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)); y+_U6rv[
} 4ai3@f5
for(int i=0;i<nEndPos.length-1;i++) G9TUU.T
{ K!j2AP3
nEndPos = nStartPos[i+1]; W&nVVV8s@
} G}x^PJJt
nEndPos[nEndPos.length-1] = nFileLength; 7Udr~0_)
} g|Cnj
} e~1??k.;=
psBBiHB[L
~EymD *
//启动子线程 qp8;=Nfa
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +a{>jzR
for(int i=0;i<nStartPos.length;i++) P^z)]K#sw
{ d4U_Wu&
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -#@;-2w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ZzY6M"eUXD
nStartPos,nEndPos,i); p}\!"&,^m
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !!AutkEg>
fileSplitterFetch.start(); (<t)5?@%
} f#?R!pR
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^"I!+Teb
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); oz QL2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )DW;Gc
nEndPos = " + nFileLength); S!uyplYKF
// fileSplitterFetch[nPos.length-1].start(); ]`x~v4JU
l?d*g&
xK f+.6 wz
//等待子线程结束 gw-l]@;1
//int count = 0; mi+I)b=
//是否结束while循环 sSxra!tv4
boolean breakWhile = false; b@k3y9&
wcO_;1_ H
6N^FJCs
while(!bStop) &7cy9Z~m
{ z]pH'c39
write_nPos(); MC3{LVNK
Utility.sleep(500); qQQ~[JL
breakWhile = true; >A6lX)
tO#y4<
#Uo 9BM
for(int i=0;i<nStartPos.length;i++) <?!#QA
{ 3:r;(IaX
if(!fileSplitterFetch.bDownOver) dCBJV
{ D<:9pLD(
breakWhile = false; >:.Bn8-
break; 3s+D x$Ud
} Z+4J4Ka^!(
} 1*s Lj#
if(breakWhile) @d)6LA9Ec
break; q;U[f6JjE
aV1(DZ83
&WIPz\
//count++; !GO4cbdQ
//if(count>4) N?aU<-Tn
// siteStop(); #qzozQ4
} giv cq'L
3;&N3:,X
p AD@oPC
System.err.println("文件下载结束！"); hP #>`)aNY
} y3lsAe#
catch(Exception e){e.printStackTrace ();} 6D>o(b2
} ~<aCn-h0
a`}HFHm\2,
:)&_
//获得文件长度 FXIQS'
public long getFileSize() ^ `!6Yax?
{ L(iWFy1& T
int nFileLength = -1; hTF]-& hZ
try{ Wn|w~{d{
URL url = new URL(siteInfoBean.getSSiteURL()); v vFX\j3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h4]yIM`8d
httpConnection.setRequestProperty("User-Agent","NetFox"); nlKWZYv
N(Cfv3{
3SDw-k
int responseCode=httpConnection.getResponseCode(); ]krOPM/
if(responseCode>=400) =6ojkTk
{ zg|]Ic
processErrorCode(responseCode); 1 #_R`(C{
return -2; //-2 represent access is error 0-7xcF@s
} #P1k5!u
3ILEc:<0J
ZT!DTb B
String sHeader; l =#uy
A@GyKx%x$
`6'fX[j5
for(int i=1;;i++) ^;M!u8[
{ e4t'3So
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); b}Jcj
//Utility.log(in.readLine()); r@ ]{`qA
sHeader=httpConnection.getHeaderFieldKey(i); A+AqlM+$i
if(sHeader!=null) 94Are<
{ U:p<pTnMR
if(sHeader.equals("Content-Length")) (2X`imJ
{ tONxV`
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); v]BN.SHE_
break; `uY77co6
} (c_E*>c)
} 26j ; RV
else Y2}\~I0
break; Go8 m
} :\>@yCD
} f$R]m2
catch(IOException e){e.printStackTrace ();} \7jK6;R<
catch(Exception e){e.printStackTrace ();} N,L$+wm
C/!kMMh>vV
? 3Td>x
Utility.log(nFileLength); so1% MV
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Bf.@B0\
return nFileLength; Ft'?43J
} Y'wQ(6ok
yi PMJ
THC34u]
//保存下载信息（文件指针位置） ;BsyN[bF
private void write_nPos() }Til $TT%H
{ x^&D8&4^
try{ ry0P\wY}
output = new DataOutputStream(new FileOutputStream(tmpFile)); !IF#L0z
output.writeInt(nStartPos.length); \G:\36l
for(int i=0;i<nStartPos.length;i++) _DS_AW}D
{ mGb,oj7l
// output.writeLong(nPos); e2~&I`ct
output.writeLong(fileSplitterFetch.nStartPos); @-)jU!
