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)); Bbk=0+ ^8I
} ;G!JKg
for(int i=0;i<nEndPos.length-1;i++) *V}T}nK7
{ ^)|8N44O
nEndPos = nStartPos[i+1]; NVqJN$z
} b7&5>Q/g
nEndPos[nEndPos.length-1] = nFileLength; v%8.o%G
} O~Eju
} ?86q8E3;&
imGg3'
"tax
//启动子线程 CHxu%-g
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; X.^S@3[
for(int i=0;i<nStartPos.length;i++) ?J[m)Uo/K
{ x,)|;HXm
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), oT9dMhx8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), tS|gQUF17
nStartPos,nEndPos,i); VHwAO:+-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); UqJ}5{rt
fileSplitterFetch.start(); Vu6$84>-,
} -2Bkun4Pt
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J@$h'YUF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !$}:4}56F
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", OUoN
nEndPos = " + nFileLength); ,|:TML
// fileSplitterFetch[nPos.length-1].start(); M.b1=Y
L-J 7z+{
B{x`^3qR
//等待子线程结束 RRXnj#<g
//int count = 0; 9@'^}c#
//是否结束while循环 #j!RbW
boolean breakWhile = false; 6}b1*xQ
q6R``
"}"hQ.kAz
while(!bStop) !'yCB9]O
{ +MHsdeGU1W
write_nPos(); d2cslDd
Utility.sleep(500); )Q:.1Hgl
breakWhile = true; TU-aL
hDPZj#(c
suo;+T=`I
for(int i=0;i<nStartPos.length;i++) Ii*tux!S
{ cOhx
if(!fileSplitterFetch.bDownOver) c~,OU7[
{ _f^JXd,7v
breakWhile = false; & B CA
break; no~Yet+<"
} NFYo@kX> G
} $9~6M*
if(breakWhile) Z{Si`GA
break; 3vcKK;qCB
(L{>la!
1$+-?:i C
//count++; nu=yE$BN{
//if(count>4) Ll2yJ .C4
// siteStop(); jUtFDw
} 6!QY)H^j9,
dq6|m }g{
pgp@Zw)r)k
System.err.println("文件下载结束！"); hN#A3FFo L
} %$'YP
catch(Exception e){e.printStackTrace ();} d9qA\ [
} ?.*^#>-
3zr95$Mt
\vKKq/f
//获得文件长度 f3[/zcm;
public long getFileSize() ,\%qERk
{ GC#s;X
int nFileLength = -1; < 2mbR
try{ zyHHz\{
URL url = new URL(siteInfoBean.getSSiteURL()); )qq5WShMJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NKyKsu
httpConnection.setRequestProperty("User-Agent","NetFox"); 8.Z9 i
oh?@[U
[yyL2=7
int responseCode=httpConnection.getResponseCode(); j=],n8_i
if(responseCode>=400) ;A\SbLM
{ GW;\3@o
processErrorCode(responseCode); #a$k3C
return -2; //-2 represent access is error w4<n=k
} Zf,9 k".'C
wf,B/[,d
CAJ]@P#Xj+
String sHeader; n2p(@
?l/$cO
O8mmS!
