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)); 2T~cOH;T
} ,Of^xER`
for(int i=0;i<nEndPos.length-1;i++) L>1hiD&
{ _\ToA9m
nEndPos = nStartPos[i+1]; =|S%Rzsk
} ~2w&+@dV%
nEndPos[nEndPos.length-1] = nFileLength; d(T4Kd$r
} ,^UqE{
} |h>PUt@LL
cz>,sz~i
F4EAC|Y
//启动子线程 fu/8r%:h
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3!"N;Q"
for(int i=0;i<nStartPos.length;i++) z8Q!~NN-K
{ W$rWg>4>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P[nc8z[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), I0Pw~Jj{
nStartPos,nEndPos,i); UN]gn>~j
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A`c%p7Z%
fileSplitterFetch.start(); ;c(a)_1
} ]pax,|+$C
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `8:)? 0Ez
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); yn4T!r "
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", : \+xXb{
nEndPos = " + nFileLength); *'<AwG&
// fileSplitterFetch[nPos.length-1].start(); 9u B?-.
)h{&O ,s
[GLH8R
//等待子线程结束 `ONjEl
//int count = 0; aF{_"X2
//是否结束while循环 RLmOg{L
boolean breakWhile = false; AjC:E+g
37#&:[w>
g{8RPw]
while(!bStop) _5oTNL2
{ 1|bXIY.J*
write_nPos(); Q#bW"},^k
Utility.sleep(500); ,T/Gv;wa2
breakWhile = true; 8:ubtB
/x<g$!`X
U&!TA(Yr
for(int i=0;i<nStartPos.length;i++) o<`vh*U@,4
{ KII{GDR]
if(!fileSplitterFetch.bDownOver) DiCz%'N
{ H|9t5
breakWhile = false; 7#V7D6j1
break; U( YAI%O
} LCF}Y{
} th?+TNb^
if(breakWhile) KkvcZs'4m
break; F'bwXb**
-t`kb*O3`
xQoZ[
//count++; +C(-f
//if(count>4) rTPgHK]?l
// siteStop(); ^7gGtz2
} cc@W 6W
(lk9](;L
--yF%tRMP
System.err.println("文件下载结束！"); ]l,BUf-O
} ?OD$`{1
catch(Exception e){e.printStackTrace ();} xc^@"
} #M,&g{
Y },E3<
M'*s5:i
//获得文件长度 'jev1u[
public long getFileSize() 'Wlbh:=$
{ 6h 0qtXn-
int nFileLength = -1; uP~,]ci7
try{ Kv_2=]H
URL url = new URL(siteInfoBean.getSSiteURL()); (gt\R}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |OeyPD#
httpConnection.setRequestProperty("User-Agent","NetFox"); ,jU>V]YC
KVi6vdgD
^q7V%{54
int responseCode=httpConnection.getResponseCode(); Xp<q`w0I,
if(responseCode>=400) W .a>K$
{ u$ts>Q;5
processErrorCode(responseCode); fSo8O
return -2; //-2 represent access is error c_/BS n
} Kb~nC6yJc
-@v^. @[Z&
u 3WU0Z`
String sHeader; w$]G$e
G%F#I
SN6 QX!3
for(int i=1;;i++) m&)/>'W
{ qe]D4K8`Q3
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); TWP@\ BQ
//Utility.log(in.readLine()); WQ|Ufl;
sHeader=httpConnection.getHeaderFieldKey(i); w,%"+tY_
if(sHeader!=null) ]LE,4[VxRz
{ 5'!fi]Z
if(sHeader.equals("Content-Length")) <ZC.9
{ Q2CGC+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \XDiw~0
break; SKG U)Rn;
} ;qmnG3;Q
} 6IqPZ{g9K'
else 8mX!mYO3c
break; 2;)IBvK
} [* xdILj
} Ar-Vu{`
catch(IOException e){e.printStackTrace ();} 2dts}G
catch(Exception e){e.printStackTrace ();} VL#:oyWA
g;l K34{
P|NGAd
Utility.log(nFileLength); Tv%7=P;r
&r,vD,
tP_.-//
return nFileLength; ,[n9DPZ
} = MByD&o`
=svFw&q"
WUS%4LL(
//保存下载信息（文件指针位置） %YVPm*J~
private void write_nPos() {OG1' m6=/
{ 'IU3Xu[-.
