http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 2]aZe4H.
} x+y!P
for(int i=0;i<nEndPos.length-1;i++) nHA`B.:B
{ }8F$& AFt
nEndPos = nStartPos[i+1]; "i{_<;p O
} >yA,@%X
nEndPos[nEndPos.length-1] = nFileLength; ^8oc^LOa~2
} KWhM
} -wRyMY_D
+>WC^s
qz=#;&ZU
//启动子线程 1'v!9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; keQXJ0
for(int i=0;i<nStartPos.length;i++) S|q!? /jqj
{ U|Z>SE<k
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ')u5l
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), P 5qa:<
nStartPos,nEndPos,i); 9oz(=R
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,D@;i
fileSplitterFetch.start(); (4/]dTb
} W93JY0Ls9|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !` M;#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3q|cZQK!1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >4|c7z4
nEndPos = " + nFileLength); lKV\1(`
// fileSplitterFetch[nPos.length-1].start(); kBiBXRt
1ntkM?
!V]MLA`
//等待子线程结束 L;--d`[
//int count = 0; N;x<| %peL
//是否结束while循环 i2FD1*=/?
boolean breakWhile = false; q1TW?\pjb:
P"bknXL
.mT#%ex
while(!bStop) txml*/zL
{ \>Ga-gv6/
write_nPos(); 5@UC c
Utility.sleep(500); 5rfH;`
breakWhile = true; ]/o12pI
Jny)uo8
Zc%foK{
for(int i=0;i<nStartPos.length;i++) P!FEh'.
{ RrO0uadmn
if(!fileSplitterFetch.bDownOver) Q$3\ /mz
{ 77xq/c[)
breakWhile = false; i[2bmd!H
break; `*" H/QG
} (zs4#ja2,
} 0eqi1;$b]
if(breakWhile) pM&]&Nk
break; b'7z DZI]
|k`f/*
*,W!FxJ
//count++; c/<Sa|'
//if(count>4) 9|N"@0<B
// siteStop(); R81{<q'%X
} 5@+4
crJ7pe9
f2O*8^^Y{Q
System.err.println("文件下载结束！"); qY$*#*Q
} ?E+:]j_
catch(Exception e){e.printStackTrace ();} O}K_l1
} -t@y\vZF,
Q%& _On
WxVn&c\
//获得文件长度 xb9Pc.A[
public long getFileSize() &o*s !u
{ t;.^K\S4
int nFileLength = -1; @K$VV^wp
try{ UCn*UX
URL url = new URL(siteInfoBean.getSSiteURL()); h"%|\o+3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yV:EK{E
httpConnection.setRequestProperty("User-Agent","NetFox"); %XP_\lu]
D!bKm[T
GJ1;\:cQq
int responseCode=httpConnection.getResponseCode(); d~{jEg
if(responseCode>=400) KE/-VjZu
{ ?$|uT
processErrorCode(responseCode); W\@?e32
return -2; //-2 represent access is error gDQkn {T.%
} .D8~)ZWN
aO.\Qe+j
w4e%-Ln
String sHeader; h4CTTe)
=tr1*s{
RzA2*]%a
for(int i=1;;i++) E`Jp(gK9F
{ &W=V%t>Z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {OB-J\7Y
//Utility.log(in.readLine()); +}_Pf{MW
sHeader=httpConnection.getHeaderFieldKey(i); ,vPe}OKj
if(sHeader!=null) m:)Z6
{ 4%g6_KB
if(sHeader.equals("Content-Length")) P%zH>K
{ )7&42>t
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {&2$[g=[ ^
break; p?+lAbe6H
} Sa3I?+
} vk @%R
else 1)TK01R8
break; $%7I:
} 8tb6 gZz
} M{`/f@z(
catch(IOException e){e.printStackTrace ();} :s'o~
catch(Exception e){e.printStackTrace ();} q} ]'Q -
j/)"QiS*?
