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)); GpGq' 8|(
} 0uhIJc'2
for(int i=0;i<nEndPos.length-1;i++) O+PRP"$g"
{ ?RU_SCp-
nEndPos = nStartPos[i+1]; ,Laz515
} g{^(EZ,
nEndPos[nEndPos.length-1] = nFileLength; 4S*7*ak{
} F?hGt]o
} 2/RW(U
!Tu4V\^~A
'OvyQ/T
//启动子线程 ^/"2s}+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3TF'[(K=
for(int i=0;i<nStartPos.length;i++) KK41I8Mw
{ p^U#1c
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), aT}?-CUxx
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), P/ 7aj:h~P
nStartPos,nEndPos,i); L^{wxOf&6E
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {z*`* O@
fileSplitterFetch.start(); 8Lh[>|~=
} -< }#ImTN
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N7}yU~j^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 'jjJ[16"d
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1j\wvPLr
nEndPos = " + nFileLength); =801nZJ
// fileSplitterFetch[nPos.length-1].start(); S'(Hl}h!.
@+(a{%~7y
3?-2~s3gp
//等待子线程结束 8npjQ;%4>
//int count = 0; 5gH'CzU?
//是否结束while循环 m"tke'a
boolean breakWhile = false; L0>w|LpRc
nWsR;~pK
Vho^a:Z9}W
while(!bStop) ^9 {r2d&c
{ ZY-mUg
write_nPos(); V(<(k,8=
Utility.sleep(500); .tt=\R
breakWhile = true; Su/}OS\R
THHA~;00YN
w$FN(BfA
for(int i=0;i<nStartPos.length;i++) >&l{_b\k
{ T[]kun
if(!fileSplitterFetch.bDownOver) m_,j)A%
{ 9<6Hs3|.!
breakWhile = false; A:YWXcg
break; <PTi>C8;r
} g].v
} .Af H>)E
if(breakWhile) #Q$`3rr
break; | sZu1K
g0"KCX
-KU@0G
//count++; 8b:\@]g$
//if(count>4) wm s@1~I
// siteStop(); n^$HC=}S
} egy#8U)Z
OvtiFN^s'
=%R|@lz_x
System.err.println("文件下载结束！"); f f_| 3G
} $-;x8O]u
catch(Exception e){e.printStackTrace ();} A3mSSc6
} k80!!S=_>
;P2(C >|
[Se0+\,&
//获得文件长度 8!VFb+
public long getFileSize() 6jo+i[h
{ u(P;) E"1
int nFileLength = -1; rBovC
try{ z{dn
URL url = new URL(siteInfoBean.getSSiteURL()); 9S$?2z".2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R;Gf3K
httpConnection.setRequestProperty("User-Agent","NetFox"); 3-$w5O3}
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ffE&=eh)
int responseCode=httpConnection.getResponseCode(); uq_h8JH$
if(responseCode>=400) |4u?Q+k%%
{ 8@'Q=".J
processErrorCode(responseCode); *'hvYl/?>
return -2; //-2 represent access is error nO7#m~
} G?QU|<mj<
VKXZA2<?'
DsH`I%w{
String sHeader; `-[+(+["
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1$adX
for(int i=1;;i++) sKuPV
{ 7{:g|dX
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5N4[hQrVJ
//Utility.log(in.readLine()); w-(^w9_e
sHeader=httpConnection.getHeaderFieldKey(i); V;SXa|,
if(sHeader!=null) x8wal[6
{ um$K^
if(sHeader.equals("Content-Length")) Afq?Ps+
{ ~\D H[Mt
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); gw`}eA$
break; <6) w
} 3O!TVSo
} jt8% L[
else *,=WaODO%
break; MX#MDA-4
} Z`lCS o;
} *^5..0du
catch(IOException e){e.printStackTrace ();} %Jc>joU
catch(Exception e){e.printStackTrace ();} x#s=eeP1
VIjsz42C
58 Rmq/6s
Utility.log(nFileLength); W9ewj:4\0
sCF7K=a
xr\wOQ*`
return nFileLength; !rMl" Y[
} 4$<-3IP,
^>fjURR
7,N>u8cTh
//保存下载信息（文件指针位置） #Zy-X_r
private void write_nPos() DG $._
{ d^<a)>5h
try{ ,Cckp! 6
output = new DataOutputStream(new FileOutputStream(tmpFile)); wf8GH}2A
output.writeInt(nStartPos.length); -O=a"G=
for(int i=0;i<nStartPos.length;i++) P"WnU'+
{ h.W;Dmf6]
// output.writeLong(nPos); );.q:"
output.writeLong(fileSplitterFetch.nStartPos); ;qF#!Kb5
output.writeLong(fileSplitterFetch.nEndPos); (~>L \]!
