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)); i,>khc
} hIy~B['
for(int i=0;i<nEndPos.length-1;i++) &J[:awQX
{ 63\/ * NNB
nEndPos = nStartPos[i+1]; %zG;Q@
} w65K[l;2
nEndPos[nEndPos.length-1] = nFileLength; 1S{D6#bE
} J]{QB^?
} ]^h]t~
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yv t.
//启动子线程 L 6c 40
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >V-A;S:
for(int i=0;i<nStartPos.length;i++) O_`VV*
{ }Yb[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^E;kgED5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), pMw*9sX
nStartPos,nEndPos,i); IwQ"eUnK
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); eD,.~Y#?=
fileSplitterFetch.start(); NjVYLn<.r
} FHj" nB
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ur)9x^y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Of*Pw[vD
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4ezEW|S
nEndPos = " + nFileLength); _ TiuY
// fileSplitterFetch[nPos.length-1].start(); wH>a~C:
VCV"S>aVf
aS{|uE]
//等待子线程结束 l3Xfc2~ 2
//int count = 0; 7%5z p|3
//是否结束while循环 g%sluT[#
boolean breakWhile = false; k.uH~S_
GWZ }7ake
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while(!bStop) @5N]ZQ9
{ smlpD3?va
write_nPos(); BF\XEm?!
Utility.sleep(500); )(bW#-
breakWhile = true; h;p>o75O
YWe{juXSw
mk;&yh
for(int i=0;i<nStartPos.length;i++) dG@%jD)
{ %RTBV9LIXr
if(!fileSplitterFetch.bDownOver) Lt u'W22
{ ?9!6%]2D
breakWhile = false; CyJEY-
break; 95ZyP!
} T$>WE= Y
} 9]k @Q_
if(breakWhile) }JF13beU
break; 3 }duG/
[$mHv,~
/KFfU1
//count++; *:Y%HAy*
//if(count>4) RSfQNc9Z
// siteStop(); 2GP=&K/A
} [)H&'5 +F
,|3MG",@@h
D9<!mH
System.err.println("文件下载结束！"); N4v~;;@(
} Y\D!/T
catch(Exception e){e.printStackTrace ();} n`#tKwWHYx
} N(;1o.~
,vr? 2k
?:vv50
//获得文件长度 RiDJ> 6S
public long getFileSize() Lf16j*}-Q
{ Xnt~]k\"
int nFileLength = -1; G? ])o5
try{ <`.X$r*
URL url = new URL(siteInfoBean.getSSiteURL()); o)h_H;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P@Hs`=
httpConnection.setRequestProperty("User-Agent","NetFox"); w^Sz#_2
CNih6R
#*D)Q/k
int responseCode=httpConnection.getResponseCode(); =b%MXT
if(responseCode>=400) 1a?!@g)
{ o2nv+fyW
processErrorCode(responseCode); o*b] p-
return -2; //-2 represent access is error *QpMF/<?
} SON-Z"v
+NeOSQSj
\.0^n3y
String sHeader; WYHQ?
