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)); JvM:xy9
} E 7"`D\*
for(int i=0;i<nEndPos.length-1;i++) MzIn~[\
{ :tX,`G
nEndPos = nStartPos[i+1]; {\ J%i|u
} JmbWEX|
nEndPos[nEndPos.length-1] = nFileLength; =7-@&S=?s
} d.p%jVO)"
} E~1"Nh
cB}6{c$_sW
H`NT`BE
//启动子线程 6='x}Qb\H
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #)( D_*
for(int i=0;i<nStartPos.length;i++) pxHJX2
{ iTJE:[W"y
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vSGvv43G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), S0tPnwco[~
nStartPos,nEndPos,i); B q7Qbj
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g UA_&_
fileSplitterFetch.start(); [u7i)fn5?
} W.TdhJW9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), myDcr|j-a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); L*1yK*
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", </|m^$v
nEndPos = " + nFileLength); b!z kQ?h
// fileSplitterFetch[nPos.length-1].start(); >e QFY^d5
HI{IC!6
nmUMg
//等待子线程结束 )"f*Mp
//int count = 0; wQN/MYF[
//是否结束while循环 /t_AiM,(
boolean breakWhile = false; xRm~a-rp
B^"1V{M
p$l'y""i
while(!bStop) xoN?[
{ \Wf1b8FW
write_nPos(); ![{0Yw D
Utility.sleep(500); S"Drg m.
breakWhile = true; <CGJ:% AY
N3?hu}
#~6au6LMC
for(int i=0;i<nStartPos.length;i++) 5U<;6s
{ \mDBOC0eK
if(!fileSplitterFetch.bDownOver) BVv{:m{w
{ l&uBEYx
breakWhile = false; N_f>5uv
break; 9NausE40
} =J^FV_1rJ
} v42Z&PO
if(breakWhile) L'<.#(|
break; d`4F
U t.#h="
'Sjt*2blq
//count++; Y%@a~|
//if(count>4) vABUUAo!Jr
// siteStop(); zfm#yDf
} &``nYI g/
utBKl'`
@;h$!w<
System.err.println("文件下载结束！"); 3}2a3)
} %q_b\K
catch(Exception e){e.printStackTrace ();} qp55U*
} 6Wc'5t3
~a` vk@8
4>t=r\"4
//获得文件长度 HHg[6aw
public long getFileSize() ?7R&=B1g
{ eTZ2f
int nFileLength = -1; {Zrf>ST
try{ Gw?$.@L'I6
URL url = new URL(siteInfoBean.getSSiteURL()); e6uVUzP4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FlepM*
httpConnection.setRequestProperty("User-Agent","NetFox"); S~Yu;
n_Bi HMIU'
MUvgmJsN
int responseCode=httpConnection.getResponseCode(); 7r wNjY#
if(responseCode>=400) &,C;_3
{ m$B)_WW
processErrorCode(responseCode); dn:/8~B"X
return -2; //-2 represent access is error 3Tz~DdB
} D4\ * ,w
Q(h/C!rKe
M3c
String sHeader; 9hdz<eFL
|J^$3RX
s!WI:E7
for(int i=1;;i++) |!"qz$8fB
{ Ygfv?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _q3|Ddm2LN
//Utility.log(in.readLine()); %S]g8O[}nl
sHeader=httpConnection.getHeaderFieldKey(i); wv&#lM(
if(sHeader!=null) q,*([yX
{ }WEF*4B!
if(sHeader.equals("Content-Length")) c<]~q1
{ lbiMB~rwI
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); y(*#0fJrTV
break; .yb=I6D;<3
} dIOiP\^
} n0tVAH'>
else +z?SKc
break; H:_R[u4r
} c,_??8
} to#N>VfD
catch(IOException e){e.printStackTrace ();} fE,Io3
catch(Exception e){e.printStackTrace ();} 0=V -{
Jj,fdP#\
hvOl9W>
Utility.log(nFileLength); I#9q^,,F
i'`[dwfS
L2\NTNY
return nFileLength; OGn-~ #E
} 4$_:a?9
p@jwHlX
@szr '&\%A
//保存下载信息（文件指针位置） J0,;F9<C#X
private void write_nPos() gMUCVKGf
{ TI}Y U
try{ q@Oe}
output = new DataOutputStream(new FileOutputStream(tmpFile)); *PF=dx<8
output.writeInt(nStartPos.length); {`=k$1
for(int i=0;i<nStartPos.length;i++) D);w)`
{ J3,m{%EtNM
// output.writeLong(nPos); n5;>e&
output.writeLong(fileSplitterFetch.nStartPos); #D|n6[Y'.t
output.writeLong(fileSplitterFetch.nEndPos); E>Lgf&R#W
} mk]8}+^.
