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)); fi[c^e+IX
} cXJtNW@
for(int i=0;i<nEndPos.length-1;i++) \c! LC4pE
{ ;NrkX?Y
nEndPos = nStartPos[i+1]; oJk$ +v6
} U?6YY`A8
nEndPos[nEndPos.length-1] = nFileLength; ezt_ct/Z
} s'V8PN+-
} C_[V[k0(
COw]1R
)y7SkH|
//启动子线程 }[u9vZL
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fNi&1J-/
for(int i=0;i<nStartPos.length;i++) dQ8}mH!
{ EX[X|"r
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6/9h=-w&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), c 25wm\\
nStartPos,nEndPos,i); 2O|o%`?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VZ*Q|
fileSplitterFetch.start(); lHpo/R:
} E(M\U5o:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .~a)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); XHO}(!l\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =L$};ko
nEndPos = " + nFileLength); &50Kn[
// fileSplitterFetch[nPos.length-1].start(); -/aDq?<<
[Bp[=\
`5`Pv'`
//等待子线程结束 Uq/(xh,t5
//int count = 0; _tQ=ASe0
//是否结束while循环 0+O)~>v
boolean breakWhile = false; %2<chq
#UC4l]Ru A
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while(!bStop) dCcV$BX,K
{ {"e/3
write_nPos(); ~?aq=T
Utility.sleep(500); CScM;U=
breakWhile = true; Y,?
J=TbZL4y}4
##,i<
for(int i=0;i<nStartPos.length;i++) hE!3kaS
{ `NV =2T
if(!fileSplitterFetch.bDownOver) 1z~;c|
{ neQ2+W%oj
breakWhile = false; g4d5G=y
break; 7F3Hkvd[k
} 'E0{zk
} @P"q`*
if(breakWhile) oCSf$g8q
break; -z0,IYG }
~MO'%'@
5Zn3s()
//count++; wH!]B-hn
//if(count>4) v(<~:]
// siteStop(); \,JRNL&
} uGLVY%N
5cyl:1Ln
.'"+CKD.N
System.err.println("文件下载结束！"); nAd 4g|
} iml*+t
catch(Exception e){e.printStackTrace ();} 7 m&M(ct
} [fR<#1Z
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Bi kCjP[b
//获得文件长度 Qkqn~>
public long getFileSize() 1y_{#,{>
{ X~G"TT$)
int nFileLength = -1; /Rk5n
try{ sj. eJX"z
URL url = new URL(siteInfoBean.getSSiteURL()); IwFg1\>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0+r/>-3]
httpConnection.setRequestProperty("User-Agent","NetFox"); ?ArQ{9c
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|ki#MtCp
int responseCode=httpConnection.getResponseCode(); jKI+-s
if(responseCode>=400) R,Tw0@{O*
{ {(7.X4\x
processErrorCode(responseCode); orzdq
return -2; //-2 represent access is error !M^pL|
} h{<^?=
wqE ]o= k
gMI%z2]'-
String sHeader; ^n]tf9{I
.Ji r<"*<
*i%!j/QDAP
for(int i=1;;i++) ,fET.s^|U
{ ]X?+]9Fr
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); A2rr>
//Utility.log(in.readLine()); {,s:vPoiA
sHeader=httpConnection.getHeaderFieldKey(i); lrq !}\aX
if(sHeader!=null) >454Yir0Mk
{ m(g$T
if(sHeader.equals("Content-Length")) m>NRIEA6
{ Z/beROW)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); h.2!d0j]
break; y62;&{?m
} uVscF 4
} M"p$9t
else V!},a@>p
break; }clFaT>m?
