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)); :o?On/
} IQf:aX
for(int i=0;i<nEndPos.length-1;i++) Z{xm(^'i
{ .&=nP?ZPC6
nEndPos = nStartPos[i+1]; ,]\L\V
} NGtSC_~d
nEndPos[nEndPos.length-1] = nFileLength; 7'z{FSS
} w`&~m:R
} "detDB
k?3NF:Yy7
vdAaqM6D
//启动子线程 ob05:D_bc9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; n.n;'p9t@
for(int i=0;i<nStartPos.length;i++) 0#0[E,
{ !#` .Mv Z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), py VTA1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), I9rWut@+
nStartPos,nEndPos,i); Pqli3(
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); vmm#UjwF3
fileSplitterFetch.start(); Lqq RuKi
} ;D&FZ|`(u
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [Nbs{f^J=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); vx62u29m
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |RS9N_eRt
nEndPos = " + nFileLength); <V0]~3
// fileSplitterFetch[nPos.length-1].start(); '`&gSL.1a@
nh"nSBRxk
UUJbF$@;
//等待子线程结束 oP;"`^_
//int count = 0; 109dB$+$
//是否结束while循环 -b"mx"'?
boolean breakWhile = false; 9`VgD<?v
fT.18{'>
pyYm<dn
while(!bStop) ^0py
{ dc.9:u*w
write_nPos(); C?m2R(RF
Utility.sleep(500); w$8Su:g=
breakWhile = true; m1H_kJ
b6Pi:!4
wO9|_.Z{
for(int i=0;i<nStartPos.length;i++) ej,j1iB
{ k/o"E
if(!fileSplitterFetch.bDownOver) EKo!vieG
{ _b|mSo,{Y
breakWhile = false; #{KYsDtvx
break; |fqYMhA U
} 2%P{fJbwd
} A?V}$PTlx
if(breakWhile) 6U~AKq"+f
break; 67/JsL
no_;^Ou?
&0cfTb)dG
//count++; ;]!QLO.bs^
//if(count>4) p^QZGu-.W
// siteStop(); BBuI|lr
} j}O~6A>|
UgI0 *PE2
~SUrbRaY>
System.err.println("文件下载结束！"); z#9Tg"8]
} }zC9;R(E
catch(Exception e){e.printStackTrace ();} U|SF;T .
} n'*4zxAA
2q]y(kW+
,yc_r=_
//获得文件长度 eA q/[(
public long getFileSize() xe?!UCUb@
{ yTJ Eo\g/@
int nFileLength = -1; G#yv$LY#
try{ !jlLF:v|1A
URL url = new URL(siteInfoBean.getSSiteURL()); %PA#x36
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c"D%c(:4|
httpConnection.setRequestProperty("User-Agent","NetFox"); ?1Os%9D*
DS;,@$N_N
X<G"GaL
int responseCode=httpConnection.getResponseCode(); `|kW%L4
if(responseCode>=400) ?-M?{De
{ .5$"qb ?
processErrorCode(responseCode); iB4`w\-o
return -2; //-2 represent access is error R|&jvG=|
} H.ha}0J
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M;2@<,rM
String sHeader; |)~t^
eka<mq|W
-)N,HAM>
for(int i=1;;i++) FK;3atrz
{ ,GOH8h
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); w{F{7X$^
//Utility.log(in.readLine()); |ppG*ee
sHeader=httpConnection.getHeaderFieldKey(i); "06t"u<%
if(sHeader!=null) I;xSd.-
{ {:=sCY!
if(sHeader.equals("Content-Length")) [}>!$::Y
{ \dAs<${(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); suOWmqLs
break; )LC"rSNx%
} /=5:@
} ^]rPda#
else |WP}y-Au
break; Xz,fjKUnN
} Lf0X(tC
} #hMS?F|
catch(IOException e){e.printStackTrace ();} 6LRvl6ik
catch(Exception e){e.printStackTrace ();} SG$V%z"e
m3T=x =
_c!$K#Yl{
Utility.log(nFileLength); xP{)+$n
r=}v` R&
sdp3geBYo
return nFileLength; #jj+/>ZOi
} `;j@v8n$*
HQkK8'\LP
nh XVc((
//保存下载信息（文件指针位置） jw5ldC>U
private void write_nPos() 'G>$W+lT^
{ i0}f@pCB?X
try{ E.N@qMn~
output = new DataOutputStream(new FileOutputStream(tmpFile)); X+2uM+
output.writeInt(nStartPos.length); gwGw
for(int i=0;i<nStartPos.length;i++) &9Kni/
{ -UB XWl
// output.writeLong(nPos); ;cEoc(<?
