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)); {8MF!CG]
} OG+$F
for(int i=0;i<nEndPos.length-1;i++) 5 9vGLN!L
{ pi{ahuI#_o
nEndPos = nStartPos[i+1]; Pm_=
} 2P=;r:cx
nEndPos[nEndPos.length-1] = nFileLength; d0^2<
} %xRS9A4
} g;h&Xkp
dB5DJ:$W$
fm*Hk57
//启动子线程 24Fxx9g
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 34=0.{qn
for(int i=0;i<nStartPos.length;i++) 5-*]PAC
{ a?kQ2<@g
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j$^]WRt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), K0\WN"ua;
nStartPos,nEndPos,i); rBf?kDt6l
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); AL0Rn e N
fileSplitterFetch.start(); 'w2;oO
} (AYD@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "->:6Oe2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `{Jb{L@f
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8(}sZ)6
nEndPos = " + nFileLength); )YFs
// fileSplitterFetch[nPos.length-1].start(); vF&b|V+,
lu_Gr=#O
tp<VOUa
//等待子线程结束 F?=u:
//int count = 0; +mQSlEo
//是否结束while循环 lI 1lP 1
boolean breakWhile = false; L ~w=O!
Sg-xm+iSDt
ja/[PHq"
while(!bStop) G$ FBx
{ nlW&(cH
write_nPos(); L|LTsRIq
Utility.sleep(500); e`r;`a&
breakWhile = true; y~7lug
8:xo ~Vc
YW<2:1A|
for(int i=0;i<nStartPos.length;i++) ]B4mm__
{ sd53 _sV
if(!fileSplitterFetch.bDownOver) p( *3U[1
{ _GqE'VX
breakWhile = false; }=a4uCE
break; fP58$pwu
} {M/c!
} lIg2iun[n
if(breakWhile) )_cv}.xe
break; s~ A8/YoU}
<q\) o_tH
de9l;zF
//count++; 31& .Lnq
//if(count>4) Nl`ry2"<
// siteStop(); 070IBAk}_
} Q/)ok$A&
,<b|@1\k
A@(h!Cq
System.err.println("文件下载结束！"); fhKiG%i'l
} ~aAJn IO
catch(Exception e){e.printStackTrace ();} Y&+_p$13
} a +yI2s4Z
mwH!:f
"H<#91^|
//获得文件长度 uz3pc;0LPY
public long getFileSize() Xe;(y "pR
{ g ypq`F
int nFileLength = -1; W'h0Zg
try{ Wx$q:$h@q
URL url = new URL(siteInfoBean.getSSiteURL()); Fx5d@WNa>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1xAFu+
httpConnection.setRequestProperty("User-Agent","NetFox"); F*t_lN5{
([b!$o<v
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int responseCode=httpConnection.getResponseCode(); +'KE T,
if(responseCode>=400) `(/saq*
{ > ' 0 ][~
processErrorCode(responseCode); 6\fMzm
return -2; //-2 represent access is error Du:p!nO
} dyiEK)$h
8<g#$(a_E
Kt,ynA
String sHeader; gT&'i(c
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4bev*[k
for(int i=1;;i++) |W*@}D
{ L3GC[$S
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); hr4ye`c j
//Utility.log(in.readLine()); b>=Wq
sHeader=httpConnection.getHeaderFieldKey(i); {XD/8m(hN|
if(sHeader!=null) |4S?>e
{ wp%FM
if(sHeader.equals("Content-Length")) 'K`Rbhy
{ &49$hF g6"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); I+"?,Ej$K
break; pq[X)]z|
} -9>LvLU
} r}0C8(oq
else ,{{#a*nd
break; h!G^dW.