for(int i=1;;i++) 9&O7F}VP2
{ wk@S+Q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?TLzOYJp
//Utility.log(in.readLine()); xIb"8,N
sHeader=httpConnection.getHeaderFieldKey(i); "<=HmE-;
if(sHeader!=null) "NMSLqO
{ C25EIIdRb
if(sHeader.equals("Content-Length")) VUQx"R9-
{ jqJ't)N
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); oNFvRb2Rd
break; VJoobu1h
} 2zlBrjk;
} Qw@_.I
else T4e-QEH
break; `iQ9 9
} >S[NI<=8S
} h3YWqSj
catch(IOException e){e.printStackTrace ();} Oe_*(q&
catch(Exception e){e.printStackTrace ();} ibqJ'@{=e
H\^zp5/
?}Y;/Lwx
Utility.log(nFileLength); of<(4<T
y yqya[-11
D"vl$BX
return nFileLength; g?1! /+
} RbN# dI'
*,y .%`o
^- H
//保存下载信息（文件指针位置） ,+U,(P5>s
private void write_nPos() AD0pmD
{ +hL%8CVU M
try{ c-".VF
output = new DataOutputStream(new FileOutputStream(tmpFile)); )W0z
output.writeInt(nStartPos.length); /s|4aro
for(int i=0;i<nStartPos.length;i++) EpdSsfDP
{ ? f>pKe
// output.writeLong(nPos); rzO5 3\
output.writeLong(fileSplitterFetch.nStartPos); 6U?z
output.writeLong(fileSplitterFetch.nEndPos); F\BD7W
} =H)"t:xE
output.close(); f~-Ipq;F
} 89+Q^79m
catch(IOException e){e.printStackTrace ();} t(Sjo8, b
catch(Exception e){e.printStackTrace ();} N~0~1 WQn
} `44 }kkBT
72akOx
d7i 0'R
//读取保存的下载信息（文件指针位置） j" ~gEGfK
private void read_nPos() tZ*z.3\<
{ {~a+dEz
try{ -V'h>K
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]J)3y+;P
int nCount = input.readInt(); nAY'1!Oi
nStartPos = new long[nCount]; Ow f:Kife
nEndPos = new long[nCount]; )DwHLaLW
for(int i=0;i<nStartPos.length;i++) %5rC`9^
{ _7P#?:h
nStartPos = input.readLong(); L.R4 iN
nEndPos = input.readLong(); 2PVtyV3;
} Di>B:=
input.close(); EN/e`S$)
} r]lPXj(`
catch(IOException e){e.printStackTrace ();} |a{~Imz{
catch(Exception e){e.printStackTrace ();} n7*.zI]%&
} i?D KKjN$
dWDM{t\}\
Bkh1VAT
private void processErrorCode(int nErrorCode) V+- ]txu|
{ p0Ra`*f
System.err.println("Error Code : " + nErrorCode); MbJ|6g99
} Qk h}=3u
JVawWw0q
$Q'S8TU
//停止文件下载 Z&[_8Y5j
public void siteStop() 9:1[4o)~
{ REc+@;B
bStop = true; ^mZeAW
for(int i=0;i<nStartPos.length;i++) ccm(r~lhJ
fileSplitterFetch.splitterStop(); %SJ2W>e
HLsG<#
/@`kM'1:
} hUO&rov3@
} /hksESiU
//负责部分文件的抓取 &|&tPD/dJ
**FileSplitterFetch.java 3wf&,4`EX
*/ {j!+\neL
package NetFox; c3]X#Qa#m$
QnN cGH
IwJ4K+
import java.io.*; nlsif
import java.net.*; n)xLEx,
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IqrT@jgN-
public class FileSplitterFetch extends Thread { ^p}|""\j
`+?g96
k3S
String sURL; //File URL EnD}|9
long nStartPos; //File Snippet Start Position 2n|]&D3V"'
long nEndPos; //File Snippet End Position ~+OAAkJ9
int nThreadID; //Thread's ID DLBHZ?+!
boolean bDownOver = false; //Downing is over 3d81]!n
boolean bStop = false; //Stop identical -Mx\W|YK
FileAccessI fileAccessI = null; //File Access interface PbpnjvVrM
!wNj;ST*
<)am]+Lswy
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #ssSs]zl
{ W _JGJV.^f
this.sURL = sURL; i0/RvrLc
this.nStartPos = nStart; i$CN{c*
this.nEndPos = nEnd; eF=cMC
nThreadID = id; {a6cA=WTPd
fileAccessI = new FileAccessI(sName,nStartPos);//定位 r)xkpa5
} 3 jRI@
Z\. n6
.0]\a~x
public void run() E8LA+dKN:
{ 0tb%h[%,M
while(nStartPos < nEndPos && !bStop) oQ:.pq{T
{ mtd ,m
SR8)4:aKW
R q |,@
try{ qr<RMs
URL url = new URL(sURL); ]/ffA|"U`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9S_PZH
httpConnection.setRequestProperty("User-Agent","NetFox"); 1XXuFa&
String sProperty = "bytes="+nStartPos+"-"; T0TgV
httpConnection.setRequestProperty("RANGE",sProperty); `WRM7
Utility.log(sProperty); ;eY.4/*R
:f_fp(T
1LZ[i89&%
InputStream input = httpConnection.getInputStream(); 0Fc^c[
//logResponseHead(httpConnection); #AO?<L
eEl71
B9(@.
byte[] b = new byte[1024]; A}3dx!?7j
int nRead; MP_LdJM1E
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) P+:DLex
{ j/p1/sJ[y
nStartPos += fileAccessI.write(b,0,nRead); NXHe;G
//if(nThreadID == 1) aM7=>
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N> jQe
} FKBI.}A?!'
