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)); pe!dm}!h[
} I>kiah*
for(int i=0;i<nEndPos.length-1;i++) .W@(nQ-<
{ m,@1LwBH
nEndPos = nStartPos[i+1]; &weY8\HD
} ( *9Ip
nEndPos[nEndPos.length-1] = nFileLength; M)`HK .
} U7]<U-.&
} }dd k}wga
sk7rU+<
uK;K{
//启动子线程 aW=By)S!Y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; J~iOP
for(int i=0;i<nStartPos.length;i++) f E.L
{ "^9[OgE:
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q4Oxs
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), uOG-IHuF
nStartPos,nEndPos,i); l- 1]w$ y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FI1THzW4J
fileSplitterFetch.start(); BLL]^qN;Y
} _}I(U?Q-C
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XdGpW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); pK6e/eC
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /B,:<&_-
nEndPos = " + nFileLength); 2ec$xms
// fileSplitterFetch[nPos.length-1].start(); e}'#Xv
]DC;+;8Jc
tjZ\h=
//等待子线程结束 $5TepH0D
//int count = 0; Pv/Pww\
//是否结束while循环 MvFM,
boolean breakWhile = false; ]a$Wxvgq
<#+oQ>5s
0W T#6D
while(!bStop) c Ndw9?Z
{ u\{qH!?t
write_nPos(); {mNdL J
Utility.sleep(500); ; D1FAz
breakWhile = true; 5a'yXB}
hP?7zz$*j
7^ 4jcfJH
for(int i=0;i<nStartPos.length;i++) g[/^cJHQ
{ 's)fO#
if(!fileSplitterFetch.bDownOver) hlX>K
{ "$GK.MP5
breakWhile = false; {tPnj_|n<
break; Z[Wlyb0
} IuNkfBe4m
} "37*A<+f
if(breakWhile) h~ $&
break; GGH;Z WSe
d-~vR(tU
$4=Ne3y
//count++; 0z/h+,
//if(count>4) x8Q~VVZr
// siteStop(); NdZ)[f:2
} S#k{e72 *
Y+FP
XM$GQn]B
System.err.println("文件下载结束！"); 9qEOgJ
} (wife#)~
catch(Exception e){e.printStackTrace ();} ~]&B>q
} V{!lk]p}a
<KtBv Ip]
TM0b-W (H
//获得文件长度 Vn'?3Eb<
public long getFileSize() 6z Ay)~
{ D3y>iQd
int nFileLength = -1; W,Ty=:qm*
try{ r&SO:#rOSM
URL url = new URL(siteInfoBean.getSSiteURL()); )!A 2>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Lx%:t YZ
httpConnection.setRequestProperty("User-Agent","NetFox"); HcA[QBh
[<yz)<<
PB+\jj
int responseCode=httpConnection.getResponseCode(); 5C B%=iL{
if(responseCode>=400) g92dw<$>
{ Hq?&Qo
processErrorCode(responseCode); yxvjg\!&
return -2; //-2 represent access is error PcB{=L
} `NQ{)N0!
UeA2c_ 5
^#;RLSv
String sHeader; MI\]IQU
Qwv '<
"qS!B.rt:
for(int i=1;;i++) ailG./I+
{ P{cos&X|
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .Vmtx
//Utility.log(in.readLine()); eQ<xp A
sHeader=httpConnection.getHeaderFieldKey(i); /ERNS/w
if(sHeader!=null) 3p_b8K_bG
{ Jn*Nao_)
if(sHeader.equals("Content-Length")) uf]Y^,2
{ B9*Sfw%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); p.C1nh
break; jn$j^51`C
} vL$|9|W(
} f>niFPW"
else )|RZa|`-G
break; A*F9\mjI5
} Hd0Xx}3&
} c4 5?St
catch(IOException e){e.printStackTrace ();} @+&'%1
catch(Exception e){e.printStackTrace ();} 2:'lZQ
skR,-:"8
4.Z(:g
Utility.log(nFileLength); O&V[g>x"U
ZoxS*Xk
\f"1}f
return nFileLength; TEWAZVE*
} M"(6&M=?
"0-y*1/m
&z>q#'X;.
