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)); ]j+J^g
} ,382O$C
for(int i=0;i<nEndPos.length-1;i++) 9YvK<i&I
{ <i ";5+
nEndPos = nStartPos[i+1]; 7?p>v34A
} Vv_lBYV
nEndPos[nEndPos.length-1] = nFileLength; V$fn$=
} s?7"iE
} 7m.>2U
3{{Ew}kZm
G0lg5iA<fC
//启动子线程 r E&}B5PN=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2o<aEn&7|e
for(int i=0;i<nStartPos.length;i++) W}P9I&3
{ DR(/|?k+
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Oq[YbQ'GE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), nU,~*Us
nStartPos,nEndPos,i); *q*$%H
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); eE5j6`5i
fileSplitterFetch.start(); h1+y.4
} NRMEZ\*L
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +GL[uxe"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #:xv]qb`k
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Zo#c[9IaC
nEndPos = " + nFileLength); |.?Xov]
// fileSplitterFetch[nPos.length-1].start(); Y<;KKD5P'j
fn, YH
71c(Nw~iQ
//等待子线程结束 6){nu rDBG
//int count = 0; ,FK.8c6g
//是否结束while循环 <AN5>:k[pM
boolean breakWhile = false; Sv\399(
)ml#2XP!f
T_ga?G<
while(!bStop) >Q2kXwN
{ 34I;DUdcE
write_nPos(); gv7@4G
Utility.sleep(500); ay,"MJ2
breakWhile = true; u+m9DNPF
?D+H2[n\a
_BI[F m
for(int i=0;i<nStartPos.length;i++) }=fls=c/0
{ u,JUMH]@
if(!fileSplitterFetch.bDownOver) UG=],\E2
{ @e2P3K gg
breakWhile = false; X}Fqif4A
break; p?O6|q
} hg-M>|s7
} 5Bp>*MR/".
if(breakWhile) 9dFo_a*?
break; *YP:-
8 Y))/]R
R,`3 SW()
//count++; ltlnXjRUv
//if(count>4) OWZ;X}x
// siteStop(); e3WEsD+
} >">grDX
F./P,hhN9
"h:#'y$V
System.err.println("文件下载结束！"); 59H~qE1Md
} &F.L*M
catch(Exception e){e.printStackTrace ();} kC iOcl*$
} KidbcZ
6E$ET5p&l
q{XeRQ'/
//获得文件长度 /hYFOZ
public long getFileSize() qT^0 %O:
{ "4L_BJZ
int nFileLength = -1; y3ST0=>j}
try{ ) ):w`^6
URL url = new URL(siteInfoBean.getSSiteURL()); ({mlA`d]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2Yg\<PsN
httpConnection.setRequestProperty("User-Agent","NetFox"); Uy<n7*H
0RHjA&r3v
)CD-cz6n
int responseCode=httpConnection.getResponseCode(); )v %tyU
if(responseCode>=400) 11B8 LX
{ w"Y'I$
processErrorCode(responseCode); `V{'GF&[
return -2; //-2 represent access is error ok{ F=z
} ,p V3O`z
I^m9(L4%
&%4A3.qE
String sHeader; m0N{%Mf-
[bjP-pX
@@& ?,3
for(int i=1;;i++) d5'4RYfkQ
{ vk<4P;A(G
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~:N 1[
//Utility.log(in.readLine()); $s,(-C
sHeader=httpConnection.getHeaderFieldKey(i); m}]\^$d
if(sHeader!=null) wu3p2#-Z
{ wRJ`RKJ-T
if(sHeader.equals("Content-Length")) :Fi$-g
{ -H$C3V3]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3aFD*S
break; [fg-"-+:M
} T^S$|d
} l@g%A# _
else C~"b-T
break; f`-UC_(;
} |3Bmsd/3
} ZdlQ}l#F
catch(IOException e){e.printStackTrace ();} _f@nUv*
catch(Exception e){e.printStackTrace ();} 2Zr,@LC
~N8$abQJV
m{by%
Utility.log(nFileLength); YXDuhrs}
ycrM8Mu 3
l8+;)2p!
return nFileLength; ft?c&h;At
} V"8w:?
