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)); ?G|*=-8
} cV|u]ce%1
for(int i=0;i<nEndPos.length-1;i++) O4l]Q
{ dE ,NG)MH
nEndPos = nStartPos[i+1]; b~5Q|3P9
} =r?#,'a
nEndPos[nEndPos.length-1] = nFileLength; [*{G,=tF`Y
} b@p3iq:
} 4/_@F>I_
ZvSWIQ6
il403Ae0
//启动子线程 n"Gow/-;
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; j$%uip{
for(int i=0;i<nStartPos.length;i++) &I=27!S
{ 1kDr;.m%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), udld[f.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $>Mqo
nStartPos,nEndPos,i); ~WKcO&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9hNHcl.
fileSplitterFetch.start(); ]CL9N
} BS(XEmJn&j
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )^D:VY92
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); =xf7lN'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 7?[{/`k~?
nEndPos = " + nFileLength); * 11|P
// fileSplitterFetch[nPos.length-1].start(); "&@v[O)!xu
`3QAXDWE
eG F{.]
//等待子线程结束 KcW]"K>p!
//int count = 0; $@R[$/
//是否结束while循环 'IykIf
boolean breakWhile = false; qad`muAd
kr=&x)Wy!
Gl@-RLo
while(!bStop) 83|7#L
{ CSBk
write_nPos(); 4/Wqeq,E8
Utility.sleep(500); s/"l ?d
breakWhile = true; CnvM>]
}2X"
/1!Wet}f
for(int i=0;i<nStartPos.length;i++) mv0JD(
{ x9lG$0k:V
if(!fileSplitterFetch.bDownOver) \{Yi7V Xv
{ 3r]m8Hp
breakWhile = false; QEb ^'y
break; EAE\'9T&g
} 3u tJlD
} Js'#=
if(breakWhile) KK|AXoBf
break; e; #"t
q\xT
.]IidsgM
//count++; W :qQ
//if(count>4) lZI?k=rWv
// siteStop(); O:hCUr
} jH4'jB
]'%Z&1 w
"'8^OZR
System.err.println("文件下载结束！"); 1X7tN2tQ
} i!U,qV1
catch(Exception e){e.printStackTrace ();} g`690
} Te:4z@?
bL)7/E
10C,\
//获得文件长度 {~lVe GBp
public long getFileSize() G5R"5d'
{ UF$JVb
int nFileLength = -1; n!Dy-)!`O
try{ ;YYo^9Lh}
URL url = new URL(siteInfoBean.getSSiteURL()); I<["ko,t@?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T/b%,!N)
httpConnection.setRequestProperty("User-Agent","NetFox"); 4J"S?HsW|
"G+g(?N]j
K:osfd
int responseCode=httpConnection.getResponseCode(); ;#goC N.
if(responseCode>=400) y7?n;3U]CS
{ v_7?Zik8E
processErrorCode(responseCode); x bsk
return -2; //-2 represent access is error Hfw*\=p
} { !;I4W%!
42{\u08Z
E5H0Yo.Wi
String sHeader; B]""%&! O
_$oN"pj
=[7[F)I~O
for(int i=1;;i++) )e1&[0
{ ev$\Ns^g$3
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "G&S`8
//Utility.log(in.readLine()); 5Wyo!pRi
sHeader=httpConnection.getHeaderFieldKey(i); hS?pc<~`#
if(sHeader!=null) WlJ$p$I`
{ 6BnP"R.
if(sHeader.equals("Content-Length")) Tf|?j=f
{ FM80F_G^z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); R[%ZyQ_
break; 9;L5#/E
} "k0bj>
} ,/XeG`vk
else a&?SRC'x
break; mw[T[
} !sJ*0
} Rfk8trD B
catch(IOException e){e.printStackTrace ();} L355uaj
catch(Exception e){e.printStackTrace ();} yqY nd<K4
t,f)!D$
'#;%=+=;
Utility.log(nFileLength); \$iU#Z
S-4C>gM
CXe2G5
return nFileLength; 8n[6BF);
} gq'}LcV
d,c8ks(
E/OJ}3Rf
//保存下载信息（文件指针位置） swfcA\7R
private void write_nPos() rmzM}T\20
{ us_o{
try{ m,u5S=3A{!
