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)); xpo^\E?2
} n:) [%on
for(int i=0;i<nEndPos.length-1;i++) vCSC:
{ kR^h@@'F"
nEndPos = nStartPos[i+1]; \[.qN
} y 5=rr3%v
nEndPos[nEndPos.length-1] = nFileLength; wVnmT94
} J:>o\%sF
} ;in-)`UC!
VP^Yf_
G/~gF7
//启动子线程 6 R})KIG
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; S-Vj$asv!
for(int i=0;i<nStartPos.length;i++) NCG;`B`i
{ q*` m%3{
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), LP|YW*i=IQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), SJMbYjn0J
nStartPos,nEndPos,i); C58o="L3S
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (l-=/6-
fileSplitterFetch.start(); S7nx4c2xK~
} Pmd[2/][
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), HF_8661g
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~n%Lo3RiP
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", J`GL_@$q
nEndPos = " + nFileLength); |Rkw/5
// fileSplitterFetch[nPos.length-1].start(); REK):(i7P
5V =mj+X?
g)r{LxT#+
//等待子线程结束 KA?%1s(kJ
//int count = 0; UdM2!f
//是否结束while循环 M|%bxG^l
boolean breakWhile = false; B>!mD{N
@P75f5p}<
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while(!bStop) gH'hA'
{ ,f:K)^yD
write_nPos(); };9s8VZE
Utility.sleep(500); .<z7$lz\
breakWhile = true; v^t7)nx^
\ f+;X
KRT&]2
for(int i=0;i<nStartPos.length;i++) .nrbd#i-
{ =d^hiR!GN
if(!fileSplitterFetch.bDownOver) [Tbnfst
{ W4d32+V
breakWhile = false; vn$=be8l4
break; ``VE<:2+
} Q. O4R_H
} n(eo_.W2|
if(breakWhile) s_fe4K
break; YF-E1`+?<
63Gq5dF
.9B@w+=6
//count++; S!=R\_{u$
//if(count>4) 8&"Jlz |
// siteStop(); Qr~!YPK\
} [(#)9/3,
GEf=A.WAfw
M`'DD-Q
System.err.println("文件下载结束！"); _1G/qHf^S
} w[gt9]}N
catch(Exception e){e.printStackTrace ();} `j)56bR
} 6#CswSpS
$RYGAh
[5p9p1@u{C
//获得文件长度 *.>@
public long getFileSize() U-1UWq
{ 2h51zG#qd
int nFileLength = -1; C@`#@1X
try{ B?8*-0a'[
URL url = new URL(siteInfoBean.getSSiteURL()); i]k)wr(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _h}(jEd!
httpConnection.setRequestProperty("User-Agent","NetFox"); BX[IWP\%
ANw1P{9*
Q?>r:vMi
int responseCode=httpConnection.getResponseCode(); )?#K0o[<
if(responseCode>=400) -kLBq:M
{ :K2 X~Ty
processErrorCode(responseCode); o<!H/PN
return -2; //-2 represent access is error N^oP,^+U
} HLV8_~gQPf
d6tLCQ
j`.&4.7+
String sHeader; }WC[<AqI
v; #y^O
|Vz)!M
for(int i=1;;i++) ' abEY
{ X(BxC<!D.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); o}KVT%}
//Utility.log(in.readLine()); 4lX_2QT]E
sHeader=httpConnection.getHeaderFieldKey(i); /FXvrH(
if(sHeader!=null) QlMLWi
{ B(s^(__]
if(sHeader.equals("Content-Length")) Q}B]b-c+E
{ Y3[KS;_fr9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); A? B+
break; xgIb6<qwY
} RA<ky*^dr
} Het"x
else 5Q8 H8!^
break; $nmt&lm
} au50%sA~
} Xv!Gg6v6
catch(IOException e){e.printStackTrace ();} X5.9~
catch(Exception e){e.printStackTrace ();} ~Oq _lM
l59\Lo:
c;q=$MO`
Utility.log(nFileLength); 6}R*7iMs
wMCg`rk
OV;VsF
return nFileLength; gkxHfm
} tTTHQ7o*BD
qQ)1+^
7$%G3Q|)L
//保存下载信息（文件指针位置） YL|)`m0-^5
private void write_nPos() CQ6I4k
{ $[`rY D/.
try{ &D{!zF
output = new DataOutputStream(new FileOutputStream(tmpFile)); M.y!J
output.writeInt(nStartPos.length); R$l- 7YSt
for(int i=0;i<nStartPos.length;i++) r{r~!=u
{ HM)D/CO,?
