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)); H@__%KBw
} 6}Y^X
for(int i=0;i<nEndPos.length-1;i++) ,_YCl09p(
{ E'Egc4Z2=l
nEndPos = nStartPos[i+1]; tb&{[|O^
} SLz^Wg._
nEndPos[nEndPos.length-1] = nFileLength; CbS9fc&
} 5Z6$90!k
} z7{b>oub('
|;{wy
lGjmw"/C
//启动子线程 ]O7I7K
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <J{VTk ~
for(int i=0;i<nStartPos.length;i++) ]_|qv1K6
{ %S.R@C[3
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), InNuK0@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), u Dm=W36
nStartPos,nEndPos,i); K-k;`s#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +Medu?K `
fileSplitterFetch.start(); W?F+QmD
} 3HFsR)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gjvKrg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); FB6`2E%o
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", E;D9S
nEndPos = " + nFileLength); f]%$HfF@
// fileSplitterFetch[nPos.length-1].start(); gHvxmIG
_hAp@? M
%{&yXi:mS
//等待子线程结束 9dJARSUuF
//int count = 0; =<iK3bPkU
//是否结束while循环 sh:sPzQ%Jv
boolean breakWhile = false; Skp&W*Ai
yYp!s
"ln(EvW
while(!bStop) 2m[z4V@`
{ a0CmCv2#
write_nPos(); qL,!
Utility.sleep(500); aJOhji<b#L
breakWhile = true; . sgV
ZnI_<iFR*
-fT]}T6=
for(int i=0;i<nStartPos.length;i++) DE^{8YX,
{ x<~ pqq8]
if(!fileSplitterFetch.bDownOver) oh:g
{ t]2~aK<]
breakWhile = false; R4]t D|
break; K82pWpR
} NK$k9,
} #fRhG^QKp
if(breakWhile) 2jOh~-LU
break; I|n<B"Q6^
GFYAg
pI,QkDJ0
//count++; 5|9,S
//if(count>4) ]06LNE
// siteStop(); M0S}-eXc5
} # ~} 26
O3j:Y|N@F
Jj8z~3XnJ
System.err.println("文件下载结束！"); .MXznz
} vjhd|
catch(Exception e){e.printStackTrace ();} m`}! dBi
} 7(QRG\G#
9H_2Y%_
C;1A$]bk
//获得文件长度 z+@aQ@75
public long getFileSize() G{pfyfF
{ 8T):b2h
int nFileLength = -1; Yo/U/dB
try{ " 2Dz5L1v
URL url = new URL(siteInfoBean.getSSiteURL()); 68[3 /
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M$B9?N6
httpConnection.setRequestProperty("User-Agent","NetFox"); 1y2D]h/'
^&03D5@LoY
C\ZL*,%}
int responseCode=httpConnection.getResponseCode(); GLp2 ?fon
if(responseCode>=400) d(3F:dbk
{ {KxeH7S
processErrorCode(responseCode); .0:BgM
return -2; //-2 represent access is error h3Nwxj~E
} *`mPPts}
:2pd2S
&=Gz[1 L
String sHeader; IEfzu L<v
CC0@RU
5Q#;4
for(int i=1;;i++) x%pC.0%
{ y>Zvose
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); I= G%r/3
//Utility.log(in.readLine()); vIF=kKl9,
sHeader=httpConnection.getHeaderFieldKey(i); 4v_?i@,L
if(sHeader!=null) D>+&= 5{
{ p(QB5at
if(sHeader.equals("Content-Length")) >6*"g{/
{ L$=@j_V2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); q#:,6HDd
break; 8c(}*,O/
} LZch7Xe3
} M$DJ$G|Z
else Gtd!Y x
break; u/Fa+S
} `zGK$,[%
} Z4A a
catch(IOException e){e.printStackTrace ();} r(h&=&T6
catch(Exception e){e.printStackTrace ();} kMWu%,s4
O<Qa1Ow7f
T)&J}^j
Utility.log(nFileLength); (JH LWAH
F's($n
]wh8m1
return nFileLength; )8kcOBG^L
} U_v{Vs
@=,2{JF*6
jCDZ$W89
//保存下载信息（文件指针位置） [t*m$0[:
private void write_nPos() F`SOF O
{ fzO4S^mTo8
try{ VgtWT`F.I
output = new DataOutputStream(new FileOutputStream(tmpFile)); YLmzMD>
output.writeInt(nStartPos.length); DeE-M"
for(int i=0;i<nStartPos.length;i++) -ZFeE[Z
{ xB_F?d40T5
// output.writeLong(nPos); F@Y)yi?z
output.writeLong(fileSplitterFetch.nStartPos); AWHB^}!}
output.writeLong(fileSplitterFetch.nEndPos); xx0s`5
} Xt~`EN
output.close(); x|i"x+o
} Xoyk 'T]-
catch(IOException e){e.printStackTrace ();} #mlTN3
catch(Exception e){e.printStackTrace ();} =]&?(Gq
} [/hS5TG|7
sUN>uroi !
