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)); c:4P%({
} E`;;&V q-
for(int i=0;i<nEndPos.length-1;i++) 3MBN:dbQ
{ OI/@3"L{
nEndPos = nStartPos[i+1]; X_TiqV
} CboLH0Fa
nEndPos[nEndPos.length-1] = nFileLength; [0@`wZ
} 4,P bg|
} >s EjR!
[ !%R#+o=F
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//启动子线程 O<*5$,K9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6[ga$nF?
for(int i=0;i<nStartPos.length;i++) p~jlx~1-]
{ VG@};dwbz*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z~oDWANP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \=2m7v#E
nStartPos,nEndPos,i); '+y_\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X`r*ob
fileSplitterFetch.start(); eEw.'B
} msx-O=4g
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Fd$!wBL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !u|Tu4G^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [0;buVU.
nEndPos = " + nFileLength); :7.Me;RA
// fileSplitterFetch[nPos.length-1].start(); W<b-r^9?s
+Wn&,?3^
q0xjA
//等待子线程结束 I*|P@0
//int count = 0; .TB"eUy
//是否结束while循环 D56<fg$
boolean breakWhile = false; LEWhb!U
7L(eh7
!X^Ce)1K
while(!bStop) PR7f(NC
{ ]/2T\w.<
write_nPos(); y0bq;(~X~
Utility.sleep(500); 8;gXg
breakWhile = true; iAn'aW\TF
T2'RATfG
PO-"M)M
for(int i=0;i<nStartPos.length;i++) Sr Ca3PA
{ f i~I@KJ>
if(!fileSplitterFetch.bDownOver) KM,|} .@:
{ wEft4o
breakWhile = false; p^)B0[P9
break; lHfe<j]
} <E,%@
} -#:zsu
if(breakWhile) %CnxjtTo
break; VU.@R,
^V*-1r1
`{K_/Cit
//count++; 5N7H{vT_
//if(count>4) q1VH5'p@
// siteStop(); pf"<!O[
} O'*@ Ytn
_wDS#t;!M
63WS7s"
System.err.println("文件下载结束！"); d=*x#In
} /*)Tl
catch(Exception e){e.printStackTrace ();} *Ust[u
} 62'1X"
zDOKShG
d' >>E
//获得文件长度 ? zDa=7 J
public long getFileSize() qPGuo5^
{ o:q1beU
int nFileLength = -1; R,2P3lv1v@
try{ w(d>HHg
URL url = new URL(siteInfoBean.getSSiteURL()); Mz]:}qmFA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `YBkF
httpConnection.setRequestProperty("User-Agent","NetFox"); [/M^[p
{No L
* *H&+T/B
int responseCode=httpConnection.getResponseCode(); $:s`4N^
if(responseCode>=400) RJeDEYXeg
{ vxQ8t!-u
processErrorCode(responseCode); ~p0c3*
return -2; //-2 represent access is error una%[jTc
} nKr9#JebRC
Fm_y&7._
FCj{AD
String sHeader; &;TJ~r#K
u6u=2
w~R`D
for(int i=1;;i++) 07g':QU@
{ sZgRt
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "Ml&[Oge
//Utility.log(in.readLine()); ykg#{9+
sHeader=httpConnection.getHeaderFieldKey(i); Sw&!y$ed
if(sHeader!=null) 0JuD^
{ TJ8E"t*)
if(sHeader.equals("Content-Length")) +k<w!B*
{ x`RTp:#
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >O9o,o/6R
break; d5 Edu44
} lK'Rn~
} h0vob_Fdl
else [P4$Khu$
break; e?0q9W
} L)QE`24
} 6M.;@t,Y
catch(IOException e){e.printStackTrace ();} /c2'dJ(H
catch(Exception e){e.printStackTrace ();} =SOe}!
