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)); 2 QmUg
} 8[C6LG
for(int i=0;i<nEndPos.length-1;i++) AVr!e
{ DOerSh_0W
nEndPos = nStartPos[i+1]; h2%:;phH
} [j?<9
nEndPos[nEndPos.length-1] = nFileLength; JLu0;XVK
} 4iz&"~&1
} %jxuH+L
m=MT`-:
B0i}Y-Z
//启动子线程 zcKC5vqb
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; w4'K2 7
for(int i=0;i<nStartPos.length;i++) <dL04F
{ hzLGmWN2j8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hPxI& :N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \=7=>x_
nStartPos,nEndPos,i); @S7=6RKa[
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l~YNmmv_
fileSplitterFetch.start(); n:'BN([]o
} 8uxFXQ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ({KAh?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); E ZKz-}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", d;SRK @
nEndPos = " + nFileLength); Q)BoWd
// fileSplitterFetch[nPos.length-1].start(); Noxz kpMF
q"D L6 >j
{H;|G0tR
//等待子线程结束 "IG$VjgcB
//int count = 0; hu(K!>{
//是否结束while循环 -Y=c g;
boolean breakWhile = false; $Q?G*@y
XOg(k(&T
!*Z)[[
while(!bStop) R%_H\-wo
{ k^5Rf
write_nPos(); 7(8
Utility.sleep(500); = )l:^+q
breakWhile = true; 'Y{ux>
'eDgeWt/CQ
ICbdKgLz
for(int i=0;i<nStartPos.length;i++) ?VZXJO{^
{ R}X_2""
if(!fileSplitterFetch.bDownOver) E'S;4B5?
{ Xb@z7X#O!
breakWhile = false; fyq]M_5
break; p:<gFZb
} w+9C/U;|s
} R^M (fC
if(breakWhile) D2%G.z
break; mz$Wo *FB
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H"GE\
//count++; e4YfTr
//if(count>4) ZYR,8y
// siteStop(); Y0X94k.u
} JeTrMa2
$F@L$&~
J%f=A1Q
System.err.println("文件下载结束！"); =PKt09b^
} MZMS?}.2
catch(Exception e){e.printStackTrace ();} BRU9LS
} [+MH[1Vr={
OwiWnS<
$Y 4ch ko
//获得文件长度 @@{_[ir
public long getFileSize() ~?`9i>3W~
{ `YmI'
int nFileLength = -1; ksOANLRN
try{ K!-&Zv
URL url = new URL(siteInfoBean.getSSiteURL()); wO_pcNYZ8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8A8xY446)
httpConnection.setRequestProperty("User-Agent","NetFox"); 3 !>L?
HDSA]{:sl
h*\TCl)
int responseCode=httpConnection.getResponseCode(); ^{fi^lL=
if(responseCode>=400) K+7yUF8XP
{ 7<QYT+6xV
processErrorCode(responseCode); {b-0_
return -2; //-2 represent access is error n$m]58w
} >xU72l#5
,Og[[0g
~E3SC@KL
String sHeader; ~aqT~TL_
:@QK}qFP
VM<oUKh_3
for(int i=1;;i++) ?HEtrX,q
{ STXqq[+Rf
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); FU]8.)`G
//Utility.log(in.readLine()); 8tT&BmT
sHeader=httpConnection.getHeaderFieldKey(i); ~.4W,QLuD
if(sHeader!=null) <i:*p1#Bm
{ *@ <8&M9x
if(sHeader.equals("Content-Length")) >ggk>s|
{ U+9-li
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {m_A1D/_
break; "LP, TC
} @Hspg^
} 8u:v:>D.'