//保存下载信息（文件指针位置） JYV\oV{
private void write_nPos() v459},!P
{ TatMf;?h&
try{ F;kvH
output = new DataOutputStream(new FileOutputStream(tmpFile)); V#J"c8n
output.writeInt(nStartPos.length); (6R4 \8z2
for(int i=0;i<nStartPos.length;i++) dB3N%pB^
{ nU17L6'$
// output.writeLong(nPos); JZ=5Bpw
output.writeLong(fileSplitterFetch.nStartPos); iBoEZEHjw
output.writeLong(fileSplitterFetch.nEndPos); jdM=SBy7q
} jNc<~{/
output.close(); 2-mQt_ i
} cPuHLwwYf
catch(IOException e){e.printStackTrace ();} CH;;V3
catch(Exception e){e.printStackTrace ();} 4AHL3@x
} tU:FX[&?R
0d4cE10
d>!p=O`>{q
//读取保存的下载信息（文件指针位置） 3cC }'j
private void read_nPos() D|Si)_ Iz
{ uyT/Xzo3
try{ >a=d;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *Jt8
int nCount = input.readInt(); &fSTR-8ev#
nStartPos = new long[nCount]; Df@/cT
nEndPos = new long[nCount]; TyOH`5D
for(int i=0;i<nStartPos.length;i++) |scUo~
{ r)b<{u=]
nStartPos = input.readLong(); <&U!N'CE
nEndPos = input.readLong(); JJ5C}`(
} 0JXqhc9'
input.close(); )ooWQ-%P
} D1Yh,P<CF\
catch(IOException e){e.printStackTrace ();} kG^dqqn6
catch(Exception e){e.printStackTrace ();} I=[cZ;t
} #C\4/g?=,
|+NuYz?
`^##b6jH
private void processErrorCode(int nErrorCode) I7mG/
{ 9+Nw/eszO
System.err.println("Error Code : " + nErrorCode); *{5>XH{ x
} "^%Z'ou
YKs4{?vw
s, XM9h>P4
//停止文件下载 5f{|"LG&
public void siteStop() CLN+I'uX0
{ AyTx'u
bStop = true; Z@J.1SaB
for(int i=0;i<nStartPos.length;i++) <4mQ*6
fileSplitterFetch.splitterStop(); DJP6TFT&G
=!,Gst_
J_ J+cRwq
} *^h_z;{,
} @J vZ[T/
//负责部分文件的抓取 l`gTU?<xd
**FileSplitterFetch.java \9/1L?@
*/ 0ar=cuDm
package NetFox; Kt `
\0AiCMX[
AS;.sjgk
import java.io.*; N5 n>
import java.net.*; /#t&~E_|
_P5P(^/
0"4@;e_)>
public class FileSplitterFetch extends Thread { 7Dt"]o"+
wUp)JI
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String sURL; //File URL zWIeHIt
long nStartPos; //File Snippet Start Position "=|t~`
long nEndPos; //File Snippet End Position T[.[ g/`
int nThreadID; //Thread's ID QzthTX<
boolean bDownOver = false; //Downing is over .>]N+:O
boolean bStop = false; //Stop identical OVswt
FileAccessI fileAccessI = null; //File Access interface dZ2`{@AYY
9P"iuU
2)\vj5<~$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException t(?<#KUB-
{ 7+XM3
this.sURL = sURL; gfo}I2"
this.nStartPos = nStart; p|VcMxT9-
this.nEndPos = nEnd; )5yj/0oT
nThreadID = id; "mZ.V
fileAccessI = new FileAccessI(sName,nStartPos);//定位 G)7)]yBL
} 9 5 H?{
,Y!zORv<7
@ajM^L!O
public void run() 9]$`)wZ
{ Y}.Ystem
while(nStartPos < nEndPos && !bStop) /iC_!nu
{ WE.Tuo5L
5$Kf]ZP
T*P+Fh"
try{ wO!u!I
URL url = new URL(sURL); +1@AGJU3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~_PYNY`"
httpConnection.setRequestProperty("User-Agent","NetFox"); {ZqQ!!b
String sProperty = "bytes="+nStartPos+"-"; Hj~O49%j&
httpConnection.setRequestProperty("RANGE",sProperty); ?`P2'i<b
Utility.log(sProperty); #T%zfcUj
_413\`%8?