// output.writeLong(nPos); 64U|]gd$
output.writeLong(fileSplitterFetch.nStartPos); z0+JMZ/
output.writeLong(fileSplitterFetch.nEndPos); `!N}u
} deYv&=SPl
output.close(); UVlB=
} .up[wt gN
catch(IOException e){e.printStackTrace ();} GO2q"a
catch(Exception e){e.printStackTrace ();} D<FQVdP
} q 6UZ`9&z
X(x,6cC
:35h0;8+
//读取保存的下载信息（文件指针位置） ;0m J4G
private void read_nPos() {G vGV
{ n6Uh%rO7S|
try{ j~\FDcG*ed
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); N}VoO0I
int nCount = input.readInt(); WGA&Lr
nStartPos = new long[nCount]; /q>ExXsEC
nEndPos = new long[nCount]; 3xW:"
for(int i=0;i<nStartPos.length;i++) wxK71OH
{ U3B&3K} ~
nStartPos = input.readLong(); v7@"9Uw}
nEndPos = input.readLong(); ,{:qbt
} -:d{x#
input.close(); S_Nm?;P
} .4E24FB[f?
catch(IOException e){e.printStackTrace ();} }*9F`=%F
catch(Exception e){e.printStackTrace ();} 5s^vC2$)
} |*J;X<Vm
xzY/$?
8g{Mv#b%
private void processErrorCode(int nErrorCode) ^pe/~ :a
{ '=+N )O
System.err.println("Error Code : " + nErrorCode); ~2hzyEh
} Y{e,I-"{
L T`T~|pz
@qcUxu4
//停止文件下载 L=Aj+
public void siteStop() E%E`\mFD
{ R6 ej
bStop = true; qOpwl*?x+
for(int i=0;i<nStartPos.length;i++) n)a/pO_
fileSplitterFetch.splitterStop(); _G-6G=q
/J-.K*xKt
S`mB1(h
} 2<0".5+I
} c{D<+XM
//负责部分文件的抓取 )2W7>PY
**FileSplitterFetch.java `r=^{Y
*/ X0ugnQ6
package NetFox; 9b-4BON{P
8TH;6-RT
SLkgIb~'X
import java.io.*; 1n2Pr'|s
import java.net.*; :SN?t
ixM#|Yq
:G9d,B7*
public class FileSplitterFetch extends Thread { yP-$@Ry
,{iMF (Nj
lv.h?"Ml
String sURL; //File URL fRk'\jzT
long nStartPos; //File Snippet Start Position <uoVGV5N
long nEndPos; //File Snippet End Position %|/\Qu
int nThreadID; //Thread's ID >PdrLwKS
boolean bDownOver = false; //Downing is over uW}M1kq?+l
boolean bStop = false; //Stop identical gQhYM7NP{5
FileAccessI fileAccessI = null; //File Access interface NV}fcZ
.gRb'
nyhHXVRH
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9ygNJX'~
{ _,Q -)\
this.sURL = sURL; M!VW/vdywL
this.nStartPos = nStart; #cD$ DA
this.nEndPos = nEnd; gHL:XW^
nThreadID = id; 0Iyb}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;L],i<F
} 2I=4l
\dB z-H'@
0yUn~'+(Sp
public void run() *&_(kq z'1
{ {c $8?6
while(nStartPos < nEndPos && !bStop) M6Ik'r"M
{ 33"!K>wC
aNICSxDN
PGTjOkx
try{ se_Oi$VZ{
URL url = new URL(sURL); |hvclEu,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ncR]@8
httpConnection.setRequestProperty("User-Agent","NetFox"); ob)c0Pz
String sProperty = "bytes="+nStartPos+"-"; \3rgwbF
httpConnection.setRequestProperty("RANGE",sProperty); i|!R*"
Utility.log(sProperty); >\lBbqa#
}mk z_P(Z
? a*yK8S
InputStream input = httpConnection.getInputStream(); (x[z=_I%`
//logResponseHead(httpConnection); ZoqE,ucH
M"OCwBTU
99Nm?$g
byte[] b = new byte[1024]; %F0.TR!!n
int nRead; %$R]NL|
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +4]f6Zz({
{ )c0Dofhg
nStartPos += fileAccessI.write(b,0,nRead); kbx4I?
