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)); ,bIJW]h0
} 3A[<LnKR^E
for(int i=0;i<nEndPos.length-1;i++) N{&Lo}6F
{ x4g/ok
nEndPos = nStartPos[i+1]; 9wGsHf8]
} X%&7-PO
nEndPos[nEndPos.length-1] = nFileLength; S w%6-
} V=th-o3[
} FE^/us7r
GG<0k\RN
>;Vfs{Z(q
//启动子线程 &7>]# *
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *| W*Mu
for(int i=0;i<nStartPos.length;i++) +F8K%.Q_
{ s3yGL
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Skr0WQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Yt,MXm\
nStartPos,nEndPos,i); ^Go,HiB
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W2fcY;HZ
fileSplitterFetch.start(); XqUQ{^;aI
} XksI.]tfj
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v_pe=LC{-e
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); n}e%c B
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Im!b-1
nEndPos = " + nFileLength); @>.aQE
// fileSplitterFetch[nPos.length-1].start(); 8 l)K3;q_
JhwHsx/
V_D wHq2
//等待子线程结束 DTM(SN8R+n
//int count = 0; Lk@+iHf
//是否结束while循环 a#%*H
boolean breakWhile = false; ts@Z5Yw*!
83 R_8
~<O.Gu&"R
while(!bStop) m.`I}
{ y6-P6T
write_nPos(); )\VuN-d
Utility.sleep(500); sJ^Ff
breakWhile = true; -64;P9:A>
/wJ4hHY
$BgaLJs/O
for(int i=0;i<nStartPos.length;i++) j6~`C ?(
{ #a~BigZ[G
if(!fileSplitterFetch.bDownOver) }cGILH%
{ z;2& d<h
breakWhile = false; ';8 ,RTe
break; 5S!j$_(
} :p@jslD
} V9}\0joM
if(breakWhile) eq8faC5
break; e!L5v?
#3LZX!
+l/kH9m
//count++; -!qjBK,`X
//if(count>4) NIQ}+xpC
// siteStop(); ZsXw]Wa
} ("j;VqYUL
u,`3_I^
GHn0(o&K
System.err.println("文件下载结束！"); 1!;~Y#
} ((#BU=0iK
catch(Exception e){e.printStackTrace ();} D_$N2>I-
} DbB<8$
nvLdgu4P>
<pa-C2Ky
//获得文件长度 d}Guj/cx,
public long getFileSize() -AD`(b7q
{ '%ZKvZ-
int nFileLength = -1; _Li.}g@Bd
try{ He4HIZ
URL url = new URL(siteInfoBean.getSSiteURL()); 0-{E% k
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $kHXt]fU
httpConnection.setRequestProperty("User-Agent","NetFox"); 7t#Q8u?
SSla^,MHef
r#1W$~?>
int responseCode=httpConnection.getResponseCode(); X(Mpg[,N"
if(responseCode>=400) w/*#TDR
{ }a,ycFt
processErrorCode(responseCode); cC/32SmY4
return -2; //-2 represent access is error sq(5k+y*J
} rr\u)D#)
$M0l (htR
y4|<+9<7
String sHeader; ^'tT_ gT
>@cBDS<6R
8%YyxoCH
for(int i=1;;i++) fK]%*i_"
{ Yy]TU} PY
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); yi~]}M
//Utility.log(in.readLine()); A&B|n!;b
sHeader=httpConnection.getHeaderFieldKey(i); 3X;>cv#B
if(sHeader!=null) _%Xp2`m
{ -zJV(`
if(sHeader.equals("Content-Length")) {{_v.d~1
{ [*(1~PrlO,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1BW9,Xr
break; jVOq/o
} ?f3R+4
} B=%%3V)2
else C{nk,j L
break; J1cz D|(
} u*5}c7)uId
} 4|5;nxkGm8
