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)); Gvt.m&_
} nzDS
for(int i=0;i<nEndPos.length-1;i++) I~S`'()J
{ 6|#^4D)
nEndPos = nStartPos[i+1]; f8! PeQ?
} \n850PS
nEndPos[nEndPos.length-1] = nFileLength; @A6\v+ih
} n@BE*I<"
} +1p>:cih
0D>~uNcT}
9`^VuC'
//启动子线程 ?B %y)K
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3V`K^X3
for(int i=0;i<nStartPos.length;i++) vi0% jsI
{ asR6,k
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XJ]MPiXj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), w\;=3C`
nStartPos,nEndPos,i); ?ZSG4La\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &a8#qv"l
fileSplitterFetch.start(); I TJ>[c]x
} @yaBtZUp3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +[r%y,k
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); tGzYO/Zp
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "zw?AC6
nEndPos = " + nFileLength); #hd<5+$U}l
// fileSplitterFetch[nPos.length-1].start(); ~GfcI:Zz&
2 <&-
MPO!qSS]
//等待子线程结束 VzpPopD,QW
//int count = 0; <_ */
//是否结束while循环 )?pin|_x
boolean breakWhile = false; hzPx8sO
ok'0Byo
_OcgD<
while(!bStop) }QncTw0
{ 5"y p|Yl
write_nPos(); svyC(m)'
Utility.sleep(500); K4n1#]8i
breakWhile = true; &tD`~
;k7` `
]Vl5v5_
for(int i=0;i<nStartPos.length;i++) xbo-~{
{ g$dL5N7
if(!fileSplitterFetch.bDownOver) Ph]e\
{ 7^KQQ([
breakWhile = false; $EviGZFAaR
break; ~<v.WP<:
} ]-%ZN+
} ]rn!+z
if(breakWhile) lIzJO$8cM
break; w}NgFrL
Eg-b5Z);
2I?HBz1v
//count++; Z6>:k,-Ot
//if(count>4) 9aZ3W<N`M
// siteStop(); r=L9x/r
} UUb!2sO
<mY`<(bc
<?qmB}Y
System.err.println("文件下载结束！"); J-?\,N1R7
} N>ct`a)BD/
catch(Exception e){e.printStackTrace ();} z8Dn<h
} !kASEjFz|f
.&@|)u
mSwOP
//获得文件长度 y13=y}dyDH
public long getFileSize() l`I]eTo)^
{ tx5_e[
int nFileLength = -1; 308w0eP
try{ nZ\,ZqV
URL url = new URL(siteInfoBean.getSSiteURL()); aE#ZTc=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;S?1E:\av
httpConnection.setRequestProperty("User-Agent","NetFox"); K/\#FJno
;xB"D0~,1
:R_{tQ-WG
int responseCode=httpConnection.getResponseCode(); 6-KC[J^Xo
if(responseCode>=400) ~O1*]
{ 0^E!P>
processErrorCode(responseCode); :WA o{|&
return -2; //-2 represent access is error {tR=D_5
} @%\ANM$S
+o'. !sRH
o4~ft!>
String sHeader; 3sp*.dk
{f^30Fw
)7j"OE
for(int i=1;;i++) E 3I'3
{ n;Iey[7_E`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ['s_qCA[
//Utility.log(in.readLine()); mH{cGu?
sHeader=httpConnection.getHeaderFieldKey(i); >P0AGZ
if(sHeader!=null) ]NFDE-Jz]
{ Gzp)OHgJ
if(sHeader.equals("Content-Length")) M\v4{\2l0
{ /$eEj
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); E0O{5YF^T
break; FJU)AjS~
} ^w&TTo(
} )D[xY0Y~
else }7.q[ ^oF
break; EL}v>sC
} Tl%4L% bE
} LWQ BGiJj
catch(IOException e){e.printStackTrace ();} f "&q~V4?
catch(Exception e){e.printStackTrace ();} b%PVF&C9W
}?fa+FQGp
8dA/dMQ
Utility.log(nFileLength); FwW%@Y
\pzvoj7{
vq5I 2
return nFileLength; <M&]*|q>g%
} n/|/Womr
|@ldXuYb
w5*18L=O\
//保存下载信息（文件指针位置） ^U`q1Pg5
private void write_nPos() <=7)t.