output.writeLong(fileSplitterFetch.nStartPos); ;F_pF+&q
output.writeLong(fileSplitterFetch.nEndPos); =\`iC6xP}
} /@ww"dmqU
output.close(); y5{Vx{V"Q
} LWdA3%
catch(IOException e){e.printStackTrace ();} J?C#'2/
catch(Exception e){e.printStackTrace ();} n58yR -"
} fI v?HD:j
!!k^M"e2
p>N8g#G
//读取保存的下载信息（文件指针位置） [$X^r<|P@
private void read_nPos() emSky-{$u
{ (b;Kl1Ql]
try{ zC,c9b
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); X$2f)3
int nCount = input.readInt(); zJ6""38Pr
nStartPos = new long[nCount]; OwCbv j0#
nEndPos = new long[nCount]; oGRd ;hsF
for(int i=0;i<nStartPos.length;i++) 6gs0Vm
{ S4U}u l
nStartPos = input.readLong(); 9-+N;g!q
nEndPos = input.readLong(); +OI<0
} 5) q_Aro
input.close(); ^c<8|lK L@
} {E[t(Ig
catch(IOException e){e.printStackTrace ();} s*Nb=v.e9
catch(Exception e){e.printStackTrace ();} bj6;>Ezp3(
} d&* c3F
2@N9Zk{{J
D7r&z?
private void processErrorCode(int nErrorCode) s0O]vDTR,H
{ [ $5u:*
System.err.println("Error Code : " + nErrorCode); 9Nw&l@
} pZcY[a
BCfmnE4%
,j6R/sg
//停止文件下载 GT7&>}FJ)
public void siteStop() &\=Tm~
{ _\.4ofK(
bStop = true; Ht:\ z;cu
for(int i=0;i<nStartPos.length;i++) dVs=*GEl9
fileSplitterFetch.splitterStop(); ODEFs?%'
~&aULY?)]
7gcR/HNeF
} = GyABK
} &]h`kvtBC
//负责部分文件的抓取 d6a3\f
**FileSplitterFetch.java Xs{PAS0
*/ x2sKj"2?@
package NetFox; 5T%2al,F`
w4fQ~rcUIc
"}"/d(
import java.io.*; C :An
import java.net.*; mW$Oi++'d
:R`e<g~4
5 JlgnxRq
public class FileSplitterFetch extends Thread { mlxtey6H3
Y&1N*@YP
3G[|4v?[<_
String sURL; //File URL "=w:LRw
long nStartPos; //File Snippet Start Position Er;qs*f
long nEndPos; //File Snippet End Position NLra"Z
int nThreadID; //Thread's ID ^Ze(WE)
boolean bDownOver = false; //Downing is over &~Y%0&F,&
boolean bStop = false; //Stop identical qm"SN<2S*
FileAccessI fileAccessI = null; //File Access interface ;mYZ@g%e
^J&D)&"j
:C>iV+B j
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8_E(.]U
{ twu,yC!
this.sURL = sURL; XG*> yra`
this.nStartPos = nStart; qyxd9Lk1
this.nEndPos = nEnd; Gy[anDE&
nThreadID = id; D>8p:^3g
fileAccessI = new FileAccessI(sName,nStartPos);//定位 `KtP;nG
} .*f6n|
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public void run() ?=LT ^Zp`
{ { "M2V+ep
while(nStartPos < nEndPos && !bStop) 41]a{A7q
{ ol41%q*
'}9 Nvr)+
7H09\g&
try{ {?Nm"#
URL url = new URL(sURL); }`2a>N: &
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z;V(YK(WO.
