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)); fJc,KZy
} Gp;[WY\
for(int i=0;i<nEndPos.length-1;i++) ;`X-.45
{ kl3#&>e
nEndPos = nStartPos[i+1]; dE/Vl/:
} 5_G7XBvD/w
nEndPos[nEndPos.length-1] = nFileLength; kW6}57iV
} ^a<=@0|
} WAqR70{KM
isWB)$q
'e;*V$+
//启动子线程 [A*vl9=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Gxm+5q
for(int i=0;i<nStartPos.length;i++) |],{kUIXO
{ 47`{ e_YP0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t!D=oBCro
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), fm&l0
nStartPos,nEndPos,i); [#3:CDT
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); HmbTV(lC
fileSplitterFetch.start(); GdL\
} 8Nci1o
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ` mALx! `
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); w V27
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6tzZ j:yq
nEndPos = " + nFileLength); Ujq)h:`
// fileSplitterFetch[nPos.length-1].start(); FE/&<g0,:
;S,g&%N
W%0-SR
//等待子线程结束 '~liDz*O
//int count = 0; \ {"8(ELX
//是否结束while循环 kJJQcjAP:
boolean breakWhile = false; W=I%3F_C"R
if#$wm%
k?|VFh1
while(!bStop) ScZ$&n
{ N;r,B
write_nPos(); rd%3eR?V
Utility.sleep(500); >4LX!^V"
breakWhile = true; !Q#u i[0q
)bPNL$O
u`E_Q8
for(int i=0;i<nStartPos.length;i++) 6Oo'&3@
{ *J1pxZ^
if(!fileSplitterFetch.bDownOver) *DDfdn
{ ;E*^AW
breakWhile = false; ,2&'8:B
break; RDzL@xCcn
} ``aoLQc`
} >%Y.X38Z[
if(breakWhile) >s[}f6*2@
break; c{||l+B
+1h^9Y'
bTHJbpt*-
//count++; 1;ZEuO
//if(count>4) ?em)om
// siteStop(); <KHB/7
} g.F{yX]
F^A1'J
$Cc4Sggq
System.err.println("文件下载结束！"); #'$CC<*vy
} A{&Etu(K
catch(Exception e){e.printStackTrace ();} b*P\a
} \f /<#'
&(Xp_3PO
\Cx3^ iX
//获得文件长度 ->8n.!F}
public long getFileSize() kE6\G}zj
{ g\ <Lb
int nFileLength = -1; ^9cqT2:t
try{ UT[KwM{y
URL url = new URL(siteInfoBean.getSSiteURL()); JhB{aW>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Fo~C,@/Qt
httpConnection.setRequestProperty("User-Agent","NetFox"); 2<u vz<B
`pII-dSC%
rp(`V@x3
int responseCode=httpConnection.getResponseCode(); &,NHk9.aq
if(responseCode>=400) YdC:P# Nf
{ J0o U5d=3
processErrorCode(responseCode); _ogT(uYyr
return -2; //-2 represent access is error 60X B
} ;&JMBn]J
#i)h0ML/e
:,GsbNKW
String sHeader; nM R_ ?g
!aLByMA
\ZCc~muR
for(int i=1;;i++) )o9CFhFB
{ ap;*qiNFQ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); i$%;z~#wW
//Utility.log(in.readLine()); 63:ZDQ
sHeader=httpConnection.getHeaderFieldKey(i); S&.DpsK
if(sHeader!=null) G V0q?