JDLTOLG
Utility.log(nFileLength); &w+;N5}3
slU
ic%?uWN
return nFileLength; .6> hD1'
} i 8l./Yt/
XB0a dp
j?EskT6
//保存下载信息（文件指针位置） h ?uqLsRl
private void write_nPos() 06 QU
{ Ho3dsh)
try{ duX0Mc.0P
output = new DataOutputStream(new FileOutputStream(tmpFile)); FH)t:!#
output.writeInt(nStartPos.length); sK+ (v
for(int i=0;i<nStartPos.length;i++) 86 *;z-G
{ Q*]$)D3n
// output.writeLong(nPos); C>.e+V+':
output.writeLong(fileSplitterFetch.nStartPos); ?2{bKIV_
output.writeLong(fileSplitterFetch.nEndPos); "r u]?{v
} /:bKqAz;M
output.close(); e# t3u_
} \[:PykS
catch(IOException e){e.printStackTrace ();} *yJ[zXXjJ
catch(Exception e){e.printStackTrace ();} l^.K'Q1~a
} kr%2w
XC=%H'p
pX@Si3G`
//读取保存的下载信息（文件指针位置） !RS9%ES_?
private void read_nPos() h@=7R
{ puOC60zI
try{ K*~]fy
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2@vJ
int nCount = input.readInt(); n5|l|#c$N
nStartPos = new long[nCount]; COR;e`%,
nEndPos = new long[nCount]; `>s7M.|X
for(int i=0;i<nStartPos.length;i++) M :V2a<!c
{ -K"4rz
nStartPos = input.readLong(); oizT-8i@N
nEndPos = input.readLong(); c! @F
} U#bl=%bF
input.close(); zbNA\.y
} dm6~
catch(IOException e){e.printStackTrace ();} Z1M>-[j)
catch(Exception e){e.printStackTrace ();} Frk cO
} "NDxgJ%J35
X 7=fX~s
7|YN:7iA
private void processErrorCode(int nErrorCode) $(ewk):
{ U[R@x`
System.err.println("Error Code : " + nErrorCode); 9M_(He -
} Z`Pd2VRp
6SVqRD<`
6xoq;=o
//停止文件下载 'n0 .#E_
public void siteStop() d6`OXTD
{ -T7xK/
bStop = true; 4[TR0bM%
for(int i=0;i<nStartPos.length;i++) 9Y/L?km_(
fileSplitterFetch.splitterStop(); b;#\~(a
3o*FPO7?
btH _HE
} c"7j3/p
} _d@=nK)
//负责部分文件的抓取 Bn?:w\%Ue
**FileSplitterFetch.java YzAFC11,
*/ Po(]rQbE
package NetFox; 9GgA6#
NBjeHtT
@b2`R3}9R
import java.io.*; c8{]]
import java.net.*; YD\]{,F|
*:_P8G;
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public class FileSplitterFetch extends Thread { vfcb:x
jij<yM8$g
; dd Q/
String sURL; //File URL S_v(S^x6
long nStartPos; //File Snippet Start Position `Gd$:qV
long nEndPos; //File Snippet End Position !g>.i`
int nThreadID; //Thread's ID ]u#JuX
boolean bDownOver = false; //Downing is over &.Q8Mi aT
boolean bStop = false; //Stop identical ymWgf6r<
FileAccessI fileAccessI = null; //File Access interface ;;Ds
{fV}gR2
:m'+tGs
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException vMla'5|l
{ NOt@M
this.sURL = sURL; T@[!A);
this.nStartPos = nStart; f?56=& pHY
this.nEndPos = nEnd; K=?VDN
nThreadID = id; RKZ6}q1n
fileAccessI = new FileAccessI(sName,nStartPos);//定位 x0Yse:RE^
} S[,8TErz
|.P/:e9
Fl3#D7K
public void run() WKmbNvN^
{ "w_N'-}#
while(nStartPos < nEndPos && !bStop) -"Q-H/qh