#,;Q|)AD:e
SA{5A 1
//保存下载信息（文件指针位置） ORhvo,.u
private void write_nPos() d?A!0;(*
{ (f
try{ j`%a2
output = new DataOutputStream(new FileOutputStream(tmpFile)); |b+CXEzo
output.writeInt(nStartPos.length); WNF#eM?[a
for(int i=0;i<nStartPos.length;i++) s ?|Hw|j
{ KVPWJHGr
// output.writeLong(nPos); 4E@_Fn_#
output.writeLong(fileSplitterFetch.nStartPos); VVk8z6W
output.writeLong(fileSplitterFetch.nEndPos); MGsY3~!K
} m:c .dei5
output.close(); +O@|bd\
} 9 OZXs2~x
catch(IOException e){e.printStackTrace ();} _z53r+A
catch(Exception e){e.printStackTrace ();} j7b4wH\#
} Xn%O .yM6
"X\6tl7a|
H4uHCkj
//读取保存的下载信息（文件指针位置） r?HbApV P
private void read_nPos() GxA[N
{ $J*lD-h-
try{ !CR#Fyt+9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :i* =s}cv
int nCount = input.readInt(); 9S8V`aC
nStartPos = new long[nCount]; R,m|+[sl
nEndPos = new long[nCount]; VTK +aI
for(int i=0;i<nStartPos.length;i++) abg`:E
{ 0}WDB_L
nStartPos = input.readLong(); 7|(o=+Bt
nEndPos = input.readLong(); fzzk#jU
} 13f'zx(AO
input.close(); h/..cVD,K
} X;CRy,
catch(IOException e){e.printStackTrace ();} LQJC]*b1
catch(Exception e){e.printStackTrace ();} n= FOB0=
} L+_ JKc
a$$aM2.2
Dmr3r[
private void processErrorCode(int nErrorCode) 7myYs7N8[
{ r+,JM L
System.err.println("Error Code : " + nErrorCode); t_id/
} Z*YS7 ~
n,`j~.l-=>
EKNmXt1 lE
//停止文件下载 N[;R8SP
public void siteStop() !YX_k<1E
{ 9}'92
bStop = true; :*eJ*(M
for(int i=0;i<nStartPos.length;i++) jz,Gj}3;
fileSplitterFetch.splitterStop(); zh9B8r)C
SDko#
s,H }km
} r)oR`\7
} R6\|:mI,$
//负责部分文件的抓取 rAA?{(!9x
**FileSplitterFetch.java X-`PF
*/ smHQ'4x9
package NetFox; 1Sd<cOEd
pI( H7 (
- @tL]]
import java.io.*; ;OSEMgB1
import java.net.*; TbgIr
U+:Mu]97
VMw[M^
public class FileSplitterFetch extends Thread { fwv.^kx
Gp2Cwyv
NGmXF_kqN
String sURL; //File URL o':K4r;
long nStartPos; //File Snippet Start Position s,-}}6WO
long nEndPos; //File Snippet End Position /}nq?Vf
int nThreadID; //Thread's ID 7E;`1lh7
boolean bDownOver = false; //Downing is over vGchKN~_
boolean bStop = false; //Stop identical lf_q6y
FileAccessI fileAccessI = null; //File Access interface p_CCKU
M2LW[z
&0SgEUZr
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException CgKFI
{ *kt%.wPJ
this.sURL = sURL; fr8hT(,s)
this.nStartPos = nStart; T*92o:^
this.nEndPos = nEnd; ;I~UQgE6H
nThreadID = id; &_,.*tha
fileAccessI = new FileAccessI(sName,nStartPos);//定位 rN`-ak
} SbH} cu8
h`4!Qv
;$FMOMR
public void run() fkD-mRKw
{ @*iT%p_L
while(nStartPos < nEndPos && !bStop) [#+klP$
{ =H?^G[y
cX|(/h,W/
R_b)2FU1y
try{ ZV$!dHW/
URL url = new URL(sURL); tD> qHR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6o~g3{Ow
httpConnection.setRequestProperty("User-Agent","NetFox"); U,Th-oU
String sProperty = "bytes="+nStartPos+"-"; sn8r`59C
httpConnection.setRequestProperty("RANGE",sProperty); C5=m~
Utility.log(sProperty); [S?`OF12
Og?P5&C"9D
fnK H<
InputStream input = httpConnection.getInputStream(); wN:vI(C
//logResponseHead(httpConnection); sq+cF/jo6
!qTP
)npvy>C'(
byte[] b = new byte[1024]; UDV6 ##$
int nRead; fcw/l,k9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) `2n%Lo?_
{ !XO"lS
nStartPos += fileAccessI.write(b,0,nRead); M7//*Q'?
