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)); naY#`xig
} nrTCq~LO(
for(int i=0;i<nEndPos.length-1;i++) 2Y}A9Veb
{ esv<b>`R
nEndPos = nStartPos[i+1]; `1 Tg8
} }V+&o\4
nEndPos[nEndPos.length-1] = nFileLength; ,+5!1>\
} (elkk#
} @<S'f<>g
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61b<6r0o
//启动子线程 'Te'wh=Y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |L)qH"Eo
for(int i=0;i<nStartPos.length;i++) kgX"I ?>d
{ 0M}Ql5+h,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i8/"|+Z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Je#3
nStartPos,nEndPos,i); lb)i0`AN+
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); eA9r M:
fileSplitterFetch.start(); @^Kw\s
} QSo48OFs
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [!#;QQ&M
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); U,`F2yD/!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", BQ~\p\
nEndPos = " + nFileLength); gqAN-b'
// fileSplitterFetch[nPos.length-1].start(); S.fb[gI]
i+Xb3+R
PiX(Ase
//等待子线程结束 |P"kJ45
//int count = 0; AIwp2Fz
//是否结束while循环 VB+y9$Y'
boolean breakWhile = false; 1i|5ii*vc
V#PT.,Xa.
|uA /72
while(!bStop) .18MMzdN
{ `$VnB
write_nPos(); kPp7;U2A
Utility.sleep(500); 6)3pnhG9
breakWhile = true; 74~%4
2CPh'7|l
T "t%>g
for(int i=0;i<nStartPos.length;i++) SM`n:{N(
{ #|}EPD9$
if(!fileSplitterFetch.bDownOver) PkdL] !:
{ Kx,<-]4
breakWhile = false; RM`iOV,Y
break; *i7|~q/u
} K&iU+
} rge/qUr/^
if(breakWhile) :LR>U;2
break; )G|'PXI@,
@(e/Y/
eq36mIo
//count++; lLL)S
//if(count>4) k`,>52
// siteStop(); flU?6\_UC
} wb-_CQ
Mg{=(No
1&YkRCn0
System.err.println("文件下载结束！"); h\OMWJ~
} @w[HXb
catch(Exception e){e.printStackTrace ();} 0qo:M3
} D +9l$**a
~jOk?^6
HS 1zA
//获得文件长度 1:q5h*
public long getFileSize() ygTc Y
{ ]AB4w+6!
int nFileLength = -1; @avG*Mr^
try{ p!~V@l
URL url = new URL(siteInfoBean.getSSiteURL()); X~g~U|B@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,A!0:+
httpConnection.setRequestProperty("User-Agent","NetFox"); p+1kU1F0
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Eg#WR&Uq"
int responseCode=httpConnection.getResponseCode(); ksli-Px
if(responseCode>=400) e:RgCDWL
{ XRWy#Pj
processErrorCode(responseCode); JE/Kf<
return -2; //-2 represent access is error !&vPG>V
} (%iCP/E3
eq$.np
|Skhx9};
String sHeader; rTtxmw0
B["C~aF
+T]D\];D
for(int i=1;;i++) X?OH//co
{ [#C(^J*@c
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .L}k-8
//Utility.log(in.readLine()); 05o 1
sHeader=httpConnection.getHeaderFieldKey(i); /gq VXDY+`
if(sHeader!=null) c\(CbC
{ &X OFc.u
if(sHeader.equals("Content-Length")) {3*Zx"e![
{ >du|DZq
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); @ M
break; Y`!Zk$8
} 5TS&NefM
} W 33MYw
else #w#:f
break; _tQR3I5
} ?=0BU}
} WBY_%RTx
catch(IOException e){e.printStackTrace ();} NN@'79x
catch(Exception e){e.printStackTrace ();} h7F5-~SpD
Fhk`qh'i
qO}Q4a+
Utility.log(nFileLength); oD&axNk
<]h?_)
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return nFileLength; k^*S3#"
} 58o'Q
jLv8K
&Z6s\r%
//保存下载信息（文件指针位置） tkKiuh?m
private void write_nPos() C0%yGLh&
{ SK;c D>)
try{ qv.s-@l8
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3DS&-rN
output.writeInt(nStartPos.length); gano>W0
for(int i=0;i<nStartPos.length;i++) d\v1R-V
{ :"I!$_E'
// output.writeLong(nPos); <#F@OU
output.writeLong(fileSplitterFetch.nStartPos); X6SWcJtSw
output.writeLong(fileSplitterFetch.nEndPos); Av_JcH
} j NkobJ1
output.close(); fKOC-%w
} ;30SnR/
catch(IOException e){e.printStackTrace ();} nb_$g@03
catch(Exception e){e.printStackTrace ();} `D={l29H
} b,uudtlH
EN;s 8sC!