else VW{aUgajO
break; "o^bN 9=
} ^Hz
} WIEx '{
catch(IOException e){e.printStackTrace ();} L)kb (TH
catch(Exception e){e.printStackTrace ();} Rm,[D)D^0N
#RR:3ZPZC
XI@6a9Uk
Utility.log(nFileLength); w&wA >q>&
F.~n
pPiYPfs
return nFileLength; 629~Uc6]
} ^MWEfPt
r3+<r<gs
Gsds!z$
//保存下载信息（文件指针位置） cW81
private void write_nPos() G8^0^@o
{ b"ol\&1 #
try{ pY{; Yn&t
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?r -\%_J_(
output.writeInt(nStartPos.length); '2Q.~6
for(int i=0;i<nStartPos.length;i++) KXoL,)Hl
{ qy7hkq.uX
// output.writeLong(nPos); Tm%$J
output.writeLong(fileSplitterFetch.nStartPos); Y=P9:unG
output.writeLong(fileSplitterFetch.nEndPos); JYZ2k=zh
} k%EWkM)?
output.close(); cPA~eZbX
} s"I-YFP%c
catch(IOException e){e.printStackTrace ();} MuDFdbtR
catch(Exception e){e.printStackTrace ();} ]^iFqQe
} c8^+^.=pX
A5CdLwk
MxM](ew~7
//读取保存的下载信息（文件指针位置） /~H[= Pf
private void read_nPos() BKa A=Bl
{ ?ada>"~GR_
try{ 3c01uObTL
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .o-0aBG
int nCount = input.readInt(); 7!O^;]+,
nStartPos = new long[nCount]; >]>0KQfO
nEndPos = new long[nCount]; *hv=~A $q
for(int i=0;i<nStartPos.length;i++) E)KB@f<g*
{ I["F+kt^^
nStartPos = input.readLong(); Cr' !"F
nEndPos = input.readLong(); Dl0/-=L
} j`>?"1e@x
input.close(); Ty`-r5
} fm3(70F\
catch(IOException e){e.printStackTrace ();} {F;,7Kn+l
catch(Exception e){e.printStackTrace ();} P#AAOSlLV
} hNH.G(l0
T&?w"T2y
@)9REA(U
private void processErrorCode(int nErrorCode) RxlszyE
{ /0Z|+L9Jo
System.err.println("Error Code : " + nErrorCode); q $t&|{
} U5|B9%:&
A;odVaH7
}16&1@8
//停止文件下载 A|2 <A !
public void siteStop() VMaS;)0f@
{ +c-6#7hh
bStop = true; \|v`l{
for(int i=0;i<nStartPos.length;i++) 2K3MAd{
fileSplitterFetch.splitterStop(); YkSuwx@5_q
)V=0IZi
1#/6r :
} [}{w
} tJff+n>
//负责部分文件的抓取 :aHcPc:
**FileSplitterFetch.java `+oV/:Q3
*/ q5%2WM]6
package NetFox; ])eOa%
*U M!(
f(!E!\&n^
import java.io.*; pQqbZ3]
import java.net.*; =D{B}=D\IM
8Bj4_!g
l`DtiJ?$$0
public class FileSplitterFetch extends Thread { \$j^_C>
mU>&ql?e
~ W@X-
String sURL; //File URL i^R{Ul[
long nStartPos; //File Snippet Start Position JwjI{,jY
long nEndPos; //File Snippet End Position \WcB9
int nThreadID; //Thread's ID kQy&I3
boolean bDownOver = false; //Downing is over }X.>4\B5
boolean bStop = false; //Stop identical 6eM6[
FileAccessI fileAccessI = null; //File Access interface #$FY+`
b"Zq0M0l
8qN"3 Et
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException te)n{K",
{ '[Xl>Z[
this.sURL = sURL; 0potz]}
this.nStartPos = nStart; V`[P4k+b
this.nEndPos = nEnd; |gW
nThreadID = id; (|dPeix|
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <~N%W#z/
} Vg{Zv4+t
p!}ZdX[u
mW~P!7]
public void run() U_l7CCK +
{ pr$~8e=c
while(nStartPos < nEndPos && !bStop) D;jK/2
{ :&9TW]*g
Ge^Qar
@ ICbKg:
try{ f|#8qiUS
URL url = new URL(sURL); Fom>'g*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]rnXNn;
httpConnection.setRequestProperty("User-Agent","NetFox"); I(n }<)eF
String sProperty = "bytes="+nStartPos+"-"; p-,Iio+
httpConnection.setRequestProperty("RANGE",sProperty); S.W^7Ap
Utility.log(sProperty); mL$f[
v77fQ0w3
ZjS(ad*.2
InputStream input = httpConnection.getInputStream(); srK53vKMHW
//logResponseHead(httpConnection); 'y.JcS!|
ab@=cL~^
wdwp9r
byte[] b = new byte[1024]; L7}i q0
int nRead; LQqfi ~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =T4u":#N;
{ tFiR!f)
nStartPos += fileAccessI.write(b,0,nRead); 3{e'YD~hP
//if(nThreadID == 1) iX%n0i
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [x5mPjgw
} w4,]2Ccn.
