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)); ;mT|0&o>#
} *B4?(&0
for(int i=0;i<nEndPos.length-1;i++) 'E\/H17
{ [Rj_p&'
nEndPos = nStartPos[i+1]; ^sF/-/ {?U
} {GH0> 1&
nEndPos[nEndPos.length-1] = nFileLength; 1K*`i(
} :EGvI
} #mIgk'kW<
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//启动子线程 JXx[e
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Mb!b0
for(int i=0;i<nStartPos.length;i++) OLH[F
{ W u C2LM
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OO?;??
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1>c^-"#e^
nStartPos,nEndPos,i); RJ\'"XQ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #&k`-@b5|
fileSplitterFetch.start(); 539fB,
} ;\'d9C
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7@W}>gnf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); w@![rH6~F
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `4SwdW n
nEndPos = " + nFileLength); n 3eLIA{
// fileSplitterFetch[nPos.length-1].start(); ~=P#7l\o1
mm dQ\\
WMw|lV r
//等待子线程结束 >P9|?:c
//int count = 0; 9ZD>_a
//是否结束while循环 (DIMt-wz
boolean breakWhile = false; whW%c8
ts:YJAu+F
Jkx_5kk/\
while(!bStop) r"_U-w
{ ^g'P H{68
write_nPos(); |j2$G~B6
Utility.sleep(500); 7DZZdH$Fm
breakWhile = true; *Cj<Vy
g1H$wU3eu
APJVD-
for(int i=0;i<nStartPos.length;i++) v:IpZ;^
{ iW?z2%#
if(!fileSplitterFetch.bDownOver) qg06*$%
{ )KdEl9o
breakWhile = false; al{}_1XoU
break; ?3_^SRW&a
} RM3"8J
} mgd)wZNV
if(breakWhile) !'z"V_x~
break; _'mK=`>u
EXbaijHQG
R:5uZAx
//count++; 1F'x$~ZI
//if(count>4) q/h, jM
// siteStop(); s~NJy'Y
} ?mp}_x#=
#rI4\K
)p`zN=t
System.err.println("文件下载结束！"); `C&@6{L
} PL|ea~/
catch(Exception e){e.printStackTrace ();} {9XN\v=$"*
} ?APCDZ^
X()yhe_
4T>d%Tt+)
//获得文件长度 [BTOs4f
public long getFileSize() "Ng%"Nz
{ 3P*[!KI
int nFileLength = -1; |W\U9n
try{ v.6K;TY.
URL url = new URL(siteInfoBean.getSSiteURL()); 3Viz0I<%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); rqWD#FB=z
httpConnection.setRequestProperty("User-Agent","NetFox"); e9;5.m
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int responseCode=httpConnection.getResponseCode(); %BwvA_T'Q
if(responseCode>=400) M,vCAZ
{ WkMB
processErrorCode(responseCode); P_.zp5>
return -2; //-2 represent access is error {O!B8a
} 4*&2D-8<K
3rj7]:Vr
7Tc^}Q
String sHeader; u#+Is4Vh
"=Cjm`9~j
zXW)v/ ZD
for(int i=1;;i++) &a'mh
{ a|-ozBFR
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1wy?<B.f
//Utility.log(in.readLine()); {Rz(0oD\
sHeader=httpConnection.getHeaderFieldKey(i); RZ0+Uu/J
if(sHeader!=null) YS bS.tq
{ A~@x8
if(sHeader.equals("Content-Length")) ^@ Xzh:
{ `PtfPt<{
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Xd@ d$
break; v[4-?7-
} /^9=2~b
} ,: Ij@u>)
else 6Zx)L|B
break; )@],0yL
} f<;eNN
} >{{0odBF
catch(IOException e){e.printStackTrace ();} !8I80:e_~
catch(Exception e){e.printStackTrace ();} Hyb_>n
fp?/Dg"49.