httpConnection.setRequestProperty("User-Agent","NetFox"); {_-T!yb
String sProperty = "bytes="+nStartPos+"-"; ">G*hS
httpConnection.setRequestProperty("RANGE",sProperty); t=X=",)f
Utility.log(sProperty); HE35QH@/`
nw\C+1F
}AA">FF'y4
InputStream input = httpConnection.getInputStream(); ,p3]`MG
//logResponseHead(httpConnection); X4]miUmh
eAo+w*D(
m94PFD@N
byte[] b = new byte[1024]; Q=8YAiCu
int nRead; bf@g*~h@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 78{9@\e"0
{ 4BUG\~eI3
nStartPos += fileAccessI.write(b,0,nRead); ?Wz2J3A.2t
//if(nThreadID == 1) 2GORGS%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (c)=Do=
} 4b[bj").A
%L^(eTi[
h]h"-3
Utility.log("Thread " + nThreadID + " is over!"); g5y`XFY
bDownOver = true; Wlxmp['Bh
//nPos = fileAccessI.write (b,0,nRead); @I-,5F|r
} $m)gfI]9
catch(Exception e){e.printStackTrace ();} [.^ol6
} &9^4-5]
} +WAkBE/
@"`}%-b
\c<;!vkZ04
//打印回应的头信息 rH!sImz,
public void logResponseHead(HttpURLConnection con) _]33Ht9
{ %'ah,2a%
for(int i=1;;i++) =y-yHRC7
{ .SjJG67OyA
String header=con.getHeaderFieldKey(i); F \ls]luN
if(header!=null) ]:#=[CH
//responseHeaders.put(header,httpConnection.getHeaderField(header)); T 5Zh2Q@
Utility.log(header+" : "+con.getHeaderField(header)); +Eh.PWEe
else bS;_xDXd
break; McN[
} 'KIT^k0"Ih
} C{}PO u
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public void splitterStop() t$(#$Z,RS
{ CDM6o!ur3
bStop = true; _\KFMe=PV
} Dc@O Mr
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+HBizJ9K
} ?[d4HKs
>({qgzV`
{QM rgyQE
/* EP#2it]0]
**FileAccess.java >U,&V%y
*//文件访问(定位，写) ttUK~%wSx
package NetFox; t*9 gusmG
import java.io.*; I)V=$r{
g%l ,a3"
s[{[pIH
public class FileAccessI implements Serializable{ 6w7;
Nna.NU1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 aaig1#a@1b
RandomAccessFile oSavedFile; u0Wt"d-=
long nPos; <HoCt8>U
I4G0!"T+
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public FileAccessI() throws IOException zawu(3?~)5
{ Rpgg :
this("",0); !nSa4U,$w<
} 8j;Un]
/Ne#{*z)hO
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public FileAccessI(String sName,long nPos) throws IOException `=H*4I-"
{ sko7,&
oSavedFile = new RandomAccessFile(sName,"rw"); .p! DVQ"a
this.nPos = nPos; YK)m6zW5
oSavedFile.seek(nPos); gMI%!Y
} }yK7LooM
x6`mv8~9Db
HP.=6bJWi
public synchronized int write(byte[] b,int nStart,int nLen) R>O_2`c
{ 3A!a7]fW
int n = -1; >O?WRCB
try{ `Y:]&w
oSavedFile.write(b,nStart,nLen); PP$sdmo
n = nLen; (DO'iCxlNh
} UsyNn39
catch(IOException e) Ob/)f)!!
{ y017 B<Ou
e.printStackTrace (); ).^d3Kp
} ]UkH}Pt'3
UE'=9{o`
?9()ya-TE
return n; UON=7}=$&
} Zu,:}+niU
`.MZ,Xhqi"
(U.Go/A#wE
} ;|WUbc6&g
OM[MRZEh G
D{N8q^Cs9
/* GK}52,NM
**SiteInfoBean.java M!J7Vj?Ps
*/ _=~u\$
package NetFox; p[C"K0>:_F
G1 "QX
k`m7j[A]l
public class SiteInfoBean { +r3)\L{U
oIE 1j?