catch(IOException e){e.printStackTrace ();} \4j_K*V
catch(Exception e){e.printStackTrace ();} 1i.3P$F
??P\v0E
0m.`$nlV-
Utility.log(nFileLength); <*^|Aj|#
kb"Fw:0
q27q/q8
return nFileLength; F@Wi[K
} <o3I<ci6
FJ!`[.t1AU
M;3q.0MU
//保存下载信息（文件指针位置） {:_*P TVk
private void write_nPos() =?+w5oI0
{ T95FoA
try{ _7';1 D
output = new DataOutputStream(new FileOutputStream(tmpFile)); lqh:c
output.writeInt(nStartPos.length); B=^M& {
for(int i=0;i<nStartPos.length;i++) n{~&^Nby*I
{ {jR3D!hK
// output.writeLong(nPos); jr.{M
output.writeLong(fileSplitterFetch.nStartPos); d_&pxy? >
output.writeLong(fileSplitterFetch.nEndPos); o+{i26%
} '~f*O0_
output.close(); zd- *UFi
} qBK68B)
catch(IOException e){e.printStackTrace ();} 6(htpT%J
catch(Exception e){e.printStackTrace ();} KVEc:<|x
} TC'SDDX
e];IQ|
XVfUr\=,T
//读取保存的下载信息（文件指针位置） *sB'D+-/
private void read_nPos() +lFBH(o]X
{ cp~6\F;c
try{ HA}q.L]#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?z-nY,'^uq
int nCount = input.readInt(); W=+AU!%
nStartPos = new long[nCount]; XUR#|
nEndPos = new long[nCount]; NM),2%<
for(int i=0;i<nStartPos.length;i++) ;*FY+jM
{ <6hs<qXqi
nStartPos = input.readLong(); aL;zN%Tw
nEndPos = input.readLong(); UA6 C/
} XH*(zTd(?
input.close(); 3d1xL+
} nZL!}3@<
catch(IOException e){e.printStackTrace ();} +Lc+"0*gV*
catch(Exception e){e.printStackTrace ();} 'Pn:10;
} fy$CtQM
GyxLzrp
z52F-<
private void processErrorCode(int nErrorCode) (;9fkqm%m
{ K%t&aRjS
System.err.println("Error Code : " + nErrorCode); +"WNG
} A(BjU:D(Oj
?aBAmyxm
[5-IkT0
//停止文件下载 g26_#4 P
public void siteStop() vmfFR
{ [4B(rra
bStop = true; vfhoN]v
for(int i=0;i<nStartPos.length;i++) $/JXI?K
fileSplitterFetch.splitterStop(); P@5-3]m=
r]QeP{
F/j ; q
} 0v1~#KCm
} +9t{ovF?L
//负责部分文件的抓取 ;"9Ks.
**FileSplitterFetch.java aYpc\jJ
*/ XS^du{ai
package NetFox; V8o, e
{IBbN05 ;
5RO6YxQ
import java.io.*; ).u>%4=6
import java.net.*; D?*du#6
sH1ucZ>9Y
VTDnh*\5
public class FileSplitterFetch extends Thread { 3?h!nVI+2J
g3%x"SlIU
TI"Ki$jC
String sURL; //File URL {LqYb:/C5U
long nStartPos; //File Snippet Start Position tId,Q>zH
long nEndPos; //File Snippet End Position lq`7$7-4
int nThreadID; //Thread's ID @V Tw>=94
boolean bDownOver = false; //Downing is over Vz!{nL0Q(
boolean bStop = false; //Stop identical "~6&rt
FileAccessI fileAccessI = null; //File Access interface I7|a,Q^f
ev/)#i#s{
Dq!YB[Z$:
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException UN;U+5,t
{ TOSk+2P
this.sURL = sURL; o2]Np~`g,
this.nStartPos = nStart; 94*MRn1E
this.nEndPos = nEnd; ) 54cG
nThreadID = id; 69uDc
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /Q#eP m
} l 8GAZ*+
7+[L6q/K
YLSDJ$K6
public void run() /9P7;1?