} 3<Z'F}lg
} 1%spzkE 3P
catch(IOException e){e.printStackTrace ();} ^+%tlX_+.
catch(Exception e){e.printStackTrace ();} Z@,PZ
hzQ+9-qA
qfGtUkSSb
Utility.log(nFileLength); xshArJ&A
}#OqU# q|
1<a@p}
return nFileLength; YWRE&MQ_
} n{^<&GWox
|O(-CDQe
b H"}w$!>r
//保存下载信息（文件指针位置） j!x<QNNX
private void write_nPos() dY/u<4
{ J1tzHa6
try{ m0|Ae@g~3
output = new DataOutputStream(new FileOutputStream(tmpFile)); sq~+1(X
output.writeInt(nStartPos.length); f2 ydL/M,
for(int i=0;i<nStartPos.length;i++) 6Lg!Lodu
{ df4sOqU
// output.writeLong(nPos); \5Vp6^
output.writeLong(fileSplitterFetch.nStartPos); L19MP
output.writeLong(fileSplitterFetch.nEndPos); qDRNtFa
} 5#0A`QO
output.close(); YX ;n6~y
} @ /UOSU
catch(IOException e){e.printStackTrace ();} [`.3f'")j
catch(Exception e){e.printStackTrace ();} ,u}<Ws8N
} .pM &jni Y
s(AJkO'`
-G],H)M
//读取保存的下载信息（文件指针位置） As@ihB+(\
private void read_nPos() Dac ^*k=D
{ j:3EpD@GS
try{ 3P//H88LY
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); D=r-
int nCount = input.readInt(); 4%wq:y< )/
nStartPos = new long[nCount]; A\".t=+7
nEndPos = new long[nCount]; >|a\>UgC
for(int i=0;i<nStartPos.length;i++) atY*8I|
{ ;/@?6T"
nStartPos = input.readLong(); i8Fs0U4"
nEndPos = input.readLong(); eo1&.FQu
} Ia=_78MgZ
input.close(); \ Y*h
} >P<z |8
catch(IOException e){e.printStackTrace ();} S dIGU[fm
catch(Exception e){e.printStackTrace ();} Zc-#;/b3T
} ^ED"rMI
nQ5N=l
U;\S(s}
private void processErrorCode(int nErrorCode) Z^s+vi
{ `#ul,%
System.err.println("Error Code : " + nErrorCode); QU:EY'2
} 2;:lK":
BwC<rOU
a3Y{lc#z}
//停止文件下载 .i$,}wtw
public void siteStop() bE?'C h
{ H(G!t`K
bStop = true; "YJ[$TG
for(int i=0;i<nStartPos.length;i++) ~<n(y-P^
fileSplitterFetch.splitterStop(); 'WK;$XQ
Uz 0W <u3v
cTM$ZNin
} k({2yc#RD&
} &K>cW$h=a
//负责部分文件的抓取 4E2yH6l
**FileSplitterFetch.java ^IBGYl5n
*/ #+9rjq:v#]
package NetFox; D?^540,b
6O9iEc,HM
20aZI2sk`
import java.io.*; 9 ~~qAoD
import java.net.*; tQrS3Hz'nA
SBTPTb
6 }!Z"
public class FileSplitterFetch extends Thread { jyiFM5&
`mzb(bE
CM9XPr
String sURL; //File URL 'w(y J
long nStartPos; //File Snippet Start Position -/>9c-F
long nEndPos; //File Snippet End Position 3?2<WEYr
int nThreadID; //Thread's ID Q"%S~&#'
boolean bDownOver = false; //Downing is over Q&xjF@I
boolean bStop = false; //Stop identical bhD ~4Rz
FileAccessI fileAccessI = null; //File Access interface H?tUCbw
g:_hj_1Y M
d",(aZ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6\4Z\82
{ :&qhJtGo
this.sURL = sURL; N5?IpE
this.nStartPos = nStart; ?`"n3!>bS
this.nEndPos = nEnd; 1a$IrQE
nThreadID = id; fG&=Ogy
fileAccessI = new FileAccessI(sName,nStartPos);//定位 EyY],W1 Y
} WULAty
,[isib3
H_w%'v&
public void run() mu[Op*)
{ N}b^fTq
while(nStartPos < nEndPos && !bStop) iA'As%S1
{ vvq/
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>{5 p0
try{ |0sPka/u16
URL url = new URL(sURL); {6*#3m Kk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V}" g~=
httpConnection.setRequestProperty("User-Agent","NetFox"); E!J=8C.:
String sProperty = "bytes="+nStartPos+"-"; $DebXxJw0l
httpConnection.setRequestProperty("RANGE",sProperty); xJc$NV-JzK
Utility.log(sProperty); ?Ik4
Qz,|mo+
d'"r("w#
InputStream input = httpConnection.getInputStream(); 1J{fXh
//logResponseHead(httpConnection); *k [J6
&Z;_TN9[
\X|sU:g
byte[] b = new byte[1024]; y('k`>C
int nRead; bgF^(T35
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) m$wlflt
{ h Dk)Qg
nStartPos += fileAccessI.write(b,0,nRead); YoKs:e2/:
//if(nThreadID == 1) g(Yb^'X/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V'G Ju
} }%TPYc
MHi8E9_O
9\JQ7$B
Utility.log("Thread " + nThreadID + " is over!"); S($Su7g%_
bDownOver = true; Vh|\_~9
//nPos = fileAccessI.write (b,0,nRead); W*N$'%
} M.q=p[
catch(Exception e){e.printStackTrace ();} % 0T+t.