output = new DataOutputStream(new FileOutputStream(tmpFile)); Zs(I]^w;d
output.writeInt(nStartPos.length); (D?%(f
for(int i=0;i<nStartPos.length;i++) QXQ'QEG
{ O]XdPH20
// output.writeLong(nPos); D.i(Irqw!
output.writeLong(fileSplitterFetch.nStartPos); }Sxuc/%:
output.writeLong(fileSplitterFetch.nEndPos); x=/`W^t2
} B5nzkJV<X
output.close(); w`N|e0G@
} wa#$9p~Q
catch(IOException e){e.printStackTrace ();} "M GX(SQ
catch(Exception e){e.printStackTrace ();} &8##)tS(y
} \e=Iw"yd
J0 [^hH
"<#-#j
//读取保存的下载信息（文件指针位置） 'T '&OA
private void read_nPos() DR d|m<Z
{ $s*nh>@7
try{ -=tf)
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); pBd_BaN
int nCount = input.readInt(); rzR=% >
nStartPos = new long[nCount]; (.CEEWj%{
nEndPos = new long[nCount]; ]ZkR~?
for(int i=0;i<nStartPos.length;i++) @y|ZXPC#
{ sULCYiT|Hn
nStartPos = input.readLong(); f>*D@TrU
nEndPos = input.readLong(); eaG_)y
} (9"w{pnlLc
input.close(); &gP/<!#
} Xscm>.di
catch(IOException e){e.printStackTrace ();} <wIz8V
catch(Exception e){e.printStackTrace ();} 4*)a3jI?
} '=M4(h
jHU5>Gt-}
Ih&rXQ$
private void processErrorCode(int nErrorCode) n^a&@?(+
{ ~36)3W[4
System.err.println("Error Code : " + nErrorCode); L.E6~Rv
} y7x&/2
&D/@H1fBe
6t,_Xqg*
//停止文件下载 &B3[:nS2
public void siteStop() )jS9p~FS
{ _$Wj1h
bStop = true; b3zxiq x
for(int i=0;i<nStartPos.length;i++) >dr34=(
fileSplitterFetch.splitterStop(); ']x`d
2!}:h5
(3_m[N\F
} #835$vOe
} @`IMR$'
//负责部分文件的抓取 dr54D
**FileSplitterFetch.java VbwB<nQl
*/ !U6 x_
package NetFox; RTLA*
[}GPo0GY
M<%g)jn_
import java.io.*; 0m,3''Q5lO
import java.net.*; )zKZ<;#y
)6t=Bel
'X$J+s}6&
public class FileSplitterFetch extends Thread { 4U;Zs3
|e]2 >NjQa
;%wY fq~P
String sURL; //File URL %mO.ur>21
long nStartPos; //File Snippet Start Position .!B>pp(9
long nEndPos; //File Snippet End Position Y*KP1=Md
int nThreadID; //Thread's ID ~vL`[JiK
boolean bDownOver = false; //Downing is over )~Pj3
boolean bStop = false; //Stop identical TTfU(w%&P
FileAccessI fileAccessI = null; //File Access interface W/\M9
W`d\A3v
kf Xg\6uKc
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /_?y]Ly[r
{ `1hM3N.nO
this.sURL = sURL; 88}=VS
this.nStartPos = nStart; Cb1fTl%
this.nEndPos = nEnd; mj!P ]
nThreadID = id; Wifr%&t{J
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \nKpJ9!
} fl4z'8P"(
X`+8rO[
c:@lR/oe"
public void run() pAm L
{ "h84D&V
while(nStartPos < nEndPos && !bStop) vz*'1ugaA
{ HXg#iP^tv
Z2t r?]
(9A`[TRwi
try{ d$;1%rRj8
URL url = new URL(sURL); +YNN$i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #% 1|$V*:
httpConnection.setRequestProperty("User-Agent","NetFox"); ,iy;L_N
String sProperty = "bytes="+nStartPos+"-"; RoY"Haa
httpConnection.setRequestProperty("RANGE",sProperty); / Ml d.