SAV%4
qo6y %[
Utility.log(nFileLength); zQ6p+R7D
0H_!Kg
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return nFileLength; wd@aw/
} ^rl"rEA
s MN*RKer
o\otgyoh
//保存下载信息（文件指针位置） M]v=-
private void write_nPos() s pLZ2]A
{ <N,)G |&
try{ T=a=B(
output = new DataOutputStream(new FileOutputStream(tmpFile)); d@0Kr5_
output.writeInt(nStartPos.length); b IW'c_ ,
for(int i=0;i<nStartPos.length;i++) DciwQcG
{ UM*jKi2]"
// output.writeLong(nPos); <AlZ]~Yct
output.writeLong(fileSplitterFetch.nStartPos); #3=P4FUz.
output.writeLong(fileSplitterFetch.nEndPos); ?Ucu#UO
} HBE.F&C88
output.close(); AGP("U'u
} e(F42;$$
catch(IOException e){e.printStackTrace ();} 4F3x@H'
catch(Exception e){e.printStackTrace ();} 'uDjFQX
} J~B 7PW
RE$`YCs5
. v@>JZC
//读取保存的下载信息（文件指针位置） OX:O^ (-r,
private void read_nPos() qH,l#I\CG
{ Fk;oE'"D
try{ {+<P:jbz;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); mnk"Vr` L
int nCount = input.readInt(); Q^K"8 ;
nStartPos = new long[nCount]; ]{~NO{0@Y
nEndPos = new long[nCount]; [[~w0G~1
for(int i=0;i<nStartPos.length;i++) g42)7
{ `cQo0{xK
nStartPos = input.readLong(); F 09DV<j
nEndPos = input.readLong(); $eV$2p3H
} :4S%'d7
input.close(); pCpb;<JG
} 4F>Urh+
catch(IOException e){e.printStackTrace ();} t&Os;x?To?
catch(Exception e){e.printStackTrace ();} /y7M lU9
} 9mc!bj^811
W>(/ bX
./j,Z$|
private void processErrorCode(int nErrorCode) |wEN`#.;b
{ o'~5pS(wq
System.err.println("Error Code : " + nErrorCode); ;|p$\26S)%
} g[>\4B9t
$N']TN
,h\sF#|
//停止文件下载 8 #X5K
public void siteStop() \k`n[{
{ (C] SH\
bStop = true; l&VjUPz_
for(int i=0;i<nStartPos.length;i++) GsbAlNP
fileSplitterFetch.splitterStop(); +QM@VQ
Mr--4D0Hk
pu!dqF<
} e7fiGl
} 3($"q]Y
//负责部分文件的抓取 %u^JpC{E
**FileSplitterFetch.java @UBjq%z
*/ wfL-oi'5
package NetFox; 8E&XbqP+
rdnno
;?}l
import java.io.*; XS0xLt=
import java.net.*; w:Jrmx
X.K<4N0A9J
``,k5!a66\
public class FileSplitterFetch extends Thread { 3lLMu B+
E+"dqSI/v
._wkj
String sURL; //File URL c(co\A.]:6
long nStartPos; //File Snippet Start Position 5Ft5@UF~
long nEndPos; //File Snippet End Position VN0mDh?E
int nThreadID; //Thread's ID iVFkYx%}
boolean bDownOver = false; //Downing is over nhSb~QqEh
boolean bStop = false; //Stop identical )5JU:jNy
FileAccessI fileAccessI = null; //File Access interface =K&\E2kA4
6qe*@o
6+V\t+aug
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException N$Y" c*
{ P+t#4J
this.sURL = sURL; V>64/
this.nStartPos = nStart; ]%uZ\Q;9p
this.nEndPos = nEnd; ,<<4*
nThreadID = id; E|YdcS
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]Mj/&b>"e
} Sp}D;7
vhvdKD
vQF vtwd
public void run() GEjd7s]C
{ VKm!Ri$
while(nStartPos < nEndPos && !bStop) FVv8--
{ !|2VWI}
.t&R>9cZ^
Mfk2mIy
try{ T,fI BD:
URL url = new URL(sURL); Tj~IaU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S1_6C:^k
httpConnection.setRequestProperty("User-Agent","NetFox"); qj01]
String sProperty = "bytes="+nStartPos+"-"; '`Bm'Dd
httpConnection.setRequestProperty("RANGE",sProperty); ky>wOaTmN6
Utility.log(sProperty); NVIK>cT6
o ]Jv;Iy@?
