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)); F C"dQ
} )Fbkt(1
for(int i=0;i<nEndPos.length-1;i++) N9hBGa$
{ /Bc ;)~
nEndPos = nStartPos[i+1]; h c"n?
} #u>JCPz
nEndPos[nEndPos.length-1] = nFileLength; JA&w"2X*E
} Tg[+K+b
} ~<aCn-h0
$?7}4u,
U_+>4zdm
//启动子线程 L(iWFy1& T
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; nI-\HAX
for(int i=0;i<nStartPos.length;i++) r__uPyIMG/
{ {min9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (URWicaB
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |<OZa;c+
nStartPos,nEndPos,i); Rh%x5RFFc
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s iC/k*
fileSplitterFetch.start(); X\_ku?]v
} ZT!DTb B
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1^vN?#Kt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); d+l@hgz~
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", i-$]Tg
nEndPos = " + nFileLength); 7JjTm^bu
// fileSplitterFetch[nPos.length-1].start(); V5m4dQ>t
4Xlq Ym
~ujY+{
//等待子线程结束 v]BN.SHE_
//int count = 0; 8|gwH2st~
//是否结束while循环 zbrDDkZ1
boolean breakWhile = false; Go8 m
PXWBc\
N|wI=To
while(!bStop) oQAD 3a
{ .z+[3Oj_E
write_nPos(); "4Cb dD//
Utility.sleep(500); h",kA(+P
breakWhile = true; re:=fC:t5A
}Til $TT%H
+9M#-:qB
for(int i=0;i<nStartPos.length;i++) _3.=| @L
{ _O{3bIay3!
if(!fileSplitterFetch.bDownOver) JHBX'1GQa
{ g,*LP
breakWhile = false; N2WQrTA:S+
break; #fd;]
} pKMy:j
} r Z%l?(
if(breakWhile) O8qA2@,
break; yP.,Dh s
@p~f*b4H?
k"7l\;N
//count++; Y {a#2(xn
//if(count>4) 'GcN9D
// siteStop(); (Rj'd>%c
} ~qekM>z
Pv@Lx+k
sF[7pE
System.err.println("文件下载结束！"); 5FKb7
} p,0J $L
catch(Exception e){e.printStackTrace ();} 9}G.Fr
} F/}(FG<'>I
t*KgCk1
7XrXx:*a5
//获得文件长度 ?QR13l(
public long getFileSize() ufq9+}
{ 2Tt^^Lb
int nFileLength = -1; |}$ZOwc
try{ xYSNop3_
URL url = new URL(siteInfoBean.getSSiteURL()); 4b5'nu
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?9W2wqN>o
httpConnection.setRequestProperty("User-Agent","NetFox"); (m:ktd=x
A}"aH
|%\>+/j$
int responseCode=httpConnection.getResponseCode(); O S?S$y
if(responseCode>=400) {_[\k^98>
{ uPh/u!
processErrorCode(responseCode); s&.VU|=VQ@
return -2; //-2 represent access is error 2":{3=oW~
} {zhajY7
QTe>EJ12
85gdmla@9
String sHeader; V\|V1c
K-X@3&X}
cI#! Y
for(int i=1;;i++) &-R(u}m-F
{ V)q|U6R
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 0Tp,b (;n
//Utility.log(in.readLine()); 4C]>{osv
sHeader=httpConnection.getHeaderFieldKey(i); crvq]J5
if(sHeader!=null) 9lU"m_ QT4
{ R%EpF'[~[
if(sHeader.equals("Content-Length")) `bAOhaB,/
{ CQ;.}=j ,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }[FP"#
break; M?[~_0_J
} Rlyx&C8
} Lkf}+aY
else d,y%:F 4
break; e<Bwduy
} )Up'W
} ))NiX^)8^
catch(IOException e){e.printStackTrace ();} -h%!#g
catch(Exception e){e.printStackTrace ();} oZS.pi
=wcqCW,]
D #Ku5~j
Utility.log(nFileLength); SW; %2
zt3y5'Nk
gR#lRA/
return nFileLength; X6Wj,a
} j84g6;4Dv
/\-iV)h1@
.$]%gjIBCl
//保存下载信息（文件指针位置） d&G#3}kOb%
private void write_nPos() ;}W-9=81
{ C]01(UoSZ
try{ ]/cVlpZ{f
output = new DataOutputStream(new FileOutputStream(tmpFile)); ZvVrbj&
output.writeInt(nStartPos.length); #]vs*Sz
for(int i=0;i<nStartPos.length;i++) tqYwPSr
{ @gM>Lxj
// output.writeLong(nPos); 9V/:1I0?&0
output.writeLong(fileSplitterFetch.nStartPos); aM6qYO!jA
output.writeLong(fileSplitterFetch.nEndPos); iD"9,1@~n
} 552yzn1
output.close(); "tX=^4
} @w[2 BaDt
catch(IOException e){e.printStackTrace ();} 2leTEs5aK`
catch(Exception e){e.printStackTrace ();} D *Hy 2eZ.
