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)); YWvD+
} -5 D<zP/
for(int i=0;i<nEndPos.length-1;i++) T7^;!;i`X
{ N+@ Ff3M
nEndPos = nStartPos[i+1]; yCvtglAJ4
} !*Eu(abD
nEndPos[nEndPos.length-1] = nFileLength; (D) KU9B>
} JE7m5kTa
} Uq$/Q7
kM{8zpn
}#7rg_O]>
//启动子线程 Cj<8r S4+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; c|;n)as9(%
for(int i=0;i<nStartPos.length;i++) UZ2_FP
{ L_RVHvA=M/
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]LUcOR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), oDMPYkpTu
nStartPos,nEndPos,i); Q_|}~4_+
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /HpM17
fileSplitterFetch.start(); .i I{
} rB$~,q&.V
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [ gMn
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); KF_fz
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 94BH{9b5
nEndPos = " + nFileLength); 1+uZF
// fileSplitterFetch[nPos.length-1].start(); ]s AuL!
jts0ZFHc-
peO@ZKmM
//等待子线程结束 w;`Jj-
//int count = 0; Ee2P]4_d
//是否结束while循环 u,So+%
boolean breakWhile = false; B[GC@]HE
J W@6m
z&amYwQcI
while(!bStop) ;+E]F8G9r
{ 0BlEt1e2T
write_nPos(); mG&A_/e!9
Utility.sleep(500); oxlor,lw/
breakWhile = true; $qQYxx@
{x_.QWe5
(4cdkL
for(int i=0;i<nStartPos.length;i++) FT-.gi0
{ eyDV911
if(!fileSplitterFetch.bDownOver) UrizZ5a
{ MONX&$
breakWhile = false; 6MT (k:
break; z}!g2d
} wS*r<zj
} ^[xcfTN
if(breakWhile) g%f5hy
break; \dtiv&x
1RYrUg"s"
e.n(NW
//count++; ~i5YqH0
//if(count>4) z3+@[I$
// siteStop(); 2e1KF=N+
} p@^G)x
mQ:{>`
5CFNBb%Xy
System.err.println("文件下载结束！"); oZvG Kf
} &W@2n&U.q
catch(Exception e){e.printStackTrace ();} gm-[x5O"
} a_>|Ny6{
X/~uF9a'<
JI5o~;}m
//获得文件长度 4b2d(x)0X
public long getFileSize() ]u|fLK.|
{ 53])@Mmus
int nFileLength = -1; T$%|=gq
try{ +-!E%$
URL url = new URL(siteInfoBean.getSSiteURL()); |3'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l{k_;i!D
httpConnection.setRequestProperty("User-Agent","NetFox"); R/hIXO
,;`f* #
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int responseCode=httpConnection.getResponseCode(); %\m"Yi]
if(responseCode>=400) p~$cwbQ!
{ *LEy#N
processErrorCode(responseCode); _%nz-I
return -2; //-2 represent access is error xLW$>;kI
} :o'x?]
5RP kAC
entU+Or
String sHeader; BX >L7n
')"+ a^c
hYW9a`Ht/
for(int i=1;;i++) sK}AS;:
{ '$9o(m#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1$>+rW{a
//Utility.log(in.readLine()); uR0UfKK
sHeader=httpConnection.getHeaderFieldKey(i); o`bc/3!
if(sHeader!=null) E/zf9\
{ PF%-fbh!~
if(sHeader.equals("Content-Length")) b:dN )m
{ >+2&7u
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Cr.YSWg)4
break; !jj`Ht)
} [l23b{
} QQ(}71U
else 4zoQe>v~
break; #<*Vc6pC
} }%|ewy9|CW
} 4>KF`?%4
catch(IOException e){e.printStackTrace ();} ]5ZXgz
catch(Exception e){e.printStackTrace ();} 2JfSi2T
]~TsmR[
>i/jqT/
Utility.log(nFileLength); /DQYlNa
EQ1**[$
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return nFileLength; V1aP_G-:
} jq+(2
"=h1gql'
IG^@VQ%
//保存下载信息（文件指针位置） rAenxZ,tF
private void write_nPos() 28MMH Q
{ .U1wVIM
try{ &,nv+>D
output = new DataOutputStream(new FileOutputStream(tmpFile)); (V{/8%mWc
output.writeInt(nStartPos.length); I ]m
for(int i=0;i<nStartPos.length;i++) Uj!3MF
{ UC!mp?
