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)); Y!C8@B$MR3
} 4>I >y@^
for(int i=0;i<nEndPos.length-1;i++) ^w(~gQ6|mP
{ okv`+VeA
nEndPos = nStartPos[i+1]; <yq kJ
} ]`,jaD
nEndPos[nEndPos.length-1] = nFileLength; ~R!M.gY[rK
} y +2
} |{en){:
FC BsC#
4`M7 3k0
//启动子线程 #lld*I"d
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b)1v:X4Bv=
for(int i=0;i<nStartPos.length;i++) F\G-. 1
{ HZDeQx`*s
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +thkx$o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $/p/9 -
nStartPos,nEndPos,i); k~,({T<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ! O~:
fileSplitterFetch.start(); 2/ES.>K!.
} <RaM@E
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZJ Ke}F`l
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?n0Z4 8%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", l1?$quM^V
nEndPos = " + nFileLength); b2<((H
// fileSplitterFetch[nPos.length-1].start(); P56B~M_
Uzzt+Iwm
<QcQ.b
//等待子线程结束 .nG14i7C
//int count = 0; a(Fx1`}
//是否结束while循环 v%2@M
boolean breakWhile = false; rUL_=>3
AIU=56+I\
:kb2v1{\
while(!bStop) xxS>O%
{ }#Gq*^w
write_nPos(); 1](PuQm7+
Utility.sleep(500); kQt#^pO)
breakWhile = true; ><Awk~KR
3<%ci&B
^_rBEyz@
for(int i=0;i<nStartPos.length;i++) Nm.G,6<J
{ yPXa
if(!fileSplitterFetch.bDownOver) K}j["p<!
{ aB*'DDlx"r
breakWhile = false; wdo(K.m
break; 99G'`NO
} gL(_!mcwu
} ]o<&Q52|
if(breakWhile) |T) $E
break; =Sp+$:q*
92 oUQ EK
q4y sTm
//count++; )kpNg:2p
//if(count>4) $3'xb/3|
// siteStop(); W_bp~Wu
} uG){0%nX
qOs'Ljx6l
\Aq$h:<
System.err.println("文件下载结束！"); Zb4+zps^-
} o6Jhl8
catch(Exception e){e.printStackTrace ();} z55g'+Kab
} &)ED||r,
E gD$A!6N8
F>lM[Lu#
//获得文件长度 :6[G;F7s
public long getFileSize() 5!Ho[
{ !+V."*]l
int nFileLength = -1; D_)N!,i
try{ !(8)'<t9
URL url = new URL(siteInfoBean.getSSiteURL()); IDK~ (t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Xf%vfAf
httpConnection.setRequestProperty("User-Agent","NetFox"); $No^\.mV
>*]dB|2
yE_T#FN
int responseCode=httpConnection.getResponseCode(); UY}EW`$#m
if(responseCode>=400) VYw<8AEFY
{ k((kx:
processErrorCode(responseCode); m>{I>:sq
return -2; //-2 represent access is error 1/tyne=m
} <Eu/f`8
uGU-MC*
>v'@p
String sHeader; Z/e^G f#i
%$6?em_
cES8%UC^i
for(int i=1;;i++) EL^j}P
{ B".3NQ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9 K~X+N\
//Utility.log(in.readLine()); E0*62OI~O
sHeader=httpConnection.getHeaderFieldKey(i); cof+iI~9O%
if(sHeader!=null) Ie7S'.Lmq
{ q${+I(b,
if(sHeader.equals("Content-Length")) n3_|#1Qu
{ 49tJ+J-N
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); A)80qx:
break; Uo0[ZsFD
} =:=s
} iit 5IV
else &~'^;hy=
break; kk$D:UQX
} )u=46EU_
} 9|l6.$Me/
catch(IOException e){e.printStackTrace ();} d04fj/B
catch(Exception e){e.printStackTrace ();} UWW'[gEP1
v`\CzT
Mt*eC)~Yx
Utility.log(nFileLength); 2v{42]XYf
sB=s .`9
C {G647
return nFileLength; l(Y\@@t1
} X3j|J/
MUi#3o\f
9/PX~j9O?