} 7)_0jp~2
} Nb]qY>K
catch(IOException e){e.printStackTrace ();} XkdNWR0
catch(Exception e){e.printStackTrace ();} gscsB4<
-'q=oTZ
7ky(g'
Utility.log(nFileLength); *^.b}K%
&I!2gf
&LL81u6=S
return nFileLength; o~iL aN\+
} lc5NC;JR
]"CAP%
C|!E'8Rw
//保存下载信息（文件指针位置） Rut6m5>
private void write_nPos() P"iqP|
{ *Z/B\nb
try{ {5%<@<?)
output = new DataOutputStream(new FileOutputStream(tmpFile)); ojIh;e
output.writeInt(nStartPos.length); Q?1 KxD!
for(int i=0;i<nStartPos.length;i++) 6#{= E@
{ ,vN#U&RS
// output.writeLong(nPos); j6v +S
output.writeLong(fileSplitterFetch.nStartPos); )YnB6@=nyk
output.writeLong(fileSplitterFetch.nEndPos); B:x4H}`vh
} i:[B#|%
output.close(); W%h<@@c4,
} R2~Rqlti
catch(IOException e){e.printStackTrace ();} C)ChF`Ru':
catch(Exception e){e.printStackTrace ();} &12aI|u^<
} 'GW@P
UoKBcarm
5 !NPqka}.
//读取保存的下载信息（文件指针位置） | c8u
private void read_nPos() =6A<>
{ =3J~Fk
try{ :nXBw%0x
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Y0eu^p)
int nCount = input.readInt(); dG)A-qbV
nStartPos = new long[nCount]; &=7ur
nEndPos = new long[nCount]; F%Mlid;1
for(int i=0;i<nStartPos.length;i++) @wa/p`gj5w
{ Jp,ohVRNq
nStartPos = input.readLong(); c2F`S1Nu<
nEndPos = input.readLong(); .#Sd|C]R7
} gXfAz,
input.close(); \+>b W(
} g@EKJFjl
catch(IOException e){e.printStackTrace ();} <$=8'$T81
catch(Exception e){e.printStackTrace ();} .g|pgFM?
} ev@1+7(
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b<7.^
private void processErrorCode(int nErrorCode) )1]C%)zn
{ >i ~zG6H
System.err.println("Error Code : " + nErrorCode); /3c1{%B\
} C<7J5
Cy2X>Tl"<E
X F40;urm
//停止文件下载 :?^(&3;
public void siteStop() U{_O=S u
{ :g\qj? o
bStop = true; }Jtaq[y\r
for(int i=0;i<nStartPos.length;i++) ![V<vIy
fileSplitterFetch.splitterStop(); TfxKvol'
=kCpCpET
\e?T9c6,
} Uexb>|
} v>e4a/
//负责部分文件的抓取 ~KNxAxyVi
**FileSplitterFetch.java N0Y!
*/ npe*A
package NetFox; WFdS#XfV
|On6?5((e
<37vWK1+
import java.io.*; tJn2:}-s
import java.net.*; S xgYq
"8rP?B(
!Zwl9DX3
public class FileSplitterFetch extends Thread { !hc7i=V?
:I7MP
ruW6cvsvet
String sURL; //File URL rm cy-}e
long nStartPos; //File Snippet Start Position o60wB-y
long nEndPos; //File Snippet End Position mB,7YZv
int nThreadID; //Thread's ID nxJhK T
boolean bDownOver = false; //Downing is over 2<O hO ^
boolean bStop = false; //Stop identical '2vlfQ@8a~
FileAccessI fileAccessI = null; //File Access interface 5_O.p3$tV
M-Js"cB[
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -g>27EI5
{ aR\=p:%jGI
this.sURL = sURL; l5MxJ>?4%B
this.nStartPos = nStart; HOw][}M_w
this.nEndPos = nEnd; " c]Mz&z
nThreadID = id; UxW>hbzr&V
fileAccessI = new FileAccessI(sName,nStartPos);//定位 FxUH?%w
} EbW7Av
}Bb(wP^B.
