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)); }LDDm/$^}
} gAgzM?A1(
for(int i=0;i<nEndPos.length-1;i++) J03yFT,dF
{ LJfd{R1y+
nEndPos = nStartPos[i+1]; cm6cW(x6
} q*?LXKi
nEndPos[nEndPos.length-1] = nFileLength; )@\= pE.H
} ^0ipM/Lg
} 5Ee%!Pk
aJOhji<b#L
&JtK<g
//启动子线程 [$;6LFs}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; m+"?;;s
for(int i=0;i<nStartPos.length;i++) +Q}Y?([
{ HPg@yx"U
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 68+9^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !d&K,k
nStartPos,nEndPos,i); iZwt,)(
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |.)oV;9
fileSplitterFetch.start(); 2u*o/L+
} 2jOh~-LU
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), lBgf' b3$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %'%ej^s-R
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]j~V01p/e
nEndPos = " + nFileLength); +(`
// fileSplitterFetch[nPos.length-1].start(); b{b2L.
w(eAmN:zR
tl (2=\
//等待子线程结束 @vCPX=c
//int count = 0; QDF1$,s4i
//是否结束while循环 .`)\GjDv
boolean breakWhile = false; 1*Yf[;L
$[by)
Gvb>M=9
while(!bStop) %kxq"=3
{ ?nn`ud?f
write_nPos(); =%%\b_\L
Utility.sleep(500); &<_*yl p
breakWhile = true; SWNi@
UwvGw5)q
" 2Dz5L1v
for(int i=0;i<nStartPos.length;i++) 68[3 /
{ lQ<2Vw#Yl
if(!fileSplitterFetch.bDownOver) E5~HH($b
{ +?w 7Nm`
breakWhile = false; 0~iC#lHO
break; (CJiCtAsl`
} `TYQ^Zm
} c*-8h{}
if(breakWhile) h3Nwxj~E
break; J}c57$Z
1XSA3;ZEc
XZEawJ0
//count++; W2D^%;mw
//if(count>4) x1:+M]Da
// siteStop(); HgvgO\`]
} cv=nGFx6
KkP}z
Dd-;;Y1C
System.err.println("文件下载结束！"); HJhPd#xCW
} 5+vCuVZ
catch(Exception e){e.printStackTrace ();} 6vbWe@#U/
} &tB|l_p_-p
kTb.I;S
|5_bFB+&
//获得文件长度 M#LQz~E
public long getFileSize() Z.am^Q^Y!
{ jJkM:iR
int nFileLength = -1; RrSSAoz1
try{ XSyCT0f08
URL url = new URL(siteInfoBean.getSSiteURL()); "u~l+aW0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z4A a
httpConnection.setRequestProperty("User-Agent","NetFox"); dB+x,+%u+
Fvf308[
Y]/(R"-2G
int responseCode=httpConnection.getResponseCode(); w$n\`rQ
if(responseCode>=400) kT@RA}
{ A%>Ir`I
processErrorCode(responseCode); /=w9bUj5v
return -2; //-2 represent access is error /d=i0E3
} O{zY(`[
pJrc\`D
MH[Zw$
String sHeader; \kqa4{7U(
%y)5:]
no- Lx-x
for(int i=1;;i++) rUEoz|e4a
{ 34-QgE
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -ZFeE[Z
//Utility.log(in.readLine()); W7>4-gk
sHeader=httpConnection.getHeaderFieldKey(i); Zx,R6@l
if(sHeader!=null) R#i|n<x
{ e:hkWcV
if(sHeader.equals("Content-Length")) DnvJx!#R
{ Rn~FCj,-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); @P#uH5U
break; oJe9H<
} AN7WMX
} L@2%a'
else /%C6e )7BL
break; 6kuN)
} n)uvN
} ^ j;HYs_
catch(IOException e){e.printStackTrace ();} }c1Vu
catch(Exception e){e.printStackTrace ();} ,oX48Wg_+
*T"JO|
s,m+q)
Utility.log(nFileLength); C=(-oI n
JIvVbI
4)BZ%1+
return nFileLength; h^^zR)EVb
} SQ|pH"
fL.;-
TU$PAwn=
//保存下载信息（文件指针位置） jT"P$0sJAd
private void write_nPos() A!Zjcp|
{ *vv<@+gA
try{ "r @RDw
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0cZyO$.