6kuN)
//读取保存的下载信息（文件指针位置） b/Y9fQn
private void read_nPos() o"~ODN"L
{ z"*X/T
try{ 9PjL 4A
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }c1Vu
int nCount = input.readInt(); ,oX48Wg_+
nStartPos = new long[nCount]; [Av#Z)R
nEndPos = new long[nCount]; ?Y+xuY/t
for(int i=0;i<nStartPos.length;i++) _/bFt6
{ s|rlpd4y
nStartPos = input.readLong(); rGuhYYvK
nEndPos = input.readLong(); ((^jyQ
} @'L/]
input.close(); 9+"D8J7
} Os^sOOSY
catch(IOException e){e.printStackTrace ();} # eqt{
catch(Exception e){e.printStackTrace ();} LO]D XW 9
} eT1b88_
UMwB.*
| qtdmm
private void processErrorCode(int nErrorCode) 0#4_vg .
{ l%\3'N]
System.err.println("Error Code : " + nErrorCode); ]'V8{l
} B3K!>lz
qKt8sxg
IGv_s+O-*
//停止文件下载 C\Q3vG
public void siteStop() F{)YdqQ
{ Mf7Q+_!
bStop = true; Af1izS3
for(int i=0;i<nStartPos.length;i++) {PgB~|W
fileSplitterFetch.splitterStop(); 3Yf%M66t
r|4jR6%<'m
,{:c<W:A]
} _ _cJ+%e
} 5,`U3na,
//负责部分文件的抓取 :J]S+tQ)
**FileSplitterFetch.java J9S9rir&
*/ #m?GBr%k
package NetFox; jm&?;~>O
:0IxnK(r&
q"ba~@<BEl
import java.io.*; q9o =,[
import java.net.*; Onb*nm
u\=gps/Z
/ U1VE|T
public class FileSplitterFetch extends Thread { B%gk[!d}8
" ] 0ER
[0.>:wT
String sURL; //File URL 75i M_e\
long nStartPos; //File Snippet Start Position LqIMU4Ex
long nEndPos; //File Snippet End Position ANtp7ad
int nThreadID; //Thread's ID *}R5=r0
boolean bDownOver = false; //Downing is over !e@G[%k
boolean bStop = false; //Stop identical pcXY6[#N
FileAccessI fileAccessI = null; //File Access interface u^a\02aV[
1Lz`.%k`:
q88p~Ccoa
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;5^grr@,4
{ MK9?81xd
this.sURL = sURL; IIeEe7%#
this.nStartPos = nStart; vLR)B@O,2
this.nEndPos = nEnd; 9\3%5B7
nThreadID = id; @z"Zj 3ti
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8yz A W&q
} &b,.W;+
.vNfbYH(
udtsq"U_%
public void run() }<7Dyn,
{ VOwt2&mZ
while(nStartPos < nEndPos && !bStop) s([9/ED
{ mXlXB#N
]W<E#^
]*j>yj.Y'~
try{ G?\o_)IJ
URL url = new URL(sURL); 6yk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L`FsK64@
httpConnection.setRequestProperty("User-Agent","NetFox"); T'i9_V{
String sProperty = "bytes="+nStartPos+"-"; ,]Yjo>`tW
httpConnection.setRequestProperty("RANGE",sProperty); v}A] R9TY
Utility.log(sProperty); B) &BqZ&
JfKhYRl
asP>(Li
InputStream input = httpConnection.getInputStream(); a8M.EFa:
//logResponseHead(httpConnection); mkYM/*qyM&
O/_}O_rR
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byte[] b = new byte[1024]; [UNfft=K3P
int nRead; mmY~V:,Kd
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ({D.oS
{ -qfd)A6]
nStartPos += fileAccessI.write(b,0,nRead); i051qpj
//if(nThreadID == 1) %_M B-
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qA9*t