G#nZ%qQ:I
//读取保存的下载信息（文件指针位置） ~X!Z+Vg
private void read_nPos() _mc-CZ
{ ~Y/o9x0
try{ 1paLxR5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _|I`A6`=
int nCount = input.readInt(); /l1OC(hm
nStartPos = new long[nCount]; 0<#>LWaM_
nEndPos = new long[nCount]; GYwU3`{
for(int i=0;i<nStartPos.length;i++) LeaJ).Maw
{ qvG@kuz8g5
nStartPos = input.readLong(); xY>@GSO1
nEndPos = input.readLong(); rc`}QoB)R
} Z]qbLxJV
input.close(); 5)iOG#8qJ
} kmT5g gy
catch(IOException e){e.printStackTrace ();} ]-"G:r
catch(Exception e){e.printStackTrace ();} f O,5 u;
} 7oV$TAAf
lgQ"K(zY
|Q+:vb:
private void processErrorCode(int nErrorCode) '|^x[8^
{ jH>`:
System.err.println("Error Code : " + nErrorCode); v8f1o$R
} 2xK v;
V;29ieE!
F(KsB5OY?
//停止文件下载 h yK&)y?~
public void siteStop() i8->3uB
{ ,9Si3vn
bStop = true; E.eUd4XG
for(int i=0;i<nStartPos.length;i++) #gsJ tT9
fileSplitterFetch.splitterStop(); <NXJ&xs-+
{ep(_1
Gy)2
} 3t9Weo)
} .C,D;T{
//负责部分文件的抓取 `Vl9/IEk
**FileSplitterFetch.java vb`R+y@
*/ qsWy <yL+
package NetFox; 75^AO>gt
#+#^cqjZ
n#^ii/H
import java.io.*; c*.-mS~Z`
import java.net.*; @L$!hTaP
yQ0:M/r;0
55Ya(E
public class FileSplitterFetch extends Thread { ( 4(,"
"fu:hHq
H)+QkQb}
String sURL; //File URL w)C5XX30;
long nStartPos; //File Snippet Start Position /V GI@"^v
long nEndPos; //File Snippet End Position uH]oHh!}j
int nThreadID; //Thread's ID Jb*E6-9G
boolean bDownOver = false; //Downing is over v=d16
boolean bStop = false; //Stop identical CorV!H4
FileAccessI fileAccessI = null; //File Access interface Xz`0nU
"S H=|5+
nvQTJ4,,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException h8dFW"cpC
{ 8qL.L(=\/
this.sURL = sURL; Swr4De_5
this.nStartPos = nStart; QQJf;p7
this.nEndPos = nEnd; 3 3zE5vr
nThreadID = id; h:RP/0E
fileAccessI = new FileAccessI(sName,nStartPos);//定位 y9b%P]i
} <*(^QOM
l];/,J^
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public void run() $*;`$5.x^
{ p(6 sN=
while(nStartPos < nEndPos && !bStop) P; h8
{ Cxeam"-HTt
H*e+ 2
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try{ BP}@E$
URL url = new URL(sURL); F3hG8YX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yd=b!\}WJ
httpConnection.setRequestProperty("User-Agent","NetFox"); *3)kr=x
String sProperty = "bytes="+nStartPos+"-"; +PS jBO4!