{ 9 [jTs3l:
5,pSg
%zeATM[`
try{ C`V)VJM
URL url = new URL(sURL); _q?<at}y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %UZVb V
httpConnection.setRequestProperty("User-Agent","NetFox"); ^j)BKD-
String sProperty = "bytes="+nStartPos+"-"; K93p"nHN
httpConnection.setRequestProperty("RANGE",sProperty); ]"~51HQZ
Utility.log(sProperty); X"q!Y#)
w$|l{VI
bU54-3Ox*
InputStream input = httpConnection.getInputStream(); hWo=;#B*
//logResponseHead(httpConnection); ]3Dl)[R
,xI%A, (,;
;heHefbvvd
byte[] b = new byte[1024]; x;\wY'
int nRead; 28andfl
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) gNpJ24QK
{ ;WU<CKYG*
nStartPos += fileAccessI.write(b,0,nRead); >dzsQ^Nj
//if(nThreadID == 1) E7zm{BX]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Bi3+)k>u7
} Pw0Ci
?=;qK{)37
^Q+i=y{W
Utility.log("Thread " + nThreadID + " is over!"); i/So6jW
bDownOver = true; ]@^coj[
//nPos = fileAccessI.write (b,0,nRead); Xz 4 x
} lb*8G
catch(Exception e){e.printStackTrace ();} ww k PF
} KvPX=/&Zu
} H ?M/mGP
=PHIpFIuk
B;K`q
//打印回应的头信息 IJIzXU
public void logResponseHead(HttpURLConnection con) zTbVp8\pI
{ C0*@0~8$9
for(int i=1;;i++) hsKmnH@#
{ `Y=WMNy
String header=con.getHeaderFieldKey(i); *Vw\'%p*
if(header!=null) 8qEK+yi,
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Rli:x
Utility.log(header+" : "+con.getHeaderField(header)); A@*:<Hs%
else efP&xk
break; '3IC*o"
} mqff]m
} K+=+?~
>wHxmq8F5<
k>jbcSY(z<
public void splitterStop() _ee dBpV
{ 7Q w|!
bStop = true; 6x)$Dl
} !R-z%
s@hRqGd:
] b9-k
} -u!FOD/
`1OgYs
2lKV#9"
/* ?E%ELs_Dl
**FileAccess.java C:8_m1Y{
*//文件访问(定位，写) :,b iyJt
package NetFox; {gNV[45
import java.io.*; 1?*
0[?ny`Y
[YrHA~=U
public class FileAccessI implements Serializable{ &N~ZI*^
UO*Ymj 1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [%Bf< J<
RandomAccessFile oSavedFile; :j')E`#
long nPos; &!aAO(g
}]n$ %g(
+Q=1AXe
public FileAccessI() throws IOException `LAR@a5i
{ l {jmlT
this("",0); ?{w3|Ef&
} -Y Bd, k3
Uy ?
;w|b0V6
public FileAccessI(String sName,long nPos) throws IOException ]lw|pvtd
{ AcI,N~~
oSavedFile = new RandomAccessFile(sName,"rw"); VvFC -r,=G
this.nPos = nPos; l\M_-:I+4
oSavedFile.seek(nPos); DrnJ;Hi"
} 7QKr_
/ N)W2
8t@p@Td|
public synchronized int write(byte[] b,int nStart,int nLen) "H-"
{ \<}&&SuH
int n = -1; f7h*Vu`>
try{ /!^&;$A'
oSavedFile.write(b,nStart,nLen); XU/QA [K
n = nLen; c|F[.;cR
} Le<wR
catch(IOException e) :1t~[-h^
{ 3d<HN6&U
e.printStackTrace (); L-B<nl
} M?&h~V1OI~
|#1(Z-}
C2Xd?d
return n; jM-)BP6f4
} &E xYXI
l]~n3IK"
"S3wk=?4
} V[-jD8='3
lEHzyh}2k
:l|%17N
/* '47P|t
**SiteInfoBean.java *(PL _/:
*/ &Ysosy*
package NetFox; |6=p{y
xI>A6
HB Iip?
