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)); MhB>bnWXR
} #k)t.P Q
for(int i=0;i<nEndPos.length-1;i++) ;&O *KhLH
{ [r'A8!/|[
nEndPos = nStartPos[i+1]; ki1j~q
} Cbm^: _LR
nEndPos[nEndPos.length-1] = nFileLength; GY^;$?
} H4sc7-
} 1<*U:W $g
}WBHuVcZG
~_g{P3
//启动子线程 hMV>5Y[s
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +F2X2e)g"
for(int i=0;i<nStartPos.length;i++) |y+_BZ5
{ 6}|h
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j"VDqDDz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "{Y6.)x
nStartPos,nEndPos,i); S.<4t*,
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j5]ul!ji
fileSplitterFetch.start(); Y4_xV&
} l/\D0\x2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'G>9iw
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \wK4bvUrX
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", VYt<j<ba
nEndPos = " + nFileLength); 3=*ur( Qy
// fileSplitterFetch[nPos.length-1].start(); |>.</68Z
`46.!
t`>Z#=cl\
//等待子线程结束 j0(jXAc;UB
//int count = 0; J(wFJg\/
//是否结束while循环 %&q}5Y4!
boolean breakWhile = false; -~X[j2
6E9/z
XP?)xDr8
while(!bStop) )OVa7[-T
{ (XY`1|])`
write_nPos(); ErQ6a%~,
Utility.sleep(500); UP%6s:>:
breakWhile = true; hhFO,
>7S@3,C3ke
5K)_w:U X
for(int i=0;i<nStartPos.length;i++) *-{|m1P
{ (mKH,r
if(!fileSplitterFetch.bDownOver) *;~u 5y2b
{ ;-;lM6zP
breakWhile = false; Z&P\}mm
break; g2=PZR$
} ts=:r
} 49c-`[d L
if(breakWhile) Vo6g /h?`
break; y\Utm$)j
()F{kM8
#N'9 w .
//count++; .aVtd [
//if(count>4) 3dolrW
// siteStop(); K>b4(^lf
} G#^0Bh&
X8N9*vy
I3d}DpPx%
System.err.println("文件下载结束！"); $$"G1<EZ
} +%u3% }
catch(Exception e){e.printStackTrace ();} p8?v o?^
} ecR)8^1 '
Hrph>v
#.$y
//获得文件长度 R^P>yk8
public long getFileSize() RVLVY:h|F
{ A^A)arJS
int nFileLength = -1; '3WtpsKA
try{ ^w2 HF
URL url = new URL(siteInfoBean.getSSiteURL()); KLE)+|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); sowwXrECg@
httpConnection.setRequestProperty("User-Agent","NetFox"); qMA-#
22U`1AD3U
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int responseCode=httpConnection.getResponseCode(); 5,g +OY=\
if(responseCode>=400) v\@RwtP
{ FF!PmfF'
processErrorCode(responseCode); ela^L_NhF
return -2; //-2 represent access is error <c:H u{D
} evYn}
o)^Wz
jX(hBnGW
String sHeader; ( }Bb=~
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2Q5@2jT
for(int i=1;;i++) Hbd>sS
{ z ynu0X
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); AX<f$%iqD
//Utility.log(in.readLine()); Y0A(-"
sHeader=httpConnection.getHeaderFieldKey(i); +@?'dw
if(sHeader!=null) uLWu. Vx
{ hpPacN
if(sHeader.equals("Content-Length")) y$SUYG'v
{ hh&$xlO)(v
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); o ]z#~^w
break; 2zW IB[
} nPqpat`E
} aekke//y
else *kg->J
break; ?+^p$'5
} p'1/J:EnV
} M*kE |q/K
catch(IOException e){e.printStackTrace ();} v^8sL` F
catch(Exception e){e.printStackTrace ();} UeLO`Ug0;
+>K&zS
i/1$uQ
Utility.log(nFileLength); ]a4+]vLK
yNP4Ey
nReld :#T
return nFileLength; ?_Z-}f
} RLB"}&SF]
'xGhMgR;