-qqI@+u+
/N9ct4 {^
Utility.log("Thread " + nThreadID + " is over!"); ORx6r=zg
bDownOver = true; ~J:]cy)Q
//nPos = fileAccessI.write (b,0,nRead); c]%~X&Tg`
} >r\q6f#J4
catch(Exception e){e.printStackTrace ();} ^V7'S<
} |}><)}
} VjLv{f<p
/Os6i&;
lc[)O3,,B
//打印回应的头信息 IhjZ{oV/@
public void logResponseHead(HttpURLConnection con) aY-7K._</
{ Qg]+&8!*
for(int i=1;;i++) LU $=j
{ 5=_bK^Am
String header=con.getHeaderFieldKey(i); 6,cJ3~!48
if(header!=null) oJ?,X^~_
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +Ly@5y"
Utility.log(header+" : "+con.getHeaderField(header)); XR_Gsb%l
else !nU|3S[b
break; v>0I=ut
} |Kb m74Z%
} UZpQ%~/
l;d4Le
AO238RC!:
public void splitterStop() [vqf hpz
{ Rt>mAU$}
bStop = true; {l"(EeW6)
} %xrldn%
)FN\jo!!.
X-*LA*xbN
} 5PsjGvm.%
,bzC|AK
lAR1gHhJ
/* @ZRg9M:N
**FileAccess.java S!rVq,| d
*//文件访问(定位，写) U(gYx@
package NetFox; #(QS5J&Qq
import java.io.*; EM(%|#
R^B8** N
P?^%i
public class FileAccessI implements Serializable{ $_3)m
8DX5bB
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5=\^DeM@ H
RandomAccessFile oSavedFile; $4*gi&
long nPos; @Ko#nDEq
Sk:x.oOZ
3xN_z?Rg
public FileAccessI() throws IOException BNe>Lko
{ X"vDFE`?
this("",0); ii&ckg>]z
} %g^:0me`
6q8PLyIp
M)U)Sc zHO
public FileAccessI(String sName,long nPos) throws IOException QeN7~ J
{ M2;6Cz>,P
oSavedFile = new RandomAccessFile(sName,"rw"); aK_k'4YTm
this.nPos = nPos; JP(0/?Q
oSavedFile.seek(nPos); )?I*zc
} @^J>. g
<2fy(9y
x0%yz+i{:
public synchronized int write(byte[] b,int nStart,int nLen) Ms5R7<O.7
{ xB]^^NYE=
int n = -1; k)[c!\a[i
try{ UkXa mGoy3
oSavedFile.write(b,nStart,nLen); OG_v[ C5
n = nLen; I0><IaFy
} ?*[35XUd
catch(IOException e) wCV~9JTJ!
{ [>U2!4=$M
e.printStackTrace (); ^w&!}f+
} ?G<?:/CU
f@$kK?c?
}$sTnea
return n; ,b5vnW\
} xZM4CR9]*C
CJDNS21m
G{O{ p
} "c?31$6
:6&#u.\u
1 .[OS
/* UR S=1+
**SiteInfoBean.java I~Qi):&x
*/ Ed{sC[j=
package NetFox; 3lEP:Jp
3xKgj5M
~=t9-AF-
public class SiteInfoBean { [wnaF|h
,rF!o_7
9qB4\ONXZ
private String sSiteURL; //Site's URL \rg;xZa5
private String sFilePath; //Saved File's Path ZR"qrCSw`
private String sFileName; //Saved File's Name sY?wQ:
private int nSplitter; //Count of Splited Downloading File \m1^sFMZ
y+V>,W)r7
*UXa.kT@
public SiteInfoBean() 9'(m"c_
{//nSplitter的缺省值为5 2- (}=N
//default value of nSplitter is 5 dWe%6s;
this("","","",5); Twr,O;*u=
} F1L[C4'
GU9p'E
4x?I,cAN
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (H:A|Lw
{ ]2ycJ >w
sSiteURL= sURL; lz1cLl m
sFilePath = sPath; hd[t&?{=
sFileName = sName; Snp(&TD<<
this.nSplitter = nSpiltter; +"JWsD(C(
~r'ApeI9
{yEL$8MC
} =<zlg~i
v6E5#pse8
u6IM~kk>5
public String getSSiteURL() qSD3]Dv"
{ o]&P0 b
return sSiteURL; *P5/S8c
} Jw^my4
~Ga{=OM??
