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)); u>#'Y+7
} H0 t1& :
for(int i=0;i<nEndPos.length-1;i++) ;wZ.p"T9^
{ wl9icrR>
nEndPos = nStartPos[i+1]; ".IhV<R
} sqRuqUj+
nEndPos[nEndPos.length-1] = nFileLength; 2ra4t]f6
} 1uMdgrJRR
} $_kU)<e3
eNb =`
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//启动子线程 {wySH[V
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; e+U o-CO
for(int i=0;i<nStartPos.length;i++) M:E#}(
{ ?Fu.,srt
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ns(F%zkm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <LY+" Y
nStartPos,nEndPos,i); YR2/`9s\QJ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?*=Jq
fileSplitterFetch.start(); `^ok5w"oi
} TzJN,]F!M
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |n;7fqK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {;r5]wimb
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 62) F
nEndPos = " + nFileLength); Q>$v~v?9
// fileSplitterFetch[nPos.length-1].start(); [PT}!X7h
sKtH4d5)
T=vI'"w
//等待子线程结束 qM'5cxe
//int count = 0; `KN{0<Ne
//是否结束while循环 -[z;y73]t
boolean breakWhile = false; =zdRoXBY[b
ryPzq}#
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while(!bStop) +}]xuYzo
{ a9%# J^!
write_nPos(); r.[kD"l
Utility.sleep(500); MeC@+@C
breakWhile = true; c{[WOrA~#
rnUe/HjH
``{xm1GK
for(int i=0;i<nStartPos.length;i++) C'Q} Z_
{ > ewcD{bt
if(!fileSplitterFetch.bDownOver) {dDU^7O
{ @xo9'M<l
breakWhile = false; =>9`qcNW_
break; y7JJ[:~~
} JdE=!~\8
} 9496ayi
if(breakWhile) 9"[#\TW9Vb
break; [1Rs~T"
09r.0Ks
o&zeOJW
//count++; /}Max@.`
//if(count>4) kAMt8
// siteStop(); rRxqV?>n!
} D?$f[+
C 7v 8
QM=X<?m/,=
System.err.println("文件下载结束！"); =Z2sQQVS
} r>Vgo):s
catch(Exception e){e.printStackTrace ();} qSON3Iid
} ,Ao8QN
."${.BPn~
1r$q $\
//获得文件长度 uv,t(a.^
public long getFileSize() L49`=p<
{ I_Q'+d
int nFileLength = -1; ^j@,N&W:lG
try{ US-P>yF
URL url = new URL(siteInfoBean.getSSiteURL()); h/d&P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YDP<
httpConnection.setRequestProperty("User-Agent","NetFox"); fN@2 B
2|+**BxHD
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int responseCode=httpConnection.getResponseCode(); vtmvvv
if(responseCode>=400) o@}Jd0D4
{ ?_IRO|
processErrorCode(responseCode); ? r^+-
return -2; //-2 represent access is error 6tVB}UKs
} S~hNSw(-
c8A //
\59+JLmP4
String sHeader; &{99Owqg
|dK_^~;o
,u/GA<'#M
for(int i=1;;i++) 88G Q F
{ 72.ZE%Ue
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); smJ%^'x
//Utility.log(in.readLine()); lj(}{O
sHeader=httpConnection.getHeaderFieldKey(i); Z':}ZXy]
if(sHeader!=null) i!9yN:m0
{ !h4L_D0
if(sHeader.equals("Content-Length")) j*xxOwf
{ 5P [b/.n
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0@vSl%I+
break; Qn_*(CSp
} 5#~u U
} <GT&q <4w
else 6p])2]N>p
break; \^i/:
} #}3$n/
} yc?+L;fN
catch(IOException e){e.printStackTrace ();} X2v|O3>/N
catch(Exception e){e.printStackTrace ();} 6x7pqHM
L> > %
>d%;+2
Utility.log(nFileLength); 9v=5x[fE
^^1rjh1I
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return nFileLength; 2Ck'A0d
} Yjx*hv&?