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public void run() AV'>
{ k-89(
while(nStartPos < nEndPos && !bStop) '5Y8 rv<
{ EmH{G
fT@#S}t
XI0O^[/n{
try{ o0/03O
URL url = new URL(sURL); ]EK"AuEz`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NBeGmC|
httpConnection.setRequestProperty("User-Agent","NetFox"); YcGqT2oLP
String sProperty = "bytes="+nStartPos+"-"; wF%XM_M
httpConnection.setRequestProperty("RANGE",sProperty); kgQEg)A]!x
Utility.log(sProperty); z!1j8o2
S)~h|&A(
IlE! zRA
InputStream input = httpConnection.getInputStream(); kxdLJ_
//logResponseHead(httpConnection); /M#A[tZ3
z><JbSE?
prwyP
byte[] b = new byte[1024]; W w8[d
int nRead; 2M;{|U
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) fEpY3od
{ RJWlG'i
nStartPos += fileAccessI.write(b,0,nRead); *R&g'y^d
//if(nThreadID == 1) A$ S9 `
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8IX6MfR}C
} R=IeAuZR4k
jem$R/4"
qH-dT,`"{
Utility.log("Thread " + nThreadID + " is over!"); 5!5P\o
bDownOver = true; *</;:?
//nPos = fileAccessI.write (b,0,nRead); UdY9*k
} 6 o+zhi;E
catch(Exception e){e.printStackTrace ();} ;~@2YPj
} !WY@)qlf
} vI+PL(T@
rbJ-vEzo.#
NZD X93
//打印回应的头信息 VRxBi!d
public void logResponseHead(HttpURLConnection con) 1LE8,Gm&
{ E7*]t_p"
for(int i=1;;i++) PM_q"}-
{ B4{A(-Tc
String header=con.getHeaderFieldKey(i); 31_5k./
if(header!=null) oACE:h9U
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ucMl>G'!gX
Utility.log(header+" : "+con.getHeaderField(header)); MBa/-fD
else bG5c~
break; nVYh1@yLy
} x^SE>dy ?z
} yP"_j&ef7
8..itty
!867DX3*
public void splitterStop() v=/V<3
{ 4BCZ~_
bStop = true; Ru sa &#[
} a1GyI
#7g~Um%p
7#<|``]zNf
} N/y.=]
!Hgq7vZG
L=VuEF
/* OCX?U50am
**FileAccess.java 5:AAqMa
*//文件访问(定位，写) FS']3uJ/
package NetFox; 9aXm}
import java.io.*; 3nG(z>
;)o%2#I
45_zO#
public class FileAccessI implements Serializable{ .&L#%C
n[{o~VN
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 v_Jp9
RandomAccessFile oSavedFile; T%ha2X=
long nPos; ZM5[ o m
B\4SB
1 iE
public FileAccessI() throws IOException y_a~>S
{ (I\aGGW
this("",0); Kp!P/Q{
} esxU44
ofN|%g /
*%g*Np_P
public FileAccessI(String sName,long nPos) throws IOException <FGM/e4
{ m-;u]X=a
oSavedFile = new RandomAccessFile(sName,"rw"); YwKY3kL
this.nPos = nPos; lZb1kq%9g
oSavedFile.seek(nPos); JSO>rpO
} "ua/65cq9
%(n4`@
8;+t.{
public synchronized int write(byte[] b,int nStart,int nLen) l%;)0gT
{ B9+oI cO
int n = -1; xOZ?zN
try{ D<nTo&m_
oSavedFile.write(b,nStart,nLen); 7+?
n = nLen; V_0e/7}Ya
} 3``$yWWg
catch(IOException e) RN!oflb
{ rMLCtGi
e.printStackTrace (); =TyN"0@
} 2W|j K
QK//bV)
[7L1y) I(
return n; wGw}a[a
} r@wWGbQ|L
,TP^i 0
$JcU0tPq0
} $zDW)%nAX
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1jQz%^~
/* !AP|ozkL
**SiteInfoBean.java CJ KFNa
*/ C9({7[k^%
package NetFox; O8n\>pkI
j2tw`*S+
2}+V3/
public class SiteInfoBean { 5GC{)#4
]Kil/Y
>.~^(
private String sSiteURL; //Site's URL 7nfQ=?XNK
private String sFilePath; //Saved File's Path k1B7uA'h"G
private String sFileName; //Saved File's Name Zj!S('hSY
private int nSplitter; //Count of Splited Downloading File BL,YJM(y
a\^DthZ!;|
oZP:}= F
public SiteInfoBean() c~z{/L
{//nSplitter的缺省值为5 OfY>~d
//default value of nSplitter is 5 hA)3Ah*
this("","","",5); p4|:u[:&
} oP_'0h0X
42 8kC,
#%B1,.A
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =as]>?<
{ e2Ba@e-
sSiteURL= sURL; ,,b_x@y*
sFilePath = sPath; @(&ki~+
sFileName = sName; ^vJ08gu_W
this.nSplitter = nSpiltter; (9@6M8A
^MDBJ0 I.