N=~DSsw
public void setSSiteURL(String value) $(08!U
{ r(_Fr#Qn
sSiteURL = value; +&J1D8
} i.eMrzJ|
olXfR-2>1
PlgpH'z4$
public String getSFilePath() 3/(eK%d4Xb
{ sEZ2DnDI
return sFilePath; QA)"3g
} P=9UK`n
=)N6R
Sco'] ^#(
public void setSFilePath(String value) BGOS(
{ osLEH?iKW
sFilePath = value; +UTBiB R
} f'`y-]"V5)
s&wm^R
$"}*#<Z
public String getSFileName() _G/uDP%
{ [;'$y:L=g
return sFileName; KF!d?
} b.}J'?yLm
nvc(<Ovw
d`j<Bbf-
public void setSFileName(String value) |Vu`-L'Jz
{ f'qM?GlET
sFileName = value; E>2AG3)
} )]E?~$,
sqRvnCD!
J%!vhQ
public int getNSplitter() N f}ZG
{ c`\qupnY
return nSplitter; _=cuOo"!
} u%OLXb
&b-&0rTqz
SaRn>n\
public void setNSplitter(int nCount) BgB0
{ $`lGPi(Jc
nSplitter = nCount; SK*<H~2
} tdp>vI!
} ^.*zBrFx
}b{7+ + Ah
GNW.n(a
/* *w6F0>u
**Utility.java 3b`#)y^y?%
*/ tCu.Fc@
package NetFox; R(f%*S4
BXytAz3
4]xD-sc
public class Utility { ?-<>he
R[QBFL<
r*FAUb`bG
public Utility() }"/>,
{ uOh
T]\'D&P~D
$j4/ohwTDY
} ]7q|) S\
~;t/VsgGW
//线程睡眠 :1v.Jk
public static void sleep(int nSecond) 9j0o)]
{ .B! Z0
try{ UI~hB4V$]
Thread.sleep(nSecond); _Y)Wi[
} FU)=+m
catch(Exception e) wb39s^n
{ on1B~?*D
e.printStackTrace (); XXXQAY-,C
} Bt(nm>Ng
} >^ E*7Bfp
x((Rm_'
//日志 |:L}/onK
public static void log(String sMsg) T5dnj&N ]
{ cXb&Rm'L
System.err.println(sMsg); N).'>
} w/9%C(w6
lnK#q.]
hzA+,
public static void log(int sMsg) vb9C&#
{ z00,Vr^m
System.err.println(sMsg); ~9@83Cs2
} &7r a
} c IPOI'3d
[n3@*)q's
!%N@>[
/* RSnBG"
**TestMethod.java Zb:Z,O(vn
*/ wR"17z7[]
package NetFox; y~Mu~/s
Q07&7SH_
yI/ FD
public class TestMethod { %8xKBL]J
3u< ntx ><
BKYyc6iE
public TestMethod() 7;pQ'FmZJ
{ ///xx/weblogic60b2_win.exe o4agaA3k
try{ ,Kt51vGi
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); o/& IT(v
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?P/73p
SiteFileFetch fileFetch = new SiteFileFetch(bean); w:mm@8N
fileFetch.start(); ,wngS=
} 5=8t<v1Bn
catch(Exception e){e.printStackTrace ();} P(a}OlG
5qFHy[IA
-lR7 @S
} Vlge*4q
$#(j2sL1
?-tNRIPW@p
public static void main(String[] args) /QQjb4S}
{ pF(6M3>IN
new TestMethod(); ,5AEtoF
} M`E}1WNQ?]
} &y7xL-xP
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