<KlG#7M>
RX3P%xZ
//保存下载信息（文件指针位置） Z(k7&^d
private void write_nPos() kdcr*7w
{ wGr5V!
try{ B@U;[cO&
output = new DataOutputStream(new FileOutputStream(tmpFile)); )*Xd
output.writeInt(nStartPos.length); d2Pqi* K
for(int i=0;i<nStartPos.length;i++) l.NV]up+
{ 3Uw}!>`%
// output.writeLong(nPos); 6qp2C]9=
output.writeLong(fileSplitterFetch.nStartPos); R-5EztmLae
output.writeLong(fileSplitterFetch.nEndPos); pCb3^# &o
} U51C /A
output.close(); KG=h!]Meq
} Pv,Q*gh`
catch(IOException e){e.printStackTrace ();} *c9/ I
catch(Exception e){e.printStackTrace ();} b+7!$
} :!Ea.v
<_(UAv
b5NPG N
//读取保存的下载信息（文件指针位置） jg%HaA<zO
private void read_nPos() tj<a , l
{ |:Q`9;
try{ jG~zpZh
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); D_VAtz
int nCount = input.readInt(); 7S'3U}Y>VX
nStartPos = new long[nCount]; 0@ccXFE
nEndPos = new long[nCount]; z86[_l:
for(int i=0;i<nStartPos.length;i++) gK7bP'S8H
{ b9FfDDOq"
nStartPos = input.readLong(); >AFX}N#
nEndPos = input.readLong(); l.gt+e
} EdgcdSb7
input.close(); oVDqX=G
} afE`GG-
catch(IOException e){e.printStackTrace ();} Vm+e%
catch(Exception e){e.printStackTrace ();} %z9eVkPI~
} V)Oj6nD]
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>d1gVBhk
private void processErrorCode(int nErrorCode) 1"7Rs}l7
{ n\CQ-*;l
System.err.println("Error Code : " + nErrorCode); rwYlg:
} Y5rR
E}&Z=+v}
8~q%H1[I\N
//停止文件下载 YTWlR]Tr6?
public void siteStop() {Ftz4y)6
{ SY: gr
bStop = true; Gn+3OI"
for(int i=0;i<nStartPos.length;i++) iobL6SUZ
fileSplitterFetch.splitterStop(); 4&TTPcSt;
Nhq&Sn2
~i3/Ec0\
} u>e4;f`F
} e<Pbsj
//负责部分文件的抓取 9t`
**FileSplitterFetch.java e~Hx+Qp.G
*/ 7F=Xn@ _
package NetFox; \Pv_5LAo
Cq-d,
@%8Xa7+
import java.io.*; Ai99:J2k
import java.net.*; yW3X<
WGG Va
>%vw(pt
public class FileSplitterFetch extends Thread { !kzC1U
m@qM|%(0x
D'dE!CAUs
String sURL; //File URL ve#*qz Y
long nStartPos; //File Snippet Start Position h"b;e2
long nEndPos; //File Snippet End Position ( Lp~:p
int nThreadID; //Thread's ID }YPW@g
boolean bDownOver = false; //Downing is over ;THb6Jz/+
boolean bStop = false; //Stop identical Yn0l}=, n
FileAccessI fileAccessI = null; //File Access interface ulcm
pH#*:v!)
]6PX4oK_t
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^\Bm5QkS
{ je9eJUKE
this.sURL = sURL; %]~XbO
this.nStartPos = nStart; bo;;\>k
this.nEndPos = nEnd; l?_h(Cq<
nThreadID = id; s|/m}n
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _;8aiZt|u
} HkGA$
P|rsq|',
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public void run() gH{X?
