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)); O<;3M'y\
} tlt*fH$.
for(int i=0;i<nEndPos.length-1;i++) 14'45
{ 9 5RBO4w%w
nEndPos = nStartPos[i+1]; bD8Gwi=iiu
} 1~QPG\cdIX
nEndPos[nEndPos.length-1] = nFileLength; CC^'@~)?
} ^Js9 s8?$
} [R7Y}k:9U
")HFYqP>9
-8rjgB~."/
//启动子线程 ApXy=?fc
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; XNu^`Ha
for(int i=0;i<nStartPos.length;i++) H1(Uw:V8
{ `%Al>u5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e01epVR;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), r_;Nt
nStartPos,nEndPos,i); m<qJcZk
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w~?~g<q
fileSplitterFetch.start(); M_w<m
} VEw"
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3J438M.ka
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); f &wb
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Y,e B|
nEndPos = " + nFileLength); fn6J*[`
// fileSplitterFetch[nPos.length-1].start(); A^EE32kbm
\K]0JH
9 ea\vZ
//等待子线程结束 yU}qOgXx
//int count = 0; qXtC^n@x
//是否结束while循环 p >t#@Eu|
boolean breakWhile = false; 7y@Pa&^8
}HePZ{PLM
pK'V9fD5J
while(!bStop) 6,9>g0y'NG
{ xDoC(
write_nPos(); _v=SH$O+
Utility.sleep(500); LRG6:&
breakWhile = true; Eq\M;aDq
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1.9}_4!
for(int i=0;i<nStartPos.length;i++) B[-v[K2
{ |:<f-j7t~
if(!fileSplitterFetch.bDownOver) !|S43i&p
{ tX %5BTv
breakWhile = false; spPNr
break; J@Q7p}
} //<nr\oP
} vv+z'(l
if(breakWhile) 0h\smqm
break; dl@%`E48w
Z%/=|[9i
f-n1I^|
//count++; D"?fn<2
//if(count>4) }m;,Q9:+m^
// siteStop(); 5VAK:eB
} \(Y\|zC'0$
:G2k5xD/E
Yqi4&~?db
System.err.println("文件下载结束！"); $$5aUI:$~$
} aV|hCN~
catch(Exception e){e.printStackTrace ();} {Um)15K
} a(b#
>X4u]>X
s`'{I8'p/
//获得文件长度 A.F738Zp{Z
public long getFileSize() ?D*/*Gk{
{ DBD%6o>]K
int nFileLength = -1; QYjsDL><
try{ 9:1Q1,-i!-
URL url = new URL(siteInfoBean.getSSiteURL()); K&70{r
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {~sDYRX
httpConnection.setRequestProperty("User-Agent","NetFox"); ^o1*a&~J@
d>fkA0G/9!
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int responseCode=httpConnection.getResponseCode(); Dq5j1m.
if(responseCode>=400) $?<Z!*x
{ u TK,&
processErrorCode(responseCode); /1Q(b
return -2; //-2 represent access is error ,\ k(x>oy
} ,5,!es@`b
s1NKLt
U4-g^S[
String sHeader; G) 7;;
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\LppYXz
for(int i=1;;i++) <55g3>X
{ 27"%"P.1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (Cd\G=PK
//Utility.log(in.readLine()); ?$^2Umt0
sHeader=httpConnection.getHeaderFieldKey(i); -~ Mb
if(sHeader!=null) lq&wXi
{ cmg^J
if(sHeader.equals("Content-Length")) 6qaQ[XTxf
{ $lIz{ySJv
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); tj4VWJK
break; V=V:SlS9|
} PGBQn#c<
} ^!z[t\$
else k"]dK,,
break; \\7ZWp\fN
} vIwCJN1C
} ?yR&/a
catch(IOException e){e.printStackTrace ();} "WK{ >T
catch(Exception e){e.printStackTrace ();} q+]h=:5=I
(%xwl
8C~]yd
Utility.log(nFileLength); *B{j.{ p(
rJ{O(n]j
[YT>*BH?