output.close(); BSHtoD@e7
} [LDY;k~5+
catch(IOException e){e.printStackTrace ();} Q+a"Z^Z|
catch(Exception e){e.printStackTrace ();} [ %6(1$Ih
} :FX|9h
O7lFg;9c`
a+PVi
//读取保存的下载信息（文件指针位置） @"__2\ 0
private void read_nPos() QZv}\C-c
{ /[+%<5s
try{ y{Vh?Z<E
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /nB|Fo_&Q
int nCount = input.readInt(); B<oBo&uA
nStartPos = new long[nCount]; ^vha4<'-qG
nEndPos = new long[nCount]; LZ<^b6Dxk
for(int i=0;i<nStartPos.length;i++) ]oxi~TwY^
{ 0Ait7`
nStartPos = input.readLong(); M*2 Nq=3
nEndPos = input.readLong(); (Fs{~4T
} J+r:7NvZ
input.close(); %3@-.=
} tZan1C%p>
catch(IOException e){e.printStackTrace ();} <BjrW]pM
catch(Exception e){e.printStackTrace ();} ][`%vj9r
} E_T!|Q.
@^Yr=d ba
p,7, tx
private void processErrorCode(int nErrorCode) \@m^w"Ij
{ :s>x~t8g#n
System.err.println("Error Code : " + nErrorCode); C@{-$z)
} IQeiT[TF
qrufnu5cC
HMmB90P`
//停止文件下载 iB#*XJ;q
public void siteStop() lb\VQZp!y
{ 4Be\5Byr
bStop = true; DhD^w;f]
for(int i=0;i<nStartPos.length;i++) D";@)\jN
fileSplitterFetch.splitterStop(); ^]MLEr!S
~DP_1V?
bk:mk[
} OTzuOP8
} +F+M[ef<ws
//负责部分文件的抓取 ,-[z?dvO
**FileSplitterFetch.java 45;ey }8
*/ % Ou'+A
package NetFox; xQkvK=~$
a!B"WNb+
bXk(wXX
import java.io.*; Dvm[W),(k
import java.net.*; |dhKeg_
:f~qt%%/
}/2M?W0
public class FileSplitterFetch extends Thread { #p2`9o
*" +u^
%S/?Ci
String sURL; //File URL 1P?|.W_^1
long nStartPos; //File Snippet Start Position Z}S7%m
long nEndPos; //File Snippet End Position J?C:@Q
int nThreadID; //Thread's ID u=t.1eS5
boolean bDownOver = false; //Downing is over qyP={E9A
boolean bStop = false; //Stop identical ZlP+t>
FileAccessI fileAccessI = null; //File Access interface MI)v@_1d
U=PTn(2
^@^K <SVc
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `T{'ufI4B
{ $4q$!jB5
this.sURL = sURL; G`RQl@W>)(
this.nStartPos = nStart; ;Vpp1mk|
this.nEndPos = nEnd; "3/&<0k
nThreadID = id; )3k?{1:
fileAccessI = new FileAccessI(sName,nStartPos);//定位 us+z8Mz
} JJK-+a6cX
bvS6xU- J
?AK`M #M
public void run() J4u>77I
{ </2 aQn
while(nStartPos < nEndPos && !bStop) O L 9(~p
{ " =6kH,
)]kxLf#
Whe-()pG{
try{ 9g]%}+D
URL url = new URL(sURL); <Xw\:5 F<7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FLXn%/
httpConnection.setRequestProperty("User-Agent","NetFox"); &x7iEbRs
String sProperty = "bytes="+nStartPos+"-"; F^81?Fi.