{ 6##}zfl
while(nStartPos < nEndPos && !bStop) mPl2y3m%
{ +Lq;0tRC
||{V*"+\
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try{ m\3r<*q6
URL url = new URL(sURL); .d\<}\zZ7J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^LA.Y)4C2%
httpConnection.setRequestProperty("User-Agent","NetFox"); buIy+
String sProperty = "bytes="+nStartPos+"-"; L&C<-BA/
httpConnection.setRequestProperty("RANGE",sProperty); ZcTxE]Y
Utility.log(sProperty); 3f 1@<7*
LGxQ>f[V
r_sZw@lqJ
InputStream input = httpConnection.getInputStream(); >JNK06T
//logResponseHead(httpConnection); (<u3<40[YN
gq$]jWtCD
,bv?c@
byte[] b = new byte[1024]; 410WWR&4_
int nRead; ,zCrix 3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) un+U_|>c
{ B3p[A k
nStartPos += fileAccessI.write(b,0,nRead); p1dqDgF*
//if(nThreadID == 1) 8vN}v3HV&
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #MZ0Sd8]&
} ]Q}z-U
RETq S
2>s@2=Aq
Utility.log("Thread " + nThreadID + " is over!"); MoKGnb
bDownOver = true; u>~G)lx%
//nPos = fileAccessI.write (b,0,nRead); J- %YmUc)
} o=!3=2@dh
catch(Exception e){e.printStackTrace ();} fk(l.A$
} /]/3)@wT
} HJY_l
d|,,,+fS
'o2V}L'nG
//打印回应的头信息 \wmNeGC2
public void logResponseHead(HttpURLConnection con) vXUrS+~x
{ ]rEFWA
for(int i=1;;i++) Zi+>#kDV
{ m6qmZ2<
String header=con.getHeaderFieldKey(i); 4|+6a6
if(header!=null) b"Hg4i)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); dAOmqu,6
Utility.log(header+" : "+con.getHeaderField(header)); 1goK>=-^
else ~jd:3ip+!
break; .Gq)@{o>
} ^s@?\v
} 05".;(
buGYHZu
'bP-pgc
public void splitterStop() `pp"htm
{ "FC;k >m
bStop = true; H'uRgBjWJ
} 1>W|vOv"Z?
y8U|A0@$`
D7%`hU
} l?_Iu_Qp
C7%+1w'D8
DUg
/* XUUl*5^
**FileAccess.java 4|fI9.
*//文件访问(定位，写) #vhxW=L`=
package NetFox; zJ42%0g
import java.io.*; \WD}@6) ~
E Kks8
"}PaMR]
public class FileAccessI implements Serializable{ .bbl-a/ 3
YPAMf&jEF
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /?l@7
RandomAccessFile oSavedFile; >Pv#)qtm
long nPos; #$(F&>pj
F9q<MTh
Oy$*ZG)
public FileAccessI() throws IOException `[V]xP%V
{ fZ6lnZ
this("",0); xW*L^97 ;
} bit&H
yG'5up
;4of7d
public FileAccessI(String sName,long nPos) throws IOException bH+p5Fd;
{ 5nIm7vlQm
oSavedFile = new RandomAccessFile(sName,"rw"); ]Y;EIn
this.nPos = nPos; <!^wGN$f
oSavedFile.seek(nPos); &eq>>
} tWVbD%u^
hKb-l`KO
NKd!i09`
public synchronized int write(byte[] b,int nStart,int nLen) vBCQ-l<Ub
{ K2<Q9 ,vt
int n = -1; uWR\#D'
try{ uArs[e|f
oSavedFile.write(b,nStart,nLen); agX-V{l.