s{ V*1$e~
InputStream input = httpConnection.getInputStream(); Q "oI])r
//logResponseHead(httpConnection); UgB'[@McS
2>}xhQJ
&)i|$J 2.
byte[] b = new byte[1024]; E6Rz@"^XV
int nRead; sfr(/mp(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) n/QF2&X7)
{ Ae^X35
nStartPos += fileAccessI.write(b,0,nRead); p <eC<dtu
//if(nThreadID == 1) @ZN^1?][
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3$vRW.c\q
} Md)zEj`\
!KKT[28v
k^$+n_
Utility.log("Thread " + nThreadID + " is over!"); J68j=`Y
bDownOver = true; q0%
//nPos = fileAccessI.write (b,0,nRead); wn Y$fT9
} D7]#Xk2
catch(Exception e){e.printStackTrace ();} _$<Gyz*
} U%7i=Z{^Ks
} 5`~mmAUk;`
8$|8`;I(
""O"
//打印回应的头信息 `<^VR[Mx
public void logResponseHead(HttpURLConnection con) I O%6 O
{ dAP|:&y@
for(int i=1;;i++) 2LCB])X
{ M)?dEgU}M
String header=con.getHeaderFieldKey(i); C\_zdADUb%
if(header!=null) N_4eM,7t
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 6,1b=2G
Utility.log(header+" : "+con.getHeaderField(header)); *KK+X07
else $=sXAK9
break; gB\T[RV
} EG'[`<*h
} -]Cc
gw+9x<e
xy+QbDT
public void splitterStop() "O+5R(XT
{ nmlPX7!{$
bStop = true; E{=2\Wkcp
} O#nR>1h
_ 7oV<
k<w(i k1bi
} 89{HJ9}
=U OLT>!
<VjJAu
/* uBg 8h{>
**FileAccess.java /)N@M
*//文件访问(定位，写) ?!w^`D0}o
package NetFox; 6nDV1O5
import java.io.*; L+B?~_*
OYM@szM
`\=Gp'&Q+
public class FileAccessI implements Serializable{ Y**|N8e
4!$ M q;U
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -7WW[ w
RandomAccessFile oSavedFile; 78n=nHS
long nPos; 2^~<("+w
(-7ZI"Ku
R7oj#
public FileAccessI() throws IOException x+? 9C
{ vv6$>SU
this("",0); [\)oo
} y<W8Q<9
Mr+@c)
Jsg I'
public FileAccessI(String sName,long nPos) throws IOException lJykyyCY+
{ ,O=a*%0rt
oSavedFile = new RandomAccessFile(sName,"rw"); \8uo{#cL8
this.nPos = nPos; KHKS$D
oSavedFile.seek(nPos); q^8EOAvnZ
} ~Y=@$!Uq
XA0(f*
0X..e$'
public synchronized int write(byte[] b,int nStart,int nLen) oC*ees g_
{ L^kp8o^$
int n = -1; +5<k-0v
try{ NW$H"}+o
oSavedFile.write(b,nStart,nLen); CozKyt/r7
n = nLen; W!$zXwY}(
} UbJ*'eoX
catch(IOException e) Qz<d~N
{ iWXc
e.printStackTrace (); -y) ,Y |
} /rB{[zk
{TSY|D2
Tm+;0
return n; dtM[E`PL
} >Dm8m[76
]>##`X
[y)FcIK}
} lYf+V8{
$<@\-vYvr@
]7sx;KFv
/* 6,Hqb<(
**SiteInfoBean.java cl[!`Z
*/ \v@({nB8
package NetFox; Z{-Lc68
wn+FTqj
BJjx|VA+
public class SiteInfoBean { ClW'W#*(Y
2)iD4G`
uE_c4Hp
private String sSiteURL; //Site's URL xc 1A$EY
private String sFilePath; //Saved File's Path +,'T=Ic{
private String sFileName; //Saved File's Name UyYfpL"$A"
private int nSplitter; //Count of Splited Downloading File _cJ[ FP1
9~AWng
/ YiQ\
public SiteInfoBean() _68BP)nz>.