Utility.log(sProperty); )d^b\On
br[n5
|nu)=Ag
InputStream input = httpConnection.getInputStream(); ]CnqPLqL
//logResponseHead(httpConnection); -IP3I
(UGmbRf&
Wb7z&vj
byte[] b = new byte[1024]; G^6\OOSy
int nRead; +'!4kwTR
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) XVRtfo
{ o<f#Zi
nStartPos += fileAccessI.write(b,0,nRead); W4ygJL7 6
//if(nThreadID == 1) A:JWUx
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); flr&+=1?D
} n?EL\B
@9}SHS
4hLv"R.
Utility.log("Thread " + nThreadID + " is over!"); Rc.8j,]
bDownOver = true; a+_F^
//nPos = fileAccessI.write (b,0,nRead); }2;{}J
} a=%QckR*
catch(Exception e){e.printStackTrace ();} km[PbC
} ;A3aUN;"I
} $At,D.mGkb
|TE\]
rf:CB&u
//打印回应的头信息 LqOjVQxz
public void logResponseHead(HttpURLConnection con) >RL|W}tI4
{ KJ]ejb$
for(int i=1;;i++) h=`1sfz
{ I8]q~Q<-P
String header=con.getHeaderFieldKey(i); ;^cc-bLvF
if(header!=null) HbUadPr
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,VTX7vaH
Utility.log(header+" : "+con.getHeaderField(header)); (!iGQj(m
else aDreN*n
break; ZR|cZH1}C
} jh*aD=y
} =>Md>VM
OlJkyL8|
R{hq1-
public void splitterStop() -?K?P=B;X
{ -Z/'kYj?U
bStop = true; nOE 1bf^l
} *?Pbk+}%
}K%y'D
_);;@T
} a!?&8$^<
;&9A Yh.
@N'0:0Nb_
/* 5csqu^/y
**FileAccess.java i H^Gv*
*//文件访问(定位，写) dAZh# i[
package NetFox; IUJRP
import java.io.*; B2uLfi$q
01-n_ $b
VIi/=mO]
public class FileAccessI implements Serializable{ o3oAk10
V`7^v:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ]mW)T0_
RandomAccessFile oSavedFile; 9j6
long nPos; V L&5TZtz
2\:z
YyZ>w2_MTi
public FileAccessI() throws IOException /h!Y/\kI
{ f4k\hUA
this("",0); xg>AW Q
} 0qV"R7TW
H:DTvv8e{
o5 fXe}pl@
public FileAccessI(String sName,long nPos) throws IOException KP[H&4eoC
{ R4RSXV
oSavedFile = new RandomAccessFile(sName,"rw"); nOd'$q
this.nPos = nPos; O+o4E?}
oSavedFile.seek(nPos); @YMQbjbr
} k$hNibpkt
njk1x
!Hk$ t
public synchronized int write(byte[] b,int nStart,int nLen) r:&"#F
{ MZ8jL,a^
int n = -1; <Rl:=(]i~
try{ P0En&g+~
oSavedFile.write(b,nStart,nLen); nn"Wn2ciS
n = nLen; jmAQ!y|W.
} &y}nd 7o
catch(IOException e) nA\9UD<G.
{ ~[CtsCiQ
e.printStackTrace (); BE;J/
} iE|qU_2Y
]vPa A
sc2nLyn$
return n; H8ws6}C
} G$5N8k[2
jQKlJi2xu
MBbycI,
} }^Unx W
h9McC3
C^hHt,&
/* Rv)!p~V8
**SiteInfoBean.java |vZ\tQ
*/ 7H-,:8
package NetFox; hm%'k~
GnE%C2L-
zs@#.OEH
public class SiteInfoBean { K8`M~P.
; )Vro
7-oH >OF^
private String sSiteURL; //Site's URL xb!h?F&
private String sFilePath; //Saved File's Path n.{+\M6k
private String sFileName; //Saved File's Name yn0OPjH
private int nSplitter; //Count of Splited Downloading File 'JBf*p".
wp!<u %
C*}TY)8
public SiteInfoBean() ({ 7tp!@
{//nSplitter的缺省值为5 _jw A_
//default value of nSplitter is 5 ) 0x*>;"o
this("","","",5); |5wuYG
} 74c1i
:<OInKE>Cx
BX|+"AeF
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E6SGK,f0D
{ p_$03q>oQ
sSiteURL= sURL; !af35WF
sFilePath = sPath; e&C(IEZ/N;
sFileName = sName; ,`/J1(\nd
this.nSplitter = nSpiltter; APT'2-I_
um@RaU
Mj&f7IUO
} GNXQD}L?b?
