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)); r8eJ&-Yi{Z
} X[r0$yuE
for(int i=0;i<nEndPos.length-1;i++) j*gJP !
{ kE.4 #
nEndPos = nStartPos[i+1]; PZJ9f8V
} IQ_s]b;z
nEndPos[nEndPos.length-1] = nFileLength; );VuZsmi
} T]Ai{@i
} _K!.TM+9
|idw?qCn
Dol{y=(3e
//启动子线程 DBB&6~;?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fglfnx0{
for(int i=0;i<nStartPos.length;i++) E/a2b(,Tg
{ pc0{
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y1I)w^}:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \.O&-oi
nStartPos,nEndPos,i); Wh| T3&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /z4c>)fV
fileSplitterFetch.start(); Y8]@y0(
} 2vLun
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z)U7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Dqii60
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |u^S}"@3sU
nEndPos = " + nFileLength); @-L]mLY
// fileSplitterFetch[nPos.length-1].start(); ltDohm?
\>Rfa+
|k90aQO
//等待子线程结束 -5 PVWL\
//int count = 0; rvy%8%e?
//是否结束while循环 ^7gKs2M
boolean breakWhile = false; cPuXye
5!fYTo|G>
) c\Y!vS
while(!bStop) |,:p[Oy
{ +llb{~ZN
write_nPos(); `62v5d*>a
Utility.sleep(500); T\bP8D
breakWhile = true; ]q{_i
m<-!~ ew
4jC)"tch
for(int i=0;i<nStartPos.length;i++) h2f8-}fsq
{ Vi-Ph;6[
if(!fileSplitterFetch.bDownOver) f+uyO7
{ +"<+JRI(M5
breakWhile = false; bV&9>fC
break; CAC4A
} f%@~|:G:
} =dDPQZEin
if(breakWhile) `}#rcDK
break; lMGO4U[z
m","m
?l?l<`sTO
//count++; =3-?$
//if(count>4) {<gv1Yht
// siteStop(); Y06^M?}
} {@)ZXg
4 O8ct,Y
hFv{?v
System.err.println("文件下载结束！"); oH%[8!#
} O8$~dzf,2
catch(Exception e){e.printStackTrace ();} w=WF$)ZU
} IUv#nB3
)wM%Ul<s
McasnjC
//获得文件长度 b-VygLN
public long getFileSize() !P=Cv=
{ VZWo.Br'W
int nFileLength = -1; * &:_Vgu
try{ 4-x<^ ev=
URL url = new URL(siteInfoBean.getSSiteURL()); b/:wpy+9Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b~,e(D9DG
httpConnection.setRequestProperty("User-Agent","NetFox"); 196a~xNV
%5gdLm!p
zFExYYd
int responseCode=httpConnection.getResponseCode(); lxL.ztL
if(responseCode>=400) ^%9oeT{
{ ?QT6q]|d0+
processErrorCode(responseCode); w/m@(EBK
return -2; //-2 represent access is error '?veMX
} N:| :L:<1
~h3G}EH
_Pqq*
String sHeader; Uw.')ZY=
Z5 IWoY
OA3J(4!"W
for(int i=1;;i++) MZ,1mR
{ b`#YJpA
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,7&\jET5^0
//Utility.log(in.readLine()); T[|#DMg$F
sHeader=httpConnection.getHeaderFieldKey(i); Qs,\P^n
if(sHeader!=null) kx;X:I(5&P
{ 3?*dv14
if(sHeader.equals("Content-Length")) 2 3PRb<q
{ HD=F2p
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +zMPkbP6
break; #!R>`l(S
} =Z:]%
} Mc@9ivwL#
else (46'#E z[F
break; $3HqVqF^R
} *XhlIQ
} JKM(fX+
catch(IOException e){e.printStackTrace ();} 0AQ4:KV(Y
catch(Exception e){e.printStackTrace ();} I </P_:4G
f $Agcy
"i;.>
Utility.log(nFileLength); sq_>^z3T
c]|vg=W
1PwtzH.w
return nFileLength; 7<^+)DsS?