{ &w/aQs~
if(sHeader.equals("Content-Length")) U$0#j
{ r}*2~;:pW
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); @["Vzg!I6"
break; Z)6bqU<LQE
} $Fd9iJ!k
} HQf[T@
else kQX,MP(
break; G=~T)e
} U%w-/!p
} wond>m 3
catch(IOException e){e.printStackTrace ();} %o^'(L@z
catch(Exception e){e.printStackTrace ();} 6pr}A
OaU$ [Z'8
&?zJ|7rh@|
Utility.log(nFileLength); @iWIgL
Q#:,s8TW[
To=1B`@-
return nFileLength; v]_{oj_(-
} oX?2fu-
FA4bv9:hi
v,p/r)E
//保存下载信息（文件指针位置） vQBfT% &Q-
private void write_nPos() WdIr3
{ hnE@+(d=qJ
try{ $7|0{Dw
output = new DataOutputStream(new FileOutputStream(tmpFile)); H6'xXS
output.writeInt(nStartPos.length); IybMO5Mwn
for(int i=0;i<nStartPos.length;i++) yKfRwO[j
{ ;=UrIA@y;=
// output.writeLong(nPos); W P.6ea7k
output.writeLong(fileSplitterFetch.nStartPos); 4(B,aU>y
output.writeLong(fileSplitterFetch.nEndPos); 2psI\7UjA]
} m$[\(Z(/
output.close(); Fnll&TF
} |q5\1}@:
catch(IOException e){e.printStackTrace ();} ??1V__w
catch(Exception e){e.printStackTrace ();} aEX+M57k~
} ?CmW{9O
4fpz;2%
B.&q]CAv-
//读取保存的下载信息（文件指针位置） `<\AnhNW]I
private void read_nPos() 0>E`9|
{ _CI!7%
try{ v\\Z[,dK
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9LCV"xgX
int nCount = input.readInt(); ]^aece t
nStartPos = new long[nCount]; -V4@BKI8
nEndPos = new long[nCount]; $C^94$W
for(int i=0;i<nStartPos.length;i++) S=M$g#X`5
{ JNX7]j\
nStartPos = input.readLong(); "v^Q !
nEndPos = input.readLong(); 8 kd
} Pf@8C{I
input.close(); k[G?22t
} s "*Cb*
catch(IOException e){e.printStackTrace ();} <VgnrqF6:
catch(Exception e){e.printStackTrace ();} ze,HNFg@>
} 8$3Tu"+;
^pZ(^
u-jGv| ,|
private void processErrorCode(int nErrorCode) Y Xn)?
{ i:{a-Bd
System.err.println("Error Code : " + nErrorCode); Y.Gr(]tk
} tr/S*0$
&?YQVwsN
-Ux/ Ug@
//停止文件下载 ,{:5Z:<|
public void siteStop() Fwho.R-.
{ -Z6ot{%
bStop = true; 5:56l>0
for(int i=0;i<nStartPos.length;i++) #l:qht
fileSplitterFetch.splitterStop(); Xg.\B1d
r7w&p.?
>Qt#6X|
} /r}t
} E!3W_:Bs
//负责部分文件的抓取 - n11L
**FileSplitterFetch.java htMpL
*/ ]km8M^P
package NetFox; (x?A#o>%
T#er5WOH
lR;<6
import java.io.*; zy5@K)
import java.net.*; \{NeDv{A
>JC.qjA
[/5>)HK} C
public class FileSplitterFetch extends Thread { `iQyKZS/+
=X-$kk
C{Aeud #5
String sURL; //File URL y>Nlj%XH
long nStartPos; //File Snippet Start Position .KRh59yg
long nEndPos; //File Snippet End Position D~2,0K
int nThreadID; //Thread's ID ?]$.3azO
boolean bDownOver = false; //Downing is over m,)Re8W-
boolean bStop = false; //Stop identical (Dc dR:/=
FileAccessI fileAccessI = null; //File Access interface N}.h_~6
p3sz32RX
a>""MC2
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException HykJ}ezX4
{ B`T9dL[E4
this.sURL = sURL; Q"QrbU
this.nStartPos = nStart; -41L^Di\
this.nEndPos = nEnd; .}a@OLJd
nThreadID = id; )+\e+Ad}H
fileAccessI = new FileAccessI(sName,nStartPos);//定位 MO/l(wO
} L`];i8=I
c5O1h8
=\oNu&Q^
public void run() R,6?1Z:J
{ EeL~`$f
while(nStartPos < nEndPos && !bStop) !~>u\h
{ qK(?\t$
S}fIZ1
6=|Q>[K
try{ !cWKY\lpv
URL url = new URL(sURL); !X |Tf
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %T1(3T{Li
httpConnection.setRequestProperty("User-Agent","NetFox"); > `z^AB
String sProperty = "bytes="+nStartPos+"-"; Z$6W)~;,
httpConnection.setRequestProperty("RANGE",sProperty); |%b'L.$4
Utility.log(sProperty); &z%7Nu
Vf O0 z5&
D>LdDhNn,`
InputStream input = httpConnection.getInputStream(); k('2K2P
//logResponseHead(httpConnection); &b{L|I'KYT
7!L"ef62o
+F+jC9j(<
byte[] b = new byte[1024]; ,4EE9 ?J
int nRead; #[Ns\%Ri0
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ZTHrjW1
{ ?4gYUEM#
nStartPos += fileAccessI.write(b,0,nRead); ~~wz05oRG
//if(nThreadID == 1) Z(.p=Wg
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mxDy!:@=
} INcJXlv
mlIc`GSI
=`.9V<
Utility.log("Thread " + nThreadID + " is over!"); Nu|?s-
bDownOver = true; 9>[$;>
//nPos = fileAccessI.write (b,0,nRead); #J1a `}x
} s}/YcUK
catch(Exception e){e.printStackTrace ();} OG}0{?
