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)); YZ}cB
} haSM=;uPM
for(int i=0;i<nEndPos.length-1;i++) Z)< wv&K
{ Q%ad q-B
nEndPos = nStartPos[i+1]; <+`(\
} ,i}|5ozj4
nEndPos[nEndPos.length-1] = nFileLength; \|=mD}N
} n$+M%}/f
} o3Ot.9L
}U5Y=RYo
GRYe<K
//启动子线程 #XIc "L)c
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; vn').\,P2O
for(int i=0;i<nStartPos.length;i++) %n?vJ#aX%
{ ?s%v0cF
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $< %B#axL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |WqOk~)[Z3
nStartPos,nEndPos,i); L^Wz vv]
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &V=7D#L
fileSplitterFetch.start(); 6DF
} Rs;15@t@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -e-e9uP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); E0f{iO;}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9t:]
nEndPos = " + nFileLength); BR_TykP
// fileSplitterFetch[nPos.length-1].start(); D#rrW?-z
C*~aSl7
HD`>-E#
//等待子线程结束 F3E[wdT
//int count = 0; AHh#Fx+K
//是否结束while循环 a' FN 3
boolean breakWhile = false; n2-0.Er
Pe7e?79
2!&pEqs
while(!bStop) 'Z!Ga.I
{ ]?l{j
write_nPos(); Q\_{d0 0
Utility.sleep(500); [[L-jq.'
breakWhile = true; :R6Q=g=
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#;r]/)>
for(int i=0;i<nStartPos.length;i++) 0&w0aP`Y
{ }p3b#fAr
if(!fileSplitterFetch.bDownOver) kyUl{Zj
{ ISqfU]>[
breakWhile = false; HMQI&Lh=U
break; $~u.Wq
} }uO5q42
} YcM;S
if(breakWhile) +&v\ /
break; U@lV
yyl#{Nl@t
QJX/7RA
//count++; Cnh|D^{s
//if(count>4) ,Qc.;4s-
// siteStop(); 7XAvd-
} IM(u<c$
e<+<lj"
!c(QSf502
System.err.println("文件下载结束！"); d,#.E@Po
} GrI&?=S^
catch(Exception e){e.printStackTrace ();} ocA]M=3~k
} wT_^'i*@I
o#hI5
5~VosUpe7
//获得文件长度 C7"HQQ
public long getFileSize() ?-~I<f]_
{ DguB
int nFileLength = -1; !q/5yEJ>h
try{ M[P^]J@
URL url = new URL(siteInfoBean.getSSiteURL()); POd/+e9d
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bg7n
httpConnection.setRequestProperty("User-Agent","NetFox"); 05e>\}{0
Wr%7~y*K
I48VNX
int responseCode=httpConnection.getResponseCode(); ,@CfVQz
if(responseCode>=400) 4('JwZw\!
{ k=n "+
processErrorCode(responseCode); 9C}qVoNu
return -2; //-2 represent access is error {U @3yB
} &"S/Lt
?l6jG
aC\4}i<
String sHeader; NB)t7/Us
F?]N8W
g:~+Pe
for(int i=1;;i++) TipHV;|e
{ Z7#7N wy4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); fN[n>%)VO<
//Utility.log(in.readLine()); otnV-7)@
sHeader=httpConnection.getHeaderFieldKey(i); ,cQA*;6
if(sHeader!=null) \(u@F<s-
{ n~%}Z[5D
if(sHeader.equals("Content-Length")) [=~!w_
{ .mt^m
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); aL)$b
break; O5MDGg
} I9/KM4&
} fI}c 71b`
else ZR mPP
break; J|?[.h7tO
} a7 )@BzF#
} MBO,\t.
catch(IOException e){e.printStackTrace ();} BhkAQEsWTQ
catch(Exception e){e.printStackTrace ();} ,\>g
m3"c (L`B
>w2f8tW`PP
Utility.log(nFileLength); ^0eO\wc?O
k+txb?
S)Mby
return nFileLength; zKMv7;s?
