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)); SCL8.%z D
} /v-:ca)7mI
for(int i=0;i<nEndPos.length-1;i++) IBm"VCg{Ew
{ |kc#=b@l
nEndPos = nStartPos[i+1]; sNHxUI
} FQe82tfV+
nEndPos[nEndPos.length-1] = nFileLength; ;6655C
} ~cH3RFV
} AI,Jy%62/
U-ADdOh"q
zI{~;`tzN
//启动子线程 vE{L`,\q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $2/v8
for(int i=0;i<nStartPos.length;i++) ]L/AW
{ U9(p ^
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ! _p(H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), vw)lD9-"
nStartPos,nEndPos,i); vAcxca">S
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |w+N(wcJ
fileSplitterFetch.start(); Q4h6K7
} FMEW['
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k0@*Up3{7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); BN%;AQV
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^-2|T__
nEndPos = " + nFileLength); M]7>Ar'zsG
// fileSplitterFetch[nPos.length-1].start(); 3R& FzLs
[]l2 `fS#
.C\##
//等待子线程结束 /8Ru O
//int count = 0; 0BrAgv"3a_
//是否结束while循环 $_f"NE}
boolean breakWhile = false; .I%`yhCW
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<44A*ux
while(!bStop) kHbH{])
{ *bSxobn
write_nPos(); <c.8f;1F
Utility.sleep(500); T)o>U&KNP
breakWhile = true; ]114\JE
~A@HW!*Z@
lPZYd8
for(int i=0;i<nStartPos.length;i++) m <'&`B;
{ <`?V:};Q
if(!fileSplitterFetch.bDownOver) qAW?\*n5N
{ TD-o-*mO
breakWhile = false; EECuJ+T
break; 2(i|n=
} `e4gneQY
} sd&^lpH
if(breakWhile) F[)5A5+:Y
break; b6UpE`\z
9Q>85IiT
vHXCT?FuG
//count++; 8/s?Gz
//if(count>4) 3eERY[
// siteStop(); pD17r}%
} XiO~^=J
+SNjU"x
g\]~H%2 ,
System.err.println("文件下载结束！"); {RC&Ub>
} :5[1Iepdn
catch(Exception e){e.printStackTrace ();} K_ Odu^
} v3b+Ddp
e!=~f%c<N
<j}A=SDZ)
//获得文件长度 He*c=^8k
public long getFileSize() ]Ns)fr6
{ xG WA5[YV
int nFileLength = -1; 2D2} *);eW
try{ Q!y%N&
URL url = new URL(siteInfoBean.getSSiteURL()); `8/D$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J%FF@.)k
httpConnection.setRequestProperty("User-Agent","NetFox"); ~@$RX:p
K$KVm^`
\b*z<Odv
int responseCode=httpConnection.getResponseCode(); 7yQw$zG,Iz
if(responseCode>=400) |8?DQhd}
{ x|$|~6f=n
processErrorCode(responseCode); 0k G\9
return -2; //-2 represent access is error +~$pkxD"
} gy Ey=@L
%JL P=(
b\S~uFq6
String sHeader; |B {*so]
*RM 3_
g.pR4Mf=Z
for(int i=1;;i++) ] @:x<>
{ N/78Ub
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); k~*%Z!V}C
//Utility.log(in.readLine()); .Ta(v3om%
sHeader=httpConnection.getHeaderFieldKey(i); ]d~2WX Y
if(sHeader!=null) 89x;~D1
{ ?$#P =VK
if(sHeader.equals("Content-Length")) ;EQ7kuJQ?
{ x c]#8K
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <Hr~|oG
break; G!+Mu2
} $!$,cKPl5
} &dG^M2g-F
else >hY.F/[
break; /2'l=R5#
} A(*c|Aj9
} "7Z-ACyF5
catch(IOException e){e.printStackTrace ();} *x:*Q \|
catch(Exception e){e.printStackTrace ();} mKsJ[)#.