try{ 5K Ij}VN
output = new DataOutputStream(new FileOutputStream(tmpFile)); =Ti!9_~
output.writeInt(nStartPos.length); W@!qp
for(int i=0;i<nStartPos.length;i++) >{AE@@PB^
{ KKwM\
// output.writeLong(nPos); <gPM/4$G
output.writeLong(fileSplitterFetch.nStartPos); j32*9
output.writeLong(fileSplitterFetch.nEndPos); q,K|1+jn
} Up Z 9g"
output.close(); SY95s
} "]3o933D
catch(IOException e){e.printStackTrace ();} 7a[6@
catch(Exception e){e.printStackTrace ();} p$"~vA .
} !S~)U{SSK
D)MFii1J~
(jKqwVs.:
//读取保存的下载信息（文件指针位置） Az8b_:=
private void read_nPos() K0>;4E>B
{ gpq ,rOIK
try{ o^@#pU <
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); KXZG42w
int nCount = input.readInt(); LYAGpcG
nStartPos = new long[nCount]; <hzHrx'o{
nEndPos = new long[nCount]; Zl[EpXlZ
for(int i=0;i<nStartPos.length;i++) U_jW5mgsG
{ Mn5(Kw?o2J
nStartPos = input.readLong(); yR5XcPoKI
nEndPos = input.readLong(); } ew{WD
} ,`U>BBBLv
input.close(); /$93#$
} 7!qeIz
catch(IOException e){e.printStackTrace ();} a<*+rGI
catch(Exception e){e.printStackTrace ();} '*[7O2\%/
} 5NkF_&S_1
eP (*.
q AVypP?J
private void processErrorCode(int nErrorCode) |>P:R4P
{ [`|t(E'
System.err.println("Error Code : " + nErrorCode); /#5rt&q
} I!b"Rv=Nf-
ju:}%'
/1TK+E$
//停止文件下载 Dj= {%
public void siteStop() :xg J2
{ ;\"5)S
bStop = true; 5%wA"_
for(int i=0;i<nStartPos.length;i++) 9t`yv@.>N
fileSplitterFetch.splitterStop(); ty[%:eG#
=ZSYg K
.NWsr*Tel
} A46dtFD{
} CUB;0J(
//负责部分文件的抓取 5>dA7j^v
**FileSplitterFetch.java [cFD\"gJAr
*/ f2tCB1[D+
package NetFox; +%<kcc3
ZK?V{X{";
|5(CzXR]
import java.io.*; *QNX?8Fm_
import java.net.*; l`75BR
}2Ge??!
DI/d(oFv`
public class FileSplitterFetch extends Thread { J<NpA(@^
ZT"vVX-)G
o^5UHFxTCB
String sURL; //File URL g[y&GCKY!=
long nStartPos; //File Snippet Start Position Ce//;Op
long nEndPos; //File Snippet End Position @@a#DjE%/
int nThreadID; //Thread's ID Bd*Ok]
boolean bDownOver = false; //Downing is over ^69(V LK
boolean bStop = false; //Stop identical TN Z-0
FileAccessI fileAccessI = null; //File Access interface -~sW@u)O
f*V^HfiQb
p%Q{Rqc)
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException e`B!)Sr
{ DZ`,QWuA
this.sURL = sURL; -5os0G80
this.nStartPos = nStart; gdAd7 T
this.nEndPos = nEnd; A?-t`J
nThreadID = id; ^-Ks_4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 AN,3[Sh
} s!W{ru
{y|.y~vW
f% 8n?f3;u
public void run() Dd OK&
{ J;V#a=I
while(nStartPos < nEndPos && !bStop) \{(cz/]G/
{ ^tyqc8&
H[R6 ?H@$F
dtQ3iuV %
try{ 'e>'JZR
URL url = new URL(sURL); PMiu "
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?mi}S${g
httpConnection.setRequestProperty("User-Agent","NetFox"); Oo!]{[}7
String sProperty = "bytes="+nStartPos+"-"; kQ[23
httpConnection.setRequestProperty("RANGE",sProperty); 6."|m+D
Utility.log(sProperty); R4D$)D
-R$Q`Xw
Us6~7L00
InputStream input = httpConnection.getInputStream(); *Qngx
//logResponseHead(httpConnection); %YuFw|wO
0m4#{^Y
l7WZ" 6d
byte[] b = new byte[1024]; /w5c:BH
int nRead; %}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) yp hd'Pu"
{ q@mZ0D-
nStartPos += fileAccessI.write(b,0,nRead); @Us#c 7/
//if(nThreadID == 1) Sw{rNzh%$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); C:!&g~{cKi
} fX LsLh+~D
.dc|?$XV
hZ>1n&[@
Utility.log("Thread " + nThreadID + " is over!"); ju.`c->k"
bDownOver = true; kT^`j^Jr
//nPos = fileAccessI.write (b,0,nRead); qP/McH?