} $QffrU'
[oJ& J>U'
~Jxlj(" 0(
//保存下载信息（文件指针位置） @7X\tV.Z
private void write_nPos() `\e'K56W6
{ w3d\0ub
try{ 0#]!#1utg
output = new DataOutputStream(new FileOutputStream(tmpFile)); #:I^&~:
output.writeInt(nStartPos.length); 7YD\ !2b
for(int i=0;i<nStartPos.length;i++) oFn4%S:
{ ++gPv}:$X
// output.writeLong(nPos); R05T5Q1]A
output.writeLong(fileSplitterFetch.nStartPos); Ks51:M
output.writeLong(fileSplitterFetch.nEndPos); K"I{\/x@
} 0@w&J9yG
output.close(); 8nf4Jk8r
} `U!(cDY
catch(IOException e){e.printStackTrace ();} F*. /D~K
catch(Exception e){e.printStackTrace ();} 9QZ}Hn`p
} sgD@}":m
'l8eH$
W=F3XYS
//读取保存的下载信息（文件指针位置） VAt>ji7c
private void read_nPos() P2|}*h5(
{ Ipg\9*c`
try{ 69-$Wn43<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _3I3AG0e
int nCount = input.readInt(); t3K>\ :
nStartPos = new long[nCount]; :nt}7Dn'
nEndPos = new long[nCount]; c.\:peDk
for(int i=0;i<nStartPos.length;i++) uH=Gt^_
{ D`8E-Bq
nStartPos = input.readLong(); I?A~zigO
nEndPos = input.readLong(); E=A/4p6\$
} xL|?(pQ/BK
input.close(); vW9^hbdx
} _AVy:~/
catch(IOException e){e.printStackTrace ();} 20n%o&kG]8
catch(Exception e){e.printStackTrace ();} ST#PMb'izn
} EWSr@}2j .
NuHL5C?To
;.L!%$0i#
private void processErrorCode(int nErrorCode) 9]"\"ka3>
{ 0qOM78rE
System.err.println("Error Code : " + nErrorCode); HE9. k.sS
} u|(aS^H=q
#@IQlqJfY7
M_yZR^;^-
//停止文件下载 >3v0yh_3
public void siteStop() W=q?tD~V
{ 7&#'c8]/qh
bStop = true; \XZU'JIO
for(int i=0;i<nStartPos.length;i++) jc3ExOH
fileSplitterFetch.splitterStop(); v\J!yz
4mki&\lw`
=B1`R%t
} \ro~-n+o
} Vx0MG{vG1
//负责部分文件的抓取 A)=X?x
**FileSplitterFetch.java }S Y`KoC1
*/ E>o&GYc
package NetFox; ZKVp[A
e&r+w!
+# m
import java.io.*; <6~/sa4GN
import java.net.*; rjq -ZrC%
Q&\ZC?y4
<e@I1iL37y
public class FileSplitterFetch extends Thread { J$o[$G_Z
2n<qAl$t
5|{ t+u
String sURL; //File URL &1\u#LU
long nStartPos; //File Snippet Start Position n:%'{}Jw
long nEndPos; //File Snippet End Position {FrHm
int nThreadID; //Thread's ID ,i1fv "
boolean bDownOver = false; //Downing is over 1KfJl S+
boolean bStop = false; //Stop identical sIP6GWK$
FileAccessI fileAccessI = null; //File Access interface )AZ`R8-A
B{=,VwaP_
#)IdJ]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /jn:e"0~
{ [C*Xk{e
this.sURL = sURL; 74</6T]^
this.nStartPos = nStart; Y+S~b
this.nEndPos = nEnd; J\,@Bm|1n{
nThreadID = id; qCv}+d)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^+YGSg7
} J{v6DYhi
3M5=@Fwkr
@=^jpSnZ
public void run() p)AvG;
{ Xqq?S
while(nStartPos < nEndPos && !bStop) c"jhbH!u4
{ ** "s~
[9##Kb
`s]zk {x
try{ *HfW(C$
URL url = new URL(sURL); *AJezhR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S a#d?:L
httpConnection.setRequestProperty("User-Agent","NetFox"); s;=J'x)~%
String sProperty = "bytes="+nStartPos+"-"; Amq8q
httpConnection.setRequestProperty("RANGE",sProperty); 3vEjf
Utility.log(sProperty); ^Ypb"Wx8
|R|U z`
omDi<-
InputStream input = httpConnection.getInputStream(); y0Q/B|&[
//logResponseHead(httpConnection); 7kew/8-
[~&:`I1
%)!~t8To
byte[] b = new byte[1024]; `dq3=
int nRead; 2+hfbFu,1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )QJU]G
{ 67hPQ/S1
nStartPos += fileAccessI.write(b,0,nRead); /R+]}Lt~%*
//if(nThreadID == 1) V-o`L`(F`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4FP~+
} mU0r"\**c3
L M<=j
"$wPq@
Utility.log("Thread " + nThreadID + " is over!"); QK/+*hr;
bDownOver = true; ?5+KHG*)
//nPos = fileAccessI.write (b,0,nRead); 7Q4PjcD
} 6d?2{_},
catch(Exception e){e.printStackTrace ();} a(QZZq};S
} gpTF^.(
} "5z6~dq
P(gID
uvc{RP
//打印回应的头信息 1Z{p[\k
public void logResponseHead(HttpURLConnection con) \(v_",
{ NX#/1=
for(int i=1;;i++) R S_lQ{'
{ ClVpb ew
String header=con.getHeaderFieldKey(i); yqc(32rF!
