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)); g9'50<|J
} K?(ls$
for(int i=0;i<nEndPos.length-1;i++) E;| q
{ [$OD+@~A2
nEndPos = nStartPos[i+1]; 2,E&}a|;b
} nPR_:_^
nEndPos[nEndPos.length-1] = nFileLength; <P(d%XEl
} cC&R~h]|
} DZRkK3
9@:H9"w
=36vsps=
//启动子线程 +:mj]`=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bX=ht^e[
for(int i=0;i<nStartPos.length;i++) J$j&j`
{ %7/XZQ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3yZtyXRPn
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (ZT*EFhb(
nStartPos,nEndPos,i); ol:,02E&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); P\*-n"
fileSplitterFetch.start(); ?dC[VYC\^
} oT5?*3f
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), aq0J }4U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); )}]<o |'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", AL&}WbUC
nEndPos = " + nFileLength); r/Qq-1E
// fileSplitterFetch[nPos.length-1].start(); \02j~r`o
s|"V$/X(W
"|.>pD#0&
//等待子线程结束 f|w+}z
//int count = 0; .A&Ey5
//是否结束while循环 +2|X 7wA
boolean breakWhile = false; >"5^]o2?~l
zPH1{|H+l
KaBze67<|
while(!bStop) J &u&G7#S
{ Bl3G_Ep
write_nPos(); =_D82`p
Utility.sleep(500); !|}J{
breakWhile = true; A5F< <
lWd)(9Kj
^$`xUKp`pn
for(int i=0;i<nStartPos.length;i++) Rr|VGtg
{ T,`'qZ>
if(!fileSplitterFetch.bDownOver) MDGcK/$')f
{ J55K+
breakWhile = false; A WMR0I
break; Haaungb"
} <@A/`3_O)
} E)09M%fe
if(breakWhile) cx1U6A+
break; {ylc2 1
J,4]du$
9K Ih}Q@P
//count++; pvDr&n9
//if(count>4) NA]7qb%%<
// siteStop(); [qIi_(%o
} wU2y<?$\8
RR75ke[Hs
pIC CjA?3@
System.err.println("文件下载结束！"); [j 'Ogm7"
} V%<<Udu<
catch(Exception e){e.printStackTrace ();} fP&F$"o8
} d[kb]lC
n-}:D<\7
yodJGGAzk
//获得文件长度 c<y.Y0
public long getFileSize() ~Rs|W;
{ >XSe[K
int nFileLength = -1; \-#~)LB]M
try{ ]BO{Q+?d2
URL url = new URL(siteInfoBean.getSSiteURL()); L<1"u.3Z`}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9bMM-~
httpConnection.setRequestProperty("User-Agent","NetFox"); wI1[I
{iYu x;(
Y)hLu:P]
int responseCode=httpConnection.getResponseCode(); U#Wc!QN-t
if(responseCode>=400) uQ vW@Tt
{ x +q"%9.c
processErrorCode(responseCode); ~V`D@-VND
return -2; //-2 represent access is error 8v*>~E/0
} >#$(M5&}-
S/G,A,"c
N`8!h:yL
String sHeader; ^t*+hFEI
d?v#gW
Mpk^e_9`<
for(int i=1;;i++) wf=#w}f
{ uZ]B?Z%y#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); bhOyx
//Utility.log(in.readLine()); 5y(irbk7
sHeader=httpConnection.getHeaderFieldKey(i); YRG+I GX
if(sHeader!=null) L`R,4mI.W
{ CbQ@l@d]
if(sHeader.equals("Content-Length")) xv$^%(Ujp
{ >QE^KtZ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >m:.5][yu
break; ^n@iCr9
} 8!VjXj"
} r[TS#hQ
else JjfNH ~
break; T9t9])
} { )'D<:T
} d#ya"e>
catch(IOException e){e.printStackTrace ();} 1.p?P] .
catch(Exception e){e.printStackTrace ();} umcbIi('
>u*woNw(XM
d=oOMXYa
Utility.log(nFileLength); O.TFV.
]N!SG@X+
r?{Vqephz
return nFileLength; Kp~k!6x
} JEdtj1v{O
(PsA[>F
\CUxGyu
//保存下载信息（文件指针位置） fOE:~3Q
private void write_nPos() pcur6:8W!