httpConnection.setRequestProperty("RANGE",sProperty); E>+>!On)b
Utility.log(sProperty); k%BU&%?1
,u>[cRqw
Ec2;?pvd%J
InputStream input = httpConnection.getInputStream(); !Au#j^5K-o
//logResponseHead(httpConnection); Q(36RX%@
V';l H2
o7t{?|
byte[] b = new byte[1024]; 5owK2
int nRead; bQ(-M:
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) rr,w/[
{ \<ysJgqUG
nStartPos += fileAccessI.write(b,0,nRead); \W]gy_=D{
//if(nThreadID == 1) .cbC2t95
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VD<z]@
} 2vWn(6`
Q8MIpa!:
7Ja*T@ !h
Utility.log("Thread " + nThreadID + " is over!"); L&s$&E%
bDownOver = true; Uo71C4ev
//nPos = fileAccessI.write (b,0,nRead); `BVmuUMm
} FgL892[
catch(Exception e){e.printStackTrace ();} 7i!VgV
} t1]/Bw`j/
} Vd(n2JMtG
z:4_f:70
{ :1XN
//打印回应的头信息 'ZB^=T
public void logResponseHead(HttpURLConnection con) ()48>||
{ &gPP#D6A
for(int i=1;;i++) &O^-,n
{ Z"RgqNf
String header=con.getHeaderFieldKey(i); *~>p;*
if(header!=null) X'-Yz7J?o
//responseHeaders.put(header,httpConnection.getHeaderField(header)); X =%8*_
Utility.log(header+" : "+con.getHeaderField(header)); 7f4O~4.[i
else :eSsqt9]9
break; &7oL2Wf
} 7[w<v(Rc
} vFB^h1k~.M
H>A6VDu
JJM<ywPGp
public void splitterStop() 2 rr=FJ
{ [orL.D]
bStop = true; =MMd&
} }zx ~
VX&PkGi?o
_bi)d201
} SI=u-'%
ddyX+.LMk
PO?_i>mA
/* r5Tdp)S
**FileAccess.java !Av9?Q:
*//文件访问(定位，写) U(9_&sL
package NetFox; ^:]$m;v]
import java.io.*; 6tndC o;`
,|B-Nq
S YDE`-
public class FileAccessI implements Serializable{ 3TH?7wi
V*{rHp{=p
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .z.4E:Iq
RandomAccessFile oSavedFile; Be=rBrI>
long nPos; &'x~<rx
Rh?bBAn8
~y2zl
public FileAccessI() throws IOException >a,D8M?
{ c%J6!\
this("",0); u;gO+)wqv
} )muNfs m
"GZieI D
!~Uj 'w
public FileAccessI(String sName,long nPos) throws IOException AoeRoqg&#
{ 3_~iq>l
oSavedFile = new RandomAccessFile(sName,"rw"); \7uM5 k}l
this.nPos = nPos; lU%}_!tp3/
oSavedFile.seek(nPos); L]|mWyzT
} 7P7OTN
Pps-,*m
{@^;Nw%J
public synchronized int write(byte[] b,int nStart,int nLen) B+j]C$8}
{ <ZF|2
int n = -1; r~lZ8$KC
try{ P}Kgh7)3
oSavedFile.write(b,nStart,nLen); k(l2`I4V
n = nLen; O,%,dtD[a
} Z0jgUq`r
catch(IOException e) /}(d'@8p
{ :Ko6.|
e.printStackTrace (); ~vFa\7sf
} ^k;]"NR
RhH1nf2UR
{K]5[bMT
return n; cKe%P|8
} C/Khp +
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]~KLdgru_
} _XV%}Xb'
GWnIy6TH l
jdP)y]c
/* LdV&G/G-#D
**SiteInfoBean.java S{rltT-
*/ rP3HR5
package NetFox; &0Yg:{k$
UJ)pae
2gPqB*H
public class SiteInfoBean { DH-M|~.sf^
IW3k{z
QEhn
private String sSiteURL; //Site's URL VThr]$2Y
private String sFilePath; //Saved File's Path Nr4:Gih
private String sFileName; //Saved File's Name ?Gki0^~J
private int nSplitter; //Count of Splited Downloading File ?;XEb\Kf
h'):/}JPl
2Wz8E2.
public SiteInfoBean() _\}'5nmw\
{//nSplitter的缺省值为5 d,V#5l-6
//default value of nSplitter is 5 ,Of^xER`
this("","","",5); ^dHQ<L3.*
} N1c=cZDV
i2~uhGJ
f"QiVJq
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (+> 2&@@<
{ [1VA`:?W
sSiteURL= sURL; QPJ\Iu@D$
sFilePath = sPath; d(T4Kd$r
sFileName = sName; {r,Uik-nL
this.nSplitter = nSpiltter; wA=r]BT
,#A(I#wL~
Ymk?@mV4
} h:YD$XE
\k.`xG?