if(header!=null) 7&S|y]$~
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B*~Bm.
Utility.log(header+" : "+con.getHeaderField(header)); N[D\@o
else ("@V{<7(t
break; 5WNRo[`7
} j`&i4K:
} .mU.eLM
2dlV'U_g
lM]),}
public void splitterStop() ~m=%a
{ Oh85*3
bStop = true; Nk~dfY<s
} mZJzBYM)
h+d;`7Z>
v\tbf
} T7_ SO,X
D{d$L9.
KO;61y:
/* av$_hEjo|D
**FileAccess.java r4>I?lD
*//文件访问(定位，写) YxqQg
package NetFox; ]O ` [v
import java.io.*; 7%FZXsD
]|BSX-V.%i
/'_ RI
public class FileAccessI implements Serializable{ nAC#_\
"8 mulE,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .v&h>@'m
RandomAccessFile oSavedFile; qiryC7.E
long nPos; 6(^9D_"@
?i=!UN
~J{{n_G{
public FileAccessI() throws IOException RUtS_Z&
{ W)~.o/;
this("",0); {EN@,3bA
} cb,sb^-
F7l:*r,O
4N0nU
public FileAccessI(String sName,long nPos) throws IOException sYI':UQe
{ f)P/@rh
oSavedFile = new RandomAccessFile(sName,"rw"); lM%fgyX
this.nPos = nPos; oA%[x
oSavedFile.seek(nPos); E-iBA(H
} kweTK]mT
{f3fc8(p
y]%,Y=%X
public synchronized int write(byte[] b,int nStart,int nLen) %.U{):lNx
{ *v3 |
int n = -1; mnjA8@1
try{ 0.0!5D[
oSavedFile.write(b,nStart,nLen); ='>UKy[=
n = nLen; @v=q,A8_
} I!O S&8:u
catch(IOException e) 0Wm-`ZA
{ kR(=VM JU
e.printStackTrace (); Z?mg1;Q
} mh]$g<*m
59]9-1" +
V,5}hQJ F
return n; @E;pT3; )
} VC7F#a*V
kc[["w&
;#j82
} = h( n+y<
RY<b]|
RkwY3s"
/* >cL2PN_y
**SiteInfoBean.java ;~1JbP
*/ I!D*(>
package NetFox; =rF8[Q0K
s\!vko'M
-~f.>@Wb
public class SiteInfoBean { s3 $Q_8H
hM w`e
3PffQ,c[~
private String sSiteURL; //Site's URL t7FQ.E,T
private String sFilePath; //Saved File's Path ;i>E@
private String sFileName; //Saved File's Name koZp~W-
private int nSplitter; //Count of Splited Downloading File Ao$z)<d'
I1O?)x~
It-*CD9
public SiteInfoBean() >oDP(]YGg
{//nSplitter的缺省值为5 Sw'?$j^3
//default value of nSplitter is 5 IOl"Xgn5
this("","","",5); 9zd/5|W
} /|AuI qW
<Q)}
4V8wB}y7e
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 12dW:#[
{ i]pG}SJ
sSiteURL= sURL; ypo=y/!