~REfr}0
S,x';"
Utility.log(nFileLength); HR;I}J 9
_2TL>1KZt
1Qw_P('}
return nFileLength; 55FRPNx-x
} @'<=EAXe
qrf90F)
*-*SCA`E^=
//保存下载信息（文件指针位置） Zs4NN2~
private void write_nPos() wjfq"7Q
{ 8S7#tb@3
try{ K#Zv>x!to
output = new DataOutputStream(new FileOutputStream(tmpFile)); iK=QP+^VN
output.writeInt(nStartPos.length); '<s54 Cb
for(int i=0;i<nStartPos.length;i++) J0Gjo9L
{ \CX6~
// output.writeLong(nPos); 2u$rloc$b
output.writeLong(fileSplitterFetch.nStartPos); _F5*\tQ
output.writeLong(fileSplitterFetch.nEndPos); ( k,?)
} 0xY</S
output.close(); pzZ+!d
} 9Dbbk/j|
catch(IOException e){e.printStackTrace ();} }3_>
catch(Exception e){e.printStackTrace ();} 7"F29\
} _u]%K-_
CeeAw_*@
n(`|:h"
//读取保存的下载信息（文件指针位置） "n_X4e+18P
private void read_nPos() pD('6C;
{ !hFhw1
try{ G\o9mEzQ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); J;=T"C&
int nCount = input.readInt(); c8T| o=`k6
nStartPos = new long[nCount]; }[R-)M
nEndPos = new long[nCount]; 53 -Owjpx
for(int i=0;i<nStartPos.length;i++) )KEW`BC5T
{ H'JU5nE
nStartPos = input.readLong(); 4,>9N9.?9
nEndPos = input.readLong(); P)cEYk
} F0~<p[9Nx
input.close(); &B]1 VZUp
} 9VanR ::XX
catch(IOException e){e.printStackTrace ();} :yRv:`r3Lt
catch(Exception e){e.printStackTrace ();} 2$ &B@\WY
} lu8*+.V
3=yfbO<-
A$]s{`
private void processErrorCode(int nErrorCode) k?$I4&|5Nt
{ Cv}^]_`Q
System.err.println("Error Code : " + nErrorCode); YN+vk}8 <
} a{@}vZx>3
|B^Mj57DO
tHAe
//停止文件下载 L^r & .N\
public void siteStop() }8POm#
{ NJ]3qH
bStop = true; a9UXg<4
for(int i=0;i<nStartPos.length;i++) Vn_~ |-Wt
fileSplitterFetch.splitterStop(); Kk*8
l*6Zh"o:
8NiR3*1
} uovv">Uw
} N/ f7"~+`
//负责部分文件的抓取 6]4#8tR1_
**FileSplitterFetch.java Nk<^ Qv
*/ 4"_`Mu_%
package NetFox; {0j_.XZ
[F'|KcE3
!=A;?Kdq
import java.io.*; bK.*v4RG
import java.net.*; WN<g _8QR
U2l3E*O
,uAp;"YJeV
public class FileSplitterFetch extends Thread { Bp3E)l
zh|9\lf
JXM]tV
String sURL; //File URL uKd4+Km
long nStartPos; //File Snippet Start Position DY9]$h*y
long nEndPos; //File Snippet End Position ]8}51y8
int nThreadID; //Thread's ID +[<YE
boolean bDownOver = false; //Downing is over AYgXqmH~+
boolean bStop = false; //Stop identical fCwE1r*^
FileAccessI fileAccessI = null; //File Access interface DU0/if9.
B6Eu."T
993f6
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :aK?DtZ
{ :8!RGtn
this.sURL = sURL; jn:_2g[
this.nStartPos = nStart; |K"Q>V2y
this.nEndPos = nEnd; ZZ7qSyBs?