{ _wW"Tn]
while(nStartPos < nEndPos && !bStop) YxU->Wi]G
{ \sW>Y#9]
!@ AnwV]
F<2gM#jLB
try{ O0pXHXSAL
URL url = new URL(sURL); *8%uXkMm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iQCs8hIR
httpConnection.setRequestProperty("User-Agent","NetFox"); 7s:cg
String sProperty = "bytes="+nStartPos+"-"; 2AxKB+c1`
httpConnection.setRequestProperty("RANGE",sProperty); a~-k} G5
Utility.log(sProperty); %^"i\-*|S
4m~p(r
kqC7^x
InputStream input = httpConnection.getInputStream(); S|yDGT1
//logResponseHead(httpConnection); dOgc%(kz
mwz!7Q
0.(7R,-
byte[] b = new byte[1024]; _R ;$tG,
int nRead; '=K~M
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "Nq5FcS9
{ vsI|HxpyC,
nStartPos += fileAccessI.write(b,0,nRead); 4Xn-L&0z
//if(nThreadID == 1) oVfRp.a
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EWVn*xl?
} iy_3#x5>
<<YH4}wZ
4Xv."L
Utility.log("Thread " + nThreadID + " is over!"); |oR{c%z05
bDownOver = true; brF) %x`
//nPos = fileAccessI.write (b,0,nRead); nnd-d+$
} y,<\d/YY@
catch(Exception e){e.printStackTrace ();} "*d%el\63
} AX )dZdd
} BBl9<ne$
Fj<a;oV
9Z3Y,`R,
//打印回应的头信息 =}SC .E\
public void logResponseHead(HttpURLConnection con) "!Hm.^1
{ Q9JT6
for(int i=1;;i++) /zir$
{ ( M3-S5
String header=con.getHeaderFieldKey(i); 5* ~EdT
if(header!=null) +6<g N[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); reoCyP\!!
Utility.log(header+" : "+con.getHeaderField(header)); 7V~ gqum
else ?U~`'^@
break; UX?S#:h
} 09Z\F^*$F
} vFgnbWxG
bGp3V. H
7zXX& S
public void splitterStop() h~&5;
{ pr1>:0dg
bStop = true; 7 /DDQ
} >?$qKu
{=y~O
:C#(yp
} r$!
re@OPiXa v
9NC'iFQ#
/* EI&)+cC
**FileAccess.java l9NET
*//文件访问(定位，写) ^JB5-EtL(
package NetFox; @c%h fI
import java.io.*; ~t.i;eu
z"{Ji{>%=
{'f=*vMI
public class FileAccessI implements Serializable{ Ar[$%
%h=cwT6
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 P# Z+:T
RandomAccessFile oSavedFile; p=f8A71
long nPos; E uk[ @1
Q\Nz^~dQ:Y
>xm:?WR
public FileAccessI() throws IOException Eg]tDPN1
{ #)<WQZ)
this("",0); :c&F\Q=
} pQBhheiM
9%bqY9NFd
zT _[pa)O`
public FileAccessI(String sName,long nPos) throws IOException 77zDHq=
{ )Yw m_f-N
oSavedFile = new RandomAccessFile(sName,"rw"); .RWKZB
this.nPos = nPos; |z.Z='`
oSavedFile.seek(nPos); qMmhmH)Gp
} 1n+JHXR\
l Gy`{E|
7E)*]7B%
public synchronized int write(byte[] b,int nStart,int nLen) { daEKac5
{ ]1i1_AR'`
int n = -1; XZ1<sm8t."
try{ UP e@>
oSavedFile.write(b,nStart,nLen); |gJI}"T
n = nLen; <a$'tw-8
} uI_h__
catch(IOException e) lEiOE]
{ v.e~m2u_F
e.printStackTrace (); DTSK*a`
} /-&a]PJ
1 c4I`#_v
~z*A%vp6ER
return n; orr6._xw
} 8>~\R=SC
JnZlz?}^
:k7h"w
} DM)%=C6<
6 2#dSd}HG
Z3Y(g
/* V|zatMHs
**SiteInfoBean.java I'T@}{h
*/ %:7fAB,PA
package NetFox; "ll TVB
r4FGz!U
Umt?COc
public class SiteInfoBean { 4?cIn4}
A@k`$xevVj
aMycvYzH
private String sSiteURL; //Site's URL wT+b|K
private String sFilePath; //Saved File's Path n*GsM6Y&
private String sFileName; //Saved File's Name bpWEF b'f
private int nSplitter; //Count of Splited Downloading File BF(.^oh"n0
j5qrM_Chg
S2EeC&-AR
public SiteInfoBean() ojQjx|Q}
{//nSplitter的缺省值为5 >`!Lh`n7_
//default value of nSplitter is 5 (}NKW
this("","","",5); r1QLSD]i6
} j@+QwZL|
)]a{cczL"
sT|FgB
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #99fFs`w
{ d%='W|i\p&
sSiteURL= sURL; NT<>LWo
sFilePath = sPath; auV<=1<zJ
sFileName = sName; pSlosv(6
this.nSplitter = nSpiltter; bB`p-1
MZInS:Vj
f)/5%W7n}
} Y<drRK!