output.writeLong(fileSplitterFetch.nEndPos); l!5fuB8
} B E!HM{-
output.close(); edD19A
} bkTk:-L5:
catch(IOException e){e.printStackTrace ();} [jU.58*
catch(Exception e){e.printStackTrace ();} ]hRCB=G
} qXcHf6
Jsde+G,N
-pvF~P?8U
//读取保存的下载信息（文件指针位置） llN#4D9s
private void read_nPos() [f 4Nq \i
{ 7S|nn|\Kp
try{ 'GcN9D
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6B'd]Fe
int nCount = input.readInt(); [,JUC<
nStartPos = new long[nCount]; VXX7Y?!
nEndPos = new long[nCount]; DvhJkdLB>
for(int i=0;i<nStartPos.length;i++) }f45>@uMW
{ 8iQ8s;@S&>
nStartPos = input.readLong(); jOV,q%)^,:
nEndPos = input.readLong(); G&,F-|`
} "k&QS@l
input.close(); xY v@
} YBF|0A{[Y
catch(IOException e){e.printStackTrace ();} 4Qwv:4La
catch(Exception e){e.printStackTrace ();} A0JlQE&U
} EbXWCD
t*KgCk1
G*`Y~SJp
private void processErrorCode(int nErrorCode) -y]e`\+[
{ u4hC/!
System.err.println("Error Code : " + nErrorCode); ;d5d$Np@m&
} ufq9+}
Q6%dM'fR
s1~&PH^
//停止文件下载 F)XO5CBK
public void siteStop() re[v}cB
{ },#@q_E
bStop = true; l<X8Ooan#{
for(int i=0;i<nStartPos.length;i++) =zBc@VTp
fileSplitterFetch.splitterStop(); c{4Y?SSx
J7a_a>Y
,0k3Qi%
} 4@0y$Dv\
} x:dI:G
//负责部分文件的抓取 n3x<L:)
**FileSplitterFetch.java BeFCt;
*/ -aSj-
package NetFox; n06T6oc
P~xP@?I%
ZE393FnE
import java.io.*; ,Kl6vw8Htg
import java.net.*; ~!//|q^J]
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a>6@1liT
public class FileSplitterFetch extends Thread { #z$g1\v
Cg#@JuwHa
T'8d|$X
String sURL; //File URL 85gdmla@9
long nStartPos; //File Snippet Start Position ';,Rq9-'
long nEndPos; //File Snippet End Position MbbKo-7F$
int nThreadID; //Thread's ID ` b$u w
boolean bDownOver = false; //Downing is over h_*!cuH
boolean bStop = false; //Stop identical }LYK:?_/
FileAccessI fileAccessI = null; //File Access interface I)s~kA.e
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v2K6y|6,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0vYHx V
{ MeCHn2zwB
this.sURL = sURL; 3+~m9:9
this.nStartPos = nStart; L>@:Xo@
this.nEndPos = nEnd; Fx!NRY_
nThreadID = id; g._`"c
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @3g$H[}
} 9lU"m_ QT4
&GKtD)
V =9
public void run() K."%PdC
{ iup "P
while(nStartPos < nEndPos && !bStop) CQ;.}=j ,
{ |g)/6jG<-
;nx? 4f+6h
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try{ @a~GHG[x
URL url = new URL(sURL); QtSJ9;eP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ZkA05wPZ#
httpConnection.setRequestProperty("User-Agent","NetFox"); 0cF+4,5
String sProperty = "bytes="+nStartPos+"-"; .+#<~Jv
httpConnection.setRequestProperty("RANGE",sProperty); (Vz\02,K
Utility.log(sProperty); Thc"QIk&4
!TwH;#U w
,Y+J.8.H
InputStream input = httpConnection.getInputStream(); E!rgR5Bd
//logResponseHead(httpConnection); JbR;E`8
XSBh+)0Ww
-h%!#g
byte[] b = new byte[1024]; z\g6E/%%
int nRead; yb4Jsk5%
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) LFwRTY,G
{ $_5a1Lq1
nStartPos += fileAccessI.write(b,0,nRead); ]:g;S,{
//if(nThreadID == 1) 09_5niaz[
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); SW; %2
} L!qXt(`
"o{o9.w
VC T~"T2R
Utility.log("Thread " + nThreadID + " is over!"); .e Jt]K
bDownOver = true; kklM"Av
//nPos = fileAccessI.write (b,0,nRead); =}pPr]Cc
} :i};]pR
catch(Exception e){e.printStackTrace ();} d&G#3}kOb%
} P\k5%
} n`TXmg
\+3P<?hD#
0x1#^dII
//打印回应的头信息 Tm) (?y
public void logResponseHead(HttpURLConnection con) $C^tZFq
{ aePLP
for(int i=1;;i++) iVdY\+N!<
{ 3;-P(G@
String header=con.getHeaderFieldKey(i); K3I|d;Y~X!