nThreadID = id; 7/ ?QZN
fileAccessI = new FileAccessI(sName,nStartPos);//定位 MUAs(M;
} ,wwO0,"y7
IHYLM;@L
dH!z<~
public void run() An$2='=/
{ xC,x_:R`
while(nStartPos < nEndPos && !bStop) bh<;px-
{ fEX=csZ86
mL=d EQ
)@X0'X<
try{ aL( hWE
URL url = new URL(sURL); 1[^YK6a/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vWZXb`
httpConnection.setRequestProperty("User-Agent","NetFox"); qD4]7"9
String sProperty = "bytes="+nStartPos+"-"; S0)JIrrHC
httpConnection.setRequestProperty("RANGE",sProperty); &CQO+Yr$l
Utility.log(sProperty); z@i4
$[A\i<#
pYx,*kG:HW
InputStream input = httpConnection.getInputStream(); D]]wJQU2
//logResponseHead(httpConnection); viG,z4Zf
)63 $,y-;$
dPwyiV0
byte[] b = new byte[1024]; L%T(H<G
int nRead; .VCY|KZ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) pA6KiY&
{ !g9k9 l
nStartPos += fileAccessI.write(b,0,nRead); V}Y*Yv
//if(nThreadID == 1) M'PZ{6;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); njF$1? )sq
} WJ25fTsG
0RT8N=B83
yGdX>h
Utility.log("Thread " + nThreadID + " is over!"); Zgo~"G
bDownOver = true; =FrB{Eu
//nPos = fileAccessI.write (b,0,nRead); Gv_~@MN
} wQSye*ec
catch(Exception e){e.printStackTrace ();} } #rTUX
} Q$c6l[(g
} )1uiY f&k
e@Lxduq
=~GP;=6
//打印回应的头信息 (Jk&U8y
public void logResponseHead(HttpURLConnection con) @PEFl"
{ <w{?b'/q
for(int i=1;;i++) Y%.o TB&
{ nt#9j',6Rn
String header=con.getHeaderFieldKey(i); dRX~eIw
if(header!=null) }IyF|[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); j#1G?MF
Utility.log(header+" : "+con.getHeaderField(header)); lh8QtPe
else P.'.KZJ:WD
break; u^~7[OkE
} 3m1(l?fp
} rm8Ys61\=
+;?mg(:
@-'a{hBR
public void splitterStop() Nmj)TOEPW
{ FH+X<
bStop = true; 5To@d|{
} Y~WdN<g
v Y0bK-
~5f&<,p!
} \8`7E1d
QB*,+u4
i6WH^IQM
/* nm-
**FileAccess.java j uA@"SG
*//文件访问(定位，写) wq$$. .E
package NetFox; tk&AZb,sP
import java.io.*; \Ii{sn9
K(EJ`2]:r
h2ROQKL"B
public class FileAccessI implements Serializable{ b=,BLe\
N1a]y/
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 gV2vwe
RandomAccessFile oSavedFile; 2:*15RH3
long nPos; m,k0 h%
r5}p .
um.ZAS_kmc
public FileAccessI() throws IOException S&_03
{ i]v3CY|3AI
this("",0); }QFL
} YThVG0I =
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sbW+vc
public FileAccessI(String sName,long nPos) throws IOException oY)eN?c
{ o,*m,Qc
oSavedFile = new RandomAccessFile(sName,"rw"); /Y#8.sr
this.nPos = nPos; ;@wa\H[3v2
oSavedFile.seek(nPos); )A8#cY!<
} b`jR("U
:_8K8Sa
rNP;53FtZl
public synchronized int write(byte[] b,int nStart,int nLen) ZcN0:xU
{ C/k#gLF`
int n = -1; Kh]es,$D
try{ kE&R;T`Gb%
oSavedFile.write(b,nStart,nLen); ZISIW!
n = nLen; =Z\q``RBy
} 4uXGpsL
catch(IOException e) Dvg'
{ OrkcY39"~a
e.printStackTrace (); &FXf]9 _X
} kTL{Q0q
Bhv;l/K])
!>sA.L&=
return n; X-\$<DiJGv
} 9q`Ewj R
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e>MtDJ5
} w <r*&
uw+nll*W%
>z<L60S
/* q,P.)\0A
**SiteInfoBean.java G_F_TNO
*/ *~PB
package NetFox; iC#a+G*N_M
1)z'-dQ-5$
f(Xin3#'
public class SiteInfoBean { $H<_P'h-B
Y=XDN:
/@`"&@W'
private String sSiteURL; //Site's URL x6/u+Urn
private String sFilePath; //Saved File's Path Fp.eucRxP
private String sFileName; //Saved File's Name o,i_py
private int nSplitter; //Count of Splited Downloading File fbApE
YEv\!%B
If&))$7u
public SiteInfoBean() h% -=8l,
{//nSplitter的缺省值为5 @/#G2<Vp1
//default value of nSplitter is 5 awzlLI<2p
this("","","",5); *d8 %FQ
} C. .|O
L1kn="5
;~F*2)
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Z\0wQ;}
{ %DttkrhL
sSiteURL= sURL; T!x/^
sFilePath = sPath; Id?-Og2iV
sFileName = sName; /Z2u0jNArP
this.nSplitter = nSpiltter; ) gl{ x
ug%7}&
.U{}N%S
} EZj rX>"#
6nA9r5Ghv
3Dr\ O_`u
public String getSSiteURL() 3cJ'tRsp<
{ #?Ix6 {R
return sSiteURL; y>C !cYB
} "smU5 s,P
L 0Ckw},,
\4 b^*`d
public void setSSiteURL(String value) 9"[,9HN
{ PS~_a
sSiteURL = value; YMo8C(
} E?]$Y[KJKs
(\qf>l+*
5B~]%_gZr
public String getSFilePath() ^qL<=UC.