return nFileLength; %V{7DA&C
} uVDa^+=
]=";IN:SU
UE ,t8j
//保存下载信息（文件指针位置） dW~*e2nq
private void write_nPos() Ii_ojQP-z
{ ugx%_x6
try{ 69NQ]{1
output = new DataOutputStream(new FileOutputStream(tmpFile)); yz*6W zD
output.writeInt(nStartPos.length); UHxE)]J
for(int i=0;i<nStartPos.length;i++) 1u(.T0j7f
{ XWs"jt
// output.writeLong(nPos); :2-pjkhiwY
output.writeLong(fileSplitterFetch.nStartPos); (tGY%oT"
output.writeLong(fileSplitterFetch.nEndPos); P(73!DT+
} J8)#PY[i4
output.close(); P7MeX(Tay
} z0*_^MH
catch(IOException e){e.printStackTrace ();} }HYjA4o\A
catch(Exception e){e.printStackTrace ();} wz.6du6-
} eT8}
=xJKIu
/E5 5Pec
//读取保存的下载信息（文件指针位置） ^:* 1d \
private void read_nPos() ?Wt$6{)
{ *`Yv.=cd
try{ JEgx@};O
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); B7<Kc
int nCount = input.readInt(); >P $;79<
nStartPos = new long[nCount]; /<8N\_wh
nEndPos = new long[nCount]; OdY=z!Fls
for(int i=0;i<nStartPos.length;i++) Vy,^)]
{ ;~u{56
nStartPos = input.readLong(); pBP.x#|
nEndPos = input.readLong(); (%o2jroQ#
} 0`A~HH}
input.close(); 0}xFD6{X
} k`p74MWu
catch(IOException e){e.printStackTrace ();} |7pR)KH3
catch(Exception e){e.printStackTrace ();} \Z/)Y;|mi0
} *"r~-&IL
o9S+6@
lF?tQB/a
private void processErrorCode(int nErrorCode) P#/HTu5q7
{ h=_0+\%
System.err.println("Error Code : " + nErrorCode); %8M)2?E
} Io|Aj
lmSo8/%T
=)` p_W
//停止文件下载 9{8GP
public void siteStop() $gM8{.!
{ JiU9CeD3
bStop = true; ?8mlZ X9C
for(int i=0;i<nStartPos.length;i++) }sFm9j7yR
fileSplitterFetch.splitterStop(); Iu*^xn
C2w2252T
m&iH2|
} Tl|:9_:t
} FSbHn{@
//负责部分文件的抓取 pdEiqLhH
**FileSplitterFetch.java ;kJA'|GX
*/ i^!ez5z
package NetFox; b(I2m
PeE/iZ.
.*JA!B
import java.io.*; F5qFYL;
import java.net.*; 'vaLUy9]
_:B1_rz7,
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public class FileSplitterFetch extends Thread { Wt9Q;hK
T}=>C+3r
awUx=%ERtA
String sURL; //File URL =}:)y0L
long nStartPos; //File Snippet Start Position BMIyskl=i
long nEndPos; //File Snippet End Position e<#DdpX!H~
int nThreadID; //Thread's ID I;?X f
boolean bDownOver = false; //Downing is over wB{;bB{
boolean bStop = false; //Stop identical /Y2/!mU</
FileAccessI fileAccessI = null; //File Access interface F[!ckes<bB
xN@Pz)yo
R1W}dRE}
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException oejfU;+$
{ M}wXJ8aF?
this.sURL = sURL; 5 VA(tzmCt
this.nStartPos = nStart; FHPXu59u
this.nEndPos = nEnd; !HJ$UG/\
nThreadID = id; AisN@
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [J0v&{)?
} N8`4veVBx'
q(5+xSg"gK
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public void run() CCGV~e+
{ ACK1@eF
while(nStartPos < nEndPos && !bStop) }V|{lvt.