} Ck0R%|
output.close(); Z 7M%}V%
} $&|*v1rH
catch(IOException e){e.printStackTrace ();} {!C';^
catch(Exception e){e.printStackTrace ();} boR&'yX
} tT;=l[7%
p8q9:Tz
"jUr[X2J
//读取保存的下载信息（文件指针位置） K$..#]\TM
private void read_nPos() B R-(@
{ )2P4EEs[
try{ 6QOdd6_d
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); y'<juaw
int nCount = input.readInt(); 3=r8kh7,
nStartPos = new long[nCount]; n_n0Q}du
nEndPos = new long[nCount]; hC.7Z]
for(int i=0;i<nStartPos.length;i++) Svmyg]
{ S)0bu(a`Z,
nStartPos = input.readLong(); t;@VsQ8
nEndPos = input.readLong(); Pb|'f(
} /WVnyz0
input.close(); |WB<yA1
} MKdBqnM(F
catch(IOException e){e.printStackTrace ();} ZN2g(
catch(Exception e){e.printStackTrace ();} t_q`wKDE
} nJ|8#U7
2b]'KiX
q(Y<cJ?X
private void processErrorCode(int nErrorCode) 4C;4"6
{ _F *(" o
System.err.println("Error Code : " + nErrorCode); }Vpr7_
} xi=qap=S^9
O\T
\"qXlTQ1_9
//停止文件下载 $+<X 1
public void siteStop() jG0{>P#+
{ +_?;%PKkuF
bStop = true; gnoV>ON0
for(int i=0;i<nStartPos.length;i++) W.ud<OKP90
fileSplitterFetch.splitterStop(); b\%=mN
OH28H),}
&DFe+y~PR
} $;_'5`xs
} ,$habq=;
//负责部分文件的抓取 2oAPJUPOJ
**FileSplitterFetch.java ^b`}g
*/ x,js}Mlw
package NetFox; >qjr7 vx
#(jozl_8
\>j._#t$h
import java.io.*; TD-d5P^Kek
import java.net.*; EvMhNq~y5
Oah}7!a)
S zOB{
public class FileSplitterFetch extends Thread { :rb<mg[
P sD+?
)@3ce'
String sURL; //File URL QJo)
long nStartPos; //File Snippet Start Position Xu$xO(
long nEndPos; //File Snippet End Position -pj&|< h+9
int nThreadID; //Thread's ID ke~O+]
boolean bDownOver = false; //Downing is over _y)#N<
boolean bStop = false; //Stop identical mj<(qZh
FileAccessI fileAccessI = null; //File Access interface {W}.z
%#NaM\=8v
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +V&b<y;?>
{ ;0}$zy1EZ
this.sURL = sURL; WZRrqrjq
this.nStartPos = nStart; A~-e?.
this.nEndPos = nEnd; K$Y!d"D
nThreadID = id; H!&]Di1Eh
fileAccessI = new FileAccessI(sName,nStartPos);//定位 TeQWrms
} BpCzmU
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O!sZMGF$p
public void run() .*D~ .!