//if(nThreadID == 1) 7a%)/)<D
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); thh0~g0/
} =kW7|c5Z
n8)eC2A
> a8'MK
Utility.log("Thread " + nThreadID + " is over!"); q+9c81b
bDownOver = true; D'_w *
//nPos = fileAccessI.write (b,0,nRead); $viZ[Lu!m
} @$|bMH*1:
catch(Exception e){e.printStackTrace ();} 8/CK(G
} @ql S #(
} ekSSqj9";
;c#jO:A5
pJ@D}2u(
//打印回应的头信息 (5=B^9{R
public void logResponseHead(HttpURLConnection con) Zx%6pZ(.
{ R\lUE,o]<q
for(int i=1;;i++) f]kG%JEK
{ 3ZL<6`YF
String header=con.getHeaderFieldKey(i); ^" UZ.@sq'
if(header!=null) ZcrFzi
//responseHeaders.put(header,httpConnection.getHeaderField(header)); p y%RR*4#
Utility.log(header+" : "+con.getHeaderField(header)); +nQp_a1{9%
else }m.45n/
break; p) m0\
} t`"pn<
} 9at_F'>R
GNI:k{H@"?
pn aSOyR
public void splitterStop() @`:z$52
{ e6I7N?j
bStop = true; %1kIaYZ
} \) g?mj^
L-Pq/x2r
7toDk$jJRg
} '>#8 F.
/yTPb
#-bz$w#*
/* (cm8x
**FileAccess.java 5/m}v'S%
*//文件访问(定位，写) %. W56
package NetFox; yuq2)
import java.io.*; |sPUb;&~
J*+[?FXRL
XWq@47FR
public class FileAccessI implements Serializable{ V5bB$tL}3
4*V[^mht
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 p?'&P!
RandomAccessFile oSavedFile; K5}0!_)G
long nPos; i^"!"&tW#
k83S.*9Mx
=&roL7ps
public FileAccessI() throws IOException |a>,FZv8e
{ !p{CsR8c
this("",0); n|eM}ymF+
} o8u;2gZx
ZP9x3MHe
w7b\?]}@
public FileAccessI(String sName,long nPos) throws IOException WGHf?G/s
{ ].Xh=7&2{
oSavedFile = new RandomAccessFile(sName,"rw"); l9f%?<2D
this.nPos = nPos; {fS~G2@1
oSavedFile.seek(nPos); )F,z pGG
} J7+[+Y
Q+ZZwqyxD
q@vqhE4
public synchronized int write(byte[] b,int nStart,int nLen) '+7"dHLC;
{ f-Zi!AGh>
int n = -1; ~{-9qOGw;
try{ 2ae"Sd!-2
oSavedFile.write(b,nStart,nLen); ]D[\l$(
n = nLen; }/MmuPp
} )Bu#ln"
catch(IOException e) 8yk4#CZ
{ OxN[w|2\4
e.printStackTrace (); %a']TX
} Lr0:yo
zJov*^T-C
m}6Jdt'|
return n; q1Mt5O}
} ]EdZ,`B4
2d&]V]:R*
ic}mru
} 7MQh,J!"