} G[4$@{
YYs/r
YEiQ`sYKG
//读取保存的下载信息（文件指针位置） ;&$Nn'~a
private void read_nPos() G\4*6iw:
{ T=~D>2C
try{ sk>E(Myo
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ZOIx+%/Vd#
int nCount = input.readInt(); #=V[vbTY
nStartPos = new long[nCount]; D.;iz>_}Y
nEndPos = new long[nCount]; UD6:X&Un
for(int i=0;i<nStartPos.length;i++) zMI_8lNz
{ \#%1t
nStartPos = input.readLong(); L!l`2[F|
nEndPos = input.readLong(); Mv%"aFC
} [!'fE#"a
input.close(); QHmF,P
} Eb.k:8?Tn
catch(IOException e){e.printStackTrace ();} 5S/YVRXq
catch(Exception e){e.printStackTrace ();} G.l ~!;
} +B#+'
*k^'xL
>"?jW@|g
private void processErrorCode(int nErrorCode) appWq}db
{ Mq,2S
System.err.println("Error Code : " + nErrorCode); tH^]`6"QUa
} !Sj0!\
EZ+L'
V X"!a
//停止文件下载 ]mZN18#
public void siteStop() U,7O{YM
{ <Y"h2#M"
bStop = true; 3-6Lbe9H
for(int i=0;i<nStartPos.length;i++) HB:VpNFn
fileSplitterFetch.splitterStop(); jBLLx{
7Bs:u
eJ3;Sd''
} 1wTPT,k
} AdGDs+at,
//负责部分文件的抓取 :JD*uu
**FileSplitterFetch.java sn-P&"q
*/ !E.CpfaC
package NetFox; dK d"2+fH
6i7+.#s
$ts1XIK%
import java.io.*; #C#*yE
import java.net.*; 5h7M3s
!HCuae3_
9kby-A4
public class FileSplitterFetch extends Thread { 7M,(!*b
`:#IZ
Zp qb0ro
String sURL; //File URL :/XWk %
long nStartPos; //File Snippet Start Position -J]j=
long nEndPos; //File Snippet End Position bx._,G
int nThreadID; //Thread's ID .g?Ppma
boolean bDownOver = false; //Downing is over 5[0W+W
boolean bStop = false; //Stop identical 5KgAY;|
FileAccessI fileAccessI = null; //File Access interface .8]buM5_G
WWgJ !Uz
4`zK`bRcK#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException PFI^+';
{ M.u1SB0
this.sURL = sURL; ^`+Kjhht
this.nStartPos = nStart; e#!,/pE
this.nEndPos = nEnd; c@|f'V4
nThreadID = id; 5H}d\=z
fileAccessI = new FileAccessI(sName,nStartPos);//定位 y"Ios:v@-
} n=A}X4^
9+"ISXS
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public void run() &|I{ju_
{ 7 0Wy]8<P
while(nStartPos < nEndPos && !bStop) ,u S)N6'b6
{ oCSJ<+[(C
Fp~0 ^
'b:UafV
try{ 63HtZ=hO7
URL url = new URL(sURL); @pN6uDD}R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~u-_DOA
httpConnection.setRequestProperty("User-Agent","NetFox"); vH@$?b3VP
String sProperty = "bytes="+nStartPos+"-"; |;R-q8
httpConnection.setRequestProperty("RANGE",sProperty); 9#a/at]
Utility.log(sProperty); Ni#y=cb
Vk%W4P"l
:|Bzbn=N2
InputStream input = httpConnection.getInputStream(); 5#::42oE
//logResponseHead(httpConnection); <Ys7`e6eY
y2Vc[o(NP
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byte[] b = new byte[1024]; RY*yj&?w[
int nRead; xI8v'[3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Nrc-@ ]
{ \$ :)Ka
nStartPos += fileAccessI.write(b,0,nRead); cyWDtq
//if(nThreadID == 1) w^/"j_p@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $'bb)@_
} g$mqAz<
fw0Z- 9*
rm,h\
Utility.log("Thread " + nThreadID + " is over!"); hYh~[Kr^@^
bDownOver = true; Y4*?QBYA
//nPos = fileAccessI.write (b,0,nRead); ? \NT'CG
} F-Ywl)
catch(Exception e){e.printStackTrace ();} DkBVk+
} =[o/D0-Kn
} -ha[xM05
k?=_p6>
U6 H@l#
//打印回应的头信息 .T}S[`Yx5
public void logResponseHead(HttpURLConnection con) *1_A$14l
{ 5<?/M<i
for(int i=1;;i++) R= *vPS
{ =JB1]b{|
String header=con.getHeaderFieldKey(i); /ee4 v!