*Q/^ib9=
//保存下载信息（文件指针位置） o5NmNOXm
private void write_nPos() ^jwzCo-
{ t'@mUX:-A
try{ G2)F<Y
output = new DataOutputStream(new FileOutputStream(tmpFile)); }X^MB
output.writeInt(nStartPos.length); ,aC}0t
for(int i=0;i<nStartPos.length;i++) 3Z=yCec]
{ }6/M5zF3
// output.writeLong(nPos); H>+])~#
output.writeLong(fileSplitterFetch.nStartPos); P=jsOuW
output.writeLong(fileSplitterFetch.nEndPos); 4Z~ nWs
} -bzlp7q*
output.close(); V3q`V/\
} >19s:+
catch(IOException e){e.printStackTrace ();} \\#D!q*
catch(Exception e){e.printStackTrace ();} UGy3B)
} to</
3?]81v/
h%ys::\zF
//读取保存的下载信息（文件指针位置） Y6VJr+Ap(
private void read_nPos() A#T"4'#?<
{ PENB5+1OK
try{ M-Efe_VRQc
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); L%is"NZh
int nCount = input.readInt(); d$3md<lIB
nStartPos = new long[nCount]; 8X"4RyNSn
nEndPos = new long[nCount]; cOX)+53
for(int i=0;i<nStartPos.length;i++) pF-_yyQ
{ sIgTSdk
nStartPos = input.readLong(); ]B=*p0~j^n
nEndPos = input.readLong(); fJc(
} u@#%SX
input.close(); f(D'qV T{
} uH%b rbrU
catch(IOException e){e.printStackTrace ();} RBn/7
catch(Exception e){e.printStackTrace ();} h]ae^M
} L,y q=%h|
(4/"uj5
$Z#~wsw
private void processErrorCode(int nErrorCode) *u"%hXR
{ 8:V,>PH
System.err.println("Error Code : " + nErrorCode); nsU7cLf"^V
} m[v0mXE
klT?h[I!
`D~oY=
//停止文件下载 f^B8!EY#:
public void siteStop() *af\U3kx
{ M=pQx$%a
bStop = true; uhfK\.3
for(int i=0;i<nStartPos.length;i++) {\`ttc>
fileSplitterFetch.splitterStop(); c-XO}\?
>jhcSvM6
E4892B:`
} ?96r7C|
} ~&D =;M/
//负责部分文件的抓取 E2>{seZ
**FileSplitterFetch.java K9%rr_ja!
*/ )2?]c
package NetFox; zMbFh_dcq
w!6{{m
E0+L?(;
import java.io.*; mB_?N $K
import java.net.*; B+Qf?1f
;QXg*GNAv$
:5%98V>02
public class FileSplitterFetch extends Thread { #C&';HB;y
s_NY#MPz[
Q^2dZXk~
String sURL; //File URL '2lzMc>wvP
long nStartPos; //File Snippet Start Position 9m$"B*&6G
long nEndPos; //File Snippet End Position V4V`0I
int nThreadID; //Thread's ID -^m?%_<50l
boolean bDownOver = false; //Downing is over 6)uBUM;i
boolean bStop = false; //Stop identical 5tbCx!tL
FileAccessI fileAccessI = null; //File Access interface 0q"4\#4l
`KA==;0
*mp:#'
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException k}fC58q
{ Tty'ysH
this.sURL = sURL; yO)xN=o^\
this.nStartPos = nStart; ) ~=pt&+
this.nEndPos = nEnd; B1 }-
nThreadID = id; \{ EVRRXn
fileAccessI = new FileAccessI(sName,nStartPos);//定位 gPk,nB
} :k1?I'q%
-#f.}H'
)v_Wn[Y.H
public void run() T"vf
{ 7wx=#
while(nStartPos < nEndPos && !bStop) cmXbkM
{ VU,G.eLW
$TXiWW+
|hika`35K
try{ l}L81t7f
URL url = new URL(sURL); aH1CX<3)~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DfAF-Yhut
httpConnection.setRequestProperty("User-Agent","NetFox"); gxVr1DIkN
String sProperty = "bytes="+nStartPos+"-"; $uTrM8
httpConnection.setRequestProperty("RANGE",sProperty); zb9G&'7
Utility.log(sProperty); '9f0UtT|[
JyE-c}I
62R";# K
InputStream input = httpConnection.getInputStream(); ,:(s=JN+
//logResponseHead(httpConnection); C;m"W5+
ZEI)U, I.