// output.writeLong(nPos); }%wd1`l7
output.writeLong(fileSplitterFetch.nStartPos); 384n1?
output.writeLong(fileSplitterFetch.nEndPos); pj>R9zpn_
} 7({)ou x
output.close(); 2b"*~O;
} F y+NJSG
catch(IOException e){e.printStackTrace ();} Xaq;d'
catch(Exception e){e.printStackTrace ();} 1.3#PdMR,
} VvhfD2*T
eM7@!CdA9q
=2R4Z8G
//读取保存的下载信息（文件指针位置） iN;Pg_Kq
private void read_nPos() y=3 dGOFB
{ w~3X m{
try{ =ZgueUz,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +f3Rzx]
int nCount = input.readInt(); "zEl2Xn28_
nStartPos = new long[nCount]; 5!c/J:z
nEndPos = new long[nCount]; A7p4M?09
for(int i=0;i<nStartPos.length;i++) *$Q>Om]
{ @Z5q2Q
nStartPos = input.readLong(); "[)G{VzT
nEndPos = input.readLong(); LlTD =tJ0
} Y{Z&W9U
input.close(); _"8n&=+
} ^C>kmo3J
catch(IOException e){e.printStackTrace ();} N,~O+
catch(Exception e){e.printStackTrace ();} #:)'D?,
} IwyA4Ak Ru
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u~uzKG
private void processErrorCode(int nErrorCode) }\a#e^-xQ+
{ ?ANWI8'_j
System.err.println("Error Code : " + nErrorCode); Cfi{%,em
} .:S/x{~
85<k'>~L
AL]gK)R
//停止文件下载 o}N@Q-i gq
public void siteStop() L%/RD2LD
{ w2LnY1A
bStop = true; , ZsZzZ#
for(int i=0;i<nStartPos.length;i++) `z!AjAT-G
fileSplitterFetch.splitterStop(); k!c7eP"%8^
$|$@?H>K
g/GI'8EMj
} WjVBz
} Mh%{cLM
//负责部分文件的抓取 j0l,1=^>l
**FileSplitterFetch.java t3L>@NWG
*/ r)<A YX]J
package NetFox; )5|9EXh
G(E1c"?
cy%M$O|hX5
import java.io.*; 0y|1@CS
import java.net.*; 2Rw<0.i|
%1TKgNf
HsYzIQLL
public class FileSplitterFetch extends Thread { BPj?l
7KiraKb|
3chx4
String sURL; //File URL B=*0
long nStartPos; //File Snippet Start Position ]0'cdC
long nEndPos; //File Snippet End Position 07SW$INb
int nThreadID; //Thread's ID cS Lj\'`b
boolean bDownOver = false; //Downing is over AO`@&e]o
boolean bStop = false; //Stop identical X[Iy6qt
FileAccessI fileAccessI = null; //File Access interface hYyIC:PXR
DSHvBFQ
_v#puFy
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #8XmOJ"W3k
{ *Z"cXg^ti
this.sURL = sURL; S8qg"YR
this.nStartPos = nStart; Y 22Ai
this.nEndPos = nEnd; r3x;lICx-
nThreadID = id; jy0aKSn8
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Otu?J_d3
} J8\l'}?&
V(kK2az
>3g`6d
public void run() _t,aPowX
{ Q^<amM!
