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)); Mx4 <F "9
} 4&&((H
for(int i=0;i<nEndPos.length-1;i++) edx-R-Dc-1
{ `og 3P:y
nEndPos = nStartPos[i+1]; Zu,rf9LMj
} "+~La{POc
nEndPos[nEndPos.length-1] = nFileLength; 'K"V{
} -1DQO|q#
} M._9/ *C U
vB hpD
3#!}W#xv
//启动子线程 Akb#1Ww4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #kR8v[Z
for(int i=0;i<nStartPos.length;i++) 8rx?mX,}
{ ,-rOfk\u
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m+?$cyA>v
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1}%vZE2
nStartPos,nEndPos,i); [z5pqd-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x9hkE!{8
fileSplitterFetch.start(); ocotO
} 5RrzRAxq
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {r yv7G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &"p7X>bd
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >ZTRwy`_(
nEndPos = " + nFileLength); XJ^dX]4
// fileSplitterFetch[nPos.length-1].start(); D C{l.a.
b MZ-{<+i
]4^9Tw6 _b
//等待子线程结束 ds}:t.3}6
//int count = 0; ]+u`E
//是否结束while循环 g\[?U9qN
boolean breakWhile = false; ABuK`(f.
U%.OH?;f
*UJ.cQ}
while(!bStop) r#M0X^4A
{ Y@)/iwq
write_nPos(); 0hVw=KDO9:
Utility.sleep(500); outAZy=R;
breakWhile = true; Q`j!$r
0<d9al|J
e%Rg,dX
for(int i=0;i<nStartPos.length;i++) yU<T_&M
{ __dSEOGoe
if(!fileSplitterFetch.bDownOver) ?Imq4I~)
{ !VBl/ aU@
breakWhile = false; X,DG2HT
break; 7jPPN
} #;4<dDVy
} D"UCe7
if(breakWhile) [CTE"@A
break; 2#%@j6
>1q W*
wK>a&`<
//count++; us%dw&
//if(count>4) 2l^hnog|
// siteStop(); VJviX[V?4
} F6^Xi"R[
_=!Rl#
]06orBV
System.err.println("文件下载结束！"); uJhB>/Og
} " iAwD8-
catch(Exception e){e.printStackTrace ();} }22h)){n#Y
} V9 Z
90<z*j$EK
~U"puEftbs
//获得文件长度 b/"&E'5-`\
public long getFileSize() "V|&s/9
{ i286 J.
int nFileLength = -1; jNV)=s^ed[
try{ H%y!lR{c^D
URL url = new URL(siteInfoBean.getSSiteURL()); <vS3[(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c"F3[mrff
httpConnection.setRequestProperty("User-Agent","NetFox"); '&v.h#<
OynQlQD/Eu
$o}Ao@WkO
int responseCode=httpConnection.getResponseCode(); LkvR]^u0
if(responseCode>=400) g}\G@7Q
{ 0G?*i_u\
processErrorCode(responseCode); 1j4tR#L
return -2; //-2 represent access is error @s7ZfV??