//保存下载信息（文件指针位置） d;g]OeF
private void write_nPos() S9E<)L
{ p>1Klh:8.'
try{ |[iEi
output = new DataOutputStream(new FileOutputStream(tmpFile)); *t bgIW+h
output.writeInt(nStartPos.length); 7b*9 Th*a
for(int i=0;i<nStartPos.length;i++) L.x`Jpq(3
{ +%H2;8{F
// output.writeLong(nPos); `,s0^?_
output.writeLong(fileSplitterFetch.nStartPos); Mi<}q@]e
output.writeLong(fileSplitterFetch.nEndPos); V;(Rg=5
} Z|BOuB^
output.close(); 9Idgib&
} o@qI!?p&
catch(IOException e){e.printStackTrace ();} `^: v+!
catch(Exception e){e.printStackTrace ();} F> b<t.yV
} %:.IG.`d
q9B5>Ye)
g>n1mK|
//读取保存的下载信息（文件指针位置） K_}81|=
private void read_nPos() ^:2>I$
{ b4CXif
try{ /rnP/X)T
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); R_duPaWc@
int nCount = input.readInt(); X=[`+=
nStartPos = new long[nCount]; oR}'I
nEndPos = new long[nCount]; vFK!LeF%
for(int i=0;i<nStartPos.length;i++) =`t%p1
{ t]6 4=
nStartPos = input.readLong(); )%bY2 pk
nEndPos = input.readLong(); 6BObV/S Jg
} l-q.VY2
input.close(); /jN&VpDG
} zJTSg
catch(IOException e){e.printStackTrace ();} Dw&_6\F@
catch(Exception e){e.printStackTrace ();} 3gz4c1 s^:
} }b/G{92
fH 0&Wc3yC
WZf}1.Mh*
private void processErrorCode(int nErrorCode) `_E@cZ4
{ fYzZW
System.err.println("Error Code : " + nErrorCode); ,,~|o3cfq
} ^fhkWx4i
Ombvp;
h"(HDnq
//停止文件下载 }O8#4-E_Ji
public void siteStop() Os)}kkja
{ ^w~Utx4
bStop = true; ;mXw4_{
for(int i=0;i<nStartPos.length;i++) |\/V1
fileSplitterFetch.splitterStop(); !z_VwZ#,
5uD'Kd$H
J-Wphc!m
} FQw@@
} \"Aw ATQ
//负责部分文件的抓取 3t$)saQR
**FileSplitterFetch.java *h2)$^P%
*/ #6za
package NetFox; (\ Gs7
^vr`t9EE
> 72qi*0
import java.io.*; N}7tjk
import java.net.*; #3((f[
YojYb]y+j
nX-%qc"
public class FileSplitterFetch extends Thread { B#K2?Et!t
J@Qw6J
psAdYEGk!
String sURL; //File URL :a y-2
long nStartPos; //File Snippet Start Position qb$f,E[
long nEndPos; //File Snippet End Position j~`rc2n%
int nThreadID; //Thread's ID k?ksv+e\
boolean bDownOver = false; //Downing is over KHt.g`1:R
boolean bStop = false; //Stop identical (C!33s1
FileAccessI fileAccessI = null; //File Access interface /@f3|L<1@V
Pt8 U0)i)
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "~aCW~
{ X5wYfN
this.sURL = sURL; Wj#Gm
this.nStartPos = nStart; AE&IN.-
this.nEndPos = nEnd; }|4dEao\
nThreadID = id; jl~?I*Gr
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &ajpD sz;
} ($Y6hn+
a%)-iL X8&
"ju0S&
public void run() R{A$hnhW6
{ t"]~e"
while(nStartPos < nEndPos && !bStop) %2TjG
{ XV*uu "F
tS&rR0<OW
mLL?n)
try{ J;cTEB
URL url = new URL(sURL); V-%Am
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gTwxmp.,
httpConnection.setRequestProperty("User-Agent","NetFox"); 5b-: e? |
String sProperty = "bytes="+nStartPos+"-"; m\?H <o0
httpConnection.setRequestProperty("RANGE",sProperty); cQldBc
Utility.log(sProperty); l]v>PIh~N
BjIKs~CT
KsBi<wY
InputStream input = httpConnection.getInputStream(); Z4@GcdZ
//logResponseHead(httpConnection); *WpDavovyB
E0a &1j
s6J`i&uu
byte[] b = new byte[1024]; 8^%Nl `_2B
int nRead; isR|K9qf^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) '{xPdN
{ #iAEcC0k5
nStartPos += fileAccessI.write(b,0,nRead); Wf>scl`s
//if(nThreadID == 1) o$_,2$>mn
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); TEi~X2u
} B M$+r(#t
`t~Zkb4>
J)leRR&
Utility.log("Thread " + nThreadID + " is over!"); )Y}8)/Pud
bDownOver = true; 9WhZ= Xk
//nPos = fileAccessI.write (b,0,nRead); #DFfySH)A
} OFe?T\dQn
catch(Exception e){e.printStackTrace ();} `@07n]KB
} #0;ULZ99aH
} yxz"9PE/P
dCkk5&2n
PhOtSml0
//打印回应的头信息 y,QJy=?
