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)); w^o}E)O
} :3?|VE F
for(int i=0;i<nEndPos.length-1;i++) ~E*d G
{ DB@EVH
nEndPos = nStartPos[i+1]; ;&,.TC?l
} Bq!cY Wj
nEndPos[nEndPos.length-1] = nFileLength; xo WT*f
} wPnybb{
} B*,?C]0{
c3k|G<C2
NHkL24ve
//启动子线程 1q]c7"
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; AuCWQ~
for(int i=0;i<nStartPos.length;i++) FT/amCRyT
{ }Bff,q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A}G|Yfn
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ( v@jc8y
nStartPos,nEndPos,i); VJ{pN~_1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); SI*^f\lu
fileSplitterFetch.start(); <y>:B}9'
} \FifzKA
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DJP6TFT&G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {$fsS&aPg
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", g-@h>$< 1
nEndPos = " + nFileLength); Nl*i5 io
// fileSplitterFetch[nPos.length-1].start(); r(`nt-o@
7&6Y
_/ Os^>R
//等待子线程结束 >.LKct*5K
//int count = 0; l`gTU?<xd
//是否结束while循环 G;]:$J
boolean breakWhile = false; _N'75
)|]Z>>%t
)+Y&4Qu
while(!bStop) hI~SAd ,#A
{ !k<:k "7
write_nPos(); ]rW8y%yD
Utility.sleep(500); AS;.sjgk
breakWhile = true; G|9B)`S
z{?4*Bq
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for(int i=0;i<nStartPos.length;i++) T:!MBWYe|
{ 509Q0 [k
if(!fileSplitterFetch.bDownOver) z[&s5"
{ ]k+m=OR{/
breakWhile = false; _;e\:7<m
break; D,rZ0?R
} Z+idLbIs
} +?d}7zh
if(breakWhile) HDS"F.l5
break; \*"`L3
xl] ;*&
=B(mIx;m
//count++; G6O/(8
//if(count>4) PZM42"[&
// siteStop(); MF.[8Zb
} T;?+kC3
K.DXJ UR
8tQ|-l*
System.err.println("文件下载结束！"); vJCf~'
} t ;-L{`mW
catch(Exception e){e.printStackTrace ();} H_B~P%E@]
} =!<G!^
^M Ey,
nGa1a
//获得文件长度 A=`*r*
public long getFileSize() <qY5SV,
{ crn k|o
int nFileLength = -1; CLK^gZ
try{ [7\>"v6
URL url = new URL(siteInfoBean.getSSiteURL()); e4.&aIC[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6 =gp:I
httpConnection.setRequestProperty("User-Agent","NetFox"); Hg(5S,O2
y\[r(4h
JO1 ,TtA
int responseCode=httpConnection.getResponseCode(); Ew4g'A:H
if(responseCode>=400) mm,lhIh
{ ULl_\5s2
processErrorCode(responseCode); y1C/v:;
return -2; //-2 represent access is error lbkLyp2
} #T%zfcUj
_413\`%8?
xzk}[3P{
String sHeader; w0Ij'=:
Y@}FL;3
D4Sh9:\
for(int i=1;;i++) uva\0q
{ E`)Qs[?Gk
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); dlD}Ub
//Utility.log(in.readLine()); :p-Y7CSSu
sHeader=httpConnection.getHeaderFieldKey(i); iJP{|-h
if(sHeader!=null) Z"tQpJg
{ qrDcL>Hrn
if(sHeader.equals("Content-Length")) /`+7_=-
{ *K)0UKBr
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4e9E' "8%
break; bUvK
} l)8sw=
} 7/>a:02
else abWl ut
break; Sdc*rpH"(
} Yx1 D)
} RvW.@#EH0
catch(IOException e){e.printStackTrace ();} aZgNPw
catch(Exception e){e.printStackTrace ();} )w"0w(
;.s:X
t)I0lnbs
Utility.log(nFileLength); \"d?=uFe
?}sOG?{
o#e7,O
return nFileLength; j'Wp
} SE!L :
e1P7 .n}
-,GEv%6c
//保存下载信息（文件指针位置） E1W:hGI
private void write_nPos() c{>|o
{ A,c'g}:
try{ \_ -DyD#3
output = new DataOutputStream(new FileOutputStream(tmpFile)); :_H>SR:
output.writeInt(nStartPos.length); Jsn <,4DO8
for(int i=0;i<nStartPos.length;i++) ]kS7n@8
{ q^Inb)FeN
// output.writeLong(nPos); ]{Ek[Av
output.writeLong(fileSplitterFetch.nStartPos); xIgql}.