} Kk% IN9
catch(Exception e){e.printStackTrace ();} Kk\,q?
} j;_E0j#
} 1"l48NLL|
b^~4k; <
;F2"gTQS
//打印回应的头信息 r"7 !J[u
public void logResponseHead(HttpURLConnection con) mt *Dx
{ 5M%)*.Y 3[
for(int i=1;;i++) REOWSs$'
{ Sfi1bsK
String header=con.getHeaderFieldKey(i); 0LWV.OIIC
if(header!=null) PywUPsJ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [7{cf`C
Utility.log(header+" : "+con.getHeaderField(header)); `j6O
else k c L +
break; w~AO;X*Ke"
} {FNCC*=
} %zjyZ{=
t4zKI~cO
?R@u'4yK
public void splitterStop() V4*/t#L/
{ bM,%+9oz;
bStop = true; 8[)"+IFN
} 9*a"^
oC TSV
H9=8nLb.
} Q-e(>=Gv_
|pT[ZT|}G
@ +>>TGC
/* nI`9|W
**FileAccess.java JGlp7wro
*//文件访问(定位，写) . N5$s2t
package NetFox; SQdK`]4
import java.io.*; O2~Q(q'
x,<|<W5<%
ZjgfkZAS
public class FileAccessI implements Serializable{ ,u5iiR
{>yy3(N
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .UUT@ w?
RandomAccessFile oSavedFile; `$] ZT>&
long nPos; \uOR1z
`! )^g/>0i
NE?tfj
public FileAccessI() throws IOException fc^d3wH0L
{ hIo^/_K
this("",0); DPWnvd
} )5<c8lzp
@(m?j1!M
ZY)&Fam}
public FileAccessI(String sName,long nPos) throws IOException GS,}]c=
{ Ye\&_w"
oSavedFile = new RandomAccessFile(sName,"rw"); [58qC:
this.nPos = nPos; 7!g4`@!5M
oSavedFile.seek(nPos); V4?]NFK
} U5;Y o+z
LV]F?O[K=
9,wU[=.0
public synchronized int write(byte[] b,int nStart,int nLen) Ix.Y_}
{ bl8y o4
int n = -1; E(an5x/r
try{ -aM7>YR
oSavedFile.write(b,nStart,nLen); \~:_h#bW
n = nLen; X> V`)
} !F)BTB7{<
catch(IOException e) )#Id=c
{ Uclta
e.printStackTrace (); KCS},X_
} NY%=6><t!