{ ez9k4IO
rqlc2m,<-p
irZFV
try{ Kw`VrcwjT
URL url = new URL(sURL); 9cv]y#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TV}}dw
httpConnection.setRequestProperty("User-Agent","NetFox"); h`}3h< 8
String sProperty = "bytes="+nStartPos+"-"; 5')8r';,
httpConnection.setRequestProperty("RANGE",sProperty); 9ElCg"
Utility.log(sProperty); uGl| pJ\y=
U`x bPQ
Q\3 Z|%
InputStream input = httpConnection.getInputStream(); M}hrO-C
//logResponseHead(httpConnection); {+g[l5CR[
=)OC|?9C\
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byte[] b = new byte[1024]; =[<m[.)i
int nRead; ;*[9Q'lI*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1SV^){5I
{ NS,5/t
nStartPos += fileAccessI.write(b,0,nRead); ag4`n:1
//if(nThreadID == 1) "XLe3n
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]fI/(e_U
} Pu>N_^ C
^ 2u/n
d'9:$!oz
Utility.log("Thread " + nThreadID + " is over!"); 9><mp]E4
bDownOver = true; r CRgzC
//nPos = fileAccessI.write (b,0,nRead); >uI$^y1D
} gX?n4Csy'
catch(Exception e){e.printStackTrace ();} 9%iFV N'
} d=]U_+
} s Fgadz6O
bxXiQa
~ekh1^evu
//打印回应的头信息 vY*\R0/a
public void logResponseHead(HttpURLConnection con) Yp4c'Zk
{ *V;3~x!
for(int i=1;;i++) gK3Mms]}m
{ - n6jG}01b
String header=con.getHeaderFieldKey(i); ; W7Y2Md
if(header!=null) s-VSH
//responseHeaders.put(header,httpConnection.getHeaderField(header)); fH8!YQG8$
Utility.log(header+" : "+con.getHeaderField(header)); &VWlt2-R0h
else Cv=GZGn-
break; ~L+]n0*
} ^Dx#7bsDZR
} ]wuy_+$
+TRy:e
cUDgM
public void splitterStop() !@ YXZ
{ nD,{3B#
bStop = true; ;</Twm;:
} (w2= 2$
'?Iif#Z1
Ca$c;
} RwTzz] M
xnq><4
qA/bg
/* ^i:\@VA:
**FileAccess.java ]R_G{%
*//文件访问(定位，写) cQFR]i
package NetFox; twk&-:'
import java.io.*; H*W):j}8
|Zq\GA
O(OmGu4%
public class FileAccessI implements Serializable{ n!N\zx8
(3EUy"z-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 M'1HA
RandomAccessFile oSavedFile; :nQp.N*p
long nPos; RFG$X-.e
qvLDfN
C 7nKk/r
public FileAccessI() throws IOException !g0cC.'
{ XSB8z
this("",0); ?(im+2
} amB@N6*
KC&`x|
+|C[-W7Sw
public FileAccessI(String sName,long nPos) throws IOException :J(sXKr[C
{ @PcCiGZ
oSavedFile = new RandomAccessFile(sName,"rw"); nJVp.*S
this.nPos = nPos; {(vOt'
oSavedFile.seek(nPos); ,{j4
} +*t|yKO>[
.T3=Eq&"W
Z%v6xP.
public synchronized int write(byte[] b,int nStart,int nLen) jFj~]]j
{ vg5NY =O
int n = -1; B2hfD-h,>
try{ P&t;WPZ
oSavedFile.write(b,nStart,nLen); H(\V+@~>AD
n = nLen; i@$-0%,
} *e<_; Kr?
catch(IOException e) _F8T\f|
{ LC'2q*:'
e.printStackTrace (); ( D}"&2
} U4_"aT>My
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:z~!p~
return n; w6EI{
} 3%M.U)|+
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v>WB FvyD
} YIDg'a+z
cjg=nTsBA
4 10:%WGc
/* ULvVD6RQ47
**SiteInfoBean.java &]3:D
*/ yzc pG6,
package NetFox; 1!s28C5u
&`PbO
j+1KNH
public class SiteInfoBean { YkbO&~.
