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)); @pH6FXVGzt
} {&L^|X
for(int i=0;i<nEndPos.length-1;i++) Db !8N
{ w`fbUh6/
nEndPos = nStartPos[i+1]; O*Y?: t
} ].2t7{64
nEndPos[nEndPos.length-1] = nFileLength; CIf@G>e-
} k7j[tB#
} 9EY`j,{4
3177R>0
j-VwY/X
//启动子线程 apt$e$g
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :X:s'I4J D
for(int i=0;i<nStartPos.length;i++) Bsha)<
{ @/:7G.
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r^H,H'BohJ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /^v!B`A@
nStartPos,nEndPos,i); 9JX@ck
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {:3:GdM6
fileSplitterFetch.start(); 1hSV/%v_
} Z>3m-:-e
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1.PN_9%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5g O9 <
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 0*+EYnu+
nEndPos = " + nFileLength); x+ER 3wDD@
// fileSplitterFetch[nPos.length-1].start(); k_uI&,
mSvSdKKKlI
U$3DIJVI
//等待子线程结束 8@LUL)"
//int count = 0; 6RguUDRQ
//是否结束while循环 >P:U9 b
boolean breakWhile = false; k+*pg4'
|QMmF"0
6 EfBz
while(!bStop) :RxMZwa=
{ s:_a.4&Y
write_nPos(); g$zGiqzMK
Utility.sleep(500); '.<c[Mp
breakWhile = true; cd=|P?Bi
q'4P/2)va
fD3'Ye<R
for(int i=0;i<nStartPos.length;i++) !Q5,Zhgr
{ U@CAQ?
if(!fileSplitterFetch.bDownOver) ob'" ^LO\
{ nK)1.KVN
breakWhile = false; *|y$z+g/
break; WRwx[[e6z
} 87W!R<G
} [@JK|50|K
if(breakWhile) +u*Pi
break; ;#S]mso1
nC!]@lA
KLj=M;$:K
//count++; 12?!Z
//if(count>4) wa{!%qu5.R
// siteStop(); m#i4_F=^b
} e|5@7~Vi
|yz o|%]3
;\6@s3
System.err.println("文件下载结束！"); 60cQ3.e
} mEu2@3^E }
catch(Exception e){e.printStackTrace ();} N~fE&@-
} i*$~uuY
=wW M\f`=
`(`-S md
//获得文件长度 JbJ!,86
public long getFileSize() cruBJZr*
{ ~d1=_p:~T
int nFileLength = -1; x X[WX#'f
try{ L N.:>,
URL url = new URL(siteInfoBean.getSSiteURL()); 6xwjKh:9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e$WAf`*
httpConnection.setRequestProperty("User-Agent","NetFox"); 6({)O1Z
Nnr[@^M5
,4`Vl<6
int responseCode=httpConnection.getResponseCode(); Y .cjEeL@
if(responseCode>=400) g/ShC8@=u
{ 9nY|S{L
processErrorCode(responseCode); J~4mp\4b
return -2; //-2 represent access is error rx 74v!
} 9S[.ESI{>
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{dh,sbl
String sHeader; C22h*QM*
r<Z.J/a
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for(int i=1;;i++) esE!i0%
{ kX`m( N$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); I)vR
//Utility.log(in.readLine()); Z 4i5,f
sHeader=httpConnection.getHeaderFieldKey(i); Ha/Qz'^S;
if(sHeader!=null) =Ul"{T<
{ i2rSP$j
if(sHeader.equals("Content-Length")) [Gv8Fn/aG
{ Y\WVkd(+G
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); lY(_e#
break; Z2`M8xEiH
} YVvE>1z
} VpAwvMw
else @ext6cFe3<
break; kksffzG
} [!wJIy?,
} /kK!xe
catch(IOException e){e.printStackTrace ();} q~5zv4NX
catch(Exception e){e.printStackTrace ();} | 4}Y:d
%4F\#" A
iGz*4^%
Utility.log(nFileLength); hmOGteAf-
FG{,l=Z0
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return nFileLength; s8 MQ:eAP
} 4X7J~
a#i|)[
hGw}o,g
//保存下载信息（文件指针位置） >5Lp;
private void write_nPos() `q*p-Ju'
{ B8"c+<b
try{ @#hvQ6u
output = new DataOutputStream(new FileOutputStream(tmpFile)); .w@B )f*
output.writeInt(nStartPos.length); +Ek1~i.