{ E/(:\Cm^
while(nStartPos < nEndPos && !bStop) KS'? DO
{ 4D[W;4/p
-) $$4<L
=4yME
try{ c\.4I4uy
URL url = new URL(sURL); [dsH0 D&T
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jh`&c{#*)M
httpConnection.setRequestProperty("User-Agent","NetFox"); G3 #c
String sProperty = "bytes="+nStartPos+"-"; i}RxTmG<
httpConnection.setRequestProperty("RANGE",sProperty); #:z.Br`
Utility.log(sProperty); DI9x]CR
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Aa.bE,W
InputStream input = httpConnection.getInputStream(); @6ZQkX/
//logResponseHead(httpConnection); }Fyf?TZ$T
hkv&Od,
,a< !d
byte[] b = new byte[1024]; 8:-[wl/@
int nRead; J}KATpHs
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) bR49(K$~
{ rO 6oVz#x
nStartPos += fileAccessI.write(b,0,nRead); ;04doub
//if(nThreadID == 1) sxl29y^*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `#2}[D
} 2#ha Icm"
%`HAg MgP
}9>W41
Utility.log("Thread " + nThreadID + " is over!"); 9pStArF?F0
bDownOver = true; =4/lJm``
//nPos = fileAccessI.write (b,0,nRead); I9ubVcV8
} 2@1A,
catch(Exception e){e.printStackTrace ();} sju. `f>-r
} {k}S!T
} <"AP&J'H
J^ryUOo}b
,S:LhgSP
//打印回应的头信息 zfO0+fMH
public void logResponseHead(HttpURLConnection con) znFa4
{ MaXgy|yB1
for(int i=1;;i++) r3/H_Z
{ V;~W,o!
String header=con.getHeaderFieldKey(i); =wPl;SDf!
if(header!=null) cW26TtU(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); D+N{'d?+
Utility.log(header+" : "+con.getHeaderField(header)); lEANNu
else >Rjk d>K3
break; O@'/B" &
} CG@ LYN
} F%lP<4Vx
X|7gj&1
]U! ?{~
public void splitterStop() Bh"o{-$p8`
{ 3uz@JY"mK
bStop = true; !V$m!i;
} PE|_V
d>)*!l2,C
9EK5#_L[=
} F.?^ko9d
>"{3lDyq-
Qy*`s
/* !CTchk<{(
**FileAccess.java I/<aY*R4
*//文件访问(定位，写) <E|i3\[p
package NetFox; :o&qJ%
import java.io.*; GG5wiN*2S
gsqlWfa
"D2`=D!+
public class FileAccessI implements Serializable{ ,*Tf9=z
.4Jea#M&x
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7pMrYIP
RandomAccessFile oSavedFile; YbND2i
long nPos; 1xar L))
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~M3`mO+^U
public FileAccessI() throws IOException #O/ihRoaO
{ s}uOht} o
this("",0); CQW#o_\
} {l%Of
,H2[["1DH
[:
public FileAccessI(String sName,long nPos) throws IOException {PnvQ?|Z
{ S2kFdx*Zf
oSavedFile = new RandomAccessFile(sName,"rw"); T+9#P4
this.nPos = nPos; -[|R\'i
oSavedFile.seek(nPos); Nj5Mc>_
} d0"Hu^]
%]h5\%@w
!<Ma9%uC{
public synchronized int write(byte[] b,int nStart,int nLen) 2)Grl;T]s
{ UIi;&[
int n = -1; Q35$GFj"jD
try{ Waj6.PCFm
oSavedFile.write(b,nStart,nLen); X&8&NkH
n = nLen; oa?bOm
} y$Sn3_9 V
catch(IOException e) 4%LGPh
{ Jajo!X*Wai
e.printStackTrace (); zXx HaM
} d`5xd@p
5f(yF
n#Q;bSw
return n; O; 7`*}m
} ?{NP3
"-88bF~
I} m\(TS-"
} W,9. z%
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oDogM`T`
/* {`2! 3= "
**SiteInfoBean.java T!0o(Pp<
*/ rkugV&BhV
package NetFox; _dky+ E
I`^ 7Bk.r
Ua\]]<hj"
public class SiteInfoBean { 47 xyS%X
umhg O.!
