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)); t"sBPLU\
} a6ekG YW
for(int i=0;i<nEndPos.length-1;i++) PgAf\.48a
{ XjBW9a
nEndPos = nStartPos[i+1]; ,S\CC{!
} S0$8@"~=
nEndPos[nEndPos.length-1] = nFileLength; MnmVl"(/
} hy9\57_#
} 1l9G[o *
Oz.HH
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//启动子线程 _OYasJUMG
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; l#&8x
for(int i=0;i<nStartPos.length;i++) j<upRS,$
{ v6|RJt?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g%o(+d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), OUE(I3_
nStartPos,nEndPos,i); REQ\>UO_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xexaQuK
fileSplitterFetch.start(); )',R[|<
} {.`vs;U
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $Ph|e)p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 2'l'8
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", pR<`H'
nEndPos = " + nFileLength); SV4E0c>
// fileSplitterFetch[nPos.length-1].start(); $+Z[K.2J
WpDSg*fk=Y
aNsBcov3O
//等待子线程结束 7lTC{7C57
//int count = 0; gE-tjoJ
//是否结束while循环 eNh39er
boolean breakWhile = false; EZgwF=lO
t6rRU~;}
KA5v+~
while(!bStop) _r#Z}HK
{ qyb?49I
write_nPos(); '(6z. toQ
Utility.sleep(500); I]|Pq
breakWhile = true; ;T\%|O=Ke
hXw]K"
AhN4mc@
for(int i=0;i<nStartPos.length;i++) _1X!EH"
{ BX/8O<s0
if(!fileSplitterFetch.bDownOver) ?JbilK}a
{ +D6YR$_<
breakWhile = false; P.se'z)E
break; W<{h,j8
} PxX4[ P
} LG0;#3YwH
if(breakWhile) h#I>M`|
break; $V;i '(&7
.D~;u-%|F
fy1|$d{'
//count++; Mc lkEfn
//if(count>4) W_293["lS
// siteStop(); R>|{N9
} Ng&%o
ejKucEgD
F~ty!(c
System.err.println("文件下载结束！"); @)F)S7
} eSn+B;
catch(Exception e){e.printStackTrace ();} Vsr.=Nd=
} 1NFsb-<u
`?H]h"{7Q
-]Bq|qTH[(
//获得文件长度 >tS'Q`R
public long getFileSize() =HK!(C
{ J`Q>3]wL
int nFileLength = -1; $GV7o{"&
try{ 3m[vXr?
URL url = new URL(siteInfoBean.getSSiteURL()); PN%zIkbo
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^S<Y>Nm]
httpConnection.setRequestProperty("User-Agent","NetFox"); ho{*Cjv
DPY}?dC
YRk(u7:0
int responseCode=httpConnection.getResponseCode(); D>r&}6<
if(responseCode>=400) &A/]pi-\
{ .Z`R^2MU
processErrorCode(responseCode); >~rTqtKd
return -2; //-2 represent access is error O^PKn_OJ
} ?5__oT
t^-d/yKt0w
R+:yVi[F]U
String sHeader; _%Bi: HG0
=[ 46`-_
z|uDy2
for(int i=1;;i++) cU (D{~
{ Y|m+dT6
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;LfXi 8)
//Utility.log(in.readLine()); %Qgw7p4
sHeader=httpConnection.getHeaderFieldKey(i); hW')Sp
if(sHeader!=null) P;y45b
{ RU{twL.B
if(sHeader.equals("Content-Length")) yF:1( 4
{ 0JS?;fk
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); bRDYGuC
break; e ,'_xV
} OKZV{Gja
} 234p9A@
else GMx&y2. Z
break; ;>hO+Wo
} `RT>}_j
} iXkF1r]i