} P7.'kX9
} hK|j6xf.o
x,n,Qlb
~" i0x
//打印回应的头信息 HKDID[d0
public void logResponseHead(HttpURLConnection con) %NHkDa!
{ BlA[T%
for(int i=1;;i++) `aC){&AP(
{ /Ncm^b4
String header=con.getHeaderFieldKey(i); =u[k1s?
if(header!=null) 2`GOJ,$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %]2,&
Utility.log(header+" : "+con.getHeaderField(header)); $za8"T*I
else eWJ`$"z
break; )wvHGecp*
} iBTYY{-wF
} sEJC-$
*)M49a*UD
q 11IkDa
public void splitterStop() 1KM`i
{ K%v1xZ
bStop = true; Vw||!d
} c2t=_aAIPQ
aFz5leD
}|u4 W?H
} *!s;"U
,I1RV
9RN-suE[
/* '(bgs
**FileAccess.java ia\eLzj
*//文件访问(定位，写) z|EEVNFd&
package NetFox; Qham^
import java.io.*; n!p<A.O7@
+_XzmjnDd
8V^oP]Y
public class FileAccessI implements Serializable{ 4RSHZAJg
35E_W>n
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 h%}/Cmx[
RandomAccessFile oSavedFile; wiz$fj
long nPos; *%{gYpn
1 $/%m_t
d ,4]VE
public FileAccessI() throws IOException ,lZB96r0
{ JSW^dw&
this("",0); At-U2a#J{
} =-IbS}3
0TQ$C-%
(M*FIX
public FileAccessI(String sName,long nPos) throws IOException +=O5YR!{
{ !%"8|)CAr
oSavedFile = new RandomAccessFile(sName,"rw"); j#cYS*^H
this.nPos = nPos; c-B cA
oSavedFile.seek(nPos); NR`C(^}
} zT!drq:x
0aG ni|
Ney/[3 A
public synchronized int write(byte[] b,int nStart,int nLen) O^oWG&Y;v
{ _lamn}(x0
int n = -1; mIK7p6
try{ |Y?HA&
oSavedFile.write(b,nStart,nLen); 9I}-[|`u
n = nLen; Tj:B!>>
} 3B84^>U<
catch(IOException e) '.:z&gSqx0
{ 8fl`r~bqZ
e.printStackTrace (); C uB`CI
} 3yVMXK
'<"s \,
C{U?0!^
return n; 3kybLOG
} E=nIRG|g
lhy*h_>
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} hb}+A=A=+
1`=nWy='
E|iQc8gr&
/* f4fvrL
**SiteInfoBean.java h2G$@8t}I
*/ aAD^^l#
package NetFox; x(1:s|Uyp{
OCe!.`
nLXlU*ES
public class SiteInfoBean { EV]1ml k$
"&Y`+0S8
+S o4rA*9
private String sSiteURL; //Site's URL ItNz}4o|d
private String sFilePath; //Saved File's Path X% t1T4
private String sFileName; //Saved File's Name 0XE4<U
private int nSplitter; //Count of Splited Downloading File l9{hq/V
~%&LTX0s|
!>FYK}c7
public SiteInfoBean() Y]'Z7<U}*E
{//nSplitter的缺省值为5 *4\:8
//default value of nSplitter is 5 geru=7
this("","","",5); m*&]!mM"0G
} 01t1Z}!y
h4fJvOk|!
j#!IuH\]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) c"f-3kFv
{ M?1Y,5
sSiteURL= sURL; +%<(E
sFilePath = sPath; <cps2*'
sFileName = sName; Ni9/}bb
this.nSplitter = nSpiltter; xQ7l~O b
R@1xt@?