} L6BHh_*E
kr8NKZ/
N\H{p%8
Utility.log("Thread " + nThreadID + " is over!"); /7@@CG6b
bDownOver = true; ;G!X?(%+
//nPos = fileAccessI.write (b,0,nRead); 25ul,t_Du
} d|on y
catch(Exception e){e.printStackTrace ();} 6`NsX
} d(,-13
} Q9K Gf;
E1 *\)q
|F<U;xV$p
//打印回应的头信息 OI %v>ns
public void logResponseHead(HttpURLConnection con) 0VoC|,$U
{ A42At]
for(int i=1;;i++) )%;#~\A
{ '7>Vmr6
String header=con.getHeaderFieldKey(i); DBCL+QHA
if(header!=null) dcU|y%k%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >~BU<#
Utility.log(header+" : "+con.getHeaderField(header)); -2> L*"^
else ?jw)%{iKYV
break; G2a fHL<
} <n }=zu
} :KX/`
`<HY$PAe
m>:%[vm
public void splitterStop() }E>2U/wpXY
{ 5F^,7A4I0
bStop = true; q>Px
} 6J%SkuxR
b@1QE
t T-]Vj.
} MLBZmM '
<@*mFq0,
]qVJ>
/* MM'<uy
**FileAccess.java 9%zR?u
*//文件访问(定位，写) 7Fy^K;V"
package NetFox; &~E=T3
import java.io.*; F,:F9r?l,H
^D.B^BR
MIR17%G
public class FileAccessI implements Serializable{ 9s*Lzi[}
oAvJ"JH@i
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >wMsZ+@m
RandomAccessFile oSavedFile; }FM<uBKW
long nPos; `M7){
HNh=igu
cz T@txF
public FileAccessI() throws IOException -w@fd]g
{ Zfb:>J@h6
this("",0); ' >\*
} ,E>VYkoA
V9<[v?.\
~{5%~8h.0r
public FileAccessI(String sName,long nPos) throws IOException t?0=;.D
{ vG\Wr.h0!=
oSavedFile = new RandomAccessFile(sName,"rw"); zkd#vAY(A
this.nPos = nPos; RMi 2Ip
oSavedFile.seek(nPos); /(}V!0\?
} 1:>RQPXcWv
yTDoS|B+)
|f>y"T+1
public synchronized int write(byte[] b,int nStart,int nLen) n[iil$VKh
{ {M%"z,GL7J
int n = -1; rg'? ?rq
try{ T8KhmO
oSavedFile.write(b,nStart,nLen); *|=&MU*+
n = nLen; G2jEwi
} N{q'wep
catch(IOException e) uj:w^t ][
{ ,LMme}FFeb
e.printStackTrace (); u!@P,,NY
} tNUcmiY
/60[T@Mz
#Se
return n; *e8V4P
} 9 /zz@
2 G"p:iPp
kfVG@o?o
} 1L9^N
22*t%{(
=~arj
/* \E#r[9F{
**SiteInfoBean.java >WD^)W fa
*/ vc!S{4bN
package NetFox; L;`4"
&x3"Rq_
z44uhRh
public class SiteInfoBean { txgGL'
BT#>b@Xub
E8j9@BHU[r
private String sSiteURL; //Site's URL KC]Jbm{y
private String sFilePath; //Saved File's Path yf8UfB#a
private String sFileName; //Saved File's Name \W\6m0-x
private int nSplitter; //Count of Splited Downloading File SP*5 W)6
2h:f6=)r/u
HaC3y[LJ0
public SiteInfoBean() RXof$2CZS
{//nSplitter的缺省值为5 RSi0IfG5
//default value of nSplitter is 5 d,[KcX
this("","","",5); .ClCP?HG
} 5\'%zZ,l
mvL'l)
\=_8G:1
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) yd%\3}-
{ 1Efl|lV
sSiteURL= sURL; $%E9^F
sFilePath = sPath; "''<:K|
sFileName = sName; s7 KKH w
this.nSplitter = nSpiltter; sogbD9Jc
?dmMGm0T9
nn
} 2(rZ@Wl
`MwQ6%lf
T7T!v
public String getSSiteURL() KALg6DZe:
{ 2at?9{b
return sSiteURL; LAKZAi%O0
} iR_Syk`G*A
VoyH:
[s34N+vU
public void setSSiteURL(String value) w@ 5/mf?