:EV.nD7
private String sSiteURL; //Site's URL $XhMI;h
private String sFilePath; //Saved File's Path DzGUKJh6
private String sFileName; //Saved File's Name }_'5Vb_
private int nSplitter; //Count of Splited Downloading File `[sFh%:
5`.CzQVb
MM@,J<
public SiteInfoBean() RRt(%Wm*
{//nSplitter的缺省值为5 &YXJ{<s
//default value of nSplitter is 5 "tCTkog3]
this("","","",5); `MVqd16Y
} G x[ZHpy;
aj`&ca8
fs ufYIf
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) J,?#O#j
{ \EfX3ghPI
sSiteURL= sURL; 49MEGl;K0\
sFilePath = sPath; F"]P|
sFileName = sName; - Z,Qj"V
this.nSplitter = nSpiltter; L[Vk6e
*SNdU^!
\P.h;|u
} rRq60A
O=2|'L'h!
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public String getSSiteURL() 6j(/uF4!#
{ Mh7m2\fLbd
return sSiteURL; yiZtG#6K{
} Ocdy;|&
UTkPA2x
LU:xmDv
public void setSSiteURL(String value) j?2~6W/[
{ ({!!b"B2
sSiteURL = value; ""-wM~^D
} }YDi/b7
f)*"X[)o
6YM X7G]
public String getSFilePath() iqDyE*a
{ }Ja-0v)Wf
return sFilePath; 4`,(*igEv
} Rml'{S
(A~7>\r +
8zx]/>
public void setSFilePath(String value) %y6Q3@
{ ?),b902C
sFilePath = value; |Vpp'ipr
} kZw"a*6
C^)Imr
z By%=)`
public String getSFileName() ;R*-cm
{ jaoZ}}V_$
return sFileName; [Fr](&Tx
} .#yg=t1C
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public void setSFileName(String value) q|D5 A|)
{ aS [[ AL
sFileName = value; L)JB^cxf
} .t@|2
t$!zgUJ
]@$^Ju,
public int getNSplitter() cLZ D\1Mt
{ P=n_wE
return nSplitter; Yqs=jTq`{
} c<$<n
*igmi9A
T3{O+aRt
public void setNSplitter(int nCount) ?J:w,,4m
{ <[db)r~c
nSplitter = nCount; vywB{%p
} ZexC3LD"
} cI2Ps3~"Q
o+1(N#?m9
R:~aX,qR
/* 81Kf X {|
**Utility.java ='m$O
*/ /z-rBfdy^
package NetFox; S8#0Vo$)a
9\_s&p=:.
Clum m@z;#
public class Utility { P =X]'m_B
$Z G&d
?Q]&;5o
public Utility() GY$Rkg6d
{ FSEf0@O:
W>pe-
JqzoF}WH
} rRe5Q
f-F=!^.
//线程睡眠 +fVvH
public static void sleep(int nSecond) 1bV G%N
{ D:@W*,
try{ :=NXwY3~M
Thread.sleep(nSecond); JQM_96\
} _BewaI;w
catch(Exception e) wo`.sB&T
{ 8:TX9`,
e.printStackTrace (); 7:UeE~uB:
} d7V/#34
} s 4`-mIa
lO-DXbgql$
//日志 xv]z>4@z,
public static void log(String sMsg) ^OV; P[
{ P'<i3#;7X
System.err.println(sMsg); ` i[26Qb
} 1TZ[i
zb0NqIN:
u2#q7}
public static void log(int sMsg) #&|"t<}
{ H:(B^uH
System.err.println(sMsg); M1Q&)am
} |P5dv>tb F
} \tgY2:
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@D9O<x
/* p cLKE ZK
**TestMethod.java 31G:[;g
*/ L2VwW
package NetFox; ,Q"'q0hM=
0fqcPi
}_lG2#Ll5
public class TestMethod { q2%cLbI F
{-5)nS^_
$1])>m_ct
public TestMethod() u#ya 8
{ ///xx/weblogic60b2_win.exe ;#Po}8Y=
try{ ?T/4 =
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); k4sV6f
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2O kID WcM
SiteFileFetch fileFetch = new SiteFileFetch(bean); !~E/Rp
fileFetch.start(); IOFXkpKR
} K28L(4)
catch(Exception e){e.printStackTrace ();} %B@NW2ZQ[
P`Zon
u$JAjA
} "Da1BuX\
9tpyrGv
ika*w
public static void main(String[] args) ?i<l7
{ }%XB*pzQ
new TestMethod(); 0N1t.3U
} ,3?=W/Um4
} "r6qFxY
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