/&(1JqzlB
e #M iaX
Utility.log("Thread " + nThreadID + " is over!"); J(e7{aRJ9
bDownOver = true; iDw.i"b
//nPos = fileAccessI.write (b,0,nRead); &\^rQi/tf
} U-g9C.
catch(Exception e){e.printStackTrace ();} Xu6K%]i^
} 036[96t,F
} t8/%Dgu
yj zK.dM
~RInN+N#
//打印回应的头信息 @VK6JjIq
public void logResponseHead(HttpURLConnection con) VoM6
{ "r..
for(int i=1;;i++) OJpj}R
{ LG&5VxT=,<
String header=con.getHeaderFieldKey(i); |` "?
if(header!=null) 2m"_z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \ha-"Aqze3
Utility.log(header+" : "+con.getHeaderField(header)); )7Ixz1I9g
else W5Zqgsy($F
break; Xa,\EEmQ
} Kam]Mn'
} Q'K$L9q
Ly>OLI0x_
j5^-.sEEw
public void splitterStop() b#a@rh
{ :Q7mV%%
bStop = true; X;VQEDMPU
} OH6n^WKY
.6m_>Y6
f{ ^:3"i
} iSiDSeW8
%w5[*V
J +q|$K6
/* YeyGN
**FileAccess.java mmP U
*//文件访问(定位，写) Pl78fs"L@
package NetFox; ]?&FOzN5$P
import java.io.*; D:JS)+]
9i%9
10O$'`
public class FileAccessI implements Serializable{ VLdB_r3lQ
BQ#L+9%
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @Y-TOCadT
RandomAccessFile oSavedFile; :=fvZAWD
long nPos; @;Y~frT
c1%rV`)]
Yb:pAzw6
public FileAccessI() throws IOException %|+E48
{ ST;t, D:
this("",0); 0m)&YFZ[(
} Ik~1:D]f
v}[dnG
_^\$"nw
public FileAccessI(String sName,long nPos) throws IOException #/ "+
{ |vu>;*K
oSavedFile = new RandomAccessFile(sName,"rw"); cdTsRS;E
this.nPos = nPos; Tlodn7%",
oSavedFile.seek(nPos); yPgmg@G@/
} fn}UBzED\
jd:B \%#![
r;gP}H ?
public synchronized int write(byte[] b,int nStart,int nLen) L CSeOR
{ *#&*`iJ(
int n = -1; e@n!x}t8
try{ I1"MPx{
oSavedFile.write(b,nStart,nLen); J|~26lG
n = nLen; 2]WE({P
} -]S.<8<$
catch(IOException e) i::\Z$L";i
{ ,1UZv>}S
e.printStackTrace (); ;[$n=VX`
} ^^Jnv{)
Y(6Sp'0
$_X|,v9
return n; \a|L/9%
} uT_!'l$fr
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%0-wpuHc(]
} R,_d1^|*w
5#2F1NX
- u3e5gW
/* -1r2K
**SiteInfoBean.java Qt+:4{He
*/ ,/,9j{|"j
package NetFox; #kmh:P
#exss=as/
{}Ejt:rKN
public class SiteInfoBean { [=%YV# O
l!~ mxUb
lWZuXb,G
private String sSiteURL; //Site's URL \wav?;z
private String sFilePath; //Saved File's Path =XY]x
private String sFileName; //Saved File's Name (lH,JX`$a
private int nSplitter; //Count of Splited Downloading File 8v92Ng7
k#JQxLy#
|M~ON=
public SiteInfoBean() vS?odqi#n
{//nSplitter的缺省值为5 "$^0%-
//default value of nSplitter is 5 &%C4Ugo
this("","","",5); 2WBq
} -$a>f4]
ljJ>;g+
; y.E!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) sd0r'jb
{ ,"?A2n-qO
sSiteURL= sURL; S"2qJ!.u
sFilePath = sPath; ^ @=^;nB
sFileName = sName; )NW6?Pu"
this.nSplitter = nSpiltter; pBJAaCGm
#gbH^a'
m}Y0xV9
} e$/B_o7(
&eZfQ27$
L2z2}U=<
public String getSSiteURL() tpf7_YP_!-
{ Zm TDQ`Ix
return sSiteURL; hkL5HzWn
} I4_d[O9
i76 Yo5
pK&I^r
public void setSSiteURL(String value) @ GDX7TPV
{ _7)F ?