Y KeOH
} A0o6-M]'0
Xpjk2[,
ATH0n>)
public String getSSiteURL() vQYd!DSh
{ w,9$*=k
return sSiteURL; V'\4sPt
} (\,mA-%E
phEM1",4T
I?Eh 0fI
public void setSSiteURL(String value) wzT+V,
{ JKGUg3\~
sSiteURL = value; b]Oc6zR,,~
} I)O%D3wfMW
v #IC
c[@>#7p`o
public String getSFilePath() BqKD+
{ !\RR UH*
return sFilePath; nakhepLN
} h9&<-k
$1#|<|
^~eT#Y8
public void setSFilePath(String value) ;x|4Tm
{ 2gb49y~
sFilePath = value; kSoAnJ|
} Jel%1'Dc^
^kt#[N
%[Ia#0'Y@
public String getSFileName() hRtnO|Z6
{ NJLU+byU
return sFileName; daY^{u3
} 4,wdIdSm4
Eki7bT@/
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public void setSFileName(String value) |o|0qG@g
{ %~ZOQ%c1
sFileName = value; UIIunA9
} w'?uJW
Y&]pC
6TlkPM$~2
public int getNSplitter() J:5%ff~r\
{ YmNBtGhT
return nSplitter; u L/*,[}'
} xAon:58m{
`b# w3 2
\ bd? `."
public void setNSplitter(int nCount) c3g\*)Jz"F
{ yrE|cH'f0
nSplitter = nCount; rqT@i(i
} MpGWt#
} Q0Dw2>~_K
f:=q=i
&yp_wW-
/* mY |$=n5X
**Utility.java & i)p^AmM
*/ pU<->d;->
package NetFox; 6*tI~
r}pYm'e
~~&8I!r e
public class Utility { h9 [ov)
$*`fn{2
: -te
public Utility() CQ"5bnR
{ <G}>Gk8x
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!C&}e8M|eX
} o%RyE]pw,
m7~kRY514
//线程睡眠 mst-:F[h
public static void sleep(int nSecond) G%Wjtrpj
{ ]M-j_("&
try{ bCy.S.`jHQ
Thread.sleep(nSecond); bt-y6,> +E
} ~eA7:dZLb
catch(Exception e) m80QMosp
{ eM*@}3
e.printStackTrace (); #zZQ@+5zw
} O{%yO=`r
} <t.yn\G-w
(wo.OH
//日志 >#)^4-e
public static void log(String sMsg) n]r7} 2hM
{ gY=nU,;
System.err.println(sMsg); j_j~BXhIS
} ri.;&
6L}$R`s5H
Kj;Q;Ii
public static void log(int sMsg) !Hr~B.f7
{ _RST[B.u6
System.err.println(sMsg); L^Fni~
} wC}anq>>
} xKv\z1ra
+A>>Ak|s
L(fOe3 v
/* ;1'X_tp
**TestMethod.java XBh0=E?qiS
*/ b>er'U
package NetFox; 0L S,(v4
%-/[.DYt
8LB,8*L^
public class TestMethod { 1I{vBeMj
6c$ so
zogw1g&C
public TestMethod() +C' u!^)
{ ///xx/weblogic60b2_win.exe G%jgr"]\z
try{ idPx! fe
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ?\"GT]5D
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :k*'MU}
SiteFileFetch fileFetch = new SiteFileFetch(bean); z"Miy
fileFetch.start(); 7l/.fSW
} O3/][\
catch(Exception e){e.printStackTrace ();} ~!;*C
($pNOGH
Ti$G2dBO
} eyUguA<lK\
bA!n;
kVz9}Xp"
public static void main(String[] args) Tsch:r S
{ b"Hc==`
new TestMethod(); 3`.*~qW
} 1j"G~TM
} T$rhz)_q
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