//if(nThreadID == 1) p?sFX$S
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bRI`ZT0
} q1Ehl S
9Rb tFwbn
7e6; |?
Utility.log("Thread " + nThreadID + " is over!"); 8^hbS%s!
bDownOver = true; ]wEFm;N
//nPos = fileAccessI.write (b,0,nRead); mg<S7+
} P>_ r6C
catch(Exception e){e.printStackTrace ();} '[Bok=$B)
} h&x;#.SYK
} VF g"AJf
3<}r+,j
_A6e|(.ll
//打印回应的头信息 GW0e=Y=LR
public void logResponseHead(HttpURLConnection con) K'b #}N\
{ o^+g2;Ro
for(int i=1;;i++) +7j7zpw
{ fn Pej?f:
String header=con.getHeaderFieldKey(i); 5wbR}`8
if(header!=null) q=;U(,Y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `]5t'Ps
Utility.log(header+" : "+con.getHeaderField(header)); 7kmd.<
else T5>'q;jM
break; sDjbvC0
} n(j5dN>]
} \6vr)1~N>
-8z@FLUK-
W.?EjEx
public void splitterStop() pW-aX)\DR
{ BP8jReX^
bStop = true; 3Cg0^~?6-
} Wn5xX5H C
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Og2G0sWRf
} }nMp.7b
j9*5Kj
~[:Cl
/* "T~A*a^
**FileAccess.java 2(25IYMS8
*//文件访问(定位，写) #* Iyvx
package NetFox; )J1xO^tE
import java.io.*; 0>U7]wZKc
ShJBOaE; -
#F ;@Qi3z
public class FileAccessI implements Serializable{ j:[#eC
0"koZd,c
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 InB'Ag"
RandomAccessFile oSavedFile; $TFWum9wO
long nPos; =S|dzgS/
l*+9R
Jv59zI
public FileAccessI() throws IOException 3EA`]&d>
{ h8:5[;e
this("",0); sEcg;LFp
} II{"6YI>
xk&#fW^r
Rz=wInFs
public FileAccessI(String sName,long nPos) throws IOException ilkN3J
{ ^) 5*?8#
oSavedFile = new RandomAccessFile(sName,"rw"); DUvF
this.nPos = nPos; SAokW,
oSavedFile.seek(nPos); Tr"Bz!
} EsjZ;D,c(
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public synchronized int write(byte[] b,int nStart,int nLen) 9lc{{)m2)
{ Gr!@ih^
int n = -1; )m>Y[)8!
try{ \04(V'`U
oSavedFile.write(b,nStart,nLen); s@pIcNvx
n = nLen; y1kI^B
} 9bu1Ax1M
catch(IOException e) pRFlmg@/}
{ Io]KlR@!T
e.printStackTrace (); qw}. QwPT
} !]=S A &
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return n; >JT^[i8[
} QI6=[
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<L:}u!
