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)); (TM1(<j
} @]uvpI!h
for(int i=0;i<nEndPos.length-1;i++) v#q7hw=
{ 4:.yE|@h[
nEndPos = nStartPos[i+1]; \L>3E#R-Q
} wb~#=6Y
nEndPos[nEndPos.length-1] = nFileLength; u27K 0}
} eU&[^
} 2a'b}<|[(
g VX
9_)*b
//启动子线程 m X{_B!j^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (S$ziV
for(int i=0;i<nStartPos.length;i++) M>nplHq
{ I(y:Td
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `qnSq(tNq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^&F8NEb=2>
nStartPos,nEndPos,i); \=Rw/[lR
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T}d%XMXq
fileSplitterFetch.start(); -7,xjn
} %"B+;{y(5
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bHZXMUewC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); I!>pHF4
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", D@A@5pvS
nEndPos = " + nFileLength); `1k0wT(
// fileSplitterFetch[nPos.length-1].start(); i,|2F9YH
$L%gQkz_
z/Z 0cM#
//等待子线程结束 }TE4)vXs
//int count = 0; ZmU7tK
//是否结束while循环 WX<),u2@
boolean breakWhile = false; uU_lC5A|
}8tD|t[
vdA3
while(!bStop) s[6y|{&ze
{ f/+UD-@%m
write_nPos(); is`O,Met
Utility.sleep(500); )vWI{Q]r
breakWhile = true; [C_Dv-d
d0ZbusHHb
fP 4
for(int i=0;i<nStartPos.length;i++) N;N,5rxV
{ c*R?eLt/
if(!fileSplitterFetch.bDownOver) C.su<B?
{ a(cZ]`s]*
breakWhile = false; \ k&(D*u
break; &\Kp_AR
} (.D|%P
} i_<Uk8
if(breakWhile) |a!y%R=
break; &.D#OnRh9
{Ee[rAVGp
\M(#FS
//count++; R8"qDj
//if(count>4) cow]qe6K
// siteStop(); #ArMX3^+w7
} 1uz7E
%v)m&VUi%
CEOD$nYc
System.err.println("文件下载结束！"); LS(J%\hMDm
} P`ZYm
catch(Exception e){e.printStackTrace ();} (}^Qo^Vr
} HzuB.B<
)wFr%wNe
;Nfd
//获得文件长度 e3YdHp
public long getFileSize() TOUP.,f/!
{ |~V`Es +j
int nFileLength = -1; R\VM6>SN'S
try{ ICbT{Mla
URL url = new URL(siteInfoBean.getSSiteURL()); /C: rr_4=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c+_F}2)
httpConnection.setRequestProperty("User-Agent","NetFox"); Z{#;my*X|
uoX] #<1J
!X 8<;e}2
int responseCode=httpConnection.getResponseCode(); C{"uz_Gh
if(responseCode>=400) +0)zB;~7
{ }3rWmo8V
processErrorCode(responseCode); |N^z=g P[
return -2; //-2 represent access is error gp?|UMA9.
} fxR}a,a
ab5uZ0@
`;'fCO!
String sHeader; }'o[6#_*X
x?|C-v
L.]mC!
for(int i=1;;i++) %uVbI'n)
{ G0u3*.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); GNv5yWQ@
//Utility.log(in.readLine()); p]7Gj&a
sHeader=httpConnection.getHeaderFieldKey(i); 1|PmZPKq9n
if(sHeader!=null) IdvBQ [Gj
{ ' YONRha
if(sHeader.equals("Content-Length")) 7+h*&f3>
{ k*;2QED
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /G>reG,G
break; qZ39TTQ*p
} 5xEk 7g.