catch(IOException e){e.printStackTrace ();} )* :gqN
catch(Exception e){e.printStackTrace ();} ]#<4vl\
]EbM9Fo-U
Kg*Q
Utility.log(nFileLength); eIF5ZPSZi
?,Xw[pR
je-!4r,
return nFileLength; y1DL,%j
} tFn)aa~L
+480 l}
JG.y,<xW
//保存下载信息（文件指针位置） )m+W j
private void write_nPos() +^ac'Y)A
{ P:S.~Jq
try{ A 'be8
output = new DataOutputStream(new FileOutputStream(tmpFile)); @s&71a
output.writeInt(nStartPos.length); Q}JOU
for(int i=0;i<nStartPos.length;i++) BVQqY$>
{ |i*37r6]=
// output.writeLong(nPos); u#fM_>ML
output.writeLong(fileSplitterFetch.nStartPos); /62!cp/F/D
output.writeLong(fileSplitterFetch.nEndPos); ,KZ~?3$yj
} !n!*/[}X
output.close(); /HEw-M9z
} s[*rzoA
catch(IOException e){e.printStackTrace ();} 7WqH&vU|
catch(Exception e){e.printStackTrace ();} VCfl`Aq'l
} s)t@ol
M?49TOQA
;d$rdFA_
//读取保存的下载信息（文件指针位置） qq`4<0I>
private void read_nPos() nPtuTySG
{ bs&43Ae
try{ }K>d+6qk5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @{e}4s?7od
int nCount = input.readInt(); ]q[D>6_
nStartPos = new long[nCount]; l'1pw
nEndPos = new long[nCount]; ~/U1xk%
for(int i=0;i<nStartPos.length;i++) [aLI '
{ @bLy,Xr&
nStartPos = input.readLong(); B@))8.h]
nEndPos = input.readLong(); 2.y-48Nz
} dQX6(Jj
input.close(); :=V[7n])
} nF:4}qy\
catch(IOException e){e.printStackTrace ();} 4@gG<QJW
catch(Exception e){e.printStackTrace ();} U>SShpmZA
} }6~hEc*/"
M0"_^?
y<3-?}.aZ
private void processErrorCode(int nErrorCode) Qljpx?E
{ V &T~zh1
System.err.println("Error Code : " + nErrorCode); MJ)RvNF
} D)P._?
3M`M
VGN5<?PrN
//停止文件下载 >6-`}G+|
public void siteStop() hfB%`x#akQ
{ Uc>lGo1j
bStop = true; Z\rwO>3
for(int i=0;i<nStartPos.length;i++) 4"ZP 'I;
fileSplitterFetch.splitterStop(); LOYk9m
_61gF[r4!Y
gJ+'W1$/
} VQ@
} e%M;?0j
//负责部分文件的抓取 Y|qTyE%
**FileSplitterFetch.java wQf-sk#
*/ ?j.,Nw4FC
package NetFox; {YC@T(
3,w_".m`#
H8jpxzXv
import java.io.*; 1GRCV8"Z^
import java.net.*; >R_&Ouh:
J)>c9w
wHLLu~m\
public class FileSplitterFetch extends Thread { q i;1L Kc
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v1JzP#
String sURL; //File URL _f,C[C[e&
long nStartPos; //File Snippet Start Position djZqc5t
long nEndPos; //File Snippet End Position c6]U E@A
int nThreadID; //Thread's ID s8Q 5ui]
boolean bDownOver = false; //Downing is over 0mVNQxHI
boolean bStop = false; //Stop identical qR{=pR
FileAccessI fileAccessI = null; //File Access interface V0YZp
F(n$
H?Wya.7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException gQuw1
{ J;e2&gB
this.sURL = sURL; C) s5D
this.nStartPos = nStart; 0+ '&`Q!u
this.nEndPos = nEnd; 5tkAFb4P
nThreadID = id; =qIp2c}Rx
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Zi i
} Q&;9x?e
b|DdG/O
(t|Zn@uY
public void run() w9imKVry
{ *^4"5X@
while(nStartPos < nEndPos && !bStop) 33q}CzK
{ ^ @5QP$.