sFilePath = sPath; &Sa~Wtm|*
sFileName = sName; puF Z~WZ
this.nSplitter = nSpiltter; \-ws[
=lQ[%&
[)n}!5fE
} %;$Y|RbmqE
|Eu~=J7@
8Oh3iO
public String getSSiteURL() x`i`]6q
{ !Jl0Eu
return sSiteURL; W[<":NX2
} vyGLn
r0 C6Ww7u
l}c2l'
public void setSSiteURL(String value) (OQ @!R&
{ :/%xK"
sSiteURL = value; !5t 3Y
} JZxF)]^
F6VIH(
QC,(rB
public String getSFilePath() )m;qv'=!
{ gi@ji-10
return sFilePath; 15DK\_;
} IkNt! 2s_
;XQ lj?:
OUO^/] J1S
public void setSFilePath(String value) pu*u[n
{ z>;+'>XXgx
sFilePath = value; l0xFt ~l
} D#}Yx]Q1
aZGDtzNG5h
UDtbfc7bk
public String getSFileName() r;8z"*
{ lNVAKwW2#
return sFileName; \[I .
} !H=k7s
]Ja8i%LjOG
Z1&GtM
public void setSFileName(String value) 3N0X?* (x|
{ f.)F8!!
sFileName = value; | 8Egw-f
} MYSc*G
^|i\d\
0W%}z}/N
public int getNSplitter() `R52{B#&/
{ $_zkq@
return nSplitter; m&0BbyE.z
} G_N-}J>EP
33*d/%N9
aX'g9E
public void setNSplitter(int nCount) ww t()
{ +xBK^5/x
nSplitter = nCount; |QNLO#$ -
} O| 6\g>ew
} 3]OP9!\6
bNpIC/#0K
'L|GClc6)
/* 'S4EKV]
**Utility.java ^@*zH?Rx{
*/ RR"WO
package NetFox; Y\Qxdq
Dq%r !)
^!p<zZ
public class Utility { 0mD;.1:
hi D7tb=g~
Ld3Bi2d|
public Utility() lH@E%
{ }A)36
0Q- Mxcj
Xm=^\K3
} ngY+Ym
&*]{"^
//线程睡眠 cov#Z ux
public static void sleep(int nSecond) Ma=6kX]
{ }vUlTH
try{ M?~<w)L}
Thread.sleep(nSecond); `KJYm|@i
} }#W`<,*rL.
catch(Exception e) >6l;/J
{ ,rB9esxic
e.printStackTrace (); <r+!hJ[s'
} ,*nZf|
} g y e(/N+I
<.=#EV^i
//日志 =Kt9,d08x
public static void log(String sMsg) ]O7.ss/2
{ Ns!3- Y
System.err.println(sMsg); <[y$D=n
} $]H=
hLytKPgt
}EedHS
public static void log(int sMsg) Ng'ZAG;O
{ _L4<^Etfm
System.err.println(sMsg); Y( $Ji12
} @"{'j
} *L;pcg8{
Q%n{*py
+r-dr>&H@
/* Rg?{?qK\K
**TestMethod.java #NN"(I
*/ [UJEU~XC
package NetFox; TXJY2J*24
c.8((h/
"0'*q<8
public class TestMethod { \>Ga-gv6/
5@UC c
Kl aZZJ
public TestMethod() j FPU zB"
{ ///xx/weblogic60b2_win.exe 4P4 Fo1
try{ Zc%foK{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *TM;trfz
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); KZrMf77=
SiteFileFetch fileFetch = new SiteFileFetch(bean); +=6RmId+X
fileFetch.start(); {C/L5cZ]J
} xMNNXPz(
catch(Exception e){e.printStackTrace ();} 9QH9gdiw
0eqi1;$b]
pM&]&Nk
} t/d',Khg
UR1JbyT
B.22 DuE#
public static void main(String[] args) 0i5y(m&7
{ bB:r]*_ s]
new TestMethod(); ~MhgAC
} 2JiAd*WK
} !EX?m }7
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