if(header!=null) U6oab9C?k
//responseHeaders.put(header,httpConnection.getHeaderField(header)); N9cUlrDO
Utility.log(header+" : "+con.getHeaderField(header)); Y--Uo|H
else Mhg_z.Z
break; Toc="F`SW
} ;923^*\:F{
} PQ[x A*
RDQK_Ef:
)wz3m L
public void splitterStop() OPVcT
{ *|k/lI
bStop = true; W=T,hOyh<W
} Fs)m;C
/|{~GD +A&
2u'h,on?
} h^"OC$
o9uir"=
}z8HS< #Q
/* mmrz:_
**FileAccess.java :u>9H{a
*//文件访问(定位，写) 0^rDf L
package NetFox; au 5qbP
import java.io.*; >0qe*4n|M
xiG_l-2l
knJoVo]
public class FileAccessI implements Serializable{ o2M4?}TpIV
MUd 9R
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5Mq7l$]h$
RandomAccessFile oSavedFile; &%4*~;o
long nPos; F[5\ x0
w>ap8><4
N61\]BN<
public FileAccessI() throws IOException csay\Q{
{ 1#<KZN =$
this("",0); ^w|apI~HSE
} Td6"o&0A!
'+cPx\4
]DO"2r
public FileAccessI(String sName,long nPos) throws IOException 'u{DFMB-A
{ g x~fZOF_
oSavedFile = new RandomAccessFile(sName,"rw"); k3wAbGp
this.nPos = nPos; <ny)yK
oSavedFile.seek(nPos); !Yan}{A,
} %VD>S
'P^6H$0
uY6|LTK&x
public synchronized int write(byte[] b,int nStart,int nLen) l@zr1g)
{ nc#}-}`5
int n = -1; Y '&&1R
try{ D.zEE-cGyb
oSavedFile.write(b,nStart,nLen); PG<tic<?