{ c*RZbE9k
try{ '8*gJ7]
output = new DataOutputStream(new FileOutputStream(tmpFile)); $#]?\psf
output.writeInt(nStartPos.length); /nv1.c)k
for(int i=0;i<nStartPos.length;i++) reu[}k~
{ [O"i!AQ
// output.writeLong(nPos); 2O<Sig=
output.writeLong(fileSplitterFetch.nStartPos); z9w@-])
output.writeLong(fileSplitterFetch.nEndPos); yC+N18y?
} K ANE"M
output.close(); .Z%7+[
} px//q4U
catch(IOException e){e.printStackTrace ();} Pk8L-[&v
catch(Exception e){e.printStackTrace ();} 2*K0~ b`
} @]3(l
nXi6Q+YI
<e/O"6='Z
//读取保存的下载信息（文件指针位置） AU87cqq
private void read_nPos() II>X6
{ Y0s^9?*
try{ y^;qT_)#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); A'[A!NL%
int nCount = input.readInt(); M?[lpH3
nStartPos = new long[nCount]; JO :m: M
nEndPos = new long[nCount]; lmH!I)5
for(int i=0;i<nStartPos.length;i++) rt^z#2$
{ &sS k~:
nStartPos = input.readLong(); _j%Rm:m;<
nEndPos = input.readLong(); ,J}lyvkd
} M#<x2ojW
input.close(); Z"Et]xSU%$
} 2<ef&?ljk
catch(IOException e){e.printStackTrace ();} /R|"/B0
catch(Exception e){e.printStackTrace ();} )z/j5tnvm
} +S;8=lzuV
@'C)ss=kj
h@{@OAu?
private void processErrorCode(int nErrorCode) cb'8Li8,j
{ wTIf#y1=9
System.err.println("Error Code : " + nErrorCode); JYv&It
} zE<vFP-1v
CvbY2_>Nh
~@'|R%jJ
//停止文件下载 &cpRB&bf
public void siteStop() sv0kksj
{ `Z%XA>
bStop = true; e% 5!
for(int i=0;i<nStartPos.length;i++) l' "<
fileSplitterFetch.splitterStop(); Nz!AR$
_F@FcFG1Z*
,x{5,K.yWq
} h(G&X9*
} ;A-Ef
//负责部分文件的抓取 _^P>@ ^
**FileSplitterFetch.java 5+ fS$Q
*/ }}_WZ},h
package NetFox; B5I(ai7<M
[]dRDe;#
QtN0|q{af
import java.io.*; i w m7M
import java.net.*; A%Bz52yg
c$e~O-OVD?
f^$\+H"W
public class FileSplitterFetch extends Thread { \s~W;m
3J(STIxg
zcxG%? Q
String sURL; //File URL OVj,qL)
long nStartPos; //File Snippet Start Position 8De `.!Gg
long nEndPos; //File Snippet End Position o,aI<5"
int nThreadID; //Thread's ID e;!<3b
boolean bDownOver = false; //Downing is over :"QRB#EC%
boolean bStop = false; //Stop identical @kqy!5)K
FileAccessI fileAccessI = null; //File Access interface X='4N<
2ZE4^j|
DcOu=Y> 1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException OcSLRN?t
{ )3G?5 OTS
this.sURL = sURL; Qz$.t>@V=
this.nStartPos = nStart; UI8M<
this.nEndPos = nEnd; niA{L:4
nThreadID = id; ~4\bR
fileAccessI = new FileAccessI(sName,nStartPos);//定位 X;6X K$"
} _')KDy7
[fW:%!Y'
jXW71$B
public void run() O]~p)E
{ ~&yaIuW<
while(nStartPos < nEndPos && !bStop) x1Si&0T0P<
{ 4p1{Ady
@NyCMe;]
[n:R]|^a
try{ E3gQ`+wNg?