{ ~IqT>
try{ njq-iU
output = new DataOutputStream(new FileOutputStream(tmpFile)); X4k/7EA
output.writeInt(nStartPos.length); F_r eBPx
for(int i=0;i<nStartPos.length;i++) /uyQ>Y*-\Y
{ ix#
// output.writeLong(nPos); D$mrnm4d
output.writeLong(fileSplitterFetch.nStartPos); l:|Fs=\
output.writeLong(fileSplitterFetch.nEndPos); ):|)/ZiC'
} ?Jr<gn^D
output.close(); /N^+a-.Qd
} zp9 ?Ia
catch(IOException e){e.printStackTrace ();} o>*{5>#k'
catch(Exception e){e.printStackTrace ();} ]_pL79y
} 7>~iS@7GV
0[i]PgIH
B}FF |0<
//读取保存的下载信息（文件指针位置） n=>Gu9`
private void read_nPos() C=b5[, UCB
{ 785iY865
try{ r9t{/})A
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *FE<'+%
int nCount = input.readInt(); PA=BNKlH
nStartPos = new long[nCount]; *7vPU:Q[
nEndPos = new long[nCount]; WcJ{}V9
for(int i=0;i<nStartPos.length;i++) tV,zz;* Oe
{ y@Or2bO#
nStartPos = input.readLong(); 'q-h kN
nEndPos = input.readLong(); .F6#s
} g Q9ff,
input.close(); 6\Z^L1973
} [T^6Kzz
catch(IOException e){e.printStackTrace ();} W&Hf}qs
catch(Exception e){e.printStackTrace ();} MmK\|CtV
} LgnGqIlx
w:N2 xI
37[C^R!1c
private void processErrorCode(int nErrorCode) Uy_=#&jg
{ 2~4C5@SxL
System.err.println("Error Code : " + nErrorCode); P>kx{^
} Tc*PDt0C
<f*0 XJ#
;i:7E#@
//停止文件下载 :ox CF0Y
public void siteStop() lt4UNJ3w
{ HkN +:
bStop = true; Rta P+6'X
for(int i=0;i<nStartPos.length;i++) MDq@:t
fileSplitterFetch.splitterStop(); +vnaEy
KqUFf@W
1_QO>T'
} :h3JDQe:.
} xVe!
//负责部分文件的抓取 CP'-CQ\Q
**FileSplitterFetch.java 7.t$#fzi
*/ wf4Q}l2,d
package NetFox; dWUu3
Uoe?5Of(*
A^7!+1*K+
import java.io.*; 6{~I7!m"
import java.net.*; f1{ckHAY55
l*u@T|Fc$
4jW{IGW
public class FileSplitterFetch extends Thread { O`=Uq0Vv
FdqUv%(Em
k?#6j1pn
String sURL; //File URL 40E[cGz$*
long nStartPos; //File Snippet Start Position neBkwXF!
long nEndPos; //File Snippet End Position <*+MBF
int nThreadID; //Thread's ID ivq4/Y]-X
boolean bDownOver = false; //Downing is over pDLo`F}A
boolean bStop = false; //Stop identical @RP|?Xc{?
FileAccessI fileAccessI = null; //File Access interface J\*d4I<(Rt
|H4'*NP"
}VGiT~2$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Uww^Sq
{ _6' g]4
this.sURL = sURL; b+hY^$//
this.nStartPos = nStart; .<B1i
this.nEndPos = nEnd; hTm}j,H
nThreadID = id; I}WJ0}R
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \);rOqh
} X@)lPr$a
2$91+N*w9
1rEP)66N
public void run() Xwi&uyvU&
{ TG9)x|!
while(nStartPos < nEndPos && !bStop) p1nA7;B-m
{ 2&m7pcls
1#(1Bs6X
"J#:PfJ%
try{ -ZB"Yg$l
URL url = new URL(sURL); Exr7vL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7E95"B&w
httpConnection.setRequestProperty("User-Agent","NetFox"); R;o_*
String sProperty = "bytes="+nStartPos+"-"; dc)Gk
httpConnection.setRequestProperty("RANGE",sProperty); _+En%p.m
Utility.log(sProperty); )R4<* /C:w
:m\KQ1sq
u_BSWhiW
InputStream input = httpConnection.getInputStream(); hqPn~Tq
//logResponseHead(httpConnection); q*OKA5
YYHm0pc
z@i4dC
byte[] b = new byte[1024]; Q\76jD`m\
int nRead; iIFQRnpu;3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <B`V
{ 4lA+V,#
nStartPos += fileAccessI.write(b,0,nRead); K^Ht$04
//if(nThreadID == 1) z"3c+?2
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (zBQ^97]
} Z3dd9m#.]