R9-Uoc/
Utility.log(nFileLength); }_oQg_-7e
5i-VnG
.|i/ a%J
return nFileLength; ig^x%!;
} r8Z.}<j
UmLBoy&*
EvptGM
//保存下载信息（文件指针位置） :j`4nXm
private void write_nPos() kA/yL]m^S
{ :{ Lihe~\
try{ moCR64n
output = new DataOutputStream(new FileOutputStream(tmpFile)); Eih6?Lpu
output.writeInt(nStartPos.length); 0D/7X9xg9+
for(int i=0;i<nStartPos.length;i++) g~XR#vl$
{ |qf ef&
// output.writeLong(nPos); GK[9Cm"v
output.writeLong(fileSplitterFetch.nStartPos); pHKc9VC
output.writeLong(fileSplitterFetch.nEndPos); hm0MO,i"
} ~{ucr#]C
output.close(); C$d b)5-
} 1fTf+P
catch(IOException e){e.printStackTrace ();} 1cS*T>`
catch(Exception e){e.printStackTrace ();} };g<|v*o
} G5NAwpZf
ujr"_ofI
$lg{J$ h8
//读取保存的下载信息（文件指针位置） ))6YOc
private void read_nPos() ?>NX}~2cf
{ N_E)f
try{ T%yGSk
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); L]E.TvM1*
int nCount = input.readInt(); oxug
nStartPos = new long[nCount]; j9R+;u/!
nEndPos = new long[nCount]; 24k;.o
for(int i=0;i<nStartPos.length;i++) deOk>v&U
{ 3F$N@K~s
nStartPos = input.readLong(); M%OUkcWCk
nEndPos = input.readLong(); ZyV^d3F@$
} 13A~."b
input.close(); Zfd `Fu
} XrJLlH>R4
catch(IOException e){e.printStackTrace ();} )3ZkKv;zY
catch(Exception e){e.printStackTrace ();} a28`)17z
} U2 Cmf
QTU$mC]
!`dMTW
private void processErrorCode(int nErrorCode) I7+yu>
{ |?v+8QL,;t
System.err.println("Error Code : " + nErrorCode); Oo/@A_JO@
} Y+gNi_dE
drJUfsxV
usw(]CnH
//停止文件下载 !O4)YM
public void siteStop() TiKfIv
{ LCqWL1
bStop = true; cvC 7#i[G
for(int i=0;i<nStartPos.length;i++) esd9N'.Q*
fileSplitterFetch.splitterStop(); _opB,,G
$49;\pBZl
7 b{y
} XdE|7=+s
} \CBL[X5tr
//负责部分文件的抓取 S<g~VK!Tt
**FileSplitterFetch.java P&Wf.qr{:
*/ J IE0O`
package NetFox; 'jYKfq~_cJ
nq\~`vH|Gd
xu@+b~C\
import java.io.*; vBV_aB1{
import java.net.*; MC1&X'
@DKph!cr
@&GY5<&b
public class FileSplitterFetch extends Thread { #e[igxwi
Jm 1n|f
HMw}pp:
String sURL; //File URL gRwRhA/
long nStartPos; //File Snippet Start Position lr=quWDY
long nEndPos; //File Snippet End Position Y8/&1s_
int nThreadID; //Thread's ID u6 4{w,
boolean bDownOver = false; //Downing is over p+CK+m
boolean bStop = false; //Stop identical P}vk5o'
FileAccessI fileAccessI = null; //File Access interface Ki(0s
IO"q4(&;P4
yY!@FGsA
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ZeH=]G4Zv7
{ ^2nH6,LPS
this.sURL = sURL; @Py?.H
this.nStartPos = nStart; juMHc$d17
this.nEndPos = nEnd; "5"{~3Gw^
nThreadID = id; %F(lq*8X
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ?>mpUH
} 4+Y9":<
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o[g]Va*8
public void run() ue -a/a
{ ,#hNHFa'JH
while(nStartPos < nEndPos && !bStop) )!5"\eys
{ HG3iK
D 1(9/;9
*LQt=~
try{ G%T<wKD<
URL url = new URL(sURL); gH0Rd WX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _8wT4|z5
httpConnection.setRequestProperty("User-Agent","NetFox"); EE*FvI`
String sProperty = "bytes="+nStartPos+"-"; X3l6b+p
httpConnection.setRequestProperty("RANGE",sProperty); rfOrh^
Utility.log(sProperty); <<&SyP
cUwR6I9
{<Xl57w-Q
InputStream input = httpConnection.getInputStream(); R.rE+gxO1
//logResponseHead(httpConnection); @4>?Y=#
)jMk~;'r
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byte[] b = new byte[1024]; V5+|H1=