DM2Q1Dh3
YZ[%uArm
private String sSiteURL; //Site's URL &"j@79Ym1~
private String sFilePath; //Saved File's Path !P"?
private String sFileName; //Saved File's Name Gj`f--2GE
private int nSplitter; //Count of Splited Downloading File Ve14rn
%vc'{`P
^W['A]l
public SiteInfoBean() MxN]7
{//nSplitter的缺省值为5 A[ 1)!e
//default value of nSplitter is 5 *tAqt2{48
this("","","",5); =8S}Iat
} 1b`G2?%
&PWf:y{R`
x<Se>+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {Tx 3$eU
{ K.h]JD]o
sSiteURL= sURL; n^6TP'r
sFilePath = sPath; 0Uaem
sFileName = sName; J3\)Jy
this.nSplitter = nSpiltter; GI4oQcJ
HWR&C
&enlAV'#)O
} s=\7)n=,M
em/Xu
2B'^`>+8S
public String getSSiteURL() {Pvr??"r
{ Isp_U5M
return sSiteURL; #wD7 \X-f
} di<B~:l58
dMgbW<uAu
WH;xq^
public void setSSiteURL(String value) h*l4Y!7
{ n +dJc
sSiteURL = value; z9fNk%
} n8?KSQy$
Hf.xd.Yw
7 FIFSt
public String getSFilePath() ,^!Zm^4,
{ />!!ch
return sFilePath; 9rWLE6`
} *lY+Yy(
cqHw^{'8
iDR6?fP
public void setSFilePath(String value) oP,RlR
{ Ebbe=4
sFilePath = value; ]kH}lr yG
} \y,;Cfl<
i/M+t~
"9u-lcQ\
public String getSFileName() Z#LUez;&t#
{ I`#EhH
return sFileName; p1uN]T7>
} =jBL'|k5
~W/}:;
Bx%=EN5.
public void setSFileName(String value) eAU"fu6d
{ <M`-`v6H
sFileName = value; "j +v,js
} Q+/R JM?3@
=G[H,;W
[5-!d!a|st
public int getNSplitter() &?v#| qIh
{ Q{`@ G"'
return nSplitter; ]uJM6QuQ
} mf#fA2[
f!^)!~
78^Y;2 P]W
public void setNSplitter(int nCount) l4DeX\ly7f
{ SUSc
nSplitter = nCount; 0ZFB4GL
} ^U" q|[qy
} vFR 1UPF
#[C< J#;
=sL(^UISl
/* 6O%=G3I
**Utility.java I S.F
*/ 4'_L W?DS
package NetFox; s"#CkG
M$gvq:}kt
# e$\~cPd
public class Utility { M'b:B*>6
^v#+PyW
2}ag_
public Utility() }t}38%1i
{ M2a}x+5'
dzpj9[
~igRg~k:/
} |F3vRt@
EmYO5Whi
//线程睡眠 _dz+2au
public static void sleep(int nSecond) [p2g_bI8yK
{ Q1K"%
try{ B<rPvM7a
Thread.sleep(nSecond); rrW! X q
} `9]P/J^
catch(Exception e) 'et(:}i
{ q`h7H][(A
e.printStackTrace (); ryz/rf
} ]cS&8{ ^2
} (}VuiNY<3
iM4mkCdOO
//日志 7^`RP e^a+
public static void log(String sMsg) qT 5WaO)
{ #}nBS-+
System.err.println(sMsg); J!ln=h
} +k#mvPq
ux)<&p.
kOo>Iy
public static void log(int sMsg) oBhL}r
{ p{+tFQy
System.err.println(sMsg); 8/Lu'rI
} n5/ZJur
} X%RQB$
/5Gnb.zN)
TG""eC!E
/* VGq{y{(
**TestMethod.java cL-6M^!a
*/ O e0KAn
package NetFox; y}3 `~a
EU`' 8*4
c80"8r
public class TestMethod { *fOS"-CL
bEOOFs
Yb,G^+;
public TestMethod() PX+"" #
{ ///xx/weblogic60b2_win.exe &lOXi?&"
try{ ]9!Gg
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); A- <.#
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7lnM|nD
SiteFileFetch fileFetch = new SiteFileFetch(bean); d!a2[2Us
fileFetch.start(); [346w <
} LIm$Wl1U
catch(Exception e){e.printStackTrace ();} *J*zml3
arpJiG~JR
IJL^dXCu
} Qe'PAN=B
X"]mR7k
7~Xu71^3s
public static void main(String[] args) #UP,;W
{ :6HiP&<
new TestMethod(); OP\^c
} m-&a~l
} Z=1,<ydKV
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