B/OO$=>(
V1.F`3h~
Utility.log("Thread " + nThreadID + " is over!"); )a\h5nQI)
bDownOver = true; +b+sQ<w?.
//nPos = fileAccessI.write (b,0,nRead); D;]%
} 7&4,',0VL
catch(Exception e){e.printStackTrace ();} L|LTsRIq
} WIm7p1U#V
} +QX>:z
y~7lug
TpgBS4q
//打印回应的头信息 &pm{7nH
public void logResponseHead(HttpURLConnection con) `qTY
{ >9`ep7
for(int i=1;;i++) vXbT E$
{ aTsfl
String header=con.getHeaderFieldKey(i); J|-HZ-Wk|J
if(header!=null) sFK<:ka
//responseHeaders.put(header,httpConnection.getHeaderField(header)); DOeKW
Utility.log(header+" : "+con.getHeaderField(header)); W#j,{&KVn
else @3YuV=QfH
break; U[l%oLra
} ItADO'M
} l #Q`f.
7h1gU
fh#_Mj+y
public void splitterStop() sE6J:m(
{ s~ A8/YoU}
bStop = true; Tm\[q
} OU@x1G{Cy
V%lGJ]ZEa
:N*T2mP
} =joXP$n^
j_@3a)[NY
Cw $^w
/* \F~Cbj+'Nu
**FileAccess.java G4' U;
*//文件访问(定位，写) cg00t+
package NetFox; YS~t d+*
import java.io.*; 9Z'eBp
X vMG09
]0 RXo3
public class FileAccessI implements Serializable{ T+RI8.#o
'*u;:[73
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 bK\WdG\;
RandomAccessFile oSavedFile; b6&NzUt34V
long nPos; !"%sp6Wc
mthl?,I|
o'/C$E4W
public FileAccessI() throws IOException ;bZ*6-\!-
{ 1Uk~m
this("",0); JyC&L6[]Z
} Z&jb,eh2
'-33iG
?i2Wst
public FileAccessI(String sName,long nPos) throws IOException wg<|@z5
{ m,C,<I|'d
oSavedFile = new RandomAccessFile(sName,"rw"); 3]n@c?lw
this.nPos = nPos; FJ8@b
oSavedFile.seek(nPos); I0+wczW,^
} 1xAFu+
%aBJ+V F
:gscW&k
public synchronized int write(byte[] b,int nStart,int nLen) w/5^R
{ yr2L
int n = -1; \&&(ytL
try{ ) Zo_6%
oSavedFile.write(b,nStart,nLen); 9,f<Nb(\
n = nLen; 7G(f1Y
} V}fKV6 v9
catch(IOException e) > ' 0 ][~
{ 6h6?BQSE
e.printStackTrace (); 1]Q2qs
} #0hNk%X=
"%''k~UD4
&4&33D
return n; nVn|$ "r
} ywynx<Wg
Kt,ynA
34wM%@D*c
} t-*|Hfp*^
s^YTI\L \
aq+IC@O
/* E\~ KVn
**SiteInfoBean.java ITIj=!F*
*/ %M#?cmt
package NetFox; C]yQ "b
h^+C)6(58n
k\sM;bCv7
public class SiteInfoBean { Nv?-*&L
|"YA<e %
/CI%XocB
private String sSiteURL; //Site's URL S=H_9io
private String sFilePath; //Saved File's Path =lC;^&D-0/
private String sFileName; //Saved File's Name hMeqs+
private int nSplitter; //Count of Splited Downloading File w zqd g
3 t88AN=4
*Ht*)l?
public SiteInfoBean() D"XX920$~
{//nSplitter的缺省值为5 \!JS7!+
//default value of nSplitter is 5 EEs-&
this("","","",5); WAB0e~e:|Q
} }PQSCl^I
0GX10*t.
