大二进制数据的存取

 

 1 package cn.itcast.jdbc.lob;
 2 
 3 import java.io.File;
 4 import java.io.FileInputStream;
 5 import java.io.FileOutputStream;
 6 import java.io.FileReader;
 7 import java.io.FileWriter;
 8 import java.io.InputStream;
 9 import java.io.OutputStream;
10 import java.io.Reader;
11 import java.io.Writer;
12 import java.sql.Connection;
13 import java.sql.PreparedStatement;
14 import java.sql.ResultSet;
15 
16 import org.junit.Test;
17 
18 import cn.itcast.util.JdbcUtil;
19 
20 //大二进制数据的存取
21 /*
22 use day15;
23 create table t2(
24     id int primary key,
25     content longblob
26 );
27  */
28 public class BlobDemo {
29     @Test
30     public void testAdd(){
31         Connection conn = null;
32         PreparedStatement stmt = null;
33         try{
34             conn = JdbcUtil.getConnection();
35             stmt = conn.prepareStatement("insert into t2 (id,content) values (?,?)");
36             stmt.setInt(1, 1);
37             
38             InputStream in = new FileInputStream("c:/1.jpg");
39             stmt.setBinaryStream(2, in, in.available());
40             
41             int i = stmt.executeUpdate();
42             if(i>0)
43                 System.out.println("插入成功");
44             
45         }catch(Exception e){
46             e.printStackTrace();
47         }finally{
48             JdbcUtil.release(null, stmt, conn);
49         }
50     }
51     @Test
52     public void testRead(){
53         Connection conn = null;
54         PreparedStatement stmt = null;
55         ResultSet rs = null;
56         try{
57             conn = JdbcUtil.getConnection();
58             stmt = conn.prepareStatement("select * from t2 where id=?");
59             stmt.setInt(1, 1);
60             //大数据要使用流的形式
61             //保存到E盘上
62             rs = stmt.executeQuery();
63             if(rs.next()){
64                 InputStream in = rs.getBinaryStream("content");
65                 OutputStream out = new FileOutputStream("e:/1.jpg");
66                 byte b[] = new byte[1024];
67                 int len = -1;
68                 while((len=in.read(b))!=-1){
69                     out.write(b, 0, len);
70                 }
71                 out.close();
72                 in.close();
73             }
74             
75         }catch(Exception e){
76             e.printStackTrace();
77         }finally{
78             JdbcUtil.release(null, stmt, conn);
79         }
80     }
81 }