httpConnection.setRequestProperty("RANGE",sProperty); >wb Uxl%{5
Utility.log(sProperty); E+lr{~
Jv}&8D
?tA%A
InputStream input = httpConnection.getInputStream(); f-p$4%(
//logResponseHead(httpConnection); -iKoQkHt
5Dzf[V^]`
$ ^@fV=e
byte[] b = new byte[1024]; 3&mpn,
int nRead; Ft38)T"2R\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Lv#0-+]$Bt
{ mm;sf
nStartPos += fileAccessI.write(b,0,nRead); w!'y,yb%
//if(nThreadID == 1) .N( X.C
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `]^W#6l
} n'0r (
> l]Ble
Ft?eqDS1
Utility.log("Thread " + nThreadID + " is over!"); RLZfXXMn
bDownOver = true; |<'6rJ[i>
//nPos = fileAccessI.write (b,0,nRead); [>t;P,
} ]|tR8`DGZ%
catch(Exception e){e.printStackTrace ();} `][vaLd`Q
} h,n}=g+?
} .+kg1=s
S`$%C=a.
x-]:g&5T
//打印回应的头信息 t+_\^Oa)
public void logResponseHead(HttpURLConnection con) D|ra ;d
{ (cyvE}g
for(int i=1;;i++) 6l[v3l"t
{ `So/G
String header=con.getHeaderFieldKey(i); +(PUiiP'"v
if(header!=null) h8X[*Wme
//responseHeaders.put(header,httpConnection.getHeaderField(header)); XwFTAaZ
Utility.log(header+" : "+con.getHeaderField(header)); .]s? 01Z
else >]8(3&zd
break; s1h|/7gG
} %P D}VF/Y
} uVKe?~RC
`S0`3q}L3%
_QEw=*.<
public void splitterStop() qoOwR[NDcq
{ .$7RF!p
bStop = true; / g{8
} _VVq&t}
_",<at
l i)6^f#
} L""ZI5J{F9
J]#rh5um
Z,O*p,Gzn
/* FzcXSKHV%
**FileAccess.java H(gY=
*//文件访问(定位，写) I;-Y2*
package NetFox; oyr b.lu/
import java.io.*; Q4_r) &np
o$eCd{HuX
^lt2,x
public class FileAccessI implements Serializable{ c?e-2Dp(
YoW)]n
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 URs]S~tk
RandomAccessFile oSavedFile; ox%j_P9@:
long nPos; AH:uG#
e4,SR(O>
f;Oh"Yt
public FileAccessI() throws IOException "[!b5f3!I
{ 'tY(&&
this("",0); +<.o,3
} LRts W(A/
qB (Pqv
#>("(euXMF
public FileAccessI(String sName,long nPos) throws IOException f}"eN/T
{ 3>^]r jFw
oSavedFile = new RandomAccessFile(sName,"rw"); 2|=hF9
this.nPos = nPos; 3qn_9f]
oSavedFile.seek(nPos); B}[f]8jrM
} &R?`QB2/
l cHf\~
ZnRT$ l O
public synchronized int write(byte[] b,int nStart,int nLen) >mX6;6FF
{ 5{oc
int n = -1; }oA>0Nw$K
try{ )WbWp4
oSavedFile.write(b,nStart,nLen); C1e@{>
n = nLen; ]95VMyN
} `BKb60
catch(IOException e) "gJ.mhHX
{ NIVR;gm
e.printStackTrace (); Ht4O5yl"
} Yj1|]i5b
X=KW >
^)?Wm,{"w
return n; [#mkTY
} N|$9v{ j_
~HhB@G!3
#Zw:&' QB
} Bh'fkW3
:MY=Q]l
:>JfBJ]|
/* P*BRebL:
**SiteInfoBean.java lYCvYe
*/ -f&vH_eK
package NetFox; !5(DU~S*@S
4pf@.ra,
,AweHUEn
public class SiteInfoBean { d}zh.O5P!
w(&EZDe
\.}T_,I
private String sSiteURL; //Site's URL XQ9W y
private String sFilePath; //Saved File's Path V%s7*`U
private String sFileName; //Saved File's Name )f|`mM4DW!
private int nSplitter; //Count of Splited Downloading File +1YEOOfVY
OyVP_Yx,V
Lo1ySLo$G
public SiteInfoBean() ;W|NG3_y
{//nSplitter的缺省值为5 XDJE]2^52?