I5`4Al
L5Ebc#
for(int i=1;;i++) SzAJ2:qhl
{ B~6&{7xc%
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |9uOUE
//Utility.log(in.readLine()); 0@[$lv;OS
sHeader=httpConnection.getHeaderFieldKey(i); -f3p U:G8
if(sHeader!=null) ?iw!OoZ`
{ o m^0}$V
if(sHeader.equals("Content-Length")) A#K14Ayr
{ \9cbI3rGz
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ERUz3mjA/
break; ]_Vx{oT7
} ~Y`ldL
} .7Dtm<K#
else lsJSYJG&
break; ojafy}
} @D.}\(
} tWJZoD6}h
catch(IOException e){e.printStackTrace ();} 2POXj!N
catch(Exception e){e.printStackTrace ();} 2V"B:X\
A}BVep@D
+O"!qAiK
Utility.log(nFileLength); 4-?C>
.~)q};Z
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return nFileLength; <->{
} o15-ZzE-
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; ^*}#Xd
//保存下载信息（文件指针位置） y0{u<"t%w
private void write_nPos() cbNTj$'b2u
{ q]\:P.x!>
try{ fX(3H1$"
output = new DataOutputStream(new FileOutputStream(tmpFile)); +Jlay1U&
output.writeInt(nStartPos.length); AV:hBoO
for(int i=0;i<nStartPos.length;i++) O_2pIbh
{ ^?-:'<4q$
// output.writeLong(nPos); Ye\rB\-
output.writeLong(fileSplitterFetch.nStartPos); Y#]+Tm(+
output.writeLong(fileSplitterFetch.nEndPos); -j+UMlkB
} 4~ q5,^kgB
output.close(); pf2[,v/
} b[sx_b
catch(IOException e){e.printStackTrace ();} J}*,HT*
catch(Exception e){e.printStackTrace ();} qaqBOHI6G
} z#8~iF1
'OE&/ C[
p?{Xu4(
//读取保存的下载信息（文件指针位置） ED2a}Tt>Z
private void read_nPos() O)C\vF#
{ zE336
try{ hP=WFD&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); H~oail{EQ
int nCount = input.readInt(); xj<Rp|7&
nStartPos = new long[nCount]; Um}
nEndPos = new long[nCount]; 5Iy|BRU(%
for(int i=0;i<nStartPos.length;i++) 2n,*Nd`
{ ~De"?
nStartPos = input.readLong(); FGPB:
nEndPos = input.readLong(); m-%E-nr
} wa(8Hl|Y
input.close(); '@cANGg7[
} kj|6iG
catch(IOException e){e.printStackTrace ();} 6 +Sxr
catch(Exception e){e.printStackTrace ();} z F_M*8=
} BIb4h
$Ad{Z
N@;?CKU
private void processErrorCode(int nErrorCode) -<c=US
{ jTf@l?|
System.err.println("Error Code : " + nErrorCode); F;>V>" edl
} u~r=)His
K#l:wH_
@+;$jRwq
//停止文件下载 @v$Y7mw3D
public void siteStop() ;5wn67'
{ v:EB*3n5
bStop = true; :Gv1?M
for(int i=0;i<nStartPos.length;i++) *w$W2I>b7
fileSplitterFetch.splitterStop(); w:??h4lt
NWP5If|'X
LnFdhrB@x
} 214Ml0/%
} ,ZKr.`B
//负责部分文件的抓取 D_?K"E=fw
**FileSplitterFetch.java MV!{j;g1<
*/ ,f kcp]}
package NetFox; &w4?)#
V@\gS"Tu
'QG xd!4
import java.io.*; \Lq h j
import java.net.*; Y}@&h!
|$+3a
ZkgV_<M|
public class FileSplitterFetch extends Thread { G=)i{oC
:fKl]XO
<i<J^-W
String sURL; //File URL :KH g&ZX7
long nStartPos; //File Snippet Start Position \/E>4)MDy
long nEndPos; //File Snippet End Position B*qi_{Gp
int nThreadID; //Thread's ID Pih tf4i
boolean bDownOver = false; //Downing is over lNNv|YiL
boolean bStop = false; //Stop identical sD<a+Lw}x
FileAccessI fileAccessI = null; //File Access interface ZjT,pOSyb
`+`Z7
I\hh8abAp
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?M$.+V{a
{ 3NZK*!@'
this.sURL = sURL; Twh!X*uQ
this.nStartPos = nStart; @)IjNplYkw
this.nEndPos = nEnd; r}Ohkr
nThreadID = id; c@YI;HS_g
fileAccessI = new FileAccessI(sName,nStartPos);//定位 gep;{G}
} *v?`<)P#
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k2E0/ @f{k
public void run() W"724fwu&
{ 5&xB6|k
while(nStartPos < nEndPos && !bStop) t4{rb, }W
{ &6DMk-
1h(0IjG8
?xK8#
try{ 1m+p;T$
URL url = new URL(sURL); ;g8R4!J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); so^lb?g
httpConnection.setRequestProperty("User-Agent","NetFox"); >82@Q^O
String sProperty = "bytes="+nStartPos+"-"; WJ)z6m]
httpConnection.setRequestProperty("RANGE",sProperty); w'L\?pI
Utility.log(sProperty); mrTlXXz
85lCj-cs
xrlmKSPa
InputStream input = httpConnection.getInputStream(); =nz}XH%=
//logResponseHead(httpConnection); QS0:@.}$E)
V=)_yIS
Gb"r|(!