4s~HfxYT
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) T3 9C lH
{ X')Zm+
sSiteURL= sURL; 3<Z'F}lg
sFilePath = sPath; AwXt @!(
sFileName = sName; !Wixs]od
this.nSplitter = nSpiltter; + sywgb)
&^7uv0M<y
jc&/}o$K
} }\f(qw
G_M:0YI@
QGr\I/Y
public String getSSiteURL() 3g0u#t{
{ HS\3)Ooj>
return sSiteURL; >bA$SN
} Yn4)Zhkk
,<$YVXe/
n{^<&GWox
public void setSSiteURL(String value) (7;J"2M
{ ~|'y+h89
sSiteURL = value; w3<"g&n|
} ~mK-8U4>K,
+~ 3w5.8
dv'E:R(a
public String getSFilePath() =@JS88+
{ n</k/Mk}
return sFilePath; qcTmsMpj
} c.(Ud`jc
ZD)0P=%
6Q2orn[
public void setSFilePath(String value) ,2,SG/BB
{ XLZ j
sFilePath = value; *Mwfod
} #dZ/UM(u
M'umoZmW0
QJ#u[hsMFp
public String getSFileName() &nqdl+|G*
{ w|}W(=#
return sFileName; NtY*sUKRD
} 9fP) Fwih
=R&)hlm
}dX/Y/
public void setSFileName(String value) r(: 8!=~K
{ tw'hh@7-Y
sFileName = value; ?7yQ&p
} jby~AJf%
/M^V2=
lf%b0na?r
public int getNSplitter() >f\zCT%cf
{ -BA"3 S
return nSplitter; ~$4]HDg
} -`!_h[
B2~f;zy`
h; 'W :P
public void setNSplitter(int nCount) F0&~ ?2nG
{ )L |tn
nSplitter = nCount; |N:MZ#};
} dD/t_ {h
} PwW^y#96
sDLS*467
:1aL9 fT
/* CAUijMI@
**Utility.java T8$%9&j!UE
*/ v"u7~Dw#1
package NetFox; !8xKf*y
zmf"I[)
/Hv*K&}M
public class Utility { ,b<9?PM
of8mwnZR
<ROpuY\!l
public Utility() hZAG (Z
{ f49"pTw7
`$S^E !=
+D:83h{
} 99^AT*ByY
2)wAFO6u
//线程睡眠 r\(v+cd
public static void sleep(int nSecond) "r8EC
{ CI,lkO|C
try{ K`hz t
Thread.sleep(nSecond); u_N\iCYp
} b.#^sm//
catch(Exception e) 8rFaW
{ J?Ck4dQ
e.printStackTrace (); F9MR5O"
} Yeqvv
} xC-BqVJ%_T
FZiZg;
//日志 ~xS@]3n=
public static void log(String sMsg) XVw-G }5
{ aH%ZetLNJ
System.err.println(sMsg); E;6~RM:
} uie~'K\y
[UMLx
?VB#GJ0M9
public static void log(int sMsg) eGLO!DdxZ
{ U,PZMz`2j
System.err.println(sMsg); k, f)2<
} <EtUnj:qK8
} ]nUR;8
cTM$ZNin
7_DG 5nT
/* D!oZ?dGCo6
**TestMethod.java &K>cW$h=a
*/ +UzXN$73
package NetFox; N31?9GE
bFg*l$`5
qxfLfgu^
public class TestMethod { ~n WsP}`n
YG4WS |
Y %K~w
public TestMethod() R'SBd}1
{ ///xx/weblogic60b2_win.exe ,eDD:#)$}
try{ EYkj@ .,
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); wf?u(3/%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); XYjcJ
SiteFileFetch fileFetch = new SiteFileFetch(bean); IAf$]Fh
fileFetch.start(); |xh&p(
} Z==!C=SBv
catch(Exception e){e.printStackTrace ();} GM](=|F
s`"OM^[-
f')c/Yw
} wepwXy"
ob E:kNE9
OkpwhkPL5
public static void main(String[] args) CM9XPr
{ |QVr`tE<
new TestMethod(); _#!U"hkH
} g<$. - g
} 87i"
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