} 2L4[~>
\yJ 4+vo2Q
DPzW,aIgv
//保存下载信息（文件指针位置） !+PrgIp>
private void write_nPos() ISpV={$Zd
{ y5j:+2|I
try{ hUlRtt
output = new DataOutputStream(new FileOutputStream(tmpFile)); Zt3sU_
output.writeInt(nStartPos.length); a|u#w~
for(int i=0;i<nStartPos.length;i++) M?h{'$T
{ G7 UUx+X
// output.writeLong(nPos); ['}|#3*w
output.writeLong(fileSplitterFetch.nStartPos); $?PI>9g!
output.writeLong(fileSplitterFetch.nEndPos); ?l9sj]^w
} XZ |L D#
output.close(); ]AY 4bm
} Ww-x+U\l
catch(IOException e){e.printStackTrace ();} vTK%8qoZ
catch(Exception e){e.printStackTrace ();} k2D*`\ D
} tw$EwNI[
I3nE]OcW@
hH1Q:}a
//读取保存的下载信息（文件指针位置） gFTU9k<
private void read_nPos() lKejWT`;
{ JI!1 .]&
try{ vMp=\U-~^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @GKDSS4jv
int nCount = input.readInt(); \|Af26
nStartPos = new long[nCount]; .z,-ThTH@\
nEndPos = new long[nCount]; ElW\;C:K*
for(int i=0;i<nStartPos.length;i++) MeBTc&S<
{ $\P/ %eP
nStartPos = input.readLong(); %HG+|)b
nEndPos = input.readLong(); 7He"IJ
} ,"`20.Lv
input.close(); ED>7
} 5<(* +mP`
catch(IOException e){e.printStackTrace ();} o!BCR:
catch(Exception e){e.printStackTrace ();} &s`)_P[
} bPFGQlmIO
R@3HlGuRKw
Y5GN7.
private void processErrorCode(int nErrorCode) @o0HDS
{ ejV`W7U
System.err.println("Error Code : " + nErrorCode); YdCl
} (sKg*G2
j-1V,V=
~%*l>GkP*
//停止文件下载 U%@PY9#
public void siteStop() y ~ K8
{ mx}5":}
bStop = true; h~#F2#.
for(int i=0;i<nStartPos.length;i++) $=plAi
fileSplitterFetch.splitterStop(); 5>9Q<*
U^7hw(}me
RDbNC v#
} _E?tVx.6
} nr]=O`Mvh
//负责部分文件的抓取 %_E5B6xi{
**FileSplitterFetch.java y05!-G:Y\
*/ %_Vz0 D!7
package NetFox; uN<=v&]q
[s^pP2
/1LN\Eu
import java.io.*; ]&]G
import java.net.*; 961&rR}d
zRjbEL
-I5]#%eX^
public class FileSplitterFetch extends Thread { 9\!&c<i=
,.P]5 lE
?/&X_O
String sURL; //File URL PJB_"?NTTC
long nStartPos; //File Snippet Start Position 1^$hbRq
long nEndPos; //File Snippet End Position rwDLBpk
int nThreadID; //Thread's ID N#M>2b<A/T
boolean bDownOver = false; //Downing is over EN`JzLjP
boolean bStop = false; //Stop identical ZiR}S
FileAccessI fileAccessI = null; //File Access interface G%~Vb
qY-aR;
:/(G#ZaV
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException IA0vSF:
{ -btNwE6[.
this.sURL = sURL; TE&E f$h
this.nStartPos = nStart; =M 8Mt/P
this.nEndPos = nEnd; ;*qXjv& K
nThreadID = id; v>K|hH
fileAccessI = new FileAccessI(sName,nStartPos);//定位 g=D]=&H
} M{p6&eg
zk$h71<{.
Ia](CN*;6
public void run() c= 2E/x?
{ TSFrv8L
while(nStartPos < nEndPos && !bStop) BMAWjEr
{ i-0 :Fs
`P\H{
`{YOl\d_
try{ :c]y/lQmV
URL url = new URL(sURL); g[i;>XyP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3\ajnd|
httpConnection.setRequestProperty("User-Agent","NetFox"); D7pQWlN\
String sProperty = "bytes="+nStartPos+"-"; Y_*KAr'{P
httpConnection.setRequestProperty("RANGE",sProperty); @GAj%MK$
Utility.log(sProperty); 'dwsm7Xd
5L6.7}B
9*iVv)jd
InputStream input = httpConnection.getInputStream(); 1N _"Mm{
//logResponseHead(httpConnection); [uqr
Q']'KU.