while(nStartPos < nEndPos && !bStop) \V'fB5
{ .4ww5k>
<`-sS]=d}
t$qIJt$
try{ .]exY i
URL url = new URL(sURL); M p<r`PM2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n]vCvmt
httpConnection.setRequestProperty("User-Agent","NetFox"); >#n"r1
String sProperty = "bytes="+nStartPos+"-"; 5Kd"W,
httpConnection.setRequestProperty("RANGE",sProperty); b`%u}^B {
Utility.log(sProperty); YL`MLt4MC
kt`ln
0X99D2c
InputStream input = httpConnection.getInputStream(); |{|B70v3Co
//logResponseHead(httpConnection); ^%%Rf
A%EhRAy
LTBH/[q5
byte[] b = new byte[1024]; 8=bn TJf
int nRead; _GY2|x2c
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Q7pCF,;
{ cl#XiyK>
nStartPos += fileAccessI.write(b,0,nRead); i+QVs_jW
//if(nThreadID == 1) C:&Sk\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3Yx'/=]
} [x?9<#T
1LFad>`
)M.g<[=^
Utility.log("Thread " + nThreadID + " is over!"); ~9@527m<',
bDownOver = true; B]hRYU
//nPos = fileAccessI.write (b,0,nRead); iiuT:r
} V!*1F1
catch(Exception e){e.printStackTrace ();} o S{hv:)>
} (MqQ3ys
} r9-ayp#pC
KN@ [hb7%
VJA/d2Oys
//打印回应的头信息 l'Li!u
public void logResponseHead(HttpURLConnection con) (-1{W^(
{ ,;MUXCC'
for(int i=1;;i++) 5m@'( ]j
{ GGLSmfb)
String header=con.getHeaderFieldKey(i); 08AD~^^
if(header!=null) FW2x
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (VkO[5j
Utility.log(header+" : "+con.getHeaderField(header)); B(FM~TVZ
else Qa9@Q$
break; AW_YlS
} g"!cO^GkT
} LO%e1y
w|I5x}ZFG
"7fEL:|j
public void splitterStop() L|D9+u L
{ TWRnty-C
bStop = true; #u"@q< )
} /EHO(d!<
?|NsaW
2u0B=0x
} 2!9W:I7
dA2@PKK
lpB:lRM
/* 4!3<[J;N;
**FileAccess.java 3ohHBo
*//文件访问(定位，写) |"b|Q
package NetFox; b{<$OVc
import java.io.*; _h,X3P
%PPy0RZ^
EKw)\T1
public class FileAccessI implements Serializable{ Jv%)UR.]
Uw5&.aqn.b
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5yJ~ q
RandomAccessFile oSavedFile; 'F*OlZ!BWy
long nPos; GVf[H2%H
'm<L}d
z#n+iC$9
public FileAccessI() throws IOException t"~X6o|R
{ 1n*"C!q
this("",0); S,'ekWVD
} 9qzHy}A
1j}e2H
$QT% -9&
public FileAccessI(String sName,long nPos) throws IOException t82*rCIB{
{ 1} _<qk9
oSavedFile = new RandomAccessFile(sName,"rw"); 8A*tpMV?J
this.nPos = nPos; hr&UD|E=
oSavedFile.seek(nPos); 31]Vo;D
} g<w1d{Td
xvWP^Qkb
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public synchronized int write(byte[] b,int nStart,int nLen) 'Vhnio;qC
{ c*(=Glzn
int n = -1; !QqVJ a{j
try{ XCez5Q1
oSavedFile.write(b,nStart,nLen); ;s4e8![o3
n = nLen; or)fx/%h
} ^g<Lu/5w
catch(IOException e) f7%g=0.F
{ ,&@FToR
e.printStackTrace (); 11!4#z6w
} Fvnf;']q
-O@/S9]S)
'&]6(+I>
return n; !:_krLB<
} }$@K
S!iDPl~
CWD $\KG
} :19s=0
Z]OX6G
&k(tDP
/* 'Rv.6>xqc
**SiteInfoBean.java eI-FJ/CJ
*/ 1aUu:#c
package NetFox; tg~7^(s
LH~ t5
tU8aPiUl
public class SiteInfoBean { Wl,I%<&j}
&';@CeK
G<~P||Lu^
private String sSiteURL; //Site's URL z-nV!#