n = nLen; )-q#hY
} 96UL](l(`
catch(IOException e) HV-c DL
{ `9BZ))Pg
e.printStackTrace (); o(GXv3L
} _KBN
@:u>
e^)+bmh
return n; ?ACflU_k
} VfWU-lJ
1t&LNIc|^
N 4Kj)E@
} @r7ekyO8)
E,u/^V9x
6Ih8~Hu
/* D%[yAr;r
**SiteInfoBean.java 8t)5b.PS
*/ KrVP#|9%"
package NetFox; vmEbk/Vy
8EbJ5wu/%S
BwpEIV@b]
public class SiteInfoBean { v\&C]W]
$?x;?wS0V
1eod;^AP9
private String sSiteURL; //Site's URL v_U+wga
private String sFilePath; //Saved File's Path CMu/n]?c
private String sFileName; //Saved File's Name 3|++2Z{},
private int nSplitter; //Count of Splited Downloading File 6:\0=k5
:$k];
;og[q
public SiteInfoBean() [f._w~
{//nSplitter的缺省值为5 0eJqDCmH
//default value of nSplitter is 5 'xK ,|U
this("","","",5); b*5Yy/U
} J}zN]|bz
A^L8"
}N^3P0XjYq
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <GdQ""X
{ !+R_Z#gB
sSiteURL= sURL; ?aMd#.&
sFilePath = sPath; G~.bi<(v
sFileName = sName; )t?_3'W
this.nSplitter = nSpiltter; Nbyc,a[o
GkU]>8E'"
:,8eM{.Q
} TyGsSc
A#;TY:D2
W)LtnD2 w
public String getSSiteURL() #Y_v0.N
{ 5Sh.4A\
return sSiteURL; }L|cg2y
} Bk yW
IKs2.sj"o
h0c&}kM
public void setSSiteURL(String value) Yn>y1~
{ .E/NlGm[
sSiteURL = value; :c/](M
} 4*9WxhJ ]0
8|2I/#F}]
|+h8g@;Z
public String getSFilePath() *Q`y'6S
{ d>bS)
return sFilePath; WoSJp5By$
} iJ%`ym4Y
Xhk_h2F[
TM*<hC
public void setSFilePath(String value) yS"; q
{ S!{Kn ;@
sFilePath = value; ptCAtEO72
} rvwfQ'14
;sZHE&+
A6AIkKjzq
public String getSFileName() ^hIKDc!.m
{ PTf.(B"z
return sFileName; QVJvuiUh
} j87IxB?o
/sa\Ze;E
$P7G,0-
public void setSFileName(String value) 0ofl,mXW
{ h 1`yW#%
sFileName = value; oHj64fE9
} Mz:t[rfs
v:w $l{7
J6m(\o
public int getNSplitter() /`YbHYNF[
{ u*C"d1v=
return nSplitter; Kj`sq":Je0
} V9r58hbVT
fPHv|_XM>
M6!kn~
public void setNSplitter(int nCount) :*1Gs,
{ 1,W%t\D
nSplitter = nCount; 2s EdN$O
} G`w,$:,
} y]?%2ud/=
~SJOynSz,
nP?(9;3*
/* <HG~#oBRq
**Utility.java *E.{i
*/ .F)b9d[?
package NetFox; Q=gVxS
HqOSQ<-Fo
3Du&KZ
public class Utility { 4ej$)AdW3
h&yaug,.
1&QI1fvx
public Utility() \I,<G7!0
{ zv#i\8h^p
GFlsI-*`
H:9( XW
} $F G4wA
K(6=)
//线程睡眠 FPFt3XL
public static void sleep(int nSecond) .1|'9@]lj4
{ &r DOqj
try{ d-N<VVcy\
Thread.sleep(nSecond); F6Q#{Ufq
} 1Q?hskL
catch(Exception e) *TE6p
{ 6/@ cP/
e.printStackTrace (); _E'M(.B<
} ej%C<0/%n
} pb E`Eq
|.(o4<nx.
//日志 yo (&~r
public static void log(String sMsg) lrq !}\aX
{ R"O9~s6N
System.err.println(sMsg); &.(ZO]
} eX_}KH-Q
p2&KGtX'
A|Y\Y}
public static void log(int sMsg) hH[JY(V
{ msY"Y*4
System.err.println(sMsg); OIewG5O
} um3 M4>K
} u%}vTCg*p
u3k+Xg:
X:62)^~'
/* 8<.KWr
**TestMethod.java C7+TnJ
*/ *^.b}K%
package NetFox; qM1$?U
]E=JUYf0
-h.YQC`
public class TestMethod { ]"CAP%
o@pM??&x
|qbJ]v!
public TestMethod() |{oKhC^yG
{ ///xx/weblogic60b2_win.exe SxH}/I|W
try{ F=P|vYL&&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); cJ[n<hTv
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5utj$ha2
SiteFileFetch fileFetch = new SiteFileFetch(bean); (1jkZ^7
fileFetch.start(); `H+Eo<U
} {L4^IKI
catch(Exception e){e.printStackTrace ();} zcZr )Oh
9Hc#[Ml
8g0& (9<)
} eq4<
{H>iL
;TW@{re
public static void main(String[] args) 41C=O@9m
{ E RMh% C
new TestMethod(); mU\$piei
} ^ul`b
} 7NXT.E~2
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