public void logResponseHead(HttpURLConnection con) 0xQ="aXE
{ I@<\DltPi
for(int i=1;;i++) /"%(i#<)xs
{ "`4V^1
String header=con.getHeaderFieldKey(i); bI"_hvcFp
if(header!=null) \tx4bV#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); v8!Ts"
Utility.log(header+" : "+con.getHeaderField(header)); QBI;aG<+b>
else ,aBo p#
break; >=Pn\"j
} :v>Nz7SB
} t}]R0O.s
qoXncdDHZ
^yo~C3r~
public void splitterStop() >MeM
{ n6Qsug$z
bStop = true; ^$I8ga
} ckTk2xPQ
1SGLA"r
c_#+xGS!7
} MQ{.%
o6[aP[~F
V"`t*m$
/* at-+%e
**FileAccess.java z[`OYwsW
*//文件访问(定位，写) (7Q Fy
package NetFox; vRQ7=N{3
import java.io.*; ',Q|g^rF]
NP#:} )
%P2l@}?a
public class FileAccessI implements Serializable{ $)O=3dNbo
q&RezHK l
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 C6T?D5
RandomAccessFile oSavedFile; T7bDt
long nPos; b&j}f
RU_wr<
9_
public FileAccessI() throws IOException +xc1cki_{
{ 0<";9qN)6
this("",0); NM{/rvM
} iUua!uC
(Iz$_(
;"K;D@xzh]
public FileAccessI(String sName,long nPos) throws IOException %7y8a`}
{ zG. \xmp
oSavedFile = new RandomAccessFile(sName,"rw"); ym=7EY?o
this.nPos = nPos; Y%1 94fY$
oSavedFile.seek(nPos); -0>gq$/N=^
} }@XokRk
JE<w7:R&
Sbp].3^j
public synchronized int write(byte[] b,int nStart,int nLen) W:gpcR]>
{ fZ5zsm'N
int n = -1; nde_%d$
try{ W Y]
oSavedFile.write(b,nStart,nLen); +\_c*'K>
n = nLen; 6B=: P3Y
} h7"c_=w+
catch(IOException e) j*'+f~A
{ p"UdD
e.printStackTrace (); L<62-+e`
} o<8('j
e>] gCa
=+z+`ot
return n; Z.l4<
} S<Os\/*
w$##GM=Tq
A 6IrA/b
} bQlvb
LN0pC}F
/L yoTBG
/* BtA_1RO
**SiteInfoBean.java Rl/5eE8
*/ 5w+KIHhN|
package NetFox; r&y0`M
{KGEv%
uSgR|b;R]
public class SiteInfoBean { iLC.?v2=
8= kwc
?l9j]
private String sSiteURL; //Site's URL -Is;cbfLj/
private String sFilePath; //Saved File's Path !y\r.fm!A
private String sFileName; //Saved File's Name L}a-c(G+8
private int nSplitter; //Count of Splited Downloading File &pzf*|}
}NJKkj?