12MWO_'g8
MehMhHY
public String getSSiteURL() wnoL<p
{ V:vYS
return sSiteURL; UL
} :#=XT9
h1'j1uI
(lBwkQNQGd
public void setSSiteURL(String value) ^saH^kg1"
{ <; (pol|
sSiteURL = value; AqHH^adzA:
} 0qUBt9rA
2En^su$
x^ruPiH
public String getSFilePath() 0X"D!G):
{ #.kDin~!
return sFilePath; )$_b?
} gnPu{-Ec*
_9Zwg+oO[
+vh 4I
public void setSFilePath(String value) o> i`Jq&
{ -*I Dzm
sFilePath = value; Z}Ld!Byz
} & NO:S
_:0
v0}R]h~>\H
public String getSFileName() ui\yY3?
{ -'iV-]<
return sFileName; - P$mN6h
} <+wbnnK
Dy[_Ix/Y,
g~i%*u,Y<
public void setSFileName(String value) j~@Hj$APa`
{ CtO`t5
sFileName = value; <.yL&$9
} ..g?po
,xeJf6es
;$Q&2}L[
public int getNSplitter() DiLZ5^`]
{ [aF^D;o
return nSplitter; 2MapB*
} n%J{Tcn6
bm+ #OI
E0Y>2HOuL
public void setNSplitter(int nCount) xy$agt>j>
{ KiDL]2
nSplitter = nCount; XpLK0YI
} ~T_4M
} /d\#|[S
)@O80uOFh
M@=eWZ<
/* !\ckUMZ\
**Utility.java ^-yEb\\i
*/ pSvqGJU3
package NetFox; vl{G;[6
?!4xtOA
V#Hg+\{d
public class Utility { d 18>0R
};z[x2l^
&u@<0 1=
public Utility() B?cn5
{ $ MN1:ih
&r)i6{w81
N^{"k,vB-
} kDz!v?Z2+B
i^2yq&uT(
//线程睡眠 Gidh7x
public static void sleep(int nSecond) !BocF<UE
{ sfv{z!mo
try{ <ETR6r
Thread.sleep(nSecond); d0Jaa1b~O
} SGuLL+|W#8
catch(Exception e) *C(/2
{ gW[(gf.oo
e.printStackTrace (); k{?Pgf27
} X \1grM
} EO<{Bj=2
NZ}DbA+g;|
//日志 HX(Z(rcI
public static void log(String sMsg) QR+{Yp
{ t=IpVl!
System.err.println(sMsg); S8{Sb>
} Q>,EYb>wI
L1'#wH
^+hqGu]M
public static void log(int sMsg) uTemAIp $u
{ h]6"~ m
System.err.println(sMsg); tdl Y
} <d$L}uQwg
} Y0f"}A1
vUX(h.}8
\ nIz5J}3
/* LZ97nvK
**TestMethod.java km)5?
*/ &rcC7v K9
package NetFox; /ynvQ1#uA
>8pmClVvmR
$<y10DfO
public class TestMethod { zPC&p{S>
ranLHm.nB
VeJM=s.y7
public TestMethod() w}OJ2^
{ ///xx/weblogic60b2_win.exe ~(BvIzzD
try{ ]7*Z'E
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); xS4B"/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); A 11w{`EM
SiteFileFetch fileFetch = new SiteFileFetch(bean); &s +DK`
fileFetch.start(); px!TRbf
} j"8f,er
catch(Exception e){e.printStackTrace ();} @dy<=bh~
_*xjG \!
A[/_}bI|
} 9{{|P=
J73B$0FP
[_jd
public static void main(String[] args) 8f^QO:
{ &I&:
new TestMethod(); Ac0^`
} 9rB,7%@EL
} AjTkQ)
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