} a%wK[yVp
else v7l4g&
break; !`VO#_TJ
} kP6P/F|RcZ
} >QusXD"L>
catch(IOException e){e.printStackTrace ();} :EUV#5V.
catch(Exception e){e.printStackTrace ();} }UzO_&Z#6
LX %8a^?;
vd5"phn 3
Utility.log(nFileLength); [|sKu#yW
wFW2m
9u'hCi(
return nFileLength; p,?8s%
} LRhq%7p7
TwZvz[u
jH*+\:UP-
//保存下载信息（文件指针位置） h&!k!Su3#
private void write_nPos() tk^1Ga3
{ AJ;Y Nb
try{ -S=Zsr\
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]`D(/l'
output.writeInt(nStartPos.length); 5k`[a93T
for(int i=0;i<nStartPos.length;i++) X7sWu{n
{ k3m|I*_\L
// output.writeLong(nPos); ;3n0 bKDY
output.writeLong(fileSplitterFetch.nStartPos); B[ f{Ys
output.writeLong(fileSplitterFetch.nEndPos); }lgqRg)F9[
} pGi "*oZD
output.close(); @1#$
} s0Ii;7fA{
catch(IOException e){e.printStackTrace ();} @j$tpz
catch(Exception e){e.printStackTrace ();} F}Bc +i#]
} DytOS}/^9
+q]
y(:hN)
//读取保存的下载信息（文件指针位置） M* W=v
private void read_nPos() F9e$2J)C
{ &7 }!U
try{ Gvt.m&_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 66=6;77
int nCount = input.readInt(); `n:IXD5'
nStartPos = new long[nCount]; ~(B\X?v
nEndPos = new long[nCount]; v&(X&q
for(int i=0;i<nStartPos.length;i++) 9`^VuC'
{ ewgcpV|spn
nStartPos = input.readLong(); zQ {g~x
nEndPos = input.readLong(); nJ4h9`[>V
} 0$,Ag;"^?
input.close(); d@"eWvnlZ
} +byw*Kk
catch(IOException e){e.printStackTrace ();} Z`"UT#^SI
catch(Exception e){e.printStackTrace ();} Ta!.oC[
} kTex>1W;
d\, 4Wet;#
W.\HfJ74
private void processErrorCode(int nErrorCode) z$-/yT"M
{ 6!bA~"N
System.err.println("Error Code : " + nErrorCode); xn@?CP`-y
} %>i7A?L
fB"3R-H?O
;0xCrE{l"
//停止文件下载 $t1]w]}d
public void siteStop() 5G){7]P+r"
{ D{.%Dr?
bStop = true; $Miii`VS9
for(int i=0;i<nStartPos.length;i++) 6FSw_[)
fileSplitterFetch.splitterStop(); Oe$cM=Yf
)dF(5,y)
N,'JQch},8
} l$,l3
} AXPUJ?V
//负责部分文件的抓取 l(=#c/f
**FileSplitterFetch.java 9aZ3W<N`M
*/ lbg6n:@
package NetFox; h#]}J}si
/gy;~eB01
(^a;2j9
import java.io.*; QJdSNkc6
import java.net.*; ]N=C%#ki!
dN |w;|M
{k?Y:
public class FileSplitterFetch extends Thread { -&,NM
nQ$N(2<Fe
,C&h~uRi#f
String sURL; //File URL (= !_5l
long nStartPos; //File Snippet Start Position Mh+'f 93
long nEndPos; //File Snippet End Position Vg \-^$
int nThreadID; //Thread's ID i6`8yw
boolean bDownOver = false; //Downing is over @/$mZ]|T
boolean bStop = false; //Stop identical x;Gyo
FileAccessI fileAccessI = null; //File Access interface n"FOCcTIs
f6|3| +
o=`9JKB~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException uhc0,V;S
{ Plq[Ml9
this.sURL = sURL; 29qQ3M?
this.nStartPos = nStart; e/Q[%y.X
this.nEndPos = nEnd; (ZEVbAY?i
nThreadID = id; t91CxZQ^s
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *|E@81s#
} cF(9[8c{
:T{or-
(B$FX<K3
public void run() @nc!(P7_
{ \clWrK
while(nStartPos < nEndPos && !bStop) epG;=\f}m`
{ hYWWvJ)S
^_=0.:QaW
[ThzLk#m
try{ WX=+\`NyJ(
URL url = new URL(sURL); ix#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F Qk;
httpConnection.setRequestProperty("User-Agent","NetFox"); C,<TAm
String sProperty = "bytes="+nStartPos+"-"; BuvBSLC~
httpConnection.setRequestProperty("RANGE",sProperty); <bjy<98LT
Utility.log(sProperty); A!Yqj~
CTP%
n=>Gu9`
InputStream input = httpConnection.getInputStream(); C {,d4KG
//logResponseHead(httpConnection); >L;O, {Px-
<n:?WP~U
6,h<0j{
byte[] b = new byte[1024]; /<2_K4(-{4
int nRead; gU%GM
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7,4x7!