output.writeInt(nStartPos.length); fiz2544
for(int i=0;i<nStartPos.length;i++) Cj%SW <v|
{ 95Bw;U3E
// output.writeLong(nPos); #q`[(`Bx
output.writeLong(fileSplitterFetch.nStartPos); P7QOlTQI
output.writeLong(fileSplitterFetch.nEndPos); (Z5=GJM?$
} Jfa=#`
output.close(); <HM\ZDo@P
} _6"vPN
catch(IOException e){e.printStackTrace ();} _Z+tb]
catch(Exception e){e.printStackTrace ();} O%5cMz?eU
} #\N?ka}!
t^ LXGQ
EQ`;=I3J9y
//读取保存的下载信息（文件指针位置） 'c5#M,G~
private void read_nPos() '<~rV
{ 6l&m+!i
try{ )~xL_yW_X
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); I2kqA5>)j
int nCount = input.readInt(); _'<V<OjVM!
nStartPos = new long[nCount]; I7TdBe-
nEndPos = new long[nCount]; jb1OcI%
for(int i=0;i<nStartPos.length;i++) *I%r
{ /tRzb8`
nStartPos = input.readLong(); B%gk[!d}8
nEndPos = input.readLong(); XRXKO>4q
} Je_Hj9#M\d
input.close(); @QI]P{
} Hn)K;?H4
catch(IOException e){e.printStackTrace ();} c'OJodpa
catch(Exception e){e.printStackTrace ();} H6E@C}cyM
} zrk/}b0j
9qD/q?Hh$
}'$6EgX
private void processErrorCode(int nErrorCode) mNN,}nHu
{ dVc;Tt
System.err.println("Error Code : " + nErrorCode); LinARMPv
} 2!f0!<te
F7a &-
u_.V]Rjc
//停止文件下载 t+}@J}b
public void siteStop() y@]4xLB]
{ &N1C"Eov?
bStop = true; &:=
for(int i=0;i<nStartPos.length;i++) udtsq"U_%
fileSplitterFetch.splitterStop(); 3~6F`G
l|O^yNS
GbUcNROr
} C&D]!ZvF
} @iB**zR/
//负责部分文件的抓取 T[a1S?_*T
**FileSplitterFetch.java /k<*!H]KSg
*/ %\N.m/5
package NetFox; A}C&WT~
'j#oMA{0
seY0"ym&e
import java.io.*; ;hF>iw
import java.net.*; Lv,~Mf1|
gJi11^PK
_tL+39 u
public class FileSplitterFetch extends Thread { . hHt+
OzBo*X/p
7}Z.g9<
String sURL; //File URL ?# >|P-4
long nStartPos; //File Snippet Start Position ~c ;7me.
long nEndPos; //File Snippet End Position ({D.oS
int nThreadID; //Thread's ID COv#dOw
boolean bDownOver = false; //Downing is over :eS7"EG{3
boolean bStop = false; //Stop identical V'c9DoSRI\
FileAccessI fileAccessI = null; //File Access interface ]@l~z0^|[_
H(Mlf
V5KAiG<d
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /r@P\_
{ X ~4^$x
this.sURL = sURL; t(lTXG
this.nStartPos = nStart; s .^9;%@$J
this.nEndPos = nEnd; 2t1WbP1
nThreadID = id; BdUhFN*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 OW)8Z60
} E1 *\)q
rd]HoFE
5gF}7D@
public void run() {ZbeF#*"
{ h1fJ`WT6,
while(nStartPos < nEndPos && !bStop) [lS'GszA
{ {xEX_$nv
tt|U,o
#`z!f0 P
try{ 4TG|
URL url = new URL(sURL); Uvf-h4^J]:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "$0f.FO:i
httpConnection.setRequestProperty("User-Agent","NetFox"); $0LlaN@e
String sProperty = "bytes="+nStartPos+"-"; 6e |
httpConnection.setRequestProperty("RANGE",sProperty); 1{o CMq/v
Utility.log(sProperty); H=X>o.iVqi
\Zoo9Wy
ddnWr"_