byte[] b = new byte[1024]; l|xZk4@_uE
int nRead; /`9sPR6e
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) z+ s6)Ad
{ sfLMkE
nStartPos += fileAccessI.write(b,0,nRead); 4f@o mAM
//if(nThreadID == 1) ^<;V]cY`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,_|]Ufr!a
} U0=]
U93}-){m
_\=`6`b)
Utility.log("Thread " + nThreadID + " is over!"); Gn&-X]Rrl
bDownOver = true; uC.K<jD%
//nPos = fileAccessI.write (b,0,nRead); Xf0M:\w=M
} jQk*8
catch(Exception e){e.printStackTrace ();} pqUCqo!m\
} "~E[)^ANxD
} ,PlO8;5]
syk!7zfK
`L:CA5sBud
//打印回应的头信息 )X04K~6lY
public void logResponseHead(HttpURLConnection con) :z}MIuf
{ El<]b7
for(int i=1;;i++) Rfn9s(m
{ 0MV>"aV
String header=con.getHeaderFieldKey(i); #G|qD
if(header!=null) 7:Ax(El
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;_8#f%Y#R
Utility.log(header+" : "+con.getHeaderField(header)); VQY&g;[d
else (Lo%9HZ1Mx
break; e'~Zo9`r6
} 5'0xz.)!
} X_qf"|i
g wz7krUTe
qL5{f(U4<
public void splitterStop() Jm|+-F@I
{ wg ^sGKN
bStop = true; b'P eH\h{
} =PUt&`1.a
jlp:lX
u4m,'XR
} 3:5 &Aa!
}YjX3|8zL=
>*@y8u*
/* (*1v\Q
**FileAccess.java |nbf'
*//文件访问(定位，写) =81@o,1w
package NetFox; N+zKr/
import java.io.*; :q ti
ii%+jdi.
RbCPmiZcH
public class FileAccessI implements Serializable{ u4.ngjJ
*"WDb|PBb
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 J\J?yo 6
RandomAccessFile oSavedFile; 7uT:b!^f[
long nPos; aUxGzMZ
Kh(ZU^{n
.U"8mP=&
public FileAccessI() throws IOException 7~9S 9
{ I96Ci2)m
this("",0); !h(|\" }
} \(VTt|}By$
I6j$X6u
,QC{3i~
public FileAccessI(String sName,long nPos) throws IOException XGJj3-eW{
{ 76wc,+
oSavedFile = new RandomAccessFile(sName,"rw"); l_EM8pL,f
this.nPos = nPos; H_EB1"C;\
oSavedFile.seek(nPos); |?Frj
} ( xXGSx
0ge$ p,
\=+b}mKV m
public synchronized int write(byte[] b,int nStart,int nLen) )foq),2
{ 6&DX] [G
int n = -1; i O/K nH
try{ 4Y,R-+f
oSavedFile.write(b,nStart,nLen); _2k]3z?
n = nLen; 1^_U;O:I
} iv?gZg
catch(IOException e) 4 SHU
{ Rop'e8Q
e.printStackTrace (); ZIPl7tTw
} _ ):d`O e
[vMvV4,
.fN"@l
return n; @mE)|.f
} ixW@7m
t|9 GS|
|u0(t,T
} AtU v71D:
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QU%I43
/* YX=2jI
**SiteInfoBean.java BBH0OiV=
*/ +j(d| L\
package NetFox; j=*l$RG
p/JL9@:'
SrFS#
public class SiteInfoBean { ?+g`HTY u
S!Omy:=;i
]?Fi$3Lm
private String sSiteURL; //Site's URL K+Z+wA?