xzk}[3P{
InputStream input = httpConnection.getInputStream(); z="L4
//logResponseHead(httpConnection); $D_HZ"ytu
D4Sh9:\
uva\0q
byte[] b = new byte[1024]; E`)Qs[?Gk
int nRead; dlD}Ub
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7rIlTrG
{ 6k9LxC:M
nStartPos += fileAccessI.write(b,0,nRead); UqtHxEI%R~
//if(nThreadID == 1) /`+7_=-
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *K)0UKBr
} 4e9E' "8%
bUvK
l)8sw=
Utility.log("Thread " + nThreadID + " is over!"); zM59UQU;
bDownOver = true; abWl ut
//nPos = fileAccessI.write (b,0,nRead); Sdc*rpH"(
} Yx1 D)
catch(Exception e){e.printStackTrace ();} RvW.@#EH0
} aZgNPw
} )w"0w(
yNva1I
4<}A]BQVkJ
//打印回应的头信息 ']?=[`#NL
public void logResponseHead(HttpURLConnection con) Y6VQ:glDT-
{ \cZfg%PN
for(int i=1;;i++) 8p=>?wG
{ iz`jDa Q|1
String header=con.getHeaderFieldKey(i); V^En8
if(header!=null) cU+>|'f&
//responseHeaders.put(header,httpConnection.getHeaderField(header)); d8:C3R
Utility.log(header+" : "+con.getHeaderField(header)); Bp3L>AcVu
else SDc" 4g`
break; &=zU611,
} sXB+s
} 3w'W~
Jz$>k$!UD
Yu3_=: <C
public void splitterStop() i<iXHBs
{ ou6j*eSN
bStop = true; [g|Hj)(
} v@_in(dk
h7?.2Q&S
H8i+'5x,?
} AZwa4n}"
ZQ[~*)
Wc;+2Hl[@
/* Cef7+fa
**FileAccess.java z%};X$V`J
*//文件访问(定位，写) EcW1;wH
package NetFox; *V|zx#RN
import java.io.*; p7UTqKi
1+^n!$
-N z}DW>
public class FileAccessI implements Serializable{ t w!.%_1^
:t>Q:mX(N
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 }17bV, t
RandomAccessFile oSavedFile; m!Af LSlwm
long nPos; /*P7<5n0
FpdHnu i1
}vD;DSz:
public FileAccessI() throws IOException GP]TnQ<*;
{ o+^Eu}[.
this("",0); vYzVY\
} `M rBav
gj;@?o0
xjrlc9
public FileAccessI(String sName,long nPos) throws IOException A& =pw#
{ stXda@y<p
oSavedFile = new RandomAccessFile(sName,"rw"); o<J5!
this.nPos = nPos; [&daG:
oSavedFile.seek(nPos); \`gEu{
} iGa}3pF
s3< F
.. UoyBV
public synchronized int write(byte[] b,int nStart,int nLen) <[9?Rj@
{ (nz}J)T&
int n = -1; " $=qGHA~
try{ (}0S1)7t
oSavedFile.write(b,nStart,nLen); cY~M4:vgT
n = nLen; 4\1;A`2%0
} yFO)<GLk
catch(IOException e) +2y&B,L_Wh
{ [<Jp#&u6sb
e.printStackTrace (); Nt,~b^9
} {F!v+W>
u _X}-U
qUg9$oh{LI
return n; v= 8VvT8
} 6ZEdihBei
8m7;x/0ld
LE|<O
} LP?P=c
_H2tZ%RM
>Bx8IO1_\d
/* e>!E=J)j
**SiteInfoBean.java >{F!ntEj
*/ os_WYQ4>j
package NetFox; +"Ub/[J{G1
+!xu{2!