output.writeLong(fileSplitterFetch.nEndPos); c]v +
} Taasi` k
output.close(); Mi74Xl i
} QymD-A"P
catch(IOException e){e.printStackTrace ();} O71BM@2<
catch(Exception e){e.printStackTrace ();} s.y}U5Ty?P
} g1qi\axm
8]C1K Zs
7) 0q--B
//读取保存的下载信息（文件指针位置） 2U%qCfh6|
private void read_nPos() }n95< {
{ [TCRB`nTQF
try{ _,Q[2gQ5N
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !$r9C/k
int nCount = input.readInt(); e?<D F.Md+
nStartPos = new long[nCount]; U;gp)=JNT
nEndPos = new long[nCount]; m!Af LSlwm
for(int i=0;i<nStartPos.length;i++) /*P7<5n0
{ -f.R#J$2
nStartPos = input.readLong(); .Cr1,Po
nEndPos = input.readLong(); &<h?''nCy
} R3G@G
input.close(); iQ{z6Qa
} C BlXC7_Mi
catch(IOException e){e.printStackTrace ();} ;+%Z@b%
catch(Exception e){e.printStackTrace ();} if@,vc
} <gcmsiB|
DMMLzS0A
W5I=X]&
private void processErrorCode(int nErrorCode) 'w6hW7"L
{ i+AUQ0Zbf6
System.err.println("Error Code : " + nErrorCode); [q$e6JwAt
} pqq?*\W&[v
\HG$V>2
} J(1V!EA
//停止文件下载 ]ymC3LV]
public void siteStop() .K7C-Xn=
{ 6Ahr_{
bStop = true; 7TdQRB
for(int i=0;i<nStartPos.length;i++) 0||F`24
fileSplitterFetch.splitterStop(); b,Lw7MY}[
kW(Kh0x
A'~#9@l<
} kaO{#i2-
} yoW> BX
//负责部分文件的抓取 5)*6V&
**FileSplitterFetch.java -fPT}v
*/ e YDUon
package NetFox; -yA3 RP
"Q?_ EEn
:rL?1"
import java.io.*; uk6g s)qxC
import java.net.*; 0BFz7
!tr9(d
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public class FileSplitterFetch extends Thread { w"6aha*%7
l $w/Fz
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String sURL; //File URL qmID-t"
long nStartPos; //File Snippet Start Position s7M}NA 0
long nEndPos; //File Snippet End Position ^$}/|d(
int nThreadID; //Thread's ID Gc^t%Ue-H)
boolean bDownOver = false; //Downing is over cIZ[[(Db
boolean bStop = false; //Stop identical ]b)!YPo
FileAccessI fileAccessI = null; //File Access interface DO%Pwfkd
, QA9k$`
ifHU|0_=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4y>(RrVG
{ K=o:V&
this.sURL = sURL; 6Ty3e|do
this.nStartPos = nStart; QES^^PQe:
this.nEndPos = nEnd; req-Q |
nThreadID = id; XLocg
fileAccessI = new FileAccessI(sName,nStartPos);//定位 QE*%HR'
} z \^
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N-Z^G<[q.