C5dM`_3L
byte[] b = new byte[1024]; c%pf,sm'
int nRead; E42)93~C
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) rt*x[5<
{ 88_ef7w
nStartPos += fileAccessI.write(b,0,nRead); b:F;6X0~Hl
//if(nThreadID == 1) PEvY3F}_rh
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +S4>}2N33
} tI{]&dev
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rq3f/_#L!O
Utility.log("Thread " + nThreadID + " is over!"); `YqtI/-w
bDownOver = true; 6o#/[Tz
//nPos = fileAccessI.write (b,0,nRead); {OPEW`F
} Qa=Y?=Za
catch(Exception e){e.printStackTrace ();} PSq?8.
} /";tkad^
} p}!i_P
ASbIc"S6
DW7E ]o
//打印回应的头信息 h s',f
public void logResponseHead(HttpURLConnection con) Zu|NF uFI
{ J;_4 3eS
for(int i=1;;i++) AA=Ob$2$
{ D^@@ P
String header=con.getHeaderFieldKey(i); D{B?2}X
if(header!=null) gEk;Tj
//responseHeaders.put(header,httpConnection.getHeaderField(header)); c@[Trk m
Utility.log(header+" : "+con.getHeaderField(header)); Bz }nP9
else G7&TMg7i
break; DK?aFSf\
} (o|bst][S
} 2@tnOs(*
9k;,WU(K<
aU(.LC
public void splitterStop() oC|oh
{ gJ|#xZ
bStop = true; %.=}v7&<z
} !lfE7|\p
Vpg>K #w
t~ {O)tt
} i,;JI>U
qa^cJ1@
Kc\8GkdB
/* 0L/chP
**FileAccess.java LnE/62){N
*//文件访问(定位，写) ,7@\e&/&
package NetFox; X,w X)9]J
import java.io.*; }BC%(ZH6
*w@1@6?j
f9K7^qwkiz
public class FileAccessI implements Serializable{ tNFw1&
8B*(P>
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _$AM=?P&
RandomAccessFile oSavedFile; q{&c?l*2
long nPos; A*DN/lG
D-{*3?x
gPCf+>X{
public FileAccessI() throws IOException aC}\`.Kb
{ jr)M],
this("",0); ppz3"5
} %l!A%fn(
'EIe5Op
ra'/~^9
public FileAccessI(String sName,long nPos) throws IOException 23r(4
{ Ni>Ns=n
oSavedFile = new RandomAccessFile(sName,"rw"); 'zm5wqrkAd
this.nPos = nPos; }MOXJb @
oSavedFile.seek(nPos); op`9(=DJ]
} %}TJr]'F
"B:FSWM_-
[Ep'm
public synchronized int write(byte[] b,int nStart,int nLen) rEWJ3*Hb
{ lkT :e)w
int n = -1; {*+J`H_G2a
try{ zn-=mk;W
oSavedFile.write(b,nStart,nLen); ~NIhS!
n = nLen; CqEbQ>?
} GPLop/6
catch(IOException e) d\>XfS
{ 01o<eZ,
e.printStackTrace (); OD~Q|I(j
} t4UK~ {gh
HY5R
}o:LwxNO
return n; `W1uU=c
} KMi$0+
GwF8ze+cH
$[A^8[//
} s]99'Q",
.9x*YS
ZX&e,X~V
/* pZS]i "
**SiteInfoBean.java ^|Z'}p|&
*/ a&JY x
package NetFox; dUa>XkPa\2
/g>-s&w
y%vAEQ2j=
public class SiteInfoBean { `0ym3}(O
!T<,fR+8X
@@*x/"GJG
private String sSiteURL; //Site's URL E\D,=|Mul
private String sFilePath; //Saved File's Path Zo2+{a
private String sFileName; //Saved File's Name H4`>B>\
private int nSplitter; //Count of Splited Downloading File \Ebh6SRp\
b|AjB:G
wzy[sB274
public SiteInfoBean() J#C4A]A
{//nSplitter的缺省值为5 @}6<,;|DQ
//default value of nSplitter is 5 H,TApF89A
this("","","",5); "=DQ {(L
} WwsNAJ
1f+A_k/@
;O)*!yA(GG
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e^N~)Nlj
{ kAp#6->(q
sSiteURL= sURL; v CsE|eMP
sFilePath = sPath; JfkEJk<
sFileName = sName; ~9o@1TO:v
this.nSplitter = nSpiltter; :2xGfy??