sSiteURL = value; 12`_;[37
} m~l F`?
L\aBc}
xK%=
public String getSFilePath() y9HK |
{ Cpl;vQ
return sFilePath; ]o/|na*
} 83ipf"]*
fZWGn6$
||B;o-
public void setSFilePath(String value) Yxd X#3
{ 3tS~:6-/
sFilePath = value; W0`Gc {
} ]dPZ.r
hZ\+FOx;
)h$NS2B`
public String getSFileName() QDmYSY$
{ 0Fr1Ku!
return sFileName; rnm03 '{
} irBDGT~
I*[tMzE
Z'v-F^
public void setSFileName(String value) Ju` [m
{ Z+:D)L
sFileName = value; K`:=]Z8
} 2s ,8R
QP I+y8N=
4jmK].
public int getNSplitter() )|#%Czd4
{ rJfqA@
return nSplitter; ``Q2P%
} b B
%,*$D}H
d4^`}6@
public void setNSplitter(int nCount) vFmJ;J
{ ?h\mk0[
nSplitter = nCount; x<(b|2qf
} zri} h/{
} PFSLyV*
h+7>#*DH
*=F(KZ
/* qB6dFl\ (
**Utility.java cSP*f0n,eo
*/ !3&kQpF
package NetFox; FpV`#6i7
L-i>R:N4
c$E)P$<j
public class Utility { >O9sk
VkmRh,T
iAO5"(>}?
public Utility() %"3 )TN4
{ G&{HTYP
3SG?W_
~XM[>M\qB
} Q'NmSX)0
|(IO=V4P
//线程睡眠 %FkLQ+v/<
public static void sleep(int nSecond) ReB7vpd
{ JMV50 y
try{ Jn}n*t3
Thread.sleep(nSecond); (yrh=6=z
} |WQ9a' '
catch(Exception e) Qc-(*}
{ o=+Z.-q
e.printStackTrace (); |WqOk~)[Z3
} `$;+g ,
} 6DF
iDb;_?
//日志 W.}].7}h
public static void log(String sMsg) 6Z:YT&,f
{ BNm4k7 ]M
System.err.println(sMsg); 5>0.NiXGf'
} 3Kq`<B~%
pK_?}~
dDcZ!rRaL@
public static void log(int sMsg) LK7Xw3
{ ETw]! br
System.err.println(sMsg); HOW7cV'X
} :-+4:S
} X)Gp7k1w
loOOmHhJ&
ISqfU]>[
/* $~u.Wq
**TestMethod.java 4jwu'7Q
*/ ur%$aX)
package NetFox; Di(9]:+
a+z2Zd!u\x
}0/a\
public class TestMethod { pa/9F[
APBK9ky
Ej(2w Q
public TestMethod() ocA]M=3~k
{ ///xx/weblogic60b2_win.exe a-0cN 9
try{ yY=<'{!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); .Ao0;:;(2-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); SG]K
SiteFileFetch fileFetch = new SiteFileFetch(bean); HkjEiU
fileFetch.start(); Eu<r$6Q0}o
} 7>.OVh<
catch(Exception e){e.printStackTrace ();} &r_uQbx
d]B=*7]
v<h;Di@
} &a #GXf
S`g;Y '
3:`XG2'
public static void main(String[] args) f\o R:%
{ #+jUhxq
new TestMethod(); zY APf &5
} zB)%lb
} 9D_wG\g
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