{//nSplitter的缺省值为5 4Wel[]
//default value of nSplitter is 5 U SOKDDm
this("","","",5); yFIy`9R
} 6y+b5-{'
~m=EM;
Hy;Hs#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) hP?fMW$V
{ W+>wu%[L
sSiteURL= sURL; BW[5o3 i
sFilePath = sPath; =y ]Jl,_.
sFileName = sName; mxTk+j=
this.nSplitter = nSpiltter; 6o3T;h
q1Qje%9@t
8 ,}ikOZ?
} #~Q=h`9
Bl.u=I:Y4
eBB:~,C^q.
public String getSSiteURL() :1fagaPg
{ I8m:3fL"
return sSiteURL; -<f/\U
} 0Vv9BL{
*DeTqO65
HB& &
public void setSSiteURL(String value) Iq'O
{ ,4F,:w
sSiteURL = value; X33v:9=
} /"AvOh*
7Ur?ep
iv%w!3#
public String getSFilePath() _."E%|5
{ ,TC~~EWq
return sFilePath; y>o>WN<q
} $%qg"
E{^^^"z P
E:A!wS`"
public void setSFilePath(String value) IhonnLLW
{ L ^Y3=1#"g
sFilePath = value; DQ6jT@ZDH
} a0_(eO-S
83;IyvbL
)qM|3],
public String getSFileName() [,f)9v)
{ *K!++k!Ixa
return sFileName; I@Z)<5Zf
} x!{
crmUrF#
hb^!LtF#Y
public void setSFileName(String value) xxX/y2\
{ [B/0-(?
sFileName = value; # mT]j""
} jz:gr=*z
a8uYs DS
o"_=K%9
public int getNSplitter() z]#hWfM4B:
{ B4W\ t{
return nSplitter; 2"/yEg*=
} 6 DP[g8
>9(i)e
2_pz3<,\
public void setNSplitter(int nCount) %`\]Y']R
{ A3UQJ
nSplitter = nCount; l8wF0|
} ?ApRJm:T
} cH"@d^"+q|
gbGTG(:1S
jXIEp01
/* y4F^|kS) [
**Utility.java {yq8<?
*/ Eb@MfL
package NetFox; ?SX_gYe9
0'yyfz
FBYODw
public class Utility { UC!5 wVY
^ }#f()
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public Utility() YFx=b!/s
{ *T4ge|zUc
1%eLs=u?
-CU,z|g+
} S}gD,7@
2V$9ei6
//线程睡眠 N$Hqa^!'T
public static void sleep(int nSecond) U42\.V0
{ lG]GlgSs
try{ Nmf#`+7gCI
Thread.sleep(nSecond); /=M.-MU2
} */U$sZQ)
catch(Exception e) ZjD2u8e
{ +"=~o5k3Q
e.printStackTrace (); ? ).(fP
} \X opU"
} }#YQg0(
m|dF30~A
//日志 )dg UmN
public static void log(String sMsg) >@Khm"/T
{ 6DZ2pT:
System.err.println(sMsg); SRk7gfP*q
} B}5XRgq
s=jO;K$
}2xb&6g~o
public static void log(int sMsg) )`RZkCe
{ 2o}8W7y
System.err.println(sMsg); MZi8Fo'
} CU !.!cZ{
} 0C7"3l
+}]wLM}\UF
@}{VM)Fc+
/* I)uASfT$
**TestMethod.java Y;PDZbK3
*/ ]eL~L_[G\
package NetFox; }'_:XKLj
-(ER4#
h=mv9=x
public class TestMethod { <on)"{W13
mZ&]
OAyE/Q|
public TestMethod() ?(M\:`G'
{ ///xx/weblogic60b2_win.exe [M2Dy{dh
try{ Ua!Odju*w
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); F13%)G(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); U#l.E1Z
SiteFileFetch fileFetch = new SiteFileFetch(bean); N>T=L0`
fileFetch.start(); &:,fb]p
} dW6Q)Rfi
catch(Exception e){e.printStackTrace ();} '|+=B u
.Px,=56$X
^f"&}%"M
} 6P6Jx;
`}n0=E
/3;=xZq
public static void main(String[] args) 'jwTGT5x
{ XAGiu;<,=
new TestMethod(); $o::PDQ?
} w7[0
} zkvH=wL
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