InputStream input = httpConnection.getInputStream(); Km+29
//logResponseHead(httpConnection); )yJeh
4 CX*,7LZ
1}[\@n+b
byte[] b = new byte[1024]; dUb(C1h
int nRead; uO[4 WZ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) xR#hU;E}
{ = 1}-]ctVn
nStartPos += fileAccessI.write(b,0,nRead); Om}&`AP};
//if(nThreadID == 1) CdZ;ZR
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _rs#h)
} M?nnpO
k[vn:
2vWkAC;
Utility.log("Thread " + nThreadID + " is over!"); &-cI|
bDownOver = true; Iu1P}R>C
//nPos = fileAccessI.write (b,0,nRead); 7/*;rT
} X]1ep
catch(Exception e){e.printStackTrace ();} t9K.Jc0
} pY8+;w EI
} (O`=$e
w-\fCp )
>F-J}P
//打印回应的头信息 -w@fd]g
public void logResponseHead(HttpURLConnection con) Zfb:>J@h6
{ "{V,(w8Dt
for(int i=1;;i++) |LNXu
{ 2>EIDRLJ-
String header=con.getHeaderFieldKey(i); yY"%6k,ZB
if(header!=null) (nE$};c<b2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3ZB;-F5v
Utility.log(header+" : "+con.getHeaderField(header)); 6]rrj
else LXXxwIBS
break; xxV{1, H2
} *Lh0E/5
} <0kRky$
/FYa{.Vlr
+Nza@B d
public void splitterStop() 2j"%}&
{ vuAAaKz
bStop = true; 3Q;^X(Ml*
} tICxAp:
b _u&%
a"EQldm|d
} & 9?vQq|%
K^w9@&g6
=riP~%_ML)
/* =x^I 5Pn
**FileAccess.java )0GnTB;5Z
*//文件访问(定位，写) 3>jz3>v@
package NetFox; S"eKiS,z
import java.io.*; #|CG %w
w{r->Phe
vEgJmHv;
public class FileAccessI implements Serializable{ W4#:_R,&,
BF_k~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 IIu3mXAw
RandomAccessFile oSavedFile; J%A`M\
long nPos; YT3QwN9
5Px.G*
ad~ qr n\
public FileAccessI() throws IOException )RkU='lB "
{ L;f=\q"g
this("",0); E8j9@BHU[r
} yf8UfB#a
Bdg*XfXXk
FQ87[| S
public FileAccessI(String sName,long nPos) throws IOException 05zHLj
{ 2+P3Sii
oSavedFile = new RandomAccessFile(sName,"rw"); cwD0 ~B
this.nPos = nPos; d,[KcX
oSavedFile.seek(nPos); y$&a(S]
} FU[,,a0<<
0F3>kp4u
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public synchronized int write(byte[] b,int nStart,int nLen) i&30n#
{ ?I0 i%nH
int n = -1; XVLuhwi
try{ n=SZ8Rj7
oSavedFile.write(b,nStart,nLen); lcP@5ZW
n = nLen; M$?6 '
} B~aOs>1 S]
catch(IOException e) X@Bpjg
{ ?rOb?cu-
e.printStackTrace (); v-gT 3kJ
} #,PAM.rH
g@y" B6X
Q)@1:(V/
return n; 9j2I6lGQ
} &KvevPF
2%qn!+.
?|8Tgs@+
} .apX72's,
(XwLKkw0n
ZYt __N
/* Fp6Y Y
**SiteInfoBean.java r:5Ve&~
*/ M$W#Q\<*#r
package NetFox; #rpqt{ml
}>w
I:_*8el&d
public class SiteInfoBean { b:QFD|
by U\I5
^'fKey`
private String sSiteURL; //Site's URL :.Qe=}9
private String sFilePath; //Saved File's Path B R:
private String sFileName; //Saved File's Name 5y3TlR
private int nSplitter; //Count of Splited Downloading File BXo|CITso
zn ?;>Bl
tvOAN|+F
public SiteInfoBean() 9f^PR|F
{//nSplitter的缺省值为5 |3,V%>z
//default value of nSplitter is 5 k2uiu
this("","","",5); KY`96~z
} MH.,s@
E.`dk.