public void run() ,\}k~ U99
{ ()B7(Y
while(nStartPos < nEndPos && !bStop) 9R>~~~{-Go
{ r},lu=em
!"%S#nrL$
vlAy!:CV
try{ UeNF^6sWu0
URL url = new URL(sURL); L5&K}F]r^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TR?Bvy2s:g
httpConnection.setRequestProperty("User-Agent","NetFox"); FR(QFt!g
String sProperty = "bytes="+nStartPos+"-"; w_!%'9m>
httpConnection.setRequestProperty("RANGE",sProperty); 2$Wo&Q^_
Utility.log(sProperty); Onyh1
n5\}KZh
w-M7opkq
InputStream input = httpConnection.getInputStream(); J7Sx!PQ
//logResponseHead(httpConnection); u9,=po=+7f
JeL~]F
18rp; l{
byte[] b = new byte[1024]; -`g J
int nRead; 2;h+;G
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) MU*It"@}2
{ cPSti
nStartPos += fileAccessI.write(b,0,nRead); pSXEJ 2k
//if(nThreadID == 1) ?F25D2[(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); eN4t1$
} -zR.'x%
g kn)V~ij
p_;r%o=
Utility.log("Thread " + nThreadID + " is over!"); D>S8$]^Dm
bDownOver = true; '?b\F~$8
//nPos = fileAccessI.write (b,0,nRead); <a fO 6?`
} ~7dF/Nn5
catch(Exception e){e.printStackTrace ();} oHk27U G
} [)0 R'xL6
} y%FYXwR{
gz#+
7<vy;"wB
//打印回应的头信息 ,k\/]9
public void logResponseHead(HttpURLConnection con) *iYMX[$
{ ~Z7)x7 z
for(int i=1;;i++) 1S&0
{ \UhGGg%
String header=con.getHeaderFieldKey(i); R7,pukK
if(header!=null) UL[uh@4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); z41D^}b
Utility.log(header+" : "+con.getHeaderField(header)); AT-0}9z{
else lqauk)(A0
break; 8'n#O>V@
} HMhLTl{;
} d0TgqO{
*0lt$F$~b
X&/(x
public void splitterStop() !%X>rGkc
{ #U:0/4P(
bStop = true; &D)Hz
} mcCB7<. e
w gmWo8
yX`J7O{=
} eXc[3ceUr
5R)[Ou.
RZ<.\N (M
/* ":nI_~q
**FileAccess.java =?^-P{:\?
*//文件访问(定位，写) 75<el.'H
package NetFox; )Gmb?!/^
import java.io.*; 3mybG%39
am3V9"\
UC.8DaIPN
public class FileAccessI implements Serializable{ DhHtz.6
N-Qu/,~+
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 x4@MO|C
RandomAccessFile oSavedFile; Cy]"
long nPos; a$A2IkD
xJ$Rs/9C
haN"/C^
public FileAccessI() throws IOException B5D3_iX]
{ Q:kwQg:~
this("",0); 0=2H9v
} IcRM4Ib))Q
87R%ke
e#K rgUG
public FileAccessI(String sName,long nPos) throws IOException x-tm[x@;o
{ Hi$#!OU
oSavedFile = new RandomAccessFile(sName,"rw"); `Yg7,{A\J
this.nPos = nPos; \MF3CK@/
oSavedFile.seek(nPos); JATS6-Lz`
} .V7Y2!4TE
<1TlW ~q<
' l|41wxk
public synchronized int write(byte[] b,int nStart,int nLen) dvC0 <*V
{ ex{)mE4Cd
int n = -1; Fka1]|j9
try{ k>7gy?Y!K<
oSavedFile.write(b,nStart,nLen); g9M')8a n
n = nLen; b$PT_!d
} C3]\$
catch(IOException e) }klE0<W|5\
{ N`J:^,H
e.printStackTrace (); L00Sp#$\
} 2*N&q|ED
6\%r6_.d
B>ms`|q=l
return n; xV"6d{+
} ?f(pQy@V
~JIywzcf8
9yO{JgKA
} qn5yD!1
@?'t@P:4
~JAH-R
/* #8P#^v]H
**SiteInfoBean.java 1'(_>S5CG
*/ .`:oP&9r
package NetFox; 'm
(xI)"{
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public class SiteInfoBean { z4 GN8:~x
,R7=]~<io"
SH .9!lQv
private String sSiteURL; //Site's URL Gw{Gt]liq
private String sFilePath; //Saved File's Path aS c#&{
private String sFileName; //Saved File's Name A@9U;8k
private int nSplitter; //Count of Splited Downloading File 6 ,7/8
?j &V:kF
%i;r]z-
public SiteInfoBean() {JCSR2BB
{//nSplitter的缺省值为5 v!WU |=u
//default value of nSplitter is 5 QC$=Fs5+
this("","","",5); QCZ,K"y
} U>e3_td3,
6n2Vx1b
_C7abw-
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) n's2/9x
{ w`H.ey
sSiteURL= sURL; [Q2S3szbt6
sFilePath = sPath; 7j9D;_(.^$
sFileName = sName; o=mq$Z:}
this.nSplitter = nSpiltter; hNu>s
S3%.-)ib
">0/>>Ry
} d A_S"Zc
eO|^Lu]+
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public String getSSiteURL() ]# tGT0
{ $Uv<LVd(
return sSiteURL; *7:u-}c!