n = nLen; w\KO1 Ob
} _*B]yz6z
catch(IOException e) tF SO"
{ aS?A3h4WM_
e.printStackTrace (); TI:-Y@8
} :.6kXX'~
WlU^+ctS
z cN1i^
return n; 8D[P*?O
} 8C4DOz|
hZ-No
49&p~g
} V*SKWP
A1x?_S"a
:9q=o|T6D
/* fk,[`n+
**SiteInfoBean.java \D>vdn"Lx
*/ x3O$eKy\|5
package NetFox; !vHUe*1a{
%,$/wh)<V
~{'.9
public class SiteInfoBean { oe,L&2Jz@
x9R_KLN:;
Qy`{y?T2
private String sSiteURL; //Site's URL AB40WCu]*
private String sFilePath; //Saved File's Path 5$0@f`sj
private String sFileName; //Saved File's Name B P%>J^
private int nSplitter; //Count of Splited Downloading File <Hl.MS
hu.c&Q>
%YLdie6c
public SiteInfoBean() _3DRCNvh
{//nSplitter的缺省值为5 7H~StdL/>
//default value of nSplitter is 5 ,2S w6u
this("","","",5); TWkuR]5
} 1?sR1du,
p*E_Po
yg\bCvL&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4tU3+e5h
{ 4.2qt
sSiteURL= sURL; Q.Uyl:^PxU
sFilePath = sPath; VqV6)6
sFileName = sName; l/0TNOA
this.nSplitter = nSpiltter; FglCqO}
@1ZLr
V~M>K-AL
} \xJTsdd
.q#2 op
'|Dm\cy
public String getSSiteURL() V}(snG,
{ [ah%>&u
return sSiteURL; RGh`=D/yE
} i{TErJ{}e
Kg^L 4Q
Z'p7I}-qr
public void setSSiteURL(String value) FM:ax{
{ ;hU56lfZ)X
sSiteURL = value; 1~NXCIdF
} V4'G%!NY
v`#T)5gl-
E&r*[;$
public String getSFilePath() xo/[,rR
{ SOQm>\U'i
return sFilePath; @q2If{Tk
} /~*U'.V
U WYLT-^x
qYZ\<h^
public void setSFilePath(String value) d4<Ic#
{ Jx[Z[RO2
sFilePath = value; Qag@#!&n
} #|`/K[.xd%
+o})Cs`|=A
KIO{6
public String getSFileName() 2}:scag
{ ^50#R<Ny
return sFileName; |mvy@hm
} d54(6N%
tkU"/$Vi\
JK0L&t<
public void setSFileName(String value) vQCRs!A
{ =BO} hk
sFileName = value; vhiP8DQ
} Cn4o^6?"
}wzU<(Rx
b?`8-g
public int getNSplitter() \2,7fy'
{ p\5DW'
return nSplitter; @4dB$QF`&
} Mo`7YS-Y
:=x-b3U
RGy4p)z*+
public void setNSplitter(int nCount) [H$37Hx!
{ |KFRC)g
nSplitter = nCount; ka3Jqy4[
} xe5|pBT
} `h+ia/
j<w";I&Diz
sLh9=Kh`
/* !l1UpJp
**Utility.java vB >7W
*/ ;KqH]h)
package NetFox; VE{[52
%|md0
)+T\LU
public class Utility { boAu
F.ml]k&(m
"F%w{bf
public Utility() L/,#:J
{ !U38aHG
;~Y0H9`
tM3eB= .*
} ],{b&\
Cw"Y=`
//线程睡眠 ]H8,}
public static void sleep(int nSecond) Z>1\|j
{ W]cJP
try{ #`R`!4
Thread.sleep(nSecond); p%A s6.
} P+00wbx0
catch(Exception e) `!{m#BBT}
{ D9`J||]E
e.printStackTrace (); %7WQb]y
} }& ;49k
} $oKT-G
mZLrU<)Y
//日志 n<47#-
public static void log(String sMsg) s"5f5Cn/Wh
{ y7J2:/@[x
System.err.println(sMsg); .9X,)^D
} 8nn%wps
!qe,&JL
CD|)TXy
public static void log(int sMsg) LPr34BK
{ ?CSc5b`eo
System.err.println(sMsg); 5&V0(LT]C
} }c/p+Wo
} ox9$aBjJ
M(>"e*Pi
et[n;nl>V
/* 2S'{$m)
**TestMethod.java Y>v(UU
*/ ;{@ [ek6
package NetFox; !Yuu~|
7P!<c/ E
M1(+_W`
public class TestMethod { #gjhs"$~
nff X
Jv*[@ -.k
public TestMethod() C>\0 "}iD
{ ///xx/weblogic60b2_win.exe uLok0"}
try{ (.6~t<DRv
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ke$g[g
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Ww8<f$
SiteFileFetch fileFetch = new SiteFileFetch(bean); f0UB? |
fileFetch.start(); dg#w/}}m
} ]&l.-0jt
catch(Exception e){e.printStackTrace ();} ')]K&
j*2Q{ik>J
;+pS-Zb 6
} ~loJYq'y
ce3w0UeV
p6=L}L
public static void main(String[] args) _ U/[n\oC
{ Skm$:`u;
new TestMethod(); .Z[Bz7
} >kK!/#ZA
} (N63k1M
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