{ co@8w!W
nStartPos += fileAccessI.write(b,0,nRead); jCl[!L5/1
//if(nThreadID == 1) o{hKt?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0x &^{P~
} Wm,,OioK
Tc*PDt0C
Rq9gtx8,=
Utility.log("Thread " + nThreadID + " is over!"); =@z"k'Vl`
bDownOver = true; 5a~1RL
//nPos = fileAccessI.write (b,0,nRead); 51,m^veO
} 3OZ}&[3
catch(Exception e){e.printStackTrace ();} \'KzSkC8
} `WT7w']NT
} ;uDFd04w [
F)IP~BE-k
Z4!3I@yZ
//打印回应的头信息 O(d'8`8
public void logResponseHead(HttpURLConnection con) 4jW{IGW
{ )?WoLEjq
for(int i=1;;i++) x9e 9$ww}
{ #n"/9%35f`
String header=con.getHeaderFieldKey(i); 6xe |L
if(header!=null) lrzW H0Q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |H4'*NP"
Utility.log(header+" : "+con.getHeaderField(header)); 'nno)kQ"
else m+=!Z|K
break; 5-*]PAC
} [ n2udV
} j$^]WRt
O2e"TH3
{V8Pn2mlo
public void splitterStop() 1dcy+ !>
{ 1#(1Bs6X
bStop = true; S(6ZX>wv:
} z#4g,)ZX
NP8TF*5V
7yp*I[1Qf>
} :m\KQ1sq
vF&b|V+,
Tt\w^Gv\d
/* q1y4B`
**FileAccess.java g8Z14'Ke
*//文件访问(定位，写) 4lA+V,#
package NetFox; .D.Rn/
import java.io.*; F 4/Uu"J:
2XHk}M|
+b+sQ<w?.
public class FileAccessI implements Serializable{ 2#3R]zIO
}H=OVbQor
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 s/M~RB!w
RandomAccessFile oSavedFile; O 0#Jl8
long nPos; `qTY
]B4mm__
i1\2lh$
public FileAccessI() throws IOException 7VcVI? ?
{ Z<W6Avr
this("",0); 4Z}{hc\J
} {M/c!
.h,xBT`}Ji
LltguNM$
public FileAccessI(String sName,long nPos) throws IOException Tm\[q
{ )/"7$2Aoy
oSavedFile = new RandomAccessFile(sName,"rw"); 7-I>53@
this.nPos = nPos; K"7;Y#1g
oSavedFile.seek(nPos); *K'ej4"u
} Q/)ok$A&
E]U0CwFtr
N?0y<S ?!
public synchronized int write(byte[] b,int nStart,int nLen) S7{.liHf
{ ~aAJn IO
int n = -1; ?4e6w
try{ :)95 b fa.
oSavedFile.write(b,nStart,nLen); R Sz[6
n = nLen; yB%)D0
} '-33iG
catch(IOException e) h;qy5KS
{ o!`O i5
e.printStackTrace (); orH0M!OtS!
} 2pa3}6P+
dqA[|bV
KTjlWxD
return n; ;+34g6
} M5WtGIV
!]+Z%ed`%
5;8B!%b
} wZ8 MhE
B36puz 0{
D%UZ'bHN*
/* l@rwf$-
**SiteInfoBean.java E8_Le
*/ ?4[Oh/]R
package NetFox; kEhm'
nIQ&gbfO
Fra>|;do
public class SiteInfoBean { hr4ye`c j
U5CPkH1
MiH}VfI
private String sSiteURL; //Site's URL 7X{bB
private String sFilePath; //Saved File's Path Fiu!!M6
private String sFileName; //Saved File's Name *Ht*)l?
private int nSplitter; //Count of Splited Downloading File #3K,V8(
N^ s!!Sbpq
guOSO@
public SiteInfoBean() Va@6=U7c
{//nSplitter的缺省值为5 y(nsyA
//default value of nSplitter is 5 p/k<wCm6
this("","","",5); /MqXwUbO
} S2&9#6
w^])(
]oeuIRyQ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^0~c7`k`V
{ wY3|#P CDV
sSiteURL= sURL; ,<$YVXe/
sFilePath = sPath; ]A]Ft!`6z
sFileName = sName; Z.:<TrN
this.nSplitter = nSpiltter; kOAY@a
&{zwM |Q@?
gX$0[ sIS.