i45.2,
\\ItN
} * ;sz/.
g5+m]3#t
+i}H $.
public String getSSiteURL() e~ OrZhJ=_
{ fLs>|Rh
return sSiteURL; (5] [L<L
} IN3-ZNx
}^$#vJ(a7K
K@e2%hk9x
public void setSSiteURL(String value) HYO/]\al
{ .X3n9]
sSiteURL = value; =_=%1rI~
} !EKt$8W
axmq/8X
l4T[x|')M
public String getSFilePath() 1v:Ql\^cT
{ 4I&(>9 @z<
return sFilePath; YSxr(\~j
} 8 !:2:
&i3SB[|
G HQ~{
public void setSFilePath(String value) QaLaw-lx
{ >x%HqP#_V
sFilePath = value; _YlyS )#@
} {i=V:$_#
\y271}'
#f(tzPD
public String getSFileName() T\Xf0|y
{ #xx.yn(7
return sFileName; T\.~!Q
} V?yQm4
MPnMLUB$\
*PlKl_nP6
public void setSFileName(String value) :j~4mb?$
{ ;g8v7>p
sFileName = value; 6I(Y<LZ5
} KW'nW
>!Y#2]@}o
^7>~y(
public int getNSplitter() x(sKkm`Q
{ 00IW9B-
return nSplitter; PdVY tK%
} f%n ;Z}=
;\}dQsX
}>AA[ba"'
public void setNSplitter(int nCount) |8{ k,!P'K
{ v(0ujfSR0
nSplitter = nCount; ]6^S:K_"
} :I"22EH
} ?99r>01>
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@?J7=}bzz
/* .!^OmT,u
**Utility.java %n6<6t`$
*/ @VHstjos^V
package NetFox; 0VQBm^$(
NApy(e5%
IHCxM|/k(M
public class Utility { LtwfL^#
88:YU4:l`N
*ze/$vz-
public Utility() 8(- 29
{ d]K8*a%[-
,Gbc4x
Ha]vG@?+
} 416}# Mk
#k/T\PQ0s
//线程睡眠 }LS.bQKqi,
public static void sleep(int nSecond) ?`Mk$Y%my
{ }vx 46
try{ /ho7~C+H*e
Thread.sleep(nSecond); #X``^
} 7gOu|t
catch(Exception e) 1Hhr6T^)
{ 6yUThv.G#
e.printStackTrace (); %j@/Tx/
} Y5ei:r|^
} hFtjw6
<#"_Qgdix
//日志 (gE<`b
public static void log(String sMsg) 6b2h\+AP
{ !S7?:MJ?p\
System.err.println(sMsg); Z$c&Y>@)
} *C|*{!
90F.9rh
/Dc54Un
public static void log(int sMsg) ?HOnDw.v1
{ U7/ =|Z
System.err.println(sMsg); SR.xI:}4
} G3!O@j!7w$
} D|$0~1y
;H8`^;
K&{ _s
/* Lwm /[
**TestMethod.java !]7b31$M_
*/ jp}.W
package NetFox; ldU ><xc2
=^Ws/k
(7,Q4T
public class TestMethod { c3rj :QK6I
opn6 C )
wNl6a9#
public TestMethod() "g"%7jK
{ ///xx/weblogic60b2_win.exe /_expSPHl
try{ v`'Iew }
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); h(~of(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 4/\Ynb.L
SiteFileFetch fileFetch = new SiteFileFetch(bean); }h/7M
fileFetch.start(); Ap"%%D^{:
} Q;y4yJ$wI
catch(Exception e){e.printStackTrace ();} 5>e<|@2 X
YsiH=x
vKPLh
} %RwWyzm#\
ow`F 7
9T$%^H9
public static void main(String[] args) &.yX41R
{ c;t3I},
new TestMethod(); Q9p7{^m&E
} {@x-T
} WHjJR
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