?Z7`TnG$uf
public String getSSiteURL() r~t`H*C)}
{ jxh:z
return sSiteURL; jwDlz.sW!
} @ _Ey"k<
r]DiB:.
}TmOoi(X@
public void setSSiteURL(String value) ~~tTr$
{ U(#<D7}
sSiteURL = value; {ez$kz
} `>gG"1,]
wA"@t
!Zz;;Z
public String getSFilePath() K}~$h,n
{ zX>W 8P
return sFilePath; >lQo _p(;
} 1-KNXGb'
KA5)]UF`l
9DxHdpOk
public void setSFilePath(String value) `8:)? 0Ez
{ zfIo]M`
sFilePath = value; yn4T!r "
} xM*_1+<dT$
B$4*U"tk
3S0.sU~_U
public String getSFileName() U0~_'&Fe
{ ?+yr7_f3*
return sFileName; {"y/;x/
} _R4}\3}!
9%!h/m>rW
[GLH8R
public void setSFileName(String value) c/;;zc
{ oL<#9)+2*
sFileName = value; )ZG;.j
} 3o<d=@`r
)dXa:h0RZ
_bFUr
public int getNSplitter() \Pg~j\;F]
{ 3nq?Y8yac
return nSplitter; +)Z]<O
} fE#(M+(<
')X(P>
DXFu9RE\{
public void setNSplitter(int nCount) $~/2!T_
{ RJrz ~,}
nSplitter = nCount; SK<Rk
} n ~t{]if"
} qpjY &3SI
1Ms[$$b$
/k#-OXP~
/* p=8Qv
**Utility.java a~$XD(w^
*/ yk+ 50/L
package NetFox; 9mF'
K`4rUEf}V"
(!~cOx
public class Utility { S*h52li
?bTfQH vX
gD,&TW
public Utility() NVyBEAoh
{ w_9^YO!!
JzyCeM =
,UNb#=it
} #lYyL`B+~
6EqA Y`y
//线程睡眠 TBj2(Z
public static void sleep(int nSecond) X8Z?G,[H
{ t*{L[c9.Uq
try{ U( YAI%O
Thread.sleep(nSecond); +&GV-z~o
} #NS|9jW
catch(Exception e) 6x+ujUBkK
{ i_Kwxn$
e.printStackTrace (); i2F7O"f.
} Ss3p6%V/
} ^QK`z@B
=7Ln&tZ
//日志 }0'=}BE
public static void log(String sMsg) 3]Z1kB
{ N5 ME_)
System.err.println(sMsg); Ltlp9 S
} w:&""'E
2M %j-yG"
W5*ldXXk
public static void log(int sMsg) 5{c;I<0
{ %xt9k9=vZ
System.err.println(sMsg); aukcO;oG<
} tpfgUZ{
} Z}W{ iD{
fr17|#L+s
( }-*irSsj
/* HiCh:IP7>/
**TestMethod.java _&<n'fK[
*/ 5mH[|_
package NetFox; _^NX`<&
> p`,
mH o#"tc
public class TestMethod { ,7{|90'V<
~q$]iwwqT
[FFr}\}bY
public TestMethod() x/|W;8g4
{ ///xx/weblogic60b2_win.exe 'jev1u[
try{ q<3nAE$?=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !09)WtsEfx
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); E^F"$Z"N
SiteFileFetch fileFetch = new SiteFileFetch(bean); DfXkLOGik
fileFetch.start(); 5`;SI36"
} 4TtC~#D:
catch(Exception e){e.printStackTrace ();} 3I)~;>meo
(gt\R}
Fmk:[hMw
} X5 vMY
,jU>V]YC
GQ2GcX(E(
public static void main(String[] args) aZ#FKp^8H
{ rRTKF0+
new TestMethod(); |IgR1kp+.
} m`yvZ4K!
} >m%_`68
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