int nRead; 9L>ep&u)^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) LG=_>:~t>
{ !X1 KOG
nStartPos += fileAccessI.write(b,0,nRead); |%j7Es
//if(nThreadID == 1) Nk?L<'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FZN}T{<
} 5G=fJAG
ZBjb f_M:
E#\'$@8j
Utility.log("Thread " + nThreadID + " is over!"); NYPjN9L
bDownOver = true; E :UJ"6
//nPos = fileAccessI.write (b,0,nRead); j:0< tjE
} ~(eD 4"
catch(Exception e){e.printStackTrace ();} `)M&^Z=D
} ]E1|^[y
} -uB*E1|Q
ES5a`"H
C+0BV~7J<<
//打印回应的头信息 c
public void logResponseHead(HttpURLConnection con) 1t7T\~+F
{ q]v{o8:U
for(int i=1;;i++) 2'8I/>-
{ Sv[+~co<l
String header=con.getHeaderFieldKey(i); Xliw(B'\a4
if(header!=null) u9{Z*w3L7
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2Iq*7n:v0
Utility.log(header+" : "+con.getHeaderField(header)); 6t4{aa!L|9
else }KV)F,`
break; `LJ.NY pP
} !~]'&9
} _ Uv3glK
^NrC8,p
F "-GhjK
public void splitterStop() ($[@'?Z1
{ _:G>bU/^
bStop = true; Yz>8 Nn'_
} 7qg. :h
6g"qwWZp
<4*)J9V^s=
} dbfI!4
Cp#}x1{
PBAQ KQ
/* E\VKlu4
**FileAccess.java .WlZT-
*//文件访问(定位，写) |qb-iXW=
package NetFox; D/tFN+|P
import java.io.*; r,ep{ p
2&:nHZ)
_+qtH< F/
public class FileAccessI implements Serializable{ UL3u2g;d
e_llW(*l8^
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #G("Oh
RandomAccessFile oSavedFile; jC'Diu4|Q
long nPos; 5,du2
vH{JLN2
V4|l7
public FileAccessI() throws IOException IKnXtydeI}
{ qhNYQ/uS
this("",0); /z4n?&tM
} 8[u$CTl7a
SOvo%L@
UeaHH]U
public FileAccessI(String sName,long nPos) throws IOException _%<qZT
{ ~.Cu,>fV
oSavedFile = new RandomAccessFile(sName,"rw"); -7m7.>/M
this.nPos = nPos; xUDXg*
oSavedFile.seek(nPos); G V%@A
} y{QF#&lW
}?Tz=hP
A )xfO-
public synchronized int write(byte[] b,int nStart,int nLen) Uy$?B"Z
{ 0lpUn74F
int n = -1; {Lvta4}7(
try{ Xl/2-'4
oSavedFile.write(b,nStart,nLen); Kk/cI6`W
n = nLen; 't3nh
} <s5s<q2
catch(IOException e) h\*I*I8C
{ zG~nRt{4
e.printStackTrace (); $!:xjb
} k#<Y2FJa
CK1gzIg>
/XwwB
return n; nY_+V{F
} >\>!Q V1@
k E-+#p
RGLi#:0_.x
} c4L++ u#
{(^%2dk83C
|3 v+&eVi
/* 3NgyF[c
**SiteInfoBean.java 3!u:*ibt
*/ +JY]J89
package NetFox; xBAASy
e",0Er FT
x$24Nc1a'
public class SiteInfoBean { vkW]?::Cfd
VY "i>Ae
79>_aD9
private String sSiteURL; //Site's URL CM+/.y T
private String sFilePath; //Saved File's Path W. p'T}2
private String sFileName; //Saved File's Name L_}F.nbS5
private int nSplitter; //Count of Splited Downloading File 7)y +QU]
.0]Odf:@
1)ZdkTF@H
public SiteInfoBean() jLreN#:9
{//nSplitter的缺省值为5 PA>su)N$
//default value of nSplitter is 5 1'9YY")#
this("","","",5); 4z!(!J)
} q@Sj$
yx/.4DW1Ua
2R`}}4<Z
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Iqb|.vLG
{ iPt{v5}]
sSiteURL= sURL; 4$8\IJ7G
sFilePath = sPath; S{c;n*xf
sFileName = sName; 0vcM+}rw
this.nSplitter = nSpiltter; 3H@29TrJ+
e"voXe
6#1:2ZHKG
} jW_FaPW(p
`rI[
XnV$}T:?X
public String getSSiteURL() 3ypf_]<
{ firiYL"=44
return sSiteURL; Be2yS]U
} BI0 A0
Qb&gKQtt@
F[==vte|
public void setSSiteURL(String value) RTvzS]
{ oHkjMqju
sSiteURL = value; qn~:B7f
} 5`[B:<E4
w1 tg7^(@
Q)}z$h55
public String getSFilePath() 5tl uS
{ HDT-f9%}<4
return sFilePath; D^\2a;[AxA
} 2V=bE-
"3:TrM$|A
$7bux1L
public void setSFilePath(String value) glP W9q,f
{ pt- 1>Ui
sFilePath = value; +@5*_n\e`
} y7Sj^muBY
m6M:l"u
Zywx.@!