{ 'A[PUSEE
return sFilePath; +P))*0(c_
} K-'uE)
4l0>['K&{
W(62.3d~}?
public void setSFilePath(String value) 56Lxr{+X
{ !~zn*Hm
sFilePath = value; O C;~ H{
} LDegJer-v
(%6fZ
O}C*weU
public String getSFileName() 6EY\
{ 5xc e1[
return sFileName; "y8W5R5kL4
} TTO8tT3[6}
-[*y{K@dh
3_RdzW}f
public void setSFileName(String value) &tUX(
{ 2?qT,pN
sFileName = value; 2a-]TVL3
} jct=Nee|
/sYr?b!/<6
8}BM`@MG
public int getNSplitter() 1#L%Q(G
{ P:Q&lnC
return nSplitter; dOaOWMrfdf
} |zRrGQYm
`j{q
eSZ':p
public void setNSplitter(int nCount) zn/>t-Bc
{ ,]t_9B QK
nSplitter = nCount; TQ![
} Lt~&K$t7~
} Eg&5tAyM
(0@b4}Z
_*z^PkH
/* OeGLMDw
**Utility.java F^.]g@g.|
*/ U `lp56
package NetFox; BJ_"FG
jcC"vr'u|
)M8,Tv*~
public class Utility { zv"NbN
id,'+<
C`ZU.|R
public Utility() OGW3Pe0Z'
{ aQHR=.S]X
vMY!Z1.*
CY=lN5!J
} I\Y N!
KO`dAB F}
//线程睡眠 Ze/\IBd
public static void sleep(int nSecond) pq_U?_5Z'r
{ <^$ppwk$
try{ ES^JRX
Thread.sleep(nSecond); u[SqZftmO
} e)s l
catch(Exception e) cD9U^SOS
{ w3VgGc~
e.printStackTrace (); Ugo!
} 1\{FKOt
} W9} ,f
$U/lm;{%
//日志 *"OlO}o
public static void log(String sMsg) *N: $,xf
{ :^paI
System.err.println(sMsg); 5MYdLAjV
} #""T>+
d=D#cs;\
>Q_ '[!S
public static void log(int sMsg) 8*Fn02 p
{ '5Kj"aD%
System.err.println(sMsg); +2tFX
} # bjK]+
} 3_9CREZCl
FzSL[S4i
Oc,HnyV+
/* OVxg9
**TestMethod.java 0$b4\.0>~
*/ 0nBDF79
package NetFox; b)#rUI|O
g9;s3qXiG
`gCJ[
public class TestMethod { =[:E
E`xpZ>$mPx
a*}>yad
public TestMethod() 4o";p}[b
{ ///xx/weblogic60b2_win.exe y8C8~-&OK
try{ 'C`Ykjf
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -da: j-_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); K} T=j+
SiteFileFetch fileFetch = new SiteFileFetch(bean); KSS]%66Y
fileFetch.start(); RO3q!+a$/
} |Vlx:
catch(Exception e){e.printStackTrace ();} G{,DoCM5WL
pd`m//G
~xDu2-5
} !/a6;:_y
O3T7O`H[
-{C Gn5]_#
public static void main(String[] args) ShlTMTgS
{ ,B_tAg4~
new TestMethod(); X!ldL|Ua%
} )}"`$6:k`
} \b6{u6?+
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