VDKS_n
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Z&w^9;30P
{ uK:-g,;
sSiteURL= sURL; ~snF20
sFilePath = sPath; d `kM0C
sFileName = sName; T4=3VrS
this.nSplitter = nSpiltter; 6eT'[Umx
}#G"!/ZA0:
@pGlWw9*
} )c*k_/4
8q [c
(bx\4Ws
public String getSSiteURL() X^D9)kel
{ s!'A\nVV1$
return sSiteURL; N+M&d3H`
} `SjD/vNE
dA} 72D?
WYC1rfd=
public void setSSiteURL(String value) EotwUT|
{ W/r mm*
sSiteURL = value; V<vPFxC
} ,![Du::1
%L j0
t\pK`DM-[
public String getSFilePath() gXu^"
{ oKYhE
return sFilePath; e[QxFg0E
} \$'m^tVU
XalJo@%-
rj,K`HD
public void setSFilePath(String value) !(*a+ur&i
{ >HPvgR/#BY
sFilePath = value; _@!QY
} 1/2V.:bg
x_<bK$OU
WBr:|F+~s
public String getSFileName() eOehgU5x
{ b6nZ55 h
return sFileName; ~`2&'8
} 'B3Wza.
.%?-As
JOrELrMx
public void setSFileName(String value) wb6L?t
{ 5fu+rU-#
sFileName = value; 7G.o@p6$
} 1l+kO,X]
Pr5g6I'G
.Iwur;/\
public int getNSplitter() >gk z4.*
{ %j'G.*TD
return nSplitter; 1E5a(
} VYamskK[G:
1Xy8|OFc[
RpO@pd m
public void setNSplitter(int nCount) Y=vVxVI\
{ YlswSQ
nSplitter = nCount; +@emX$cFV
} VG_uxKY
} YDQ:eebg(
qH#r-
C4QeDvpI
/* jR{-
**Utility.java yoBgr7gS
*/ _wf5%(~b
package NetFox; (O\U /daB
Y5dD|]F|
^WE4*.(
public class Utility { O'k+7y
m\>|C1oRy
X E|B)Q(
public Utility() 0b/ir2
{ bIgh@= 2
CSMeSPOm]
Y3-gUX*w0
} {?E<](+0
^SZw`]
//线程睡眠 G&q'#3ieC
public static void sleep(int nSecond) t3PtKgP-6
{ ?4XnEDAm
try{ 9O;cJ)tXY
Thread.sleep(nSecond); V=pMq?Nr
} NJtQx2Sd'H
catch(Exception e) .%=V">R
{ f-;$0mTQ
e.printStackTrace (); NXpmT4
} U{6oLqwq3Y
} x^G'rF"nT
9lf*O0Z&n
//日志 ~q)u(WC|
public static void log(String sMsg) +`@M*kd
{ M=OCzgj
System.err.println(sMsg); ,`k_|//}=
} #05jC6
!b8uLjd;
hi ~}
public static void log(int sMsg) -$(Jk<
{ DAfyK?+UL
System.err.println(sMsg); zN#*G i'
} Z(j{F<\jS
} )VSwTx&
(hIF]>,kl
?38lHn`FyQ
/* >nzu],U
**TestMethod.java -w1@!Sdd
*/ %Y]=1BRk}
package NetFox; @@@=}!<H=
:_5/u|{
7tNc=,x}
public class TestMethod { "g>.{E5
j%L&jH6@
.Obn&S
public TestMethod() K*q[(,9
{ ///xx/weblogic60b2_win.exe .f:n\eT):
try{ V8WFQdXc
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); D-2.fjo9!
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); K<4Kk3
SiteFileFetch fileFetch = new SiteFileFetch(bean); -`+<{NHv\
fileFetch.start(); ]}Z4P-"t
} j'?7D0>
catch(Exception e){e.printStackTrace ();} jCioE
!8 -oR6/$%
=w$tvo/
} POAw M
Os&n
~1 ~Xfo>
public static void main(String[] args) cc}Key@D
{ JhHWu<
new TestMethod(); xYfD()w<I
} {2&m`Dbm
} &<y2q/U}
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