private String sFilePath; //Saved File's Path `KP}pi\
private String sFileName; //Saved File's Name L$ju~0jl)%
private int nSplitter; //Count of Splited Downloading File )VG_Y9;Xk:
ggHl{cl)
O-+!KXHd[
public SiteInfoBean() k{\a_e`
{//nSplitter的缺省值为5 4DGKZh'm"
//default value of nSplitter is 5 S.owVMQ
this("","","",5); Wk/Il^YG
} _<)HFg6
^P*+0?aFr
1a#R7chl
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ksqb& ux6
{ >>>MTV f
sSiteURL= sURL; :XO7#P
sFilePath = sPath; )Mw 3ZE92
sFileName = sName; :*Z@UY
this.nSplitter = nSpiltter; J]&nZud`
&y7~
u%CJjy
} []H0{a2{<
9sB LCZ
R)GDsgXy
public String getSSiteURL() 0h"uJco,
{ p/jAr+XM
return sSiteURL; rGSi !q
} /oU$TaB>(
xb^M33-y
S%w67sGl4n
public void setSSiteURL(String value) Now2ad&
{ Qlhm:[
sSiteURL = value; C2K<CDVw
} 1++Fs
n,|YJ,v[
FVoKNaK-
public String getSFilePath() <V4"+5cJ8
{ D+Z,;XZ
return sFilePath; G4,BcCPQ
} G)7J$4R
"I45=nf
N|s8PIcSp
public void setSFilePath(String value) 7, :l\t
{ xh!aB6m8R
sFilePath = value; )0 i$Bo
} !Y]%U @4}
!Ka~X!+\
;+VHi%5Z
public String getSFileName() vXcgl
{ N'0fB`:kz
return sFileName; {Gr"oO`&"
} ]"\XTL0
!o/;"'&E
P,SI0$Z
public void setSFileName(String value) (I(k$g[>
{ ;5}y7#4C
sFileName = value; W:=CpbwENX
} I6F $@
4S,/Z{ J.
0XrOOYmx
public int getNSplitter() :<E\&6# oC
{ \E2S/1p
return nSplitter; H6-{(: *<
} <fcw:Ae
Ty"=3AvRLV
=`BPGfCb
public void setNSplitter(int nCount) \G &q[8F\
{ !fG`xZ~
nSplitter = nCount; I KDh)Zm
} wi-{&
} q e;O Ox
vke]VXU9z
}WG -R
/* U-:_4[
**Utility.java =)y=39&;/
*/ 'O]Ja-
package NetFox; "]{"4qV1=
dq$CCOC^F
O\qY?)
public class Utility { DM@&=c
wKs-<b%;
.TWX,#
public Utility() I`}<1~ue
{ 4'-GcH
Ty>g:#bogI
/Q[M2DN@
} `` mi9E
)Y+?)=~
//线程睡眠 *]_GFixi
public static void sleep(int nSecond) 9d!}]+"d42
{ 6 bnuC
try{ VpMPTEZ*L
Thread.sleep(nSecond); We*)RXm%
} H/6GD,0
catch(Exception e) A/"p PO
{ IW'2+EGc
e.printStackTrace (); ,o)U9<
} l6Q75i)eF
} \LS+.bp%
|.Pl[y
//日志 UPkD^D,
public static void log(String sMsg) 1y5$
{ _('KNA~
System.err.println(sMsg); j\SW~}d9
} Uwqm?]
?geEq'
J12ZdC'O
public static void log(int sMsg) @pD']=d}t
{ afMIqQ?
System.err.println(sMsg); "HQH]?!k
} [af<FQ{
} ,1YnWy*
1Bz'$u;
[T.BK:
/* 1+^L,-k!
**TestMethod.java +0O{"XM
*/ sQS2U6
package NetFox; ya'@AJS
iM Xl}3
>, &6zj
public class TestMethod { ~qiSkG
66%#$WH#
G'z&U?Ng
public TestMethod() BK'!WX
{ ///xx/weblogic60b2_win.exe iD|"}}01
try{ WQ]~TGW
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); eD, 7gC-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %&"_=Lc
SiteFileFetch fileFetch = new SiteFileFetch(bean); Iy](?b
fileFetch.start(); d+|8({X]D8
} v5t`?+e
catch(Exception e){e.printStackTrace ();} 2f]9I1{
56o?=|
*4^!e/
} X./4at`
=ot`V; Q>
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public static void main(String[] args) R9yK"
{ UJ)\E ^Hp
new TestMethod(); )*^PMf
} S{z%Q
} 'W$jHs
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