} EGJ d:>k
wN}@%D-[v
[{@0/5i
String sHeader; %# M=qP
"wqN,}bj\
Uphme8SX
for(int i=1;;i++) $>if@}u
{ KNvvYwFH]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 0i|z$QRL~
//Utility.log(in.readLine()); TjDDvXY
sHeader=httpConnection.getHeaderFieldKey(i); _`|te|ccF
if(sHeader!=null) MuI>ZoNF
{ #^FDG1=
if(sHeader.equals("Content-Length")) 9$<1<
{ {"e)Jj_=
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4zo^ b0v
break; GQ-fEIi{
} ]]"O)tWHj
} ^qR2!fwm<
else ;-]' OiS;
break; )SjhOvm
} }Zuk}Og9+
} {~*^jS']5
catch(IOException e){e.printStackTrace ();} Ij w{g%
catch(Exception e){e.printStackTrace ();} @*>kOZ(3
}X|*+<
t,P_&0X
Utility.log(nFileLength); mc FSWmq
p<[gzmU9\b
E^K<b7
return nFileLength; \mo NpKf
} IJ[r!&PY
(D5sJ$&E@\
cVb&Jzd
//保存下载信息（文件指针位置） b aO^Z
private void write_nPos() UA0j#
{ .Tm m
try{ t@"i/@8x$
output = new DataOutputStream(new FileOutputStream(tmpFile)); arWP]%E0W
output.writeInt(nStartPos.length); s^\ *jZ6
for(int i=0;i<nStartPos.length;i++) A.YXK%A%
{ E&z`BPd
// output.writeLong(nPos); Vf*Z}'
output.writeLong(fileSplitterFetch.nStartPos); or<n[<D-C
output.writeLong(fileSplitterFetch.nEndPos); iY[+BI:
} 3bU(ea^e$
output.close(); Bz+zEXBC
} R"2wop
catch(IOException e){e.printStackTrace ();} %$Smei
catch(Exception e){e.printStackTrace ();} 5|<jPc
} ](@HPAG]
:z-UnC||j
#Ch*a.tI@
//读取保存的下载信息（文件指针位置） ~vPR9\e
private void read_nPos() .D8|_B
{ Tf*DFyr
try{ 4AWL::FU5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =tS#t+2S
int nCount = input.readInt(); ybY[2g2QJ
nStartPos = new long[nCount]; N e<D'-
nEndPos = new long[nCount]; R\T1R"1
for(int i=0;i<nStartPos.length;i++) Q\moR^>
{ {VmJVO]S
nStartPos = input.readLong(); gJFx#s0?6.
nEndPos = input.readLong(); zBjtPtiiI8
} 7{JIHY+
input.close(); nDU=B.?E{O
} p[^a4E_v
catch(IOException e){e.printStackTrace ();} t@vVE{`
catch(Exception e){e.printStackTrace ();} Kg;u.4.-M
} h<0&|s*a)
4roqD;5|~|
eJ ;a}{ 4%
private void processErrorCode(int nErrorCode) b0|;v-v
{ ASU.VY
System.err.println("Error Code : " + nErrorCode); ou\M}C`E
} b/soU2?^
V<A$eb>6
\9!hg(-F
//停止文件下载 -_?U/k(Hi
public void siteStop() cF V[k'F
{ +Y! P VMF
bStop = true; V] 0T P#
for(int i=0;i<nStartPos.length;i++) UTS.o#d
fileSplitterFetch.splitterStop(); _c$F?9:
"p@EY|Zv%I
"xduh3/~=
} fMm.V=/+
} =pk5'hBAi
//负责部分文件的抓取 p6c&vEsNj
**FileSplitterFetch.java 1DRih>+#
*/ kMx^L;:n
package NetFox; @>Bgld&vl
eQU~A9
SNOML7pd
import java.io.*; DJJd_
import java.net.*; MXa(Oi2Gg
j;yKL-ycB
p>=i'~lQ6
public class FileSplitterFetch extends Thread { V'^E'[Dd{
/UG]hJ-wn
vrq5 +K&||
String sURL; //File URL +l27y0>t
long nStartPos; //File Snippet Start Position vq` M]1]FO
long nEndPos; //File Snippet End Position +(U;+6 b
int nThreadID; //Thread's ID csjCXT=Ve
boolean bDownOver = false; //Downing is over <N(r-
boolean bStop = false; //Stop identical 90Bn}@t=Q
FileAccessI fileAccessI = null; //File Access interface *8Kx y@
vdaG?+_o
s9rKXY',:l
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException M.oH,Kd6
{ &WKAg:^k)
this.sURL = sURL; d=C&b]
this.nStartPos = nStart; Q+7+||RW
this.nEndPos = nEnd; z]/!4+
nThreadID = id; .LI(2lP
fileAccessI = new FileAccessI(sName,nStartPos);//定位 N8KH.P+
} -{z<+(K!$
92(P~Sdv
n@$("p
public void run() 6PyW(i(bs
{ `lcQ Yd<,4
while(nStartPos < nEndPos && !bStop) ,(3oAj\
{ 2DNB?,uP,'
A}4 ",
x8!uI)#tS
try{ lj /IN[U/
URL url = new URL(sURL); cd._q2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D k<NlH zp
httpConnection.setRequestProperty("User-Agent","NetFox"); c5(4rT{(m
String sProperty = "bytes="+nStartPos+"-"; rrP_7D
httpConnection.setRequestProperty("RANGE",sProperty); -q30tO.