E7h@c>IK
byte[] b = new byte[1024]; 0*:n<T9
int nRead; h(q4 B~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) BpA7 z/
{ KD#zsL)3
nStartPos += fileAccessI.write(b,0,nRead); D`n<!"xg@$
//if(nThreadID == 1) d3EN0e+^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oa+'.b~
} =KR^0<2r
?z)2\D
<EyJ $$
Utility.log("Thread " + nThreadID + " is over!"); d.ywH;
bDownOver = true; @~{TL
//nPos = fileAccessI.write (b,0,nRead); FBP #_"z
} ~*h)`uM
catch(Exception e){e.printStackTrace ();} Flpl,|n a
} ST#)Fl
} ,^4"e (
5D3&E_S
:fX61S6)
//打印回应的头信息 ce4rhtkV
public void logResponseHead(HttpURLConnection con) q@1A2L\Om
{ .))k
for(int i=1;;i++) M97+YMY)
{ uR")@Tc
String header=con.getHeaderFieldKey(i); sfG9R"
if(header!=null) LU*mR{B
//responseHeaders.put(header,httpConnection.getHeaderField(header)); vIi&D;
Utility.log(header+" : "+con.getHeaderField(header)); QN;NuDHN
else i{:?Iw 'ay
break; 3|e~YmZx
} 0*^f EoV
} :;#^gvH
*>iJ=H
M2:3k
public void splitterStop() l+(B~v
{ 5FJ%"5n&
bStop = true; !pa7]cZ
} .}R'(gN\6
qYqd-R
9%k4Ic%P
} T8LvdzS
kVWrZ>McK
'#K~hep
/* ZnbpIJ8cV
**FileAccess.java JKYtBXOl
*//文件访问(定位，写) M9Z9s11{H
package NetFox; pOy(XUV9O
import java.io.*; |<]wM(GxE
|a1zJ_t4
/$8& r
public class FileAccessI implements Serializable{ F":dS-u&L
1:h(8%H@"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Nde1`W]:
RandomAccessFile oSavedFile; K/(Z\lL
long nPos; O>wGJ.
VF-[O
}sZy|dd
public FileAccessI() throws IOException A?ESjMy(R
{ ;%n(ARZ#
this("",0); $H,9GIivD
} [eF|2:
Y% [H:
&6Wim<*
public FileAccessI(String sName,long nPos) throws IOException jN+2+P%OL
{ up3mum
oSavedFile = new RandomAccessFile(sName,"rw"); D1fUEHB}A8
this.nPos = nPos; )A;jBfr
oSavedFile.seek(nPos); fK4O N'[R:
} Xp|$z~
3v~}hV/RUy
)6he;+
public synchronized int write(byte[] b,int nStart,int nLen) w/0;N`YB
{ 9Xh<vh8&
int n = -1; ,(yaWd6
try{ ]G~u8HPH!m
oSavedFile.write(b,nStart,nLen); j1@PfKh
n = nLen; {>&M:_`k
} 'xOH~RlE
catch(IOException e) :)Nk
{ t1l4mdp
e.printStackTrace (); Gm\jboef]
} {2&MyxV
^6,}*@
mc6W"
return n; s[*I210
} F.R0c@&W
aOW~! f/M
\?k"AtL
} tUFXx\p
"FfP&lF/
o, qBMo^.