public String getSFileName() ]eIV'lP,j/
{ ~3s\Q%
return sFileName; =hB0p^a
} 7NDjXcuq
8S7 YVsDz"
ouR(l;
public void setSFileName(String value) gPg2Ve0Qy
{ nW`EBs
sFileName = value; TGu]6NzyZ
} <Z8^.t)|
#[ch?K
{aq}Q|?/
public int getNSplitter() g\foBK:GE
{ k;?E,!{
return nSplitter; L64cCP*
} ~TfQuIvQB
\h 1T/_4
lT~A~O
public void setNSplitter(int nCount) ;OfZEy>7
{ wQ/Z:
nSplitter = nCount; 088"7 s
} u3@v
} e&J_uG
qI#ow_lL#
uV+.(sjH
/* %t<ba[9F
**Utility.java UV8K$n<
*/ W05>\Rl
package NetFox; &[|P/gj#>
5 ]v]^Y'?
;m cu(J
public class Utility { hz~jyH.h_
g?d*cwtU
zCdzxb_h"
public Utility() >gLLr1L\
{ f6zS_y9gn
JW-!m8
5D%gDw+"
} A%c)=(,
qmM%MPv
//线程睡眠 wx%TQ!
public static void sleep(int nSecond) -C<Ni
{ bem-T`>'
try{ "[BDa}Il
Thread.sleep(nSecond); ,3E9H&@j
} XT0:$0F
catch(Exception e) Ar VNynQ
{ 8}(ul
e.printStackTrace (); $(U}#[Vie
} 7f\@3r
} A T'P=)F@
zm('\KvT
//日志 K?:wX(JYT
public static void log(String sMsg) F_&bE@k
{ 0[T>UEI?
System.err.println(sMsg); WbP*kV{
} nfbqJ
c/\$AJV.H
#\)tz z
public static void log(int sMsg) yL>wCD,L
{ t=Um@;wh
System.err.println(sMsg); ,t=12R]>
} ,dO$R.h
} )mbRG9P
XU19+mW=P
J%n{R60b
/* SS/t8Y4W
**TestMethod.java SJdi*>
*/ r9d dVD
package NetFox; t@O4!mFH
9M$N>[og
f8'$Mn,
public class TestMethod { O#5ll2?
, JUP
p&#*
public TestMethod() Y!tjaL 9D
{ ///xx/weblogic60b2_win.exe >&3ATH;&(
try{ OK^0,0kS3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); N2x!RYW
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Vt!<.8&`
SiteFileFetch fileFetch = new SiteFileFetch(bean); _noQk3N
fileFetch.start(); \"u3x.!
} f!"Y"g:@E
catch(Exception e){e.printStackTrace ();} Ft)Z'&L
_%$(D"^j
(s\":5 C
} 0fd\R_"d.
U~w g'
MN22#G4j^w
public static void main(String[] args) m*^|9*dIC
{ 4JD 8w3u/
new TestMethod(); GqrOj++>
} A|esVUo<3^
} 9IRvbE~2
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