?Uzs^rsb
?-,v0#
public String getSSiteURL() krTH<- P
{ IKM=Q. 7j
return sSiteURL; "HW~|M7>(
} DT #1*&-
VT1W#@`e-
`zHtfox!
public void setSSiteURL(String value) ,CguY/y
{ W'\{8&:!
sSiteURL = value; ZpPm>|w
} YMG{xGPtM
+MKr.k2
XljiK8q;%
public String getSFilePath() ?lzg )88I
{ [{_JO+)+n
return sFilePath; >9D=PnHnD
} JBdZ]
@b2{'#9]}
/<Cl\q2 A
public void setSFilePath(String value) H~+D2A
{ |b'fp1</
sFilePath = value; PA"xb3@I
} q('O@-HA
@B$ Y`eK\
HoGrvt<:.P
public String getSFileName() w,]cFT
{ h\KQ{-Bl
return sFileName; 8^;[c
} tv)x(MX
MP?9k)f
|_aE~_
public void setSFileName(String value) .O'S@ %]
{ +Ij>\;vM"
sFileName = value; .l5y!?
} ;}3wT,=sN
\`r5tQr
zt!mx{l'
public int getNSplitter() gOa'o<
{ z>NRvx0
return nSplitter; 4~4PZ
} g ZhE\
TPp%II'*
!1!;}uzt
public void setNSplitter(int nCount) r ,|T@|{
{ O'U0Y8HN
nSplitter = nCount; #"%oz^~\
} #b []-L!
} URmx8=q
(7`&5md
ROr$Sz
/* .Nr}V.?57
**Utility.java wH~Q4)#=o
*/ gSK (BP|
package NetFox; ^]^Y~$u
S1wt>}w0$
"jmi "O*
public class Utility { =&xamA)
EUmQn8
m C_v!nL.
public Utility() j"HB[N
{ PX52a[wNDH
WZdA<<,:o
&G5+bUF,
} W}+Q!T=
d4/snvq
//线程睡眠 "lx}.
public static void sleep(int nSecond) fyT:I6*
{ :}FMauHh
try{ {%^q8l4j
Thread.sleep(nSecond); Pe!uk4}w
} AF ZHS\
catch(Exception e) J:)Q)MT24:
{ o;M"C[
e.printStackTrace (); d%VGfSrKq
} !0`44Gbq
} ny'~pT'00
1Jc-hrN-
//日志 G9:[W"P
public static void log(String sMsg) tx}{E<\>$
{ 8#2PJHl;
System.err.println(sMsg); }7+G'=XI/
} 0XSZ3dY&+
G#@o6r
F=Z|Ji#
public static void log(int sMsg) rr'RX
{ O1Ey{2Q
System.err.println(sMsg); >e($T!}Z
} Tf Q(f?
} FGG Fi(
E).Nu
52q@&')D4M
/* IX']s;b
**TestMethod.java ]Hc`<P
*/ :R{Xd{?
package NetFox; %L:e~*
X2(TuR*t
jAfUz7@
public class TestMethod { hvQOwA;e
iyc}a6g
y+_GL=J
public TestMethod() qS*qHT(u19
{ ///xx/weblogic60b2_win.exe ",(-AU!a)h
try{ R#`hT
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {kD|8["Ie'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1mwb&j24n3
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]$KyZHj{
fileFetch.start(); 79n,bb5
} u^s{r`/
catch(Exception e){e.printStackTrace ();} ={~`0,
%g^dB M#
A 7'dD$9
} #yFDC@gH1
MScjq
e57}.pF^
public static void main(String[] args) XG@_Lcv*
{ rOm)s'
new TestMethod(); 2shr&Mfp[
} BLgmFE2
} B%6>2S=E
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