} m0|Ae@g~3
6h2x~@
W(2+z5z
public String getSSiteURL() @A2/@]HBm
{ F_nZvv[H?
return sSiteURL; tE]5@b,R
} }PI35i1!t
+ze}0lrEL
3w/( /|0
public void setSSiteURL(String value) ?dsf@\
{ ?7yQ&p
sSiteURL = value; %2Epgh4?
} h L]8e>a?
(Qk&g"I
As@ihB+(\
public String getSFilePath() # 0GGc.
{ :tMre^oP
return sFilePath; {)B9Z I{+A
} uxa=KM1H
)=jT_?9b
A\".t=+7
public void setSFilePath(String value) k> b&xM!
{ rDVgk6
sFilePath = value; J3;Tm~KJ_
} )A="eW_>
Ia=_78MgZ
ku{XW8
public String getSFileName() bh6d./
{ 4~O6$;!|~
return sFileName; "r8EC
} =op`fn%
1"}B]5!
%_R$K#T^,
public void setSFileName(String value) $^}[g9]1
{ 0Tcz[$?
sFileName = value; ^vpIZjN
} ~xS@]3n=
<tFSF%vG=
(lb6]MtTHY
public int getNSplitter() R N@^j
{ ?*[\UC
return nSplitter; %X;7--S%?g
} Bc@30KiQ^
[s~JceUyX
k({2yc#RD&
public void setNSplitter(int nCount) 2\VAmPG.Zs
{ q]px(
nSplitter = nCount; QU.0Elw
} 7i8eg*Gl
} Va7c#P?
czI{qi5N
n@ 4@,
/* 5G#$c'A{4
**Utility.java SBTPTb
*/ 6 }!Z"
package NetFox; wepwXy"
uFZ~
-0$:|p?@^
public class Utility { QBoFpxh=
b6"}"bG
o~#f1$|Xn
public Utility() qe$33f*
{ 86%%n?"}
%:3'4;jh%
l-}KmZ]
} .n`( X#,*l
~.Cv DJy
//线程睡眠 o'Wz*oY))\
public static void sleep(int nSecond) ?`"n3!>bS
{ BFWi(58q
try{ Q(Gyq:L=>
Thread.sleep(nSecond); BC! 6O/kr
} =A@>I0(7
catch(Exception e) @QdnjXII*
{ {~N3D4n^
e.printStackTrace (); S/4r\6
} NQX>Qh 2
} >;4!O%F
LL(|$}yW
//日志 R>2IRvY(
public static void log(String sMsg) ?mx\eX{
{ {6*#3m Kk
System.err.println(sMsg); 2q PhLCeZ
} 0{+.H_f`
nPFwPk8=M
`G!M>h@
public static void log(int sMsg) icgJ;Q 5
{ hJ*Ihwn|
System.err.println(sMsg); 1J{fXh
} 5\hd4
} |=6_ xRyr
W.I\J<=V
tY+$$GSQj
/* PFrfd_s{>\
**TestMethod.java ?9mkRd}c
*/ mwC=o5O
package NetFox; $,fy$ Qk,S
$t}<85YCQ
ZmEEj-*7s
public class TestMethod { y(W|eBe
i47j lyH
S`!-Cal`n
public TestMethod() 0 1V^L}
{ ///xx/weblogic60b2_win.exe $}GTG'*.
try{ g}x(hF
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); YXW%]Uy+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "V&I^YSc>
SiteFileFetch fileFetch = new SiteFileFetch(bean); !w39FfU{
fileFetch.start(); mGjN_
} @-&MA)SN
catch(Exception e){e.printStackTrace ();} CGbwmPx
wkUlrL/~
V~@^`Gd
} #,d I$gY
CW&.NT
O%8EZyu
public static void main(String[] args) TZR)C P5
{ 5=|hC3h
new TestMethod(); ml`8HXK0
} aj^wRzJ}zA
} t. ='/`!N
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