F ESl#.}
R5&<\RI0
/* zxkO&DGRbN
**SiteInfoBean.java /QT>"
*/ q7<=1r+
package NetFox; EvH/d4V;
29cx(
'2 Y8
public class SiteInfoBean { -ijzo%&qA
m^ Epw4eg
Kg`P@
private String sSiteURL; //Site's URL 9WI5\`*"
private String sFilePath; //Saved File's Path X *EseC
private String sFileName; //Saved File's Name "!CVm{7[
private int nSplitter; //Count of Splited Downloading File z?pi/`y8>
bg|dV
;M~9Yr=1
public SiteInfoBean() >'4$g7o,
{//nSplitter的缺省值为5 @ qi|}($
//default value of nSplitter is 5 oY0*2~sg
this("","","",5); 3iUJ!gK
} "?<(-,T
K1o>>388G
KDP"z
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) rIb~@cR)
{ {~w(pAx
sSiteURL= sURL; -v-kFzu
sFilePath = sPath; %8wBZ~1-
sFileName = sName; y5F"JjQAa
this.nSplitter = nSpiltter; |?ZU8I^vW
ZjY,k
RyU8{-q
} TGU7o:2
$gN\%X/n"1
hW'b'x<
public String getSSiteURL() egBk7@Ko
{ 8)>T>-os
return sSiteURL; wEwRW
} vq.o;q /
ZZZ`@pXm;
Thu_`QP^
public void setSSiteURL(String value) ij#v_~g3
{ q'a]DJ`
sSiteURL = value; rk4KAX_[
} +H?g9v40
I'^XEl?
6"Lyv
public String getSFilePath() 6P}?+ Gc
{ ]kx<aQ^
return sFilePath; ^;h\#S[%
} TB?'<hD:
f0Q! lMv
xb%Q[V_m
public void setSFilePath(String value) }!k?.(hpE
{ ;dMr2y`6
sFilePath = value; }No#_{
} JP0aNu
.a :7|L#a
,/GFD[SQ
public String getSFileName() !vRN'/(Vyu
{ :RukW.MR
return sFileName; lhJY]tQt/
} kjp~:Bg_(
t(V2
p/Q< VV
public void setSFileName(String value) |v@_~HV
{ ~Q Q1ZP3
sFileName = value; &Ep$<kx8
} TCzlu#w
h$$JXf
UMBeY[?
public int getNSplitter() FN/l/OSb
{ H1%o)'Kut4
return nSplitter; [h-NX
} yK"\~t[@X:
#K@!jh)y^
0YL*)=pD,
public void setNSplitter(int nCount) Fje /;p
{ *oIIcE4g7
nSplitter = nCount; /6[vF)&
} !Sy9v
} roAHkI
+}(]7du
g#l!b%$
/* YqXN|&
**Utility.java n#WOIweInf
*/ muF&t'k
package NetFox; |5FEsts[
s0vcGh#w
q[vO mes
public class Utility { WuF\{bUh
qFDy)4H)
;sf'"UnL
public Utility() ? N]bFW"t|
{ -V@ST9`
xDekC~Zq
X=6L-^o)
} x~8R.Sg
/i Xl]<
//线程睡眠 &.z-itiV
public static void sleep(int nSecond) c<cYX;O
{ jL4"FTcE]3
try{ QJkiu8r
Thread.sleep(nSecond); Ebi~gGo
} p((.(fx
catch(Exception e) s%>u[-9U
{ M_75bU
e.printStackTrace (); w8>bct3@
} tC f@v'1t
} ^( C,LVP<
rvnm*e,
//日志 +&_n[;
public static void log(String sMsg) *x2u
{ }!s$ /Kn
System.err.println(sMsg); Xe/7rhov
} Mwj7*pxUh
.&^M Z8
l>HB0o
public static void log(int sMsg) zn*i
{ MD>E0p)
System.err.println(sMsg); nu|odP
} .J5or
} X)9|ZF2`
`wLmGv+V
kwt;pxp i
/* 9x8Ai
**TestMethod.java uA%F0oM
*/ tE=$#
package NetFox; Rg~[X5
Qm?o^%a
<jVk}gi)Jp
public class TestMethod { "r{ ^Y??
B"RZpx
{+QQ<)l^tJ
public TestMethod() 9>5]y}.{
{ ///xx/weblogic60b2_win.exe V3\}]5
try{ )jRaQ~Sm
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ou&7v<)x4
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); QlxlT$o}
SiteFileFetch fileFetch = new SiteFileFetch(bean); j%*<W> O
fileFetch.start(); FkoN+\d
} lGX_5R
catch(Exception e){e.printStackTrace ();} 9n".Q-V;k
2) A$bx
Bk1gE((
} `qbsDfq@
?DJ,YY9P
4\8k~#
public static void main(String[] args) en gh3TZC
{ 4T#Z[B[
new TestMethod(); #1f8A5<
} )'?@raB!
} UBy:W^\g
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