D+lAhEN
} \V;F/Zy(
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- YEZ]:"
public String getSSiteURL() W!Gq.M
{ n@<YI
return sSiteURL; 3#3n!(
} 5TH~.^`Fi
YL!P0o13r
Ytn9B}%o
public void setSSiteURL(String value) 94'&b=5+
{ ~[t[y~Hup
sSiteURL = value; g|o,uD
} E>6MeO
Kg{+T`
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public String getSFilePath() W: z6Koc0
{ .73X3`P25
return sFilePath; 8SMxw~9$
} S\CCrje
(>LF(ll
9SX +
public void setSFilePath(String value) 'p^t^=dQ
{ Ki;*u_4{
sFilePath = value; A7%)~z<
} 0Um2DjTCG
7y.kQI?3
VF+KR*
public String getSFileName() tR#OjkvX
{ 34f?6K1c
return sFileName; eb?x9h
} em y[k
H%[eV8
l|u>Tb|V
public void setSFileName(String value) (^ JI%>
{ 0j^Kgx
sFileName = value; n*h)'8`Ut
} y5vvu>nd
1a/++4O.|
y#`tgJ:
public int getNSplitter() ~]sc^[
{ &j;wCvE4+
return nSplitter; 9[#pIPxNK
} {4l8}w
zOJ%}
)j6~Wy@4
public void setNSplitter(int nCount) =0 #OU
{ r-,%2y?
nSplitter = nCount; 59LG{R2
} ~-k9%v`
} BT !^~S%w
<NMEGit
_T60;ZI+^
/* 5=-Q4d
**Utility.java juJklSD
*/ GblA9F7
package NetFox; ,KH#NY]
I{|O "8
!t"4!3
public class Utility { ~g91Pr
=nHUs1rKn
&$+AXzn
public Utility() Xg6Jh``
{ gb1V~
KYm0@O>;
l$KA)xbI
} AI2)g1m
phXGnm
//线程睡眠 hgG9m[?K
public static void sleep(int nSecond) iI T;K@&
{ M/f<A$xx_
try{ E:68?IJ
Thread.sleep(nSecond); =jN.1}
} `7E;VL^Y1
catch(Exception e) u,ho7ht3(
{ qz_7%c]K[
e.printStackTrace (); .vf'YNQ%
} (TtkFo'!U
} (XTG8W sN
uo9B9"&
//日志 I9A~Ye 5O&
public static void log(String sMsg) BKCiIfkZ
{ dl)Y'DI
System.err.println(sMsg); C^Yb\N}S
} :LQYo'@yB
5{WE~8$
o'aEY<mZ7
public static void log(int sMsg) 2QcOR4_V
{ B:Oa}/H
System.err.println(sMsg); +.PxzL3?
} z|J_b"u4
} R_cA:3qc~
/U*C\ xMm
9<?M8_
/* e)k9dOR
**TestMethod.java HyQJXw?A:
*/ oCv.Ln1;Z
package NetFox; |3b^~?S
net@j#}j-
ub0.J#j@
public class TestMethod { P`+{@@
,8uqdk-D
PdFKs+Z`
public TestMethod() (8DC}kckE
{ ///xx/weblogic60b2_win.exe :S83vE81WK
try{ |Zpfq63W
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); tY<4%~%X
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Jt<_zn_FG
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2wg5#i
fileFetch.start(); :r,pqnH_
} &{hL&BLr
catch(Exception e){e.printStackTrace ();} \)904W5R
n,(sBOQ
IMFDM."s
} U$.@]F4&
On:il$MU
myQagqRx
public static void main(String[] args) 2;`1h[,-^
{ (t K||*u
new TestMethod(); 7>0o&
} %lhEM}Sm
} CyFrb`%
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