if(header!=null) wR@"]WkR=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); &ZR}Z7E*=
Utility.log(header+" : "+con.getHeaderField(header)); {37v.4d;
else +$SJ@IH[<
break; L0QF(:F5
} >3SZD
} +BaZl<ZP1s
,e93I6
$kD;*v=
public void splitterStop() l2|[
{ :d{-"RAG"
bStop = true; a?K3/0G
} Ro:DAxi@L
xa&5o`>1G
lHI;fR
} '2=$pw
BK/_hNz
zMI_8lNz
/* 9o<5Z=
**FileAccess.java /$Ca}>
*//文件访问(定位，写) e]Q bC"
package NetFox; ?y`we6~\1
import java.io.*; S?BI)shmg
KP*cb6vA
Wm#F~<$
public class FileAccessI implements Serializable{ 8H7=vk+
1Ht&;V
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 QoBM2QYO
RandomAccessFile oSavedFile; (_.0g}2
long nPos; >"?jW@|g
mYRsM s
kh5VuXpe
public FileAccessI() throws IOException )/mBq#ZS
{ j.:I{!R#
this("",0); -qNun3
} fnZ?YzLI
2Q81#i'Cm
F!*tE&Se+
public FileAccessI(String sName,long nPos) throws IOException -RKqbfmi=
{ b2vCr F;
oSavedFile = new RandomAccessFile(sName,"rw"); Yk @/+PE
this.nPos = nPos; .tQeOZW'
oSavedFile.seek(nPos); `-)Hot)
} `~;`q
jBLLx{
zNRR('B?
public synchronized int write(byte[] b,int nStart,int nLen) HpGI\s
{ Zv|TvlyT"
int n = -1; Uw5AHq).
try{ =6H
oSavedFile.write(b,nStart,nLen); 'fS&WVR?
n = nLen; i8Xz'Sw07
} FhJtiw@
catch(IOException e) bg/a5$t
{ |SSe n#PYp
e.printStackTrace (); !E.CpfaC
} t;/s^-}
kPvR ,
{[:]}m(c
return n; ~/m=Q<cV
} ?Jy/]j5fI
W\1V`\gF
4qvE2W}&
} +.pri
j[Z<|Da
[$e\?c
/* 4Gor*{
**SiteInfoBean.java )Rc
*/ MfG8=H2#|
package NetFox; PW QRy
MiN|u
C.N#y`g
public class SiteInfoBean { o8c5~fG1
F\Q X=n
M"!{Dx~
private String sSiteURL; //Site's URL P0<)E
private String sFilePath; //Saved File's Path >hv8zHOO:
private String sFileName; //Saved File's Name vlVHoF;&
private int nSplitter; //Count of Splited Downloading File .8]buM5_G
FXG,DJ:
6^NL>|?