URL url = new URL(sURL); `mWg$e,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9]7^/g*!
httpConnection.setRequestProperty("User-Agent","NetFox"); vkt)!hl `
String sProperty = "bytes="+nStartPos+"-"; -7pZRnv
httpConnection.setRequestProperty("RANGE",sProperty); l[.pI];T
Utility.log(sProperty); !MGQ+bD6
Y.}n,y|J}
"arbUX~d
InputStream input = httpConnection.getInputStream(); gqC:r,a
//logResponseHead(httpConnection); Gm6^BYCk
HX=`kkX
_C*}14 "3
byte[] b = new byte[1024]; ,>~92
int nRead; a{-}8f6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,YiBu^E9
{ U#Z}a d?VX
nStartPos += fileAccessI.write(b,0,nRead); leyX: +
//if(nThreadID == 1) &j>`H:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); P"xP%zqo
} O^IpfS\/
rsc8lSjH
)?_c7 R
Utility.log("Thread " + nThreadID + " is over!"); W}Z|v M$
bDownOver = true; s+(8KYTs`
//nPos = fileAccessI.write (b,0,nRead); VTV-$Du[}
} H~$a6T"&
catch(Exception e){e.printStackTrace ();} XGO_n{x
} =UYc~VUYnT
} ~5JXY5*o
i4uUvZf
IB?5y~+h
//打印回应的头信息 9pk<=F
public void logResponseHead(HttpURLConnection con) )9PQj
{ VvPTL8Z
for(int i=1;;i++) \.*aC)
{ lJKU^?4S8
String header=con.getHeaderFieldKey(i); 7d9%L}+q
if(header!=null) Put+<o <
//responseHeaders.put(header,httpConnection.getHeaderField(header)); C"YM"9JSJ
Utility.log(header+" : "+con.getHeaderField(header)); .IG(Y!cB
else mk0rAN
break; e<IT2tv>u
} jt;,7Ek
} /O&j1g@
gN(8T_r
K\;b3
public void splitterStop() IJs`3?
{ 0_%u(?
bStop = true; BGUP-_&
} 8WaVs6
7[8PSoo
J.*dA j
} jT'1k[vJj
hDfsqSK0 /
cQN}z Ke
/* ;up89a-,9
**FileAccess.java @y}1%{,%
*//文件访问(定位，写) h"q`gj
package NetFox; ymzlRs1^Ct
import java.io.*; N.3M~0M*
%pV/(/Q
EY&hWl*a^
public class FileAccessI implements Serializable{ W**a\[~$
&%INfl>o7.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 G#K=n
RandomAccessFile oSavedFile; Qs*g)Yr
long nPos; Y.=v!*p?}
M3x%D)*
O[q {y
public FileAccessI() throws IOException dx:],VB
{ 6R#f 8
this("",0); `F(KM '
} s_VP(Fe@K
)Ibp%'H
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public FileAccessI(String sName,long nPos) throws IOException rbs:qLa%
{ V~ZAs+(2Z
oSavedFile = new RandomAccessFile(sName,"rw"); Bm.%bA>
this.nPos = nPos; &|55:Y87
oSavedFile.seek(nPos); 5H>[@_u+:
} l*/I ;a$
@@_f''f$
@Vc*JEW
public synchronized int write(byte[] b,int nStart,int nLen) H}X3nl\]
{ 6x6PP}IX
int n = -1; `&j5/[>v
try{ ?!8M I,c/
oSavedFile.write(b,nStart,nLen); r1xNU0A
n = nLen; V[Auw3)
} NtSa#$A
catch(IOException e) )CEfG
{ ~x`OCii
e.printStackTrace (); `0Qzu\gRb
} k6.}.
pT.iQ J|
c`AtKs)u
return n; WOR~tS
} V% psaT=)P
g/'MECB
oJ>]=^?k
} k)dLJ<EM
OZs^c2 W
t-i;
/* KR%DpQ&{'
**SiteInfoBean.java @'s^
*/ -AJe\ J 2
package NetFox; 591Syyy
"{j4?3f)
$#8dtF
public class SiteInfoBean { .[NB"\<q
R/xeC [r
MAQkk%6[g
private String sSiteURL; //Site's URL E"nIC,VZ
private String sFilePath; //Saved File's Path `(.K|l}
private String sFileName; //Saved File's Name PiP\T.XANa
private int nSplitter; //Count of Splited Downloading File y2yW91B,
OT&J OTk\
hK&jo(V
public SiteInfoBean() 9v8{JaI3
{//nSplitter的缺省值为5 TE3A(N'
//default value of nSplitter is 5 a9`E&Q}z
this("","","",5); v&D^N9hy9
} tc.R(F96
5ZSV)$t
8dNwi&4
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7q^osOj"
{ y08.R. l
sSiteURL= sURL; VkZrb2]v
sFilePath = sPath; >/Gz*.
