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[专业语言] Java认证关于JDBC中处理二进制类型数据

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发表于 2012-8-4 12:44:44 | 显示全部楼层 |阅读模式
Java认证关于JDBC中处理二进制类型数据( E3 |9 D+ y  I  ~- n$ D# I* R' C
JDBC中处理二进制类型数据/ A" J  U) H5 S4 u6 t& x
package jdbc;
# o$ r6 ]9 [9 V# nimport java.io.BufferedInputStream;
+ p. F$ I/ m$ R8 S. aimport java.io.BufferedOutputStream;5 c$ L& w1 x* N, k
import java.io.File;; k; Q0 P4 {& g
import java.io.FileInputStream;
8 I+ p# v4 c, Timport java.io.FileOutputStream;
) f9 ^1 O, _/ ]" X4 r" O4 A6 i8 oimport java.io.InputStream;
0 C  n! {* |( N. J0 G: |- C; jimport java.io.OutputStream;- W, |. W$ i- M" |0 f1 d  ^  k
import java.sql.Connection;
) R% u& C6 c# Q- l8 _9 V8 l3 s9 |6 nimport java.sql.PreparedStatement;
3 b8 X$ c( N9 {; mimport java.sql.ResultSet;! D- [, f& ]- |  i! F$ D
/**4 v6 ^/ ]" Q$ S1 g4 m$ ^. Z
*
1 V8 D: y! q; u0 L# Z* @author HaoWang
% H. L9 c  [# V% c1 l9 j0 S*/3 ]4 Y9 X& u- }1 B$ v, {
public class BlobTest {* S; f- W3 j! n. d( [0 r
public static void main(String[] args) {
, C- J5 [8 c5 j$ |9 Z// create(1,“C:\\a.jpg”);, `, w7 }  O( N( h3 M
read(1,“C:\\a_bak.jpg”);
: D% a" I5 X4 W0 f# B}
" g+ I" H# O# G5 ^0 D7 J$ spublic static void create(int bid, String path) {
/ z3 _' @: Y& oConnection conn = null;
- x# E# l( _8 k, ?  ~' u5 s; r9 CString sql = null;! k% P$ O0 D# P0 {3 a- F) G
PreparedStatement ps = null;) F4 j$ e  T+ c& Q. ]- p$ v" J
ResultSet rs = null;
$ _4 M7 B- N- r2 r8 Rtry {
* F3 g' @) b7 \# a9 n, s9 ^conn = JdbcUtils.getConnection();+ t. r: R0 e2 ~- l2 D
sql = “insert into blob_test(bid,content) value(?,?)”;2 Z7 Q' R- [/ d4 |8 F+ m4 K; J
ps = conn.prepareStatement(sql);+ u( I" v5 w% Z0 i' q  W) a: h
ps.setInt(1, bid);# L2 t( m; H" t& F2 u; Y+ F
File file = new File(path);
7 j3 D* Q0 B# [  BInputStream in = new BufferedInputStream(new FileInputStream(file));& i1 D( k4 c0 _& ]3 L  }& `, u
ps.setBinaryStream(2, in, file.length());" z+ b+ g, S8 P4 m' ~5 E  k
int i = ps.executeUpdate();
. {- m1 j$ j& n1 z" X7 rSystem.out.println(“i=”+i);
3 ^. C$ r( c- b! E, min.close();
: D7 f" R2 g, P8 Z" v4 s
0 ?9 @, D, ~$ D& r' d- t  J7 H} catch (Exception ex) {! j. o7 @7 Q$ |+ A
System.out.println(ex.toString());
  N, r# q1 n' I  a) j4 ^} finally {
) T. v# P, K5 cJdbcUtils.free(conn, ps, rs);' }, M( [0 I! R- [- f
}5 X% l/ A6 x, c1 P6 f
}
4 c! }6 I- `. w6 h& C" D0 npublic static void read(int bid, String path) {8 u5 W) V( c; L# O) r
Connection conn = null;1 v' j# d+ g1 ^; a. h( b
String sql = null;0 T; |7 ?5 Y( j. s( ~' w
PreparedStatement ps = null;- z) W2 Z' c. h, f# e4 _1 k
ResultSet rs = null;: {" G, X; E. D9 i  A/ X6 l
try {1 d6 i; _' u% u5 k" m
conn = JdbcUtils.getConnection();0 l6 [" I$ u5 h4 R: D
sql = “select content from blob_test where bid=?”;1 b8 A: d3 `) u) e, W7 A
ps = conn.prepareStatement(sql);, }- @" h& Y! C5 N1 p2 U9 L
ps.setInt(1, bid);
# v* w) Y" k, z% S* Nrs = ps.executeQuery();# T/ {( A6 @( m1 {3 k0 {
while(rs.next()) {* N' {7 p# U! n5 N
InputStream in = rs.getBinaryStream(bid);
& P# n/ v8 |& t6 r  K8 bFile file = new File(path);
2 V" h( b' m; X1 kOutputStream out = new BufferedOutputStream(new FileOutputStream(file));
! v( S/ h2 h7 ~. }7 xbyte[] buff = new byte[1024];
& V: m2 ^7 [9 P. c2 pfor(int i=0; (i=in.read(buff))》0;) {
/ i+ P- R8 B4 E! H" rout.write(buff, 0, i);
6 n" y5 F. s8 Q) R) V7 c* Y! t}
+ ^1 M/ p  [! W) Z0 G* n& G. P# c( Kout.close();
9 m; e/ ~0 O  y1 M  i5 S, Zin.close();: S! L8 M! I' _! c  T# ^
}- v; l+ J# N% \3 j
} catch (Exception ex) {
- L7 \  ]2 H. `( r+ r! u8 WSystem.out.println(ex.toString());
2 P* v6 T2 t3 n. z/ [% U  {. W& u- v} finally {
: j6 C" F2 N3 V4 oJdbcUtils.free(conn, ps, rs);
0 O8 ?% w* n! t% G& A% n}5 e* W# K) ^' M
}6 }% s6 P8 Y' L1 o5 [
}
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