for(int i=0;i<nStartPos.length;i++) RSbq<f>BFo
{ |<,0*2
// output.writeLong(nPos); I= <eCv
output.writeLong(fileSplitterFetch.nStartPos); koS?UYF`
output.writeLong(fileSplitterFetch.nEndPos); )u28:+8
} &4}=@'G@
output.close(); ot2zY dWAz
} 42tZBz&
catch(IOException e){e.printStackTrace ();} ?PTXgIC
catch(Exception e){e.printStackTrace ();} ILl~f\xG)
} S ~h*U2
nK+ke)'Zv=
,ayJgAD
//读取保存的下载信息（文件指针位置） cN?/YkW?]
private void read_nPos() r-!Qw1
{ ^2 H-_
try{ !9YCuHj!p
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $ (xdF
int nCount = input.readInt(); R) dP=W*
nStartPos = new long[nCount]; r)Lm| S
nEndPos = new long[nCount]; &fWC-|
for(int i=0;i<nStartPos.length;i++) Gos#=H
{ |ka/5o
nStartPos = input.readLong(); <fDT/
nEndPos = input.readLong(); 1P1h);*Z
} 9kF0H a}J
input.close(); hDSf>X_*_G
} i/'bpGrQ(
catch(IOException e){e.printStackTrace ();} IvkYM`%
catch(Exception e){e.printStackTrace ();} 1:^Xd~X
} l4r>#n\yj
){#INmsF
K$qY^oyQFw
private void processErrorCode(int nErrorCode) y9/nkF1p
{ jVN06,3z
System.err.println("Error Code : " + nErrorCode); @MTv4eC}e
} P*7G?
Nb !i_@m%s
rFzj\%xa[
//停止文件下载 ^Mq@} 0
public void siteStop() [pmIQ228
{ ~+t@7A=
bStop = true; lOeX5%$Z
for(int i=0;i<nStartPos.length;i++) !1i-"rR
fileSplitterFetch.splitterStop(); R-NM ~gp
)fIG4#%\
$.d,>F6
} 8UgogNR\
} "]q xjs^3?
//负责部分文件的抓取 3T0-RP*
**FileSplitterFetch.java fR@Cg sw
*/ ilJ`_QN
package NetFox; 0k16f3uI
*<67h*|)
<&) hg:
import java.io.*; V,Nu!$)J
import java.net.*; wL, -"
<7rj,O1=
=$gBWS
public class FileSplitterFetch extends Thread { ^W:a7cMw
: Bo
:n{{\SSIgX
String sURL; //File URL D^m2iW;
long nStartPos; //File Snippet Start Position 0?/gEr
long nEndPos; //File Snippet End Position ^zO{Aks
int nThreadID; //Thread's ID T!y 9v5
boolean bDownOver = false; //Downing is over d^6-P R_
boolean bStop = false; //Stop identical X-<,zRM
FileAccessI fileAccessI = null; //File Access interface pKq[F*Lut
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bsU$$;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Y %bb-|\W
{ SZ[?2z
this.sURL = sURL; UxHI6,b
this.nStartPos = nStart; aAGV\o{^
this.nEndPos = nEnd; e<9 ^h)G
nThreadID = id; 3fQ`}OcNr
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }cCIYt\RK
} YU[#4f~
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public void run() P%l?C?L
{ PcT]
while(nStartPos < nEndPos && !bStop) `f&::>5tD
{ a*X{hU9P
=0EKrG
9,_~qWw
try{ S g1[p#U
URL url = new URL(sURL); 8+gp"!E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j?|Vx'
httpConnection.setRequestProperty("User-Agent","NetFox"); w8Z#]kRv
String sProperty = "bytes="+nStartPos+"-"; `3VI9GmQ
httpConnection.setRequestProperty("RANGE",sProperty); 8M,o)oH
Utility.log(sProperty); Q0jg(=9wP
A~nqSe
sPW:[
InputStream input = httpConnection.getInputStream(); uk$MQv*D
//logResponseHead(httpConnection); H3R{+7
59j`Z^e
`Rt w'Uz
byte[] b = new byte[1024]; ><"|>(y