V!=,0zy~Z
3d]S!=4H"
try{ J8(lIk:e
URL url = new URL(sURL); &z3o7rif$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0d&6lqTo
httpConnection.setRequestProperty("User-Agent","NetFox"); NI]N4[8(
String sProperty = "bytes="+nStartPos+"-"; aXYY:;
httpConnection.setRequestProperty("RANGE",sProperty); Y.UFbrv
Utility.log(sProperty); Vb_4f"
,4$>,@WW~
0OE:[pR
InputStream input = httpConnection.getInputStream(); x9g#<2w8
//logResponseHead(httpConnection); p6@)-2^
n\DV3rXI9
t:Q*gWRh
byte[] b = new byte[1024]; xp{tw$
int nRead; q9_OGd|P
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "8MF_Gu):
{ 7$=InK
nStartPos += fileAccessI.write(b,0,nRead); 0S~rgq|O
//if(nThreadID == 1) 2ilQXy
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); vE?G7%,
} HV|,}Wks6s
u6agoK|^9
h]gp^?=
Utility.log("Thread " + nThreadID + " is over!"); n>YKa)|W`
bDownOver = true; NLqzi%s
//nPos = fileAccessI.write (b,0,nRead); da(<K}
} PZ9I`P!C
catch(Exception e){e.printStackTrace ();} R 9\*#c
} Yq KCeg
} %u'ukcL7
uXvtfc
0,")C5j
//打印回应的头信息 ZE}}W_
public void logResponseHead(HttpURLConnection con) :I#V.
{ &QgR*,5eo
for(int i=1;;i++) Rm( "=(
{ }7Q%6&IR
String header=con.getHeaderFieldKey(i); 5b*C1HS@X
if(header!=null) T~e.PP
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |{ip T SH
Utility.log(header+" : "+con.getHeaderField(header)); L8B!u9%
else 77Y/!~kd
break; w?[upn:K
} 7.oM J
} fHFE){
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k(HUUH_z
public void splitterStop() |L ev.,,Ph
{ %ET+iIhK
bStop = true; g7H(PF?
} 1qA;/-Zr<o
{IjR^J=k
(LCfUI6;
} })%{AfDRF
JZx[W&]zT
AwR=]W;j
/* 5H^(2w
**FileAccess.java o]V^};B
*//文件访问(定位，写) F^:3?JA_
package NetFox; t6c4+D'{].
import java.io.*; l/5 hp.
[/r(__.
{Sh ;(.u^
public class FileAccessI implements Serializable{ J&_n9$
RA 6w}:sq7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9(Xn>G'iT
RandomAccessFile oSavedFile; Di{de`
long nPos; wCBplaojJ
:ws<-Qy
(bS&D/N.
public FileAccessI() throws IOException }SZd
{ ~} ~4
this("",0); Vurqt_nb
} %cn<ych G
dZuOrTplA
UEL_uij
public FileAccessI(String sName,long nPos) throws IOException #'`{Qv0,
{ KI.hy2?e
oSavedFile = new RandomAccessFile(sName,"rw"); vY3h3o
this.nPos = nPos; n@3>6_^rwT
oSavedFile.seek(nPos); V7/Rby Q
} [}m[)L\
gX@aG9
DlJo^|5
public synchronized int write(byte[] b,int nStart,int nLen) {!`6zBsP
{ #vlgwA
int n = -1; lOp`m8_=
try{ 8@R|Km5h
oSavedFile.write(b,nStart,nLen); Fr-SvsNFB
n = nLen; 7tp36TE
} l[J8!u2Xp
catch(IOException e) P+}h$_x
{ j~MI<I+l[
e.printStackTrace (); WIGi51yC.x
} rJB}qYD
9gIrt 6
6]wIG$j
return n; eMzk3eOJ
} ar,7S&sH
\U_@S.
`]aeI'[}R
} rm_Nn8p,
7zc^!LrW<
^.y\(=
/* iy"*5<;*DD
**SiteInfoBean.java ?JUeuNs9
*/ O6Y0XL
package NetFox; :T~[
EQ_aa@M7
h+,@G,|D
public class SiteInfoBean { >Q*Wi
Wp,R^d
pR_9NfV{
private String sSiteURL; //Site's URL \2z>?i)
private String sFilePath; //Saved File's Path 2AdDIVYC
private String sFileName; //Saved File's Name mkpMfPt
private int nSplitter; //Count of Splited Downloading File unxqkU/<Z
]$hBMuUa
$cgcX
public SiteInfoBean() Hr C+Yjp
{//nSplitter的缺省值为5 tJmTBsn
//default value of nSplitter is 5 2 E=L8<
this("","","",5); ;VK.2^jW!