public class SiteInfoBean { l;y7]DO
>.dWjb6t
vSi_t K4
private String sSiteURL; //Site's URL '*\|;l#1
private String sFilePath; //Saved File's Path zC_<(4$-"
private String sFileName; //Saved File's Name TuW%zF/
private int nSplitter; //Count of Splited Downloading File rx(2yf
N3u((y/
>#,G}xf
public SiteInfoBean() 6JKqn~0Kk
{//nSplitter的缺省值为5 PJcwH6m
//default value of nSplitter is 5 G$ _yy:
this("","","",5); s'kDk2r
} }%Bl>M
^v.,y3
@?YRuwp L
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) vjjSKP6B
{ )(y)A[
sSiteURL= sURL; pb#?l6x$+
sFilePath = sPath; r5!/[_l
sFileName = sName; CHV*vU<N
this.nSplitter = nSpiltter; kcb.Wz~=
JyR/1 W
}Tf9S<xpq3
} p~*UpU8u
71vkyn@"
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public String getSSiteURL() !S&L*OH,
{ Bz5-ITX
return sSiteURL; $Y5)(
} o.q/O)'V u
:n /@z4#
|&Ym@Jyj
public void setSSiteURL(String value) 6252N]*
{ f4L`.~b'hb
sSiteURL = value; TEDAb>
} rj6#1kt
$H+VA@_
e["2QIOe
public String getSFilePath() H,N)4;F<c
{ =m5SK5vLKT
return sFilePath; gn3jy^5
} Nbp!teH6
-?(E_^ng
r#xg#uoj
public void setSFilePath(String value) )Tk1 QHU
{ 6;|n]m\Vd
sFilePath = value; ]O]GeAGC2
} ;vt8R=T
M`ip~7"
Yv:55+e!|
public String getSFileName() y#XbJuN/
{ }#X8@
return sFileName; _x!7}O#k
} A^p[52`
|g=="
qL,tYJ<m%
public void setSFileName(String value) wC5ee:u C%
{ 1UKg=A-q
sFileName = value; CZ nOui
} $z+8<?YD
I_A@BnM{I
Yot?=T};3{
public int getNSplitter() D$T%\ P
{ 6P';DB
return nSplitter; Br`IW
} tO0!5#-VR
[H=)
W^s ;Bi+Nw
public void setNSplitter(int nCount) )n,P"0
{ (&!NC[n,
nSplitter = nCount; 4._(|
} |jM4E$
} Dgy]ae(Hb3
[ :zO}r:
K# Jk _"W
/* F{UP;"8'
**Utility.java e@IA20
*/ 3;a<_cE*@
package NetFox; }Q";aU0^
zL\OB?)5J
*6} N =Z
public class Utility { VO"("7L
1bH;!J
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public Utility() X$yN_7|+
{ 3"O>&Q0c
U4cY_p?
&8z[`JW,T
} Z ,EvQ8i
/ 4lvP
//线程睡眠 d'Zqaaf k%
public static void sleep(int nSecond) '7oA< R
{ ,u/aT5\_
try{ 435;Vns\n
Thread.sleep(nSecond); 9ksE>[7
} 2Y7)WPn
catch(Exception e) +=:#wzK@
{ # 0Lf<NZ
e.printStackTrace (); ;s52{>&F]
} _%GGl$kH
} /IsS;0K%L
.j-IX1Sa
//日志 {6}eN|4~#
public static void log(String sMsg) IV)<5'v
{ I6Ce_|n ?k
System.err.println(sMsg); lIProF0
} #es9d3~\
SXy=<%ed
F}=aBV|-
public static void log(int sMsg) w08?DD]CDt
{ G8;w{-{m
System.err.println(sMsg); S*n@81Z
} 0A( +ZMd
} :duo#w"K
=dFv/F/RW
W]nSR RWco
/* X@f "-\
**TestMethod.java $ mI0Bk
*/ \.3D~2cU
package NetFox; tQylT0'[+o
0q'w8]m
L>YU,I\o
public class TestMethod { qBCK40
Dre]AsgiV
rf$X>M=G
public TestMethod() rp0ZvEX
{ ///xx/weblogic60b2_win.exe +gLPhX:`
try{ ? 8LXP
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4vwTs*eB`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Rb{U+/gq
SiteFileFetch fileFetch = new SiteFileFetch(bean); et }T%~T
fileFetch.start(); [AW" D3
} R[;zX(y
catch(Exception e){e.printStackTrace ();} V#`fs|e;y
K5XK%Gl"
IhA*"
} Oj^,m.R
Q_Gi]M9
s%W<dDINl
public static void main(String[] args) sx`O8t
{ QV&D l_
new TestMethod(); 3l#IPRn9AO
} uxzze~_+C
} P<f5*L#HD
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