int nRead; D-C]0Jf3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;4b=/1M'
{ 5&EBUl}
nStartPos += fileAccessI.write(b,0,nRead); 3$YbEl@#
//if(nThreadID == 1) 0<@['W}G
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \rUKP""m
} 8VQ!&^9!U#
5;/q[oXI
}2RbX,0l9
Utility.log("Thread " + nThreadID + " is over!"); E+XS7':I
bDownOver = true; LB]3-FsU+
//nPos = fileAccessI.write (b,0,nRead); K O\HH
} l"dXL"h
catch(Exception e){e.printStackTrace ();} c\rP -"C
} 0H4|}+e
} e4Ibj/
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l\AdL$$Mb
//打印回应的头信息 r`Fs"n#^-4
public void logResponseHead(HttpURLConnection con) S{e3aqT#N
{ 9<3}zwJ
for(int i=1;;i++) dg#Pb@7a
{ C|Gk}
String header=con.getHeaderFieldKey(i); VV$#<D<)
if(header!=null) j?o6>j
//responseHeaders.put(header,httpConnection.getHeaderField(header)); W>+`e]z
Utility.log(header+" : "+con.getHeaderField(header)); :PN%'~}n
else Q~wS2f`)
break; J`[jub
} wI 7gHp
} #P}n+w_@
w$iPFZC'
:qj^RcmVPL
public void splitterStop() ydOG8EI
{ Oj%5FUP~[%
bStop = true; jGkDD8K [
} v+g:0 C5 (
x(EwHg>;
mpk+]n@
} nTGf
F?a 63,r
"pK<d~Wu
/* d]|K%<+(
**FileAccess.java _>`9]6\&
*//文件访问(定位，写) @,,G]4zZ!
package NetFox; xWY\,'+Q
import java.io.*; kGnT4R*E
i;]0>g4
MYVVI1A
public class FileAccessI implements Serializable{ .3_u5N|[=W
j]%XY+e
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 t D 8l0
RandomAccessFile oSavedFile; xa]yq%
long nPos; yId1J
Y[PC<-fyf
aLW3Ub{h
public FileAccessI() throws IOException Sw>>]UjU
{ rt*>)GI]b
this("",0); ~cO iv
} vdUKIP =|_
.UX4p =
kUGFg{"
public FileAccessI(String sName,long nPos) throws IOException GL9'dL|
{ d#d&CJAfr
oSavedFile = new RandomAccessFile(sName,"rw"); lcpiCZ
this.nPos = nPos; ZVdQ$
oSavedFile.seek(nPos); a"O;DYh
} p]y.N)a
SfY 5Xgp
G,<d;:
public synchronized int write(byte[] b,int nStart,int nLen) T3=h7a %=
{ [x, `)Fk
int n = -1; -:r<sv$
try{ 0>-}c>
oSavedFile.write(b,nStart,nLen); t~ I;IB
n = nLen; St!0MdCH
} K@[Hej6d
catch(IOException e) T?A3f]U
{ aYk: CYQ
e.printStackTrace (); vY.VFEP/
} dJrUcZBr
CflyK@
^uw]/H3?L
return n; bnvY2-O6
} ^%Y-~yB-
ps`j>vX*
:,qvqh][
} 3jW&S
4|cRYZj5
g#6R(
/* FaWc:GsfB
**SiteInfoBean.java 9o?\*{'KT
*/ F_w+8)DZ
package NetFox; ->IZZ5G<
JP( tf+
;C1#[U1Uy
public class SiteInfoBean { T)q Uf H
mb3aUFxA;
BaP'y8dVN
private String sSiteURL; //Site's URL tG9C(D`G
private String sFilePath; //Saved File's Path &F7_0iAP(
private String sFileName; //Saved File's Name =)jo}MB
private int nSplitter; //Count of Splited Downloading File }|8^+V&
An?#B4:
hD?6RVfG
public SiteInfoBean() rk;]7Wu
{//nSplitter的缺省值为5 E&t8nlTx
//default value of nSplitter is 5 Fx1FxwIJ
this("","","",5); d5{=<j
} hRB?NM
T?Z&\g0yp
f9y+-GhaD
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 92D~trn
{ L|s\IM1g
sSiteURL= sURL; e87a9ZPm
sFilePath = sPath; ?+Vi !eS
sFileName = sName; H13\8Te{
this.nSplitter = nSpiltter; J2oh#TGp
u+6D|
KC:6^h'.