Utility.log(sProperty); 3}2;*:p4Y
lBzfBmEB
><xJQeW
InputStream input = httpConnection.getInputStream(); eb>jT:
//logResponseHead(httpConnection); lOy1vw'
<nU8.?\?~
H7 "r^s]D
byte[] b = new byte[1024]; e<$s~ UXv
int nRead; ^{Fo,7
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }2hU7YWt
{ NjbIt=y
nStartPos += fileAccessI.write(b,0,nRead); \GPTGi5A
//if(nThreadID == 1) l T#WM]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )kEH}P&
} {X10,
ntQW+!s;P
/:@)De(S
Utility.log("Thread " + nThreadID + " is over!"); 6~OJB!
bDownOver = true; kgHZaQnD
//nPos = fileAccessI.write (b,0,nRead); ?kULR0uL+
} W3gHzT?{
catch(Exception e){e.printStackTrace ();} "&C>=
} ` >loleI
} cD t|v~
12@Ge]
~gdnD4[G
//打印回应的头信息 ?sv[vR(
public void logResponseHead(HttpURLConnection con) .hRtQU
{ Dkg^B@5Xr
for(int i=1;;i++) dpvEY(Ds
{ }g& KT!r
String header=con.getHeaderFieldKey(i); `=lo.c
if(header!=null) /?NfU.+K
//responseHeaders.put(header,httpConnection.getHeaderField(header)); K;ocs?rk/
Utility.log(header+" : "+con.getHeaderField(header)); 7J1f$5$m5
else 3 MCV?"0
break; TVF:z_M9
} 3BSZz%va
} o@L2c3?c5
lnGg1/
D*/fY=gK
public void splitterStop() \M;cF"e-S
{ qpjiQ,\:b
bStop = true; \]0#jI/:
} C;?<WtH
\dbaY:(
d;nk>6<|
} RI<&cgWn+<
:F_>`{
'~VF*i^4
/* rZ&li/Z
**FileAccess.java WRrg5&._q
*//文件访问(定位，写) hC4 M}(XM
package NetFox; ibn\&}1
import java.io.*; ;xL8W
L}7 TM:%
.kTOG'K\e
public class FileAccessI implements Serializable{ ;ojJXH~$}
8)>4ZNXz
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 BOD!0CR5
RandomAccessFile oSavedFile; L|nFN}da
long nPos; ?Y 5Vje[^
ehLn+tg
< lUpvr
public FileAccessI() throws IOException b2H-D!YO^
{ 0p+36g
this("",0); kjDmwa+91T
} Nza@6nI"
oIniy{
p +nh]
public FileAccessI(String sName,long nPos) throws IOException @{Dfro
{ .7M.bpmqE
oSavedFile = new RandomAccessFile(sName,"rw"); SkmKf~v
this.nPos = nPos; *zMt/d*<&
oSavedFile.seek(nPos); Jpc%i8
} /A+5q\8G
/Ny#+$cfk
7uf5w0]
public synchronized int write(byte[] b,int nStart,int nLen) 2St<m-&
{ ;U3K@_
int n = -1; 1p$*N
try{ /l+"aKW 2
oSavedFile.write(b,nStart,nLen); :2V|(:^'
n = nLen; 1,7 }ah_
} <rvM)EJv|
catch(IOException e) BC5R$W.e
{ q VavP6I
e.printStackTrace (); "YAnGGx)LZ
} >*uj )u%
q8uq%wf
"Th;YJu
return n; m.<or?l'y>
} j{johV+`8
%<r}V<OeR
<m0=bm{j
} E@6gTx*
a|(|!=
5A^8?,F@
/* Xpv<v[a
**SiteInfoBean.java -zWNQp$
*/ $$SJLV
package NetFox; C$$Zwgy
RR|X4h0.
VrWQ]L
public class SiteInfoBean { QpA$='
#R7hk5/8n}
"Pu917_P
private String sSiteURL; //Site's URL ?]aVRmL
private String sFilePath; //Saved File's Path 8hYl73#
private String sFileName; //Saved File's Name ?2R!n"m-d
private int nSplitter; //Count of Splited Downloading File 76]Z~^Y
^=a:{["@!
