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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
8 o& f1 B- C; i  s, G( J5 ^JDBC中处理二进制类型数据) k0 \& @6 C8 l0 g
package jdbc;# z  B% h* s9 [7 p( d3 t
import java.io.BufferedInputStream;9 v# W4 c) q* ^' N6 A9 J8 V
import java.io.BufferedOutputStream;$ {; W3 ^6 G4 s" @
import java.io.File;" ^  u! E: ]4 I0 `
import java.io.FileInputStream;8 O1 J2 v2 [, e, _% Y
import java.io.FileOutputStream;
1 q* d( B" g9 J- U; e& N0 zimport java.io.InputStream;
' ^- \  i- [5 C/ b2 `import java.io.OutputStream;6 l9 R! K; ~6 p3 _% Z- {
import java.sql.Connection;
* Y2 r5 x# C7 A2 X0 fimport java.sql.PreparedStatement;
. w, q& h7 F( ]9 ^( }! Ximport java.sql.ResultSet;/ [% R7 m3 |( p0 t, I9 ^
/**
- V% o5 h0 }: M9 h8 k*
) V. E0 V' n4 B  ^' P* @author HaoWang/ P# ?- W' @. I% ?$ ?4 g9 [" o6 a
*/4 V% S7 P# Y. y- [* ?8 g7 q
public class BlobTest {$ N# L; o+ G* l7 |* x) f  Z
public static void main(String[] args) {
5 i0 E* d. x7 L+ Z// create(1,“C:\\a.jpg”);. [6 g2 H6 i& a; W
read(1,“C:\\a_bak.jpg”);
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public static void create(int bid, String path) {, J' l. {* {4 \; S1 h& j6 ?! k
Connection conn = null;
& t& }8 w8 [/ N6 p; S) OString sql = null;1 W( o9 ]& r; |, b- k
PreparedStatement ps = null;
; n- t/ F8 G3 y" }" mResultSet rs = null;
( i! c, v' @0 C) G( e' b' ltry {
( `) ~0 H' O1 E( a0 Cconn = JdbcUtils.getConnection();' R; n1 V. n+ s8 u1 @) t
sql = “insert into blob_test(bid,content) value(?,?)”;7 F7 D5 D) }8 F5 w
ps = conn.prepareStatement(sql);
/ V& s+ h6 H" e# e0 T" [0 ?) Gps.setInt(1, bid);
* y$ `* c6 Y# t4 C, @File file = new File(path);- P- b1 |+ d' E0 X! `* t
InputStream in = new BufferedInputStream(new FileInputStream(file));0 M8 e$ q+ f: Q- p
ps.setBinaryStream(2, in, file.length());8 }9 G+ f$ N2 Z0 }; S. E; z
int i = ps.executeUpdate();
# R5 Q- ~8 |2 N' E" |# M, C! vSystem.out.println(“i=”+i);2 @5 R, r. A6 ]
in.close();) e, e6 f, G* }! G; k4 D3 _  O. r4 Y2 o
& \' R: ^- z/ L5 l8 _  r. H
} catch (Exception ex) {
5 }* y, o2 }, V5 T* lSystem.out.println(ex.toString());
, Q" c. d6 {9 S1 G0 n  K4 S} finally {
  I9 a2 W5 B7 \3 N1 q  z" l8 mJdbcUtils.free(conn, ps, rs);
3 H1 [% J5 @- ]/ _}% N6 l0 g" \0 H1 P1 U& ~
}
/ C  E+ s9 @) D7 a2 K; `: Bpublic static void read(int bid, String path) {  \$ l$ q8 l) d/ B8 ~' R
Connection conn = null;
8 J: E7 O& o! ZString sql = null;) C% e5 u" {" x+ z: f" S* y
PreparedStatement ps = null;
2 r4 L* @/ E. L/ k/ UResultSet rs = null;0 b8 l+ J: P1 V0 b9 s* k: b
try {
% S' e% z4 t* D& c! @conn = JdbcUtils.getConnection();, x& n1 z, W8 L) m: ]
sql = “select content from blob_test where bid=?”;2 \$ Y, O5 k' H7 e7 z
ps = conn.prepareStatement(sql);. |0 j& w9 N$ w
ps.setInt(1, bid);- r# o% A/ E7 _" _, {: W7 k
rs = ps.executeQuery();; V( |3 s$ U0 b6 f$ v
while(rs.next()) {9 q' K1 ?$ i# n4 W: x/ }) g3 \5 ?
InputStream in = rs.getBinaryStream(bid);
; M+ _; Z1 l5 f" N- e" s& n& tFile file = new File(path);
5 H: p6 m* p! hOutputStream out = new BufferedOutputStream(new FileOutputStream(file));+ B; v5 Q+ E( T3 p; ^( |; ]6 a# s
byte[] buff = new byte[1024];9 P2 m- X# y4 w: S7 S; ?' p, }& C
for(int i=0; (i=in.read(buff))》0;) {
* e* y, f4 v8 v3 C) kout.write(buff, 0, i);
. }8 D  [  P4 A. z5 S5 }}
- `1 j) w9 n; ^+ n' ^out.close();
; P, I  j2 f, X" A0 ain.close();
0 _+ m8 V6 V) ?}
" @2 k* L/ M8 K; {. W} catch (Exception ex) {- {- W2 ?6 d  T' m
System.out.println(ex.toString());
& W8 I7 S% h; J* s8 Z% A2 v} finally {
! J, D8 P# f1 J4 j2 gJdbcUtils.free(conn, ps, rs);
! j0 a3 S1 o, G- G}
5 M1 J$ S  L* F}" G7 B. _" F# J$ l0 f- E( T( r7 Z
}
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