V4\560
public class SiteInfoBean { xp=Zd\5W$
-3]|[
9m~t j_
private String sSiteURL; //Site's URL qp@m&GH
private String sFilePath; //Saved File's Path [DhEh@
private String sFileName; //Saved File's Name ]|y}\7Aa
private int nSplitter; //Count of Splited Downloading File B{99gwMe]
jYk5~<\k
@E(P9zQ/zy
public SiteInfoBean() L]*`4L
{//nSplitter的缺省值为5 _'lmCj8L
//default value of nSplitter is 5 uAT/6@
this("","","",5); Y2D>tpqNw
} `~h0?g
!"%S#nrL$
Oc~VHT
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) lfgtcR{l5
{ {RJ52Gx(
sSiteURL= sURL; Z:TFOnJ
sFilePath = sPath; n5\}KZh
sFileName = sName; /D8EI
this.nSplitter = nSpiltter; K?JV]^
=tHD 4I
LGXZx}4@;
} ;tXY =
@x*.5:[
w#rVSSXQ3
public String getSSiteURL() Yq{jEatY{/
{ ]h0Y8kpd
return sSiteURL; Zg2]GJP
} A`g.[7
:k\}Ik
\D ^7Z97
public void setSSiteURL(String value) VH[l\I(h
{ ,k\/]9
sSiteURL = value; ,,7.=#
} \UhGGg%
UL[uh@4
vLr&ay!w
public String getSFilePath() l-XnB
{ [Zh2DNp
return sFilePath; m+p4Mc%u
} y]w )`}Ax
~PCTLP~zI
mcCB7<. e
public void setSFilePath(String value) X:DMT>5k
{ \6Xn]S
sFilePath = value; y _6r/z^
} ~R)1nN|
4_WH 6Z
I{Rz,D uAL
public String getSFileName() =%xIjxYl
{ . c#90RP
return sFileName; *Gf&q
} 3Sk5I%
.x]'eq}
$tEdBnf^ca
public void setSFileName(String value) cl?< 7
{ .[#xQ=9`
sFileName = value; }F~f&<GX6
} ]Qh[%GD
X #&(~1O
m9 ^m
public int getNSplitter() U<K|jsFo
{ jQO*oq}
return nSplitter; hkkF1 h
} K<D`(voL
)j]gm i"
+Kxe ymwr2
public void setNSplitter(int nCount) )Uc$t${en
{ f34_?F<h
nSplitter = nCount; od;Bb
} 9yO{JgKA
} oXnC"y}0P
~JAH-R
LZgwIMd
/* <)r,CiS
**Utility.java K(%dcUGDK>
*/ Tnzco
package NetFox; 8XLxT(YFIs
n ;Ql=4
}qG?Vmq*R[
public class Utility { #|)JD@;Q
WZfk}To1#
Z'7 c^c7_
public Utility() \]tq7
{ O|A~dj`
_C7abw-
:DS2zA
} .=.yZ
=NVZ$KOZ
//线程睡眠 S3%.-)ib
public static void sleep(int nSecond) DDqC}l_
{ S!`4Bl
try{ #u}v7{4
Thread.sleep(nSecond); *7:u-}c!
} 4~]8N@Bii
catch(Exception e) N7RG5?
{ 7Va#{Y;Zy
e.printStackTrace (); $sd3h\P&R
} Zi[{\7a
} 4)x3!Ol
7?n*t
//日志 `? 9]'
public static void log(String sMsg) #z-iL!?
{ u8{@PlS
System.err.println(sMsg); `Yo-5h
} ?<>,XyY
X:xC>4]gG'
[0**&.obz
public static void log(int sMsg) S<2CG)K[
{ Q KcF1?
System.err.println(sMsg); d[P>jl%7
} ~P"!DaAf
} B BApL{
*pS7/Qe
LX(iuf+l
/* Nj3^"}V
**TestMethod.java Y*5@|Q
*/ "df13U"
package NetFox; {"gyXDE1
..Uw8u/
ZH`K%h0
public class TestMethod { rlUdAa3
Je4.9?Ch
@kCD.
public TestMethod() 1"4nmw}
{ ///xx/weblogic60b2_win.exe %1 VNP(E
try{ vxzf[
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); WO+?gu
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); SG+i\yu$h0
SiteFileFetch fileFetch = new SiteFileFetch(bean); K,L>
fileFetch.start(); #0YzPMV
} \0^rJ1*
catch(Exception e){e.printStackTrace ();} X,JWLS J
yTq(x4]
J?n)FgxS
} K+`-[v5\
.1[2 CjQ
. ;ea]_Z
public static void main(String[] args) Fgc:6<MGM
{ }Nd`;d
new TestMethod(); Q 2SSJ
} n[MIa]dK
} o,''f_tRQ|
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