KD8,a+GL
z#srgyLt
return n; %xN91j["
} !?GW<Rh
QqB9I-_
!@f!4n.e|I
} M~*o =t
Y#oY'S .;y
wN$u^]
/* ByW,YKMy
**SiteInfoBean.java k mX:~KMb
*/ tZN'OoZ
package NetFox; Wo/LrCg
Ft 2u&Rtx
C<q@C!A
public class SiteInfoBean { g:[yA{Eh
T3/Gl6f
0t0m?rVW
private String sSiteURL; //Site's URL O.'\GM
private String sFilePath; //Saved File's Path b[my5Ol
private String sFileName; //Saved File's Name ka| 8 _C^z
private int nSplitter; //Count of Splited Downloading File /~_,p,:aP
j<-YK4.t
?`=r@
public SiteInfoBean() F'JceU
{//nSplitter的缺省值为5 2PEA<{u
//default value of nSplitter is 5 pa6-3c
this("","","",5); F)uS2
} ]|K@0,
1|H(q
j<'ZO)q`Q
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Bpdx]5qfK
{ ck#MpQ!An
sSiteURL= sURL; ),4cb
sFilePath = sPath; %gV~e@|
sFileName = sName; Kd').w
this.nSplitter = nSpiltter; J+f*D+x1
G>j4b}e
DBZ^n9
} L%0G >2x
Hge0$6l
hH=}<@z
public String getSSiteURL() qku!Mg
{ {Nny.@P)H
return sSiteURL; c>yqq'
} //-;uEO
U<.,"`=l
$g]'$PB
public void setSSiteURL(String value) bv4G!21]*;
{ W3 2]#M=
sSiteURL = value; >Ef{e6
} vFl06N2
^#&:-4/
ffoLCx4o0E
public String getSFilePath() vjO@"2YEw
{ 5YnTGf&
return sFilePath; GGkU$qp2~
} i>=!6Hu2
NT<vs"<B
3YJa3fflK
public void setSFilePath(String value) q#t&\M.U
{ K}9c$C4
sFilePath = value; \"?5CHz*
} Z-rHYfa4
TAKvE=a;
Eh/Z4pzT
public String getSFileName() eaCh;IpIf
{ !5=S2<UX
return sFileName; %g{<EuK]p
} gP:H_nVh
Xi81?F?[
`w#p8vR
public void setSFileName(String value) 31k2X81;a
{ Tt\G y
sFileName = value; (|.rEaTA[1
} $ {5|{`
!ui:0_
<5:`tC2
public int getNSplitter() Z<@dM2b)
{ @w5x;uB|%G
return nSplitter; ]U)Yg
} 9a3mN(<
pkT26)aW
\9T/%[r#
public void setNSplitter(int nCount) ~Rk~Zn
{ 0`%Ask
nSplitter = nCount; We?cRb
} g]E>e v{`
} E7>D:BQ\2
^%jk.*
,7mB`0j>
/* _2E*
**Utility.java hmM2c15T5
*/ u5E\wRn
package NetFox; P&}J(;Lbl
v2;'F
5><KTya?=
public class Utility { q>Kzl/~c.P
xmNs<mz
gvu1
public Utility() o* C_9M
{ >dYN@cB$}
\zx$]|AQ
}\3jcnn
} c=#V*<
L wP
//线程睡眠 UNJAfr P
public static void sleep(int nSecond) 83g$k 9lG.
{ >Pf\"%*
try{ q!4eVg*
Thread.sleep(nSecond); "'v^X!"
} W|4h;[w
catch(Exception e) + [~)a4#
{ DuI>z?bS
e.printStackTrace (); (L'|n*Cr
} g#b9xTGJ^
} 8~ wP?
,jq:%Y[KZ
//日志 nN5fP<H2x
public static void log(String sMsg) xZ(ryE%
{ 8T?D#,/
System.err.println(sMsg); (d>}Fp
} _bn "c@s
Z~1uyr(
Q:U>nm>xA
public static void log(int sMsg) Yaj}_M-
{ rt'pc\|O&
System.err.println(sMsg); Fxv5kho
} Wn-'iD+9<
} 0)rayzv
SW)jDy
SZ1yy["
/* NOFuX9/'w
**TestMethod.java $8WWN} OC
*/ C`qE ,2.
package NetFox; vEw8<<cgg
7j8lhrM}^
6uIgyO*;k
public class TestMethod { kgh0
K5^`,}Q^
@Yn+ir0>O
public TestMethod() K5!OvqzG
{ ///xx/weblogic60b2_win.exe '<{Jlz(u9
try{ gY!?JZC-0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }0,dG4Oo=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); K[yP{01
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4W#DLip9
fileFetch.start(); SHT`
} :!Nx'F9a
catch(Exception e){e.printStackTrace ();} +ZOKfX
_L+j6N.h1
?|~KF:,#}
} U"=Lzo.0
+)LCYDRV7
C\4d.~C:w3
public static void main(String[] args) ,0c]/Sd*p
{ ;Yt+{pI
new TestMethod(); zf>*\pZE
} )-0+O=v
} Gt)ij?~
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