//default value of nSplitter is 5 6T'UWh0S
this("","","",5); =DJ:LmK
} EN\cwa#FU
,\iHgsZ
0(wu
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (Fon!_$:
{ KCyV |,+n
sSiteURL= sURL; sdZ$3oE.
sFilePath = sPath; BP@tI|
sFileName = sName; P?/JyiO}
this.nSplitter = nSpiltter; JkWhYP}
?&#LmeZ}K
wDh]vH[
} ;&O?4?@4
p"p~Bx
a%B&F|u
public String getSSiteURL() wpM2{NTP
{ __'4Qt
return sSiteURL; 4F|79U #
} @d0f+9d
7/IL" D
Q}@t'
public void setSSiteURL(String value) xyL)'C
{ B#S8j18M
sSiteURL = value; 0fXMY-$I
} NUYKMo1ze
(Of6Ij?
W+!UVUpW
public String getSFilePath() AE}cHBwZE
{ o'$"MC+
return sFilePath; ]6^<VC`5D
} {IJ;)<>&VE
YUEyGhkMV{
ESRj<p%W
public void setSFilePath(String value) &~P4yI;,
{ 1OMXg=Y
sFilePath = value; Gy/w #4xj
} uKP4ur@1
FSA%,b;U
y<Q"]H.CkQ
public String getSFileName() uVn"L:_
{ Ahwi
return sFileName; sWo`dZ\6WB
} |ZH(Z}m
'-%1ILK$3r
.@,t}:lD
public void setSFileName(String value) UmWXv#q\l
{ /%& d:
sFileName = value; dR]-R/1|
} kP%hgZ
UA8hYWRP
losqc *|
public int getNSplitter() (p%|F`
{ pz /[${X
return nSplitter; 7?=^0?a
} XG.[C>
V+"%BrM
'%rT]u3U
public void setNSplitter(int nCount) p3U)J&]c6
{ Rsfb?${0G
nSplitter = nCount; M9W zsWM
} r&E gP
} =%7drBoD
nXRa_M(z8
L5FOlzn
/* k)n b<JW|r
**Utility.java 6#+&/ "*
*/ 9Y,JYc#
package NetFox; GP%V(HhN
}N[X<9^Z
zkRAul32|
public class Utility { Z&n[6aV'F
(&e!u{I
D!o[Sm}JO[
public Utility() fIoc)T
{ 4$KDf;m@
]#]Z]9w
!Ap5Uwd
} xx`YBn~"
*lSu=dk+
//线程睡眠 LIcc0w3
public static void sleep(int nSecond) [LnPV2@e
{ Vn^GJ'^
try{ 0P5VbDv$r7
Thread.sleep(nSecond); A7X a
} $yASWz
catch(Exception e) f=l/Fp}4UH
{ +^Xf:r` G
e.printStackTrace (); bZYayjxZ5i
} ZG^<<V$h
} ] ]U)wg
.#QE*<T)]
//日志 @A1f#Ed<
public static void log(String sMsg) $t;:"i>
{ 7~XC_Yc1
System.err.println(sMsg); Z`tmuu
} 1jg* DQ7L
YcobK#c
t<8)h8eW
public static void log(int sMsg) MIZdk'.U
{ G]ek-[-
System.err.println(sMsg); {1SsHir>
} xfb .Z(
} G+<XYkz*
0*XsAz1,9
+LRKS
/* be8T<F
**TestMethod.java 0/su`
*/ H@uu;:l<7A
package NetFox; |E1U$,s~u
DJ"PP5d
,m#
public class TestMethod { ni?k' \\
;A,X,f
T>B'T3or
public TestMethod() dkw.o.e
{ ///xx/weblogic60b2_win.exe D0\>E}Y E
try{ <,)R`90_X6
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,&UKsrs_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); a dqS.xs
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,->K)Rs;
fileFetch.start(); So&gDR;b
} /"Vd( K2Z
catch(Exception e){e.printStackTrace ();} XjN4EDi+E
KmNnW1T
|HmY`w6*z
} V;%ug'j
_;k<=ns(=
,H{9`a#+:
public static void main(String[] args) ,4Q4{Tx
{ RzqgN*]lY
new TestMethod(); -hXKCb4YU
} T aS1%(
} F{ %*(U
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