} sHPeAa22
2g_mQT
74 )G.!
public String getSSiteURL() Tu}EAr
{ \=|=(kt)
return sSiteURL; vQ2{+5!|
} e~'z;%O~
/d"@$+
g;[t1~oF
public void setSSiteURL(String value) ofz?L#:2
{ (IjM
sSiteURL = value; km^ZF<.@
} ~@@$-,}X
@6R6.i5d
p9\*n5{
public String getSFilePath() IW@phKz
{ {w"Cr0F,
return sFilePath; }$uwAevP{y
} `0_ Y| 4KB
>mMfZvxl%
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public void setSFilePath(String value) VhMVoW
{ # &5.
sFilePath = value; \3K7)o^
} 1BEc"
C+`V?rp=s
H{9P=l
public String getSFileName() g6.I~oQj
{ ;:R2 P@6f
return sFileName; CZ$B2i6
} ;0?OBUDO
:mLXB75gH
ywyg(8>zE
public void setSFileName(String value) fiU#\%uJg
{ *D[yA
sFileName = value; _"t>72 `
} S+t2k&pm
*6=9 8C4I
Ayn$,
public int getNSplitter() NZ!I >
{ 1#+|RL4o
return nSplitter; ./'d^9{
} eMV8`&c'
"j8=%J{
l1L8a I,8
public void setNSplitter(int nCount) `e3$jy@
{ JwWxM3(%t
nSplitter = nCount; T9kc(i'
} 9CN'29c
} B#5[PX
FK-q-PKO#.
jpW_q+^?
/* gyh8
**Utility.java V=1zk-XC
*/ |:2B)X
package NetFox; fWri7|"0h
<_=O0 t|6
b<"jmB{
public class Utility { {%y|A{}c
W|n$H`;R
Z8Vof~
public Utility() n6Z!~W8
{ bt.3#aj
N@!PhP
Ix@B*Xz:`
} gsa@ci
vMJ(Ll7/
//线程睡眠 oaILh
public static void sleep(int nSecond) NNE(jJ`/
{ 6zNWDUf
try{ U:c0s
Thread.sleep(nSecond); `/!FZh<
} 7d|1T'
catch(Exception e) i`vy<Dvpz
{ utC^wA5U~
e.printStackTrace (); 7&%#bMnw
} l2dj GZk
} cF9oo%3
(mI590`f
//日志 \"Z\Af<
public static void log(String sMsg) kr |k \
{ `cN8AcRHP
System.err.println(sMsg); vv^y V"0Y
} aXZi2
5gC>j(
5e0d;Rd
public static void log(int sMsg) ),j6tq[
{ bF+j%=
System.err.println(sMsg); =d:3]M^
} >NV1#\5_R@
} oEFo7X`t
)<_qTd0`
u5KAwMw%Q
/* /nX_Q?mo
**TestMethod.java IX<9_q
*/ :7dc;WdM
package NetFox; '}bmDb*
+ DE/DR:
8xhx*A
public class TestMethod { A2A_F|f
v.u 5%
Xrpvq(]
public TestMethod() C>,> _
{ ///xx/weblogic60b2_win.exe ! R3P@,j
try{ R?- zJ ;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); qcQq.cS_'N
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); U^U hZ!
SiteFileFetch fileFetch = new SiteFileFetch(bean); -:J<JX)o
fileFetch.start(); 72*j6#zS
} KMQPA>w#
catch(Exception e){e.printStackTrace ();} T,vh=UF%]
Q|S>C%4?
BS?$eai@:9
} bz~aj}"`
[cl+AV "
2cRru]VZ5
public static void main(String[] args) IXm[c@5l
{ v'^}zO
new TestMethod(); Sl<1Rme=w
} AP1ZIc6
} Z'}%Mkm`i}
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