} [TiTff&LV
w>H%[\Qs
/K2.V@T
public void setSSiteURL(String value) ;o~+2Fir
{ ~frPV8^DP
sSiteURL = value; `dG.L
} <>&e/
J4Q)`Y\~
r'mnkg2,
public String getSFilePath() _qO;{%r
{ orcZyYU
return sFilePath; /-G qG)PX
} !`O_VV`/@
G#9o?
}J'5EAp
public void setSFilePath(String value) >#"jfjDuR
{ #cSw"A
sFilePath = value; {2'74
} j. ks UJ
ims=-1,
&vJ(P!2f<
public String getSFileName() 9H !B)
{ ^a:vJ)WB7
return sFileName; e4>L@7
} IGF37';;
xVh\GU855
Cn6n4, 0
public void setSFileName(String value) )<]w23i
{ q>(I*=7
sFileName = value; 1?e>x91
} Oo3qiw
_.Z&<.lJ
<'o'H
public int getNSplitter() A .jp<>
{ MQbNWUi
return nSplitter; ..Uw8u/
} 2]_4&mU
R&x7Iq:=D
]P}K3tN%]
public void setNSplitter(int nCount) &bS"N)je
{ @gu77^='
nSplitter = nCount; }jyS\drJ
} (to/9OrG
} 0$F _hZU
=Nv=Q mO
+,{Wcb
/* 98b9%Z'2f
**Utility.java Z+`{JE#
*/ 5b{yA~ty
package NetFox; >2/wzsW
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#<WyId(
public class Utility { 5u u2 _B_L
3wa<,^kqy
r:8]\RU
public Utility() 5.C[)`_
{ P98X[0&
-UD~>s
NZ%~n:/V#
} ?V\9,BTb)
0,L$x*Nj5
//线程睡眠 gqJEJ~
public static void sleep(int nSecond) Cr V2 V)|G
{ ~\@<8@N2a6
try{ :}3qZX
Thread.sleep(nSecond); iuU3*yyn
} wE8a4.
catch(Exception e) /F8\%l+
{ xJF6l!`
e.printStackTrace (); W:+2We@
} 0imqj7L
} _'v }=:X
u=v%7c2Mx}
//日志 Ae{4AZ
public static void log(String sMsg) H>X>5_{}
{ Z.Y;[Y
System.err.println(sMsg); {KpH|i
} "ZJ1`R=Mj
J:mu%N`
(fk, 80
public static void log(int sMsg) 2 Zjb/
{ G4iLCcjY
System.err.println(sMsg); n%MYX'0
} !EmR(x
} \dxW44sM
pD}VB6=
_G}CD|Kx
/* 5(MZ%-~l
**TestMethod.java [;V1y`/K1
*/ Er)_[^) HG
package NetFox; [nPzhXs
FOUs= E[
<*(UvOQuX
public class TestMethod { oN6*WNtJ
fFTvf0j
B,m$ur#$
public TestMethod() }2!5#/^~
{ ///xx/weblogic60b2_win.exe 3EW f|6RI
try{ UN .[,%<s
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2Fp]S a
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); d`],l\oC
SiteFileFetch fileFetch = new SiteFileFetch(bean); {+UNjKQC
fileFetch.start(); 4pTuP /
} _]~ht H
catch(Exception e){e.printStackTrace ();} 84oW
o|*|
A@
} WJh;p: q[
!wR{Y[Yu
MCrO]N($b
public static void main(String[] args) i>if93mpj
{ I.\f0I'.
new TestMethod(); 2}#wdJ`
} feq6!k7
} kx:lk+Tx
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