} ~J]qP#C
rl.}%Ny
7 8,n%=nG
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) X3& Jb2c2
{ ^J{:x
sSiteURL= sURL; PY'2h4IL
sFilePath = sPath; y7<|_:00
sFileName = sName; CJyevMf'
this.nSplitter = nSpiltter; +[ZY:ZQ
#9s,# }
(k P9hcV
} (m$Y<{)2
+`15le`R
p<%d2@lp
public String getSSiteURL() 4ppz,L,4
{ JGZBL{8
return sSiteURL; I=#$8l.*
} 8EYkQ
~6gPS 13
@F>D+=hS
public void setSSiteURL(String value) [>9is=>o.
{ gDzK{6Z}
sSiteURL = value; u&e~1?R
} YkADk9fE
A}w/OA97RO
?A0)L27UE&
public String getSFilePath() sos5Y}
{ z9"U!A4
return sFilePath; .Y|!:t|
} $Kd>:f=A
7$#u
UZ";a453r
public void setSFilePath(String value) xx $cnG
{ BLFdHB.$T
sFilePath = value; 8,|kao:
} I 6O
';"VDLb3
MOC/KNb
public String getSFileName() YZ7.1`8
{ z!\*Y =e
return sFileName; 7Yy ;
} /V By^L:
ABkl%m6xf
"jCu6Rjd
public void setSFileName(String value) _dg\\c
{ WzWXE(
sFileName = value; U!]dEW|G
} .]Z"C&"N]
|?9HU~B
L.IlBjD
public int getNSplitter() ! P4*+')M
{ 2zpr~cB=
return nSplitter; DwF hK*
} :KO2| v\
7[7"A
JS77M-Ac
public void setNSplitter(int nCount) 6C)_
{ xD$\,{
nSplitter = nCount; -qoH,4w
} 8Y?;x}
} X?Au/
L(\cHb9`
.^.z2 e
/* ce(#2o&`
**Utility.java Ca\6vR
*/ E"0>yl)
package NetFox; p[cX O=
4+ig' |o
{Ha57Wk8D
public class Utility { M3AXe]<eC1
Pc9H0\+Xk
zreU')a
public Utility() iQ{VY ^ 0
{ ite~E5?#
0$njMnB2l
#;<Y[hR{P
} @|r{;'
F}zDfY\-
//线程睡眠 9FX-1,Jx
public static void sleep(int nSecond) ~s{$WL&
{ svSVG:48
try{ f 1d?.)
Thread.sleep(nSecond); /O9EQPm(
} '<M{)?
catch(Exception e) uq{beC
{ ?4B`9<j8%
e.printStackTrace (); cNH7C"@GVu
} _G0x3
} ##{taR8
~5g~;f[4
//日志 `{Ul!
public static void log(String sMsg) [ 3HfQ
{ ctUp=po
System.err.println(sMsg); YzWz|
} <QvOs@i*
@8 6f
A=4OWV?
public static void log(int sMsg) /j^
{ $J2Gf(RU
System.err.println(sMsg); 0aAoV0fMDz
} 2?x4vI np;
} H#&00Q[
Lr<cMK<
U~8g_*
/* _Y!IEAU/#
**TestMethod.java 8-i#8'/x
*/ n|;Im&,
package NetFox; 6wxs1G
$u.z*b_yy
D]}G.v1
public class TestMethod { Yz bXuJ4
"]dI1 g_
AR=]=8
public TestMethod() kP"9&R`E
{ ///xx/weblogic60b2_win.exe v:U-6W_)|
try{ 4Up/p&1@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); MJvp6n
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Vc2`b3"Br
SiteFileFetch fileFetch = new SiteFileFetch(bean); m2o0y++TjW
fileFetch.start(); ]tD]Wx%
} SdWV3
catch(Exception e){e.printStackTrace ();} &o*A{
l\mPHA23
wbHb;]
} TNth
+0~YP*I`/
grYe&(`X
public static void main(String[] args) G?ZXWu.
{ weQ_*<5%
new TestMethod(); 8RX&k
} uS-|wYE
} 2?5>o!C
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