sFileName = sName; 8lg$]
this.nSplitter = nSpiltter; bO8g#rO
@GK0j"_
/Z94<}C6b
} nGZZCsf <
4%0eX]
#ih(I7prH
public String getSSiteURL() T'"aStt6
{ Np$pz
return sSiteURL; odD^xg"L
} kG^DHEne
/Q8E12
?YOH9%_cs
public void setSSiteURL(String value) Lo5itW
{ !-_0I:m
sSiteURL = value; ba^B$$?Bo
} #HfvY}[o
z:{'IY
waz)jEk
public String getSFilePath() Zui2O-L?V
{ I6,'o)l{_
return sFilePath; l\I#^N
} `lX |yy"
/GD4GWv :
yZj:Kp+7
public void setSFilePath(String value) 7F!_gj p
{ xT6&;,|`
sFilePath = value; wt0^R<28
} B"ZW.jMaI
.DiH)
AKk6kI8F
public String getSFileName() ,u8)g;8s
{ [*GIR0
return sFileName; B"rnSui
} yV,ki^^
{4SwCN /
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public void setSFileName(String value) tpOMKh.`
{ z-$bce9*
sFileName = value; XkLl(uyh
} kscZ zXv
G0Q} 1
aw&:$twbM
public int getNSplitter() :8\!;!
{ ,K'>s<}
return nSplitter; FR&4i" +
} YNyaz\L
MB06=N
?f<JwF<
public void setNSplitter(int nCount) nk|j(D
{ = _X#JP79
nSplitter = nCount; Q\|72NWS
} 2#:/C:
} (C>FM8$J
&7"a.&*9xX
/T1zz2l~
/* yV[9 (
**Utility.java "Ah (EZAR
*/ l$N b1&
package NetFox; bL soKe
onL&lE
AlT41v~6
public class Utility { 3C'`K,
A(zF[\{]
;43Ye ^=
public Utility() *y<Ru:D
{ __o`+^FS
^K*uP^B=
BB@I|)9O(
} WJ":BK{NM
U+:oy:mz
//线程睡眠 5mxHOtvtWM
public static void sleep(int nSecond) /J!C2
{ IA_>x9 (~
try{ 6$c,#%Jt*
Thread.sleep(nSecond); 7ADh
} e&%m[:W:<
catch(Exception e) |TM&:4D]^
{ '?7th>pC
e.printStackTrace (); ii&{gC
} x dDR/KS
} >fHg1d2-
&Uq++f6
//日志 o_;pEe
public static void log(String sMsg) J%}9"Q5
{ <q|IP_
System.err.println(sMsg); q,6 y{RyS
} 5(e?,B }
G%0G$3W"
H^_]' ~.
public static void log(int sMsg) rw_T&>!
{ dayp1%d
System.err.println(sMsg); 6QS[mWU
} eLE9-K+
} *: )hoHp&
{T|sU\|Q
ZfalB
/* U U!M/QJ
**TestMethod.java . +_IpygQ
*/ GtI]6t
package NetFox; j$r.&,m
B198_T!
;m6Mm`[i<
public class TestMethod { BkfWZ O{7
\bAsn89O
E><!Owxt/
public TestMethod() F%QZe*m[
{ ///xx/weblogic60b2_win.exe p_h)|*W{
try{ +9Z RCmV
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); R7aS{8nn
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {6MLbL{
SiteFileFetch fileFetch = new SiteFileFetch(bean); /?X1>A:*
fileFetch.start(); K|*Cka{
} h $)thW
catch(Exception e){e.printStackTrace ();} s)Sa KE*d
FkJa+ZA
K0B J
} N}{CL(xi
/E>z8J$
,Nl]rmI
public static void main(String[] args) mtDRF'>P:
{ e iS~*@
new TestMethod(); x" 21 Jh
} }G n2%
} AU1P?lk
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