/* `MMZR=LA
**SiteInfoBean.java hcD.-(-;)
*/ iEBxBsz_
package NetFox; e]d\S]5
k*T&>$k}^
"CT`]:GGK
public class SiteInfoBean { ^W,x
kh*td(pfP9
FwSV \N+#'
private String sSiteURL; //Site's URL QtqE&j
private String sFilePath; //Saved File's Path 2Y9@[
private String sFileName; //Saved File's Name gG6BEsGa,
private int nSplitter; //Count of Splited Downloading File h6gtO$A|p=
]FO)U
xHwcP21
public SiteInfoBean() A `=.F
{//nSplitter的缺省值为5 {$-\)K
//default value of nSplitter is 5 C'0=eel[
this("","","",5); .$-%rU:*}
} 1\Vp[^#Vx
!%yd'"6Dl
ez*O'U
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) cU=/X{&Om
{ (@u"
sSiteURL= sURL; v%2Jm!i+
sFilePath = sPath; o7 X5{
sFileName = sName; u!VY6y7p
this.nSplitter = nSpiltter; ;hU~nj+{
fxX4 !r
kv/mqKVr
} A v%'#1w<"
,G(bwE9~
u*H V
public String getSSiteURL() c"@,|wCUi
{ N%+C5e<
return sSiteURL; 8U&93$
} `wLa.Gzj
J|I&{
e;)&Hc:Z
public void setSSiteURL(String value) ,n+~S^r
{ E@$HO_;&
sSiteURL = value; c`G~.paY|
} V4 Wn
|zSoA=7?
<DM:YWNa
public String getSFilePath() i/WiSwh:
{ 8Ow0A
return sFilePath; GGwHz]1L
} be{tyV
< {dV=
naKB2y]l
public void setSFilePath(String value) 2(sq*!tX
{ cn!Y7LVr
sFilePath = value; k7Z1Y!n7
} T$;N8x[
Lv?e[GA
ZYX(Cf
public String getSFileName() 0E#3XhU
{ dy*CDRU4
return sFileName; at `\7YfQp
} /WKp\r(Hp
~,.}@XlgT.
#>\+6W17U
public void setSFileName(String value) v5o@ls
{ 86\B|!
sFileName = value; Arb-,[kwN
} KFMEY\6\h
X>y6-%@
b}#ay2AR
public int getNSplitter() u0& dDZ
{ oVSq#I4
return nSplitter; ;iEFG^'tG
} KUqD<Jj?
HNtl>H
?rn#S8nNx<
public void setNSplitter(int nCount) y7CrH=^jc
{ ()v{HBi
nSplitter = nCount; & ]/Z~Vt
} C|A:^6d3=
} _~E&?zR2>"
p#95Q
PH}^RR{H[
/* _mw(~r8R
**Utility.java ~?)ST?&
*/ \!4sd2Yi
package NetFox; %v(\;&@
(7g1eEK%
c);(+b
public class Utility { aBLE:v
qrmJJSJ
b 64~Y|8
public Utility() )cy_d!
{ 3;J)&(j0
{~ngI<
A;A>Q`JJF
} !mX 2
_ADK8a6%)
//线程睡眠 pPdOwK#
public static void sleep(int nSecond) ~\z\f}w
{ jci'q=Vpu
try{ JUlV$b.)J
Thread.sleep(nSecond); 4V`ypFme
} YbrsXp"
catch(Exception e) qeyBZ8BG
{ HEjrat;5
e.printStackTrace (); Wh)QCp0|n
} ? h$>7|
} 7QlA/iKqK
5!PU+9Kh
//日志 m{bw(+r
public static void log(String sMsg) +FoR;v)z=F
{ t3 q0|S
System.err.println(sMsg); IRZ?'Im
} ;?9u#FRtw
|'2E'?\/x
P2`!)teN
public static void log(int sMsg) ~ 0x9`~
{ b:S#Sz$
System.err.println(sMsg); `~"l a>}
} "yI)F~A
} '%>$\Lv
Q b5AQf30
PQ2u R
/* *HwTq[y
**TestMethod.java IdlW[h3`[
*/ m3k}Q3&6Z
package NetFox; \7}X^]UVx
bqMoO7&c
TWC^M{e
public class TestMethod { 7ST[XLwt%}
TCSm#?[B
m(Cn'@i`"0
public TestMethod() $ #C$V>
{ ///xx/weblogic60b2_win.exe ) tGC&l+?/
try{ o(. PxcD
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); JeJc(e
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7K`A2
SiteFileFetch fileFetch = new SiteFileFetch(bean); L44-: 3
fileFetch.start(); a<[@p
} Ywf.,V
catch(Exception e){e.printStackTrace ();} |/g\N,]
Zjt3U;Y
DiAPs_@
} pbivddi2
eA>O<Z1>
'$M=H.
public static void main(String[] args) :Q\b$=,:
{ >sP-)ZeuU[
new TestMethod(); `n7z+
} \HDRr*KO
} Y>+\:O
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