} E-Cj^#OY|N
} >/evL /
~Dgui/r9J
Sh{odrMj*
//打印回应的头信息 |)GE7y0Q
public void logResponseHead(HttpURLConnection con) <fN?=u+
{ u3"F7 lJ
for(int i=1;;i++) X8?|5$Ey
{ 4sROMk=l
String header=con.getHeaderFieldKey(i); [+ 1([#
if(header!=null) )mp0k%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); VYlg+MlT0
Utility.log(header+" : "+con.getHeaderField(header)); [(UQQa=+
else uw;s](~E
break; H^'EY:|
} VZw("a*TB
} >;0z-;k6
4[rD|
9u"im+=:
public void splitterStop() @Q TG
{ Z#^2F8,]
bStop = true; &W|'rA'r
} S@Jl_`<
85Ms*[g
Y@;bA=Du}
} /kNr5s
aD0w82s]J
ka"jv"z
/* g/JAr<
**FileAccess.java -+?0|>Nh
*//文件访问(定位，写) qH"0?<$9
package NetFox; Ntg#-_]
import java.io.*; 0^{zq|%Q!
M!mTNIj8~
=XudL^GF
public class FileAccessI implements Serializable{ Awe\KJ^`
WET $H,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5%,n[qj4IT
RandomAccessFile oSavedFile; .DCp)&m l;
long nPos; }RW4
BOfO$J}
%Sxy!gGz%%
public FileAccessI() throws IOException \h_hd%'G
{ ${e(#bvGZ
this("",0); tHhY1[A8m
} 6S]GSS<
[yjC@docH
iY.~N#Q
public FileAccessI(String sName,long nPos) throws IOException `M"b L|[R
{ "eGS~-DVK
oSavedFile = new RandomAccessFile(sName,"rw"); xI_WkoI
this.nPos = nPos; QT^( oog=
oSavedFile.seek(nPos); zXZy:SD
} pmHd1 Wub
QIo|t!7F
7Zr jU{
public synchronized int write(byte[] b,int nStart,int nLen) <%) :'0q&
{ u%v^(9z
int n = -1; s7df<dBC
try{ r|0C G^:C
oSavedFile.write(b,nStart,nLen); Re,0RM\
n = nLen; ^!Bpev
} ,gD30Pylz
catch(IOException e) mX,#|qLf
{ } vcr71u
e.printStackTrace (); ZOS{F_2.
} 5p"*nkF
t41\nTZr
ki}Uw#
return n; G|Q}.v
} F-_RL-hbN%
Rp.@
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} ^JYR^X>_
t}NxD`8
& }k=V4L
/* l\MiG Na
**SiteInfoBean.java aU#8W.~
*/ M(oW;^B
package NetFox; <2|x]b8
@0B<b7Jv
F~RUb&*/<
public class SiteInfoBean { 1Kwl_jf
ilFM+x@
RAf+%h*
private String sSiteURL; //Site's URL &QCqaJ-
private String sFilePath; //Saved File's Path V 9=y@`;
private String sFileName; //Saved File's Name 15nc
private int nSplitter; //Count of Splited Downloading File f ( UcJx
Fi*6ud\n!
r@s, cCK9?