'w z6Zt
public SiteInfoBean() QJ,[K_
{//nSplitter的缺省值为5 5(=5GkE)>
//default value of nSplitter is 5 9,wD
this("","","",5); 4^Y{ BS fF
} 7M/v[dwL
m!K`?P]:N
('k9XcTPP
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9?XQB%44
{ 4=~+Bz
sSiteURL= sURL; n "bii7h
sFilePath = sPath; #PkZi(k hv
sFileName = sName; [} zzG@g,J
this.nSplitter = nSpiltter; l@)`Q
8g0VTY4$jP
r@a]fTf
} YO'aX
bEKhU\@=J
%b[>eIJU#
public String getSSiteURL() 21$E.x 6
{ nSv@FT'~z
return sSiteURL; D"V(A\sZ
} 7tbY>U8
vc0LV'lmg
uc>":V
public void setSSiteURL(String value) ; I;&O5Y
{ SF=TG84<
sSiteURL = value; $niG)@*
} Kr5(fU
AP:Q]A6}
I`f5)iF?0
public String getSFilePath() O joa3
{ ]t0St~qUL)
return sFilePath; J%u,qF}h
} 'Qh1$X)R7a
T-LX>*
j'k <
public void setSFilePath(String value) jsFfrS"*
{ jF}-dfe
sFilePath = value; L^jjf8_
} "Ccyj/
%s! |,Cu
H76iBJ66
public String getSFileName() s IFE:/1,
{ g<N;31:c\
return sFileName; e\em;GTy
} .* )e24`
.P <3+
byFO^pce
public void setSFileName(String value) l*?_@
{ Z]e`bfNnI
sFileName = value; +Bf?35LP
} s&hr$`V4
lA pZC6Iwk
P8(hHuO
public int getNSplitter() wRvh/{xB
{ =EYWiK77a
return nSplitter; z2>LjM) #
} [l3ys
$nb.[si\
6w=`0r3hy
public void setNSplitter(int nCount) ny cn
{ <iA\ZS:
nSplitter = nCount; %q}[ZD/HD
} /w1M%10
} q3<kr<SP
En:>c
6`@b@Kd
/* F"bz<{
**Utility.java =?c""~7
*/ hrm<!uKn
package NetFox; =ecLzk"+F
eP,bFc
"M, 1ElQ
public class Utility { $~S~pvT
~nTj't2R
kU+|QBA@
public Utility() L R\LC6kM
{ drMMf[
(6.uNLr
z&WtPSyGj
} 'zM=[#!B
[}YUi>NGA
//线程睡眠 Q6W![571;
public static void sleep(int nSecond) i!zFW-*5
{ 8L,=Eap
try{ FieDESsX>
Thread.sleep(nSecond); >MGWN
} c}+*$DeT
catch(Exception e) *5 +GJWKN
{ g@37t @I
e.printStackTrace (); <|3%}?
} P`ou:M{8
} .%s U)$bH
~_-]> SI
//日志 jM&di
public static void log(String sMsg) ;F#(:-:
{ F~8'3!<9
System.err.println(sMsg); R0}1:1}$Sn
} WFiX=@SS
s(nT7x+W
b,^Gj]7
public static void log(int sMsg) 'Y/0:)
{ O5:bdt.
System.err.println(sMsg); Z(7kwhP[`
} g_1#if&
} <(q(5jG
]'`E
m/1FVC@*
/* b?l>vUgAg
**TestMethod.java GPGE7X'
*/ 0muC4
package NetFox; B ytx.[zbX
{Q3OT
+?Ii=*7n
public class TestMethod { eD?&D_l~6
1!KROes4
~PI2G9
public TestMethod() 9H/>M4RT
{ ///xx/weblogic60b2_win.exe f4h~c
try{ R7/S SuG6\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Xva(R<W7d<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ts!tv6@
SiteFileFetch fileFetch = new SiteFileFetch(bean); .P$m?p#
fileFetch.start(); oGRk/@
} -BH/)$-$
catch(Exception e){e.printStackTrace ();} ;NR|Hi]
A<ds+0
uYMn VE"
} Xj 1Oxm42
:YI5O/gsk?
=3.dgtH
public static void main(String[] args) 393c |8M
{ "5&"Ij,/
new TestMethod(); ^o{{kju
} tL$,]I$1+
} 0+e=s0s.
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