{ /SKr.S61e
sSiteURL = value; ~76.S
} 0C p}
oe*&w9Y}&
ZYt __N
public String getSFilePath() )e2IT*7
{ z-gwNE{
return sFilePath; u`'z~N4}
} RsD`9>6)
}>w
I:_*8el&d
public void setSFilePath(String value) D+)=bPMe
{ |Hm'.-
sFilePath = value; UjDF
} u#M)i30j
s4gNS eA
r^E]GDz
public String getSFileName() &o/4hnHYt
{ #VV.[N
return sFileName; uT/B}`md
} Y+ Z9IiS7
z;C=d(|nN
M&ij[%i
public void setSFileName(String value) Vrj1$NL%
{ 3NN'E$"3
sFileName = value; <VU4rk^=
} &&}5>kg>d
o1WidJ"
E)JyKm.
public int getNSplitter() 7Hl_[n|
{ e^NEj1
return nSplitter; K~8tN,~&
} uvDoo6'
]kkBgjQbS
2]3HX3
public void setNSplitter(int nCount) yJ8}*Gj&
{ 3> #mO}\
nSplitter = nCount; P"x-7>c>Y
} |NU0tct^
} Dum`o^l#
5g1M_8e'+
Ke?gz:9j
/* p$nK@t}
**Utility.java <i'u96
*/ [u9JL3
package NetFox; f4k5R
=/g$bZ
T_x+sv=|X!
public class Utility { K@P`_yxN
'K3s4x($
I\upnEKKzZ
public Utility() +F o$o
{ zZ9<4"CIk
hO/5>Zv?
*?bk?*?s
} 6"i{P
Q*:h/Lhb&
//线程睡眠 FGwnESCC
public static void sleep(int nSecond) ,xYsH+ybA
{ R6Zj=l[
try{ %XI"<Y\yL
Thread.sleep(nSecond); &'(a$S>v
} adI!W-/R:
catch(Exception e) )@,90Vhh
{ < m enABN4
e.printStackTrace (); H=&/Q
} 2]D$|M?$~
} xegQRc
Y=a v8Y|`
//日志 sm;E2BR$ `
public static void log(String sMsg) 6~ 7 ;o_>
{ S,9NUt
System.err.println(sMsg); eA?uny f2r
} 5@czK*5
q9^Y?`
LZr0]g{Pu/
public static void log(int sMsg) A<SOT>m]
{ KQ4kZN
System.err.println(sMsg); ACigeK^C}E
} v7;J%9=0D`
} 2.LJp}>
y9C;T(oi;
*N-;V|{
/* @S}/g/+2
**TestMethod.java U g}8y8
*/ NoCDY2 $
package NetFox; 9- xlvU,o
JF~1'"_f:
<0u\dU
public class TestMethod { /m`}f]u
qoC]#M$oo#
gA~20LSt
public TestMethod() ?a5h iN0
{ ///xx/weblogic60b2_win.exe C.J`8@a]?
try{ ~;M)qR?]W
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); E X%6''ys
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); d/D,P=j"
SiteFileFetch fileFetch = new SiteFileFetch(bean); _wf5%(~b
fileFetch.start(); "]VDY)
} h+,'B&=|_
catch(Exception e){e.printStackTrace ();} 3k#[(phk
/g_9m
i2){xg~c
} #`W=mN(+k
10wvfRhng
)~ 0}Et l
public static void main(String[] args) >i "qMZ
{ nX0HT )}
new TestMethod(); x_*%*H
} Qg(Z{V
} :e*DTVv8
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