public SiteInfoBean() Qy7pM8~h
{//nSplitter的缺省值为5 $i;m9_16
//default value of nSplitter is 5 TW~%1G_v
this("","","",5); /H~]5JZ3-E
} 8z)J rO}
S(#v<C,hd
]Il}ymkIZ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8/"R&yAh
{ WbJ
sSiteURL= sURL; JJ4w]Dd4
sFilePath = sPath; .Ge`)_e
sFileName = sName; <pIel
this.nSplitter = nSpiltter; 2OZ<t@\OY
L#MgoBXr
9+"ISXS
} `;)op3A'
E++3GagdiD
8;y\Ln?B
public String getSSiteURL() 4L<;z'
{ S5/p3;O\c
return sSiteURL; K_GqM9
} FM,o&0HSd
'4)4*3z,
,Q,3^v-
public void setSSiteURL(String value) e!N%
{ Y,M2D
sSiteURL = value; b NR@d'U
} 2Kz407|'
.1F41UyL
WCyjp
public String getSFilePath() KMP[Ledr
{ lXip%6c7
return sFilePath; yi:1cLq2
} 1k!$#1d<
=;{8)m
iLk"lcX
public void setSFilePath(String value) %@^9(xTE
{ &UIS17cT
sFilePath = value; Rja>N)MzBf
} iD)P6"
NszqI
H,Yrk(O-
public String getSFileName() KvmXRf*z
{ 9E2OCLWrE
return sFileName; >2ny/AK|
} Gdv{SCV
I<!,_$:
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public void setSFileName(String value) Lm7fz9F%
{ ~}g)N
sFileName = value; ?P"j5
} e$N1m:1*
I>:.fHvUC
,~>u<Wc!S
public int getNSplitter() Bxk2P<d
{ N4w&g-
return nSplitter; Dpkc9~z
} g-<[* nF
5@EX,$h
wpa^]l
public void setNSplitter(int nCount) b|u,[jEB
{ x }i'2
nSplitter = nCount; 7'RU\0QG
} (|sqN8SbA
} MrhJk
Hh'o:j(^
# 66vkf*
/* j1K?QH=e#{
**Utility.java >=YQxm}GJ
*/ b X4]/4%
package NetFox; dF'oZQz
iCdq-r/r!6
Z4{~
public class Utility { :tp{(MF
Y|L]#
85ND 3F6q4
public Utility() ,8+Jt@L
{ Ae'N1V
=|qYaXjT$
$O,IXA
} 7%yP5c B
r-ljT<f%J[
//线程睡眠 VE*&t>I
public static void sleep(int nSecond) ^K[[:7Aem
{ 4_w{~
try{ |VmQ
Thread.sleep(nSecond); w C-x'
} T^H`$;\
catch(Exception e) *wV`7\@
{ L87=*_!B;
e.printStackTrace (); %i@Jw
} .1h1J
} m-R`(
{%QWv%|
//日志 ty b-VO
public static void log(String sMsg) -bp7X{&
{ ;xjw'%n,
System.err.println(sMsg); T9]:, z
} :.?%e{7
e`;U9Z
s3oQ( wC %
public static void log(int sMsg) Df0m
{ v}&J*}_XZ
System.err.println(sMsg); y-vQ4G5F|
} }bYk#6KX
} 5Cl;h^R|m
c'Zs2s7$
WxS$yUu
/* N>',[4pJ|
**TestMethod.java 6adXE
*/ rM)-$dZ
package NetFox; 2IFEl-IB[
=R0#WMf$@
dPyZzMes=
public class TestMethod { #i|AE`
5 DvD
Cm[^+.=I
public TestMethod() ui1h M
{ ///xx/weblogic60b2_win.exe l5l#LsaQb
try{ <9aa@c57
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); q|kkdK|N/Y
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); );*#s~R
SiteFileFetch fileFetch = new SiteFileFetch(bean); Rx.dM_S
fileFetch.start(); |gM@}!DL
} ]VHO'z\m
catch(Exception e){e.printStackTrace ();} .{66q#.
n]snD1?KX
8?&!@3n
} h}f l:J1C
h0Ilxa
PVX23y;
public static void main(String[] args) jHBP:c
{ .?;"iv+
new TestMethod(); mE3M$2}
} xQ@gh ( (
} DT>Giic
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