) { String filename=rs.getString("name"); Reader reader=rs.getCharacterStream("content"); Writer writer=new FileWriter(filename); char []cs=new char[1024]; int i=0; while ((i=reader.read(cs))!=-1) { writer.write(cs,0,i); } reader.close(); writer.close(); } }catch(Exception e){ e.printStackTrace(); }finally{ JDBCUtils.close(rs, ps, conn); } } }
二、大二进制存取:
我们有一个mp3文件,现存入数据库
代码如下:
package com.dzq.lob; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.InputStream; import java.io.OutputStream; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import org.junit.Test; import com.dzq.util.JDBCUtils; public class BlobDemo1 { @Test public void addBlob(){ Connection conn=null; PreparedStatement ps=null; ResultSet rs=null; String sql="insert into blobdemo values (null,?,?)"; try{ conn=JDBCUtils.getConn(); ps=conn.prepareStatement(sql); ps.setString(1, "洛天依.mp3"); File file=new File("1.mp3"); ps.setBinaryStream(2, new FileInputStream(file),(int)file.length()); ps.executeUpdate(); }catch(Exception e){ e.printStackTrace(); }finally{ JDBCUtils.close(rs, ps, conn); } } @Test public void findBlob(){ Connection conn=null; PreparedStatement ps=null; ResultSet rs=null; String sql="select * from blobdemo"; try{ conn=JDBCUtils.getConn(); ps=conn.prepareStatement(sql); rs=ps.executeQuery(); while (rs.next()) { String filename=rs.getString("name"); InputStream in=rs.getBinaryStream("content"); OutputStream out=new FileOutputStream(filename); byte []bs=new byte[1024]; int i=0; while ((i=in.read(bs))!=-1) { out.write(bs,0,i); } in.close(); out.close(); } }catch(Exception e){ e.printStackTrace(); }finally{ JDBCUtils.close(rs, ps, conn); } } }
三、其中出现的问题见链接:
20160408javaweb之JDBC 大二进制和大文件存取
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原文地址:http://www.cnblogs.com/xiaoduc-org/p/5369319.html