A-d<[@d0
public SiteInfoBean() Z78i7k}
{//nSplitter的缺省值为5 k2fJ
//default value of nSplitter is 5 gvPHB+#A
this("","","",5); S(^YTb7
} &kn?=NW
BS?i!Bm7
6pt|Crvu
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R+!oPWfb
{ 'n^?DPvD
sSiteURL= sURL; K4o']{:U
sFilePath = sPath; Aar]eY\
sFileName = sName; _yF@k~ h
this.nSplitter = nSpiltter; e z_c;
4E_u.tJ
}gFa9M<
} b4EUrSL
Y+kuj],h
{U@"]{3Qx
public String getSSiteURL() i[MBO`FF
{ y~Yv^'Epf
return sSiteURL; ,7 m33Pv*
} _\8E/4zh
-SLk8x
_zzT[}
public void setSSiteURL(String value) 6`%|-o :
{ LpI4R
sSiteURL = value; %%I:L~c
} bKsEXS
`Y+R9bd
e@]m@
public String getSFilePath() vbX.0f "n
{ y+=s/c
return sFilePath; 6 8fnh'I!
} /x]^Cqe
LN5BU,4=
_/"e'@z
public void setSFilePath(String value) F>^KXq:Z
{ X\w["!B
sFilePath = value; cvf?ID84
} j?T>S]xOX
BHS@whj
vl6|i)D
public String getSFileName() @P>>:002/
{ 8G2QI4
return sFileName; B5h)F> &G
} `sy_'`i>X
L_|iQwU%
gwsOw [;k
public void setSFileName(String value) O/$41mK+!
{ >|gXE>
sFileName = value; 8r:T&)v
} 9$qw&j[
-e?n4YO*\
VKw.g@BY
public int getNSplitter() XR p60i6f
{ lqgR4 !
return nSplitter; 2^75|Q
} TKbfZw
Tr4\ `a-i
Yt{Z+.;9OI
public void setNSplitter(int nCount) 5\O&pz@D
{ {5HQ=&
nSplitter = nCount; PMX'vA`
} :Ig9n:
} YHke^Ind
(CtRU
*a0#PfS[
/* aIr"!. 4
**Utility.java Sn 7h$
*/ k2_y84;D
package NetFox; I>w|80%%
'vZy-qHrV
EZVgTySd
public class Utility { p2fzbBt
t$p%UyVE
LaZ @4/z!
public Utility() S$P=;#r
{ wlh%{l
tNOOaj9mw
W>c*\)Xk !
} JlawkA
w@YPG{"j
//线程睡眠 {j<?+o5A
public static void sleep(int nSecond) SMU8U
{ > PL}7f&:
try{ a@9W'/?igk
Thread.sleep(nSecond); |mdf u=
} 0R0_UvsXU
catch(Exception e) n$h+_xN
{ $GQEdVSNo
e.printStackTrace (); - K"L6m|
} 6/p9ag]
} P1]F0fR
$]W*;MTI}
//日志 &uV|Ie8@q
public static void log(String sMsg) BLt_(S?Z`
{ (JE&1 @
System.err.println(sMsg); /}%C'
} o/vD]Fs
>}C:EnECy
1N{ >00
public static void log(int sMsg) h+cOOm-)
{ VP?Q$?a
System.err.println(sMsg); *IF~ab2
} <]#_&Na
} Z^J)]UL/
d7x6r3J$
[iyhrc:@
/* xk,1D
**TestMethod.java RUut7[r
*/ JE@3UXg
package NetFox; zP@\rZ@4
onS4ZE3B
*13-)yfd
public class TestMethod { M0)ZJti
Fa </
OU^I/TU
public TestMethod() &sXk!!85:
{ ///xx/weblogic60b2_win.exe N[DKA1Ei
try{ %+;amRb
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @kba^z
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); bIk4?S
SiteFileFetch fileFetch = new SiteFileFetch(bean); M?n}{0E4
fileFetch.start(); mM+^v[=
} -:Juxh
catch(Exception e){e.printStackTrace ();} 9`@}KnvB?
@)z?i
e;"%h%'
} )IIWXN2A
gy#G;9p
_?bF;R
public static void main(String[] args) EU Oa8Z
{ YW8Odm
new TestMethod(); 8)b*q\O'
} n2["Ln mO
} Np.<&`p!
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