} mEq>{l:
~o8x3`CoF
3(=QY)
/* l'kVi
**SiteInfoBean.java YguY5z
*/ T!QAcO
package NetFox; {i/7Nx
tJ Mm
}W5~89"
public class SiteInfoBean { I$JyAj
j&"GE':Y
].3@ Dk
private String sSiteURL; //Site's URL @%rj1Gn
private String sFilePath; //Saved File's Path +=#@1k~
private String sFileName; //Saved File's Name %(izKJl q
private int nSplitter; //Count of Splited Downloading File KqFiS9 N5
i#(+Kxr]>
/9SNXjfbt
public SiteInfoBean() 0"DS>:Ntk
{//nSplitter的缺省值为5 |!*abc\`(`
//default value of nSplitter is 5 mjJ/rx{kbw
this("","","",5); xOdLct
} -\V;Gw8mD
Zxn>]Z_
7nk3^$|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?io,8
{ ![/ QW
sSiteURL= sURL; QA# 7T3|
sFilePath = sPath; u^+ (5|
sFileName = sName; ]RTK:%
this.nSplitter = nSpiltter; z_A34@a
`k~w 14~w
?/^{sW' |
} ad`=A V]
Jek3K&
15"[MX A
public String getSSiteURL() F{FSmUxzK
{ jP"yG#
return sSiteURL; Zl{DqC^
} t[X,m]SX
Sbjc8V ut
PAs.T4Av^
public void setSSiteURL(String value) R6qC0@*
{ BaOPtBYA:
sSiteURL = value; 1JF>0ijU@
} %oiA'hz;*
vz`r !xj)
s^ K:cz
public String getSFilePath() J9XV:)Yv#
{ c}D>.x|]
return sFilePath; z-;yDB:~t
} 1L<X+,]@
G33'Cgo:,
!E_RD,_
public void setSFilePath(String value) gbN@EJ
{ %e1`wMa
sFilePath = value; SOQR(UT
} ;N!W|G
tnFhL&
^1`T_+#[s
public String getSFileName() jn#Ok@tZ
{ n/Dk~Q)
return sFileName; `g:bvIV5x>
} |5me }!C
5g4xhYl70n
<O9.GHV1v
public void setSFileName(String value) Y\{&chuF
{ r9$7P?zm
sFileName = value; s]i<D9h
} 9Q:}VpT~nG
8M7pc{
2jH&@g$cl;
public int getNSplitter() f<P>IE
{ $iOkn|~<@W
return nSplitter; 0xpE+GY
} VMV~K7%0
>@L^^-r
?Fj>7
public void setNSplitter(int nCount) $d%NFc&
{ gclw>((5
nSplitter = nCount; q%c"`u/v/
} X1\ao[t<;c
} GM>Ms!Y
cK6IyJx-
1iIag}?p
/* mY/x|)MmM
**Utility.java #GA6vJ4^s
*/ H"%SzU
package NetFox; ~6Df~uN
=.f<"P51k
cKH By
public class Utility { O -N> X
=-8y=
5.FAuzz
public Utility() {^SHIL
{ !-Md+I_
n<66 7 <
c`4i#R
} 4@*`V
MU5#ph
//线程睡眠 R9O[`~BA2
public static void sleep(int nSecond) il>XV>
{ e*jfxQ=qG
try{ ^%2S,3*0
Thread.sleep(nSecond); 7s.vJdA]6
} A_<1}8{L
catch(Exception e) &Un^ _M
{ Pqb])-M9p
e.printStackTrace (); ]>k>Z#8E*
} rc)vVv
} yB,{:kq7D
:gacP?
//日志 lO5*n|Ic,
public static void log(String sMsg) D-4\AzIb
{ e8$OV4X
System.err.println(sMsg); D}7G|gX1
} +hKH\]
qW'5Zk
%[7<GcWl
public static void log(int sMsg) WbDD9ZS
{ EJZb3
System.err.println(sMsg); )Qx&m}
} LwS>jNJx
} +q@g
sH{4.tw
34Z$a{ w
/* 5W~-|8m
**TestMethod.java aO>Nev
*/ >KMTxHE`+
package NetFox; K18Sj,]B
jbK<"T5
o5|P5h
public class TestMethod { !'T,%8']
ECEDNib
>;zQ.2*
public TestMethod() hp)k[|u;
{ ///xx/weblogic60b2_win.exe 3# r`e
try{ R=u!RcvR
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )#_:5^1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); qLh[BR
SiteFileFetch fileFetch = new SiteFileFetch(bean); (L7@ez
fileFetch.start(); @8qo(7<~Q
} IL2OVLX
catch(Exception e){e.printStackTrace ();} J|GEt@o3
NgPY/R>
1>e%(k2w%
} l4`HuNR1
cl3Dwrf?
-McDNM
public static void main(String[] args) j[y,Jch
{ v a j
new TestMethod(); h`:f
} I&Y9
} li Hz5<|
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