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private String sSiteURL; //Site's URL thy)J.<J
private String sFilePath; //Saved File's Path sG[v vm
private String sFileName; //Saved File's Name ``$Dgj[
private int nSplitter; //Count of Splited Downloading File E #q gt9
8[\F*H
Yj3j?.JJk
public SiteInfoBean() /'k4NXnW3
{//nSplitter的缺省值为5 [-5%[ty9X
//default value of nSplitter is 5 Sio^FOTD
this("","","",5); 0tyoH3o/d
} z SDRZ!
v._Q XcE
\{``r
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) W/DSj :
{ y.PWh<dI
sSiteURL= sURL; }K':tX?
sFilePath = sPath; Q#w mS&$f
sFileName = sName; &YC Z L
this.nSplitter = nSpiltter; }N[|2nR'
r@b M3V_o
mo+zq~,M
} v|fA)Ww
;,2i1m0"
v;m`d{(i2
public String getSSiteURL() o81RD#>E)
{ fy]z<SPhVJ
return sSiteURL; hEUS&`K
} Z>hS&B
ZeM~13[
[d 30mVM
public void setSSiteURL(String value) Sggha~E2s
{ KZrg4TEVi
sSiteURL = value; a,mG5bQ!
} r&
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qaJ$0,]H+
public String getSFilePath() O&BNhuW2
{ " kp+1sG8
return sFilePath; } DQ<YF+
} dpG l
>=Bl/0YH
lw+Y_;
public void setSFilePath(String value) ASGV3r(
{ {zzc/!|
sFilePath = value; SB~HHx09
} Q1f)uwh
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public String getSFileName() bd|ZhRsL
{ j IO2uTM~
return sFileName; g Va;!
} P:D@5
p+x}$&<|
p>M8:,
public void setSFileName(String value) 9;2{=,
{ .-ihxEbzr
sFileName = value; 7x>\/l(
} eBT+|
!s^[|2D_U
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public int getNSplitter() up_Qv#`Q
{ %u=b_4K"j
return nSplitter; Oq3aboAt
} FYBW3y+AF&
,8.Fd|#L
!2=m |,
public void setNSplitter(int nCount) Gx)U~L$B
{ MZIZ"b
nSplitter = nCount; y26?>.!
} M{GT$Q
} FTgqE@
. E8Gj'yO
" fXs!
/* Mi^/`1
**Utility.java WRCf[5
*/ q"LE6?hs
package NetFox; '@6O3z_{
evSr?ys
} "QL"%
public class Utility { Wf!u?nH.5
$y$E1A6h+
%ztv.K(8
public Utility() ]0o_- NI
{ TI5<' U)
k,,Bf-?
D[p_uDIz
} l=&\luNz
ZrNBkfe:
//线程睡眠 qV{iUtYt
public static void sleep(int nSecond) g:oB j6$ q
{ b?U2g?lN:
try{ [iXkv\
Thread.sleep(nSecond); 61SbBJ6[
} =w;~1i%.k
catch(Exception e) o? LJ,Z
{ `G'Z,P-a
e.printStackTrace (); M o?y4X
} |=u }1G?
} 4e20\q_{
50`=[l`V
//日志 zI7iZ"2a
public static void log(String sMsg) Um~DA
{ BMdcW MYU\
System.err.println(sMsg); he!Uq%e
} 'ZFbyt Q2
mufXM(
u>\u}c
public static void log(int sMsg) bHRRgR`,
{ Xmny(j)g
System.err.println(sMsg); d-{1>\-_
} s&d!+-\6_
} wbQs>pc
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~ugyUpY"
/* IY,n7x0d
**TestMethod.java 0'Uo3jAB
*/ [;Y*f,UG_-
package NetFox; ruU &.mZ
$tqr+1P
_T.T[%-&=
public class TestMethod { ;9;jUQ]MyG
bLsN?_jy
7pO/!Lm
public TestMethod() >&[q`i{
{ ///xx/weblogic60b2_win.exe i%GNmD
try{ yPoa04!{=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); WRqpQEY
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N{&Hq4^c
SiteFileFetch fileFetch = new SiteFileFetch(bean); exxH0^
fileFetch.start(); F-=Xbyr3@
} o`M.v[O
catch(Exception e){e.printStackTrace ();} 9GgXX9K
e~ %=H 0n
Z,I0<ecaD
} *&BS[0;
)|,Zp`2/
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public static void main(String[] args) -Oplk*
{ sTmdoqTK!
new TestMethod(); KY+BXGW*
} h4E[\<?
} a}g<<{
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