public SiteInfoBean() Km\M/j|
{//nSplitter的缺省值为5 !M3IuDN
//default value of nSplitter is 5 :!{aey
this("","","",5); uiHlaMf
} Y^3tk}yru
X3a:*1N
b/ZX}<s(1=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :(I)+;M}P
{ @JN%P}4)
sSiteURL= sURL; _k6N(c2Nd
sFilePath = sPath; 4Ag+
sFileName = sName; U.>n]/&
this.nSplitter = nSpiltter; ,9W0fm\t
t}*teo[
3PBg3Y$
} !gJAK<]iW
R<JI
Hi.JL
public String getSSiteURL() = ng\
{ 5<d Y,FvX
return sSiteURL; P=u)Q _
} nc$?tC9V
|L]dJ<
lzuPE,h
public void setSSiteURL(String value) x-%nnC6e
{ h"ZF,g;a
sSiteURL = value; d@#=cvW
} paMw88*u
*%8,G'"r?
%tQIKjsVaY
public String getSFilePath() Mc@p~5!M
{ NK"y@)%0
return sFilePath; QRt(?96
} }14.u&4
]G|@F :
"q]v2t
public void setSFilePath(String value) u45e>F=
{ V|b?H6Q
sFilePath = value; \a|gzC1G
} YK"({Z>U
ZO0_:T#Z
_KD(V2W
public String getSFileName() ijoR(R^r
{ R`s /^0
return sFileName; )NyGV!Zuu
} t'[vN~I'
$,6=.YuY
6 t A?<S
public void setSFileName(String value) S:^Q(w7
{ z!RA=]3h
sFileName = value; Z39^nGO
} >1joCG~
3zh'5qQ
kTFN.kQx@
public int getNSplitter() ;B1}so1]
{ lkw[Z}\
return nSplitter; Li<c
} k$I[F<f
Dw.>4bA.
B5tJ|3!
public void setNSplitter(int nCount) eeL%Yp3+
{ ~r>WnI:vg
nSplitter = nCount; gb@!Co3
} <u^41
} Ww8C![ ,
b<:s{f"t,
egP3q5~
/* kW-5H;>
**Utility.java #!,xjd
*/ T,H]svN5p
package NetFox; XP{ nf9&
;gW~+hW^
qTffh{q V
public class Utility { dB_\,%vAd
]FFU,me2
/Ee0S8!Z!1
public Utility() .h7b 4J
{ sav2.w
MfYe @;m
1noFXzeU3
} fcV/co_S6
[5m;L5
//线程睡眠 ?*4]LuK6
public static void sleep(int nSecond) LO` (V
{ `w~ 9/sty
try{ -3w? y
Thread.sleep(nSecond); nS4~1a
} yK}#|b'cM
catch(Exception e) d628@~Ekn
{ *riGi
e.printStackTrace (); RmzK?muk
} />f`X+d
} Nwu#,f=X
nLQ X?:
//日志 ^[id8
public static void log(String sMsg) 4|XE f,
{ hs/nM"V
System.err.println(sMsg); +x+H(of.
} "bw4{pa+
x80~j(uVf
"`&?<82
public static void log(int sMsg) ZS}2(t
{ EoOrA@N
System.err.println(sMsg); (tVY /(~#
} !N)oi$T%
} Qh{=Z^r
gu"Agct4
'fg`td
/* aC%0jJ<eo
**TestMethod.java 2b3*zB*@V
*/ *nH?o* #
package NetFox; Zj}DlNkVu
|d,1mmv@K
^ro?.,c T
public class TestMethod { S++}kR);
ZZeqOu7^
u\Xi]pZ@X]
public TestMethod() b LxV
{ ///xx/weblogic60b2_win.exe wS:323 !l$
try{ <'gCIIa2
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); sL!6-[N
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =B?uNoe
SiteFileFetch fileFetch = new SiteFileFetch(bean); @l@lE0
fileFetch.start(); UO!OO&l!
} !\"C<*5
catch(Exception e){e.printStackTrace ();} !CsoTW9C:
SJy?^
QDgOprha
} _`;6'}]s
QY{f=
b[u_r,b
public static void main(String[] args) ,:,c kul
{ 9OTw6
new TestMethod(); 0J_Np
} 40:YJ_n
} Q)Ppx7)
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