private String sFilePath; //Saved File's Path )uK{uYQl
private String sFileName; //Saved File's Name S-7'it!1
private int nSplitter; //Count of Splited Downloading File `W dD8E
5k6mmiaKk
gXonF'
public SiteInfoBean() R)F;py8)I
{//nSplitter的缺省值为5 >w-;Z>3Q@
//default value of nSplitter is 5 j.*VJazb;
this("","","",5); KhCzD[tf
} TMs,j!w?I
lc2i`MC
Z4A!U~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) W%.v.0
{ L KCb_9
sSiteURL= sURL; U\veOQ;mW
sFilePath = sPath; PqyA1
sFileName = sName; J4"mK1N(
this.nSplitter = nSpiltter; -+7uy.@cS
?lbH02P{v
;<$H)`*
} !/^-;o7
7_.11$E=H
,g7.rEA
public String getSSiteURL() a-"k/P#
{ "V>R9dO{"!
return sSiteURL; q}/WQ]p} <
} uKz,SqX
i `s|,"0o
H;U)b{
public void setSSiteURL(String value) &?uz`pv2
{ Py>{t4;S
sSiteURL = value; `+zWu55;
} >iOzl wmG
/0W9g
aWwPvd3
public String getSFilePath() v~T7`
{ :Gu+m
return sFilePath; qS/V"|G(
} $`8Ar,Xz`
1=|7mehL%
{^m(,K_
public void setSFilePath(String value) ?_oF:*~\
{ 277ASCWLkU
sFilePath = value; UWZa|I~:J
} e/*$^i+S
|.F
op"$E1+
public String getSFileName() !" JfOu
{ :-iMdtm
return sFileName; Ja]?&j
} t4qej
'DCFezdf3
5jgdbHog]
public void setSFileName(String value) j}BHj.YuP
{ { F'Kk\f%:
sFileName = value; ?\U!huu
} yJsH=5A
&f>eQS=(
l{:a1^[>y
public int getNSplitter() 8K;Y2 #
{ GyW.2
return nSplitter; SR^_cpZoi
} D?~8za`5
aZet0?Qr
Aj9Ji"18za
public void setNSplitter(int nCount) x$wd O
{ [xfaj'j=@
nSplitter = nCount; ewuXpv%vwW
} ="%W2
} `gpQW~*R-;
ExSO|g]%
Q \]Xm>
/* -/x W
**Utility.java uNHdpni
*/ TZ;p0^(
package NetFox; !Y<oN~<%)
Uw/l>\
vBvNu<v7te
public class Utility { 1AHx"e,;L
g7CXlT0Q6
W%e_~$H0
public Utility() Sf/q2/r?6[
{ x|0:P sE
_TUt9}
$&Kq*m 0g
} kvGCbRC
'r} zY-FM`
//线程睡眠 <w>/^|]#
public static void sleep(int nSecond) ?Pwx~[<1""
{ LF?P> 1%-
try{ Sd))vS^g
Thread.sleep(nSecond); w?mEuXc
} F52B~@.
catch(Exception e) _Mc>W0'5@
{ "BVdPSDBk
e.printStackTrace (); xMs]Hs
} h(B,d,q"
} pi@Xkw
Ogg#jx(4
//日志 /%n`V
public static void log(String sMsg) ~~F2Ij
{ I\Glc=T*
System.err.println(sMsg); ;pJ2V2 g8
} aF8k/$u
/}5B&TZ=(3
T7$S_
public static void log(int sMsg) k$Rnj`*^
{ wU`!B<,j
System.err.println(sMsg); yg;_.4TpIO
} Q0_>'sEM
} Ybg-"w
yPu4T6Vv
(0Naf
/* J?n<ydZSH
**TestMethod.java R^MiP|?ZH
*/ f+Dn9t
package NetFox; w7-WUvxl
XD-^w_
,xths3.K
public class TestMethod { 5IqQ|/m<6
fT Y/4(
!q4x~G0d
public TestMethod() %do1i W
{ ///xx/weblogic60b2_win.exe h4fLl3%H
try{ \k.vN@K#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~ eN8|SR
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); C:\(~D*GS
SiteFileFetch fileFetch = new SiteFileFetch(bean); $v}<'
fileFetch.start(); Ulqh@CE)
} ?M6ag_h3
catch(Exception e){e.printStackTrace ();} ujgLJ77
qJ8-9^E,L
oP,9#FC|(
} R9r+kj_
`_ (~ Ud
> %*B`oqo
public static void main(String[] args) Vm8D"I5i
{ lQ*eH10H
new TestMethod(); dEp/dd~(&
} Jm(ixekp
} =qoRS0Qa
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