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)); VH=S?_RY>
} PH> b-n
for(int i=0;i<nEndPos.length-1;i++) \3'9Uz,OC
{ aX~%5mF
nEndPos = nStartPos[i+1]; AX= 1b,s
} 3t<a $i
nEndPos[nEndPos.length-1] = nFileLength; Y`o+XimX
} Qb)C[5a}
} X66VU
]da^xWK
INkD=tX
//启动子线程 ?Y:8eD"*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; zN{K5<7o
for(int i=0;i<nStartPos.length;i++) "y_#7K
{ ;=<-5;rI
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [8Qro8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), TQ{Han!
nStartPos,nEndPos,i); }|5VRJA
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -T&.kYqnb$
fileSplitterFetch.start(); e.@uhB.
} `.T}=j|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8me ]JRw
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $&<uT
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", m=:4`_0Q
nEndPos = " + nFileLength); e|&6$A>4]
// fileSplitterFetch[nPos.length-1].start(); `5~ +,/Ys
$2M#qkik-
[74F6Qp
//等待子线程结束 4#5:~M }
//int count = 0; w.lAQ5)I%\
//是否结束while循环 =xNv\e
boolean breakWhile = false; /Nr*`l
hgLj<
?{U m
while(!bStop) 0H0-U'l
{ Gg~QAsks
write_nPos(); >[Ye
Utility.sleep(500); sf]s",t~J
breakWhile = true; \EKU*5\Hp>
CBDG./
{5d9$v7k4
for(int i=0;i<nStartPos.length;i++) Xe#K{gA
{ (`6T&>(4
if(!fileSplitterFetch.bDownOver) 9elga"4:'
{ OKi\zS
breakWhile = false; vTaJqEE
break; $b<6y/"
} =xsTDjH>
} ovwQ2TuK
if(breakWhile) ,(.MmP`
break; ;U<rc'qE
[tg^GOf '
LY[~Os W
//count++; M.nvB)
//if(count>4) uP<0WCN
// siteStop(); &AlJ "N|
} 2_ :n
t=*@yQ nB
U,+[5sbo
System.err.println("文件下载结束！"); ,R$u?c0>'&
} zNY)'
catch(Exception e){e.printStackTrace ();} rU;RGz6}
} 4J?t_)
Ug:\
}hYZ" A~
//获得文件长度 h'$QC )P
public long getFileSize() 8)kLV_+%
{ A>[|g`;t
int nFileLength = -1; >Bs#Xb_B]
try{ RZe'Kw -
URL url = new URL(siteInfoBean.getSSiteURL()); U|HB=BP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); K_ lVISBQ
httpConnection.setRequestProperty("User-Agent","NetFox"); A<\JQ
TRZRYm"
pDQ}*
int responseCode=httpConnection.getResponseCode(); p~.8\bI=
if(responseCode>=400) ~+<olss_
{ /XudV2P-CA
processErrorCode(responseCode); +dBz`WD
return -2; //-2 represent access is error c*`>9mv
} zE)~0v4
X[2[!)Rk
\uME+NF
String sHeader; Mc-)OtmG[
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341?0%=
for(int i=1;;i++) 0wFH!s/B
{ 2Bk$ lx7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;Nr]X
//Utility.log(in.readLine()); AH4EtZC=W
sHeader=httpConnection.getHeaderFieldKey(i); -`f04_@>d
if(sHeader!=null) IScRsxFb
{ w#N?l!5
if(sHeader.equals("Content-Length")) -o+74=E8[?
{ $ n,Z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); F`nb21{0y&
break; cst}Ibfi
} 9s}Kl($
} uY< H#k
else ^`SA'F,
break; )2DQ>cm
} XhdSFxW}
} \([WH!7
catch(IOException e){e.printStackTrace ();} Z+pom7A"E
catch(Exception e){e.printStackTrace ();} GHF_R,7
o$C|J]%
?R-9W+U%f
Utility.log(nFileLength); 6DL[aD
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return nFileLength; VD4C::J
} FuX 8v
dY"}\v6
$|KaBx1
//保存下载信息（文件指针位置） i)Lp7m z
private void write_nPos() [!^-J}^g~\
{ 4yaxl\2
try{ T\VNqs@
output = new DataOutputStream(new FileOutputStream(tmpFile)); 55t\Bms{
output.writeInt(nStartPos.length); l7JY]?p
for(int i=0;i<nStartPos.length;i++) pium$4l2#
{ y[O-pD`
// output.writeLong(nPos); +pH@oFNK
output.writeLong(fileSplitterFetch.nStartPos); $jd<v1"o
output.writeLong(fileSplitterFetch.nEndPos); aTGdmj!
} A=Dhod
output.close(); Px M!U!t
} kl1Y] ?z}
catch(IOException e){e.printStackTrace ();} e75UMWaeC
catch(Exception e){e.printStackTrace ();} <Fs-3(V+\
} _,6f#t
,}xbAA#
P6Bl *@G
//读取保存的下载信息（文件指针位置） 9Q W&$n^
private void read_nPos() kC$&:\Rh
{ (#q<\`
try{ 4R>zPEo
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); o2-@o= F
int nCount = input.readInt(); }a&mY^
nStartPos = new long[nCount]; R7~Yw*#,
nEndPos = new long[nCount]; 5&CDHc7Oj
for(int i=0;i<nStartPos.length;i++) rZ_>`}O2
{ VohhQ
nStartPos = input.readLong(); kllQca|$4
nEndPos = input.readLong(); /?"8-0d
} JO@Bf
input.close(); O`cu_
} TO;.eN!sv
catch(IOException e){e.printStackTrace ();} RV-hIdAU
catch(Exception e){e.printStackTrace ();} ? 81X
} ,pq{& A
Wv!<bT8r
N0n^L|(R
private void processErrorCode(int nErrorCode) /T0nLp`gi
{ K#K\-TR|$
System.err.println("Error Code : " + nErrorCode); #>@z 2K7
} v_PdOp[ k
lf>nbvp
AF4?IH
//停止文件下载 A1cb"N^
public void siteStop() tPHS98y
{ 1'6cGpZY
bStop = true; ZF#Rej?
for(int i=0;i<nStartPos.length;i++) o%M<-l"!/
fileSplitterFetch.splitterStop(); Bk|K%K
Jx-wO/
WVkR56
} <c,~aq#W'
} tUE'K.-
//负责部分文件的抓取 ]*%+H|l
**FileSplitterFetch.java ~3WL)%
*/ z&nZ<ih
package NetFox; icUT<@0
*QE<zt
Z&!!]"I
import java.io.*; j?(!^ _!m
import java.net.*; sCH)gr@gJ^
v.Ogf5
H D/5!d
public class FileSplitterFetch extends Thread { FQeYx-7
XOb}<y)r~
^9"KTZc-*
String sURL; //File URL E\)eu1Hw4B
long nStartPos; //File Snippet Start Position Mxz,wfaH>
long nEndPos; //File Snippet End Position UWG+#,1J.\
int nThreadID; //Thread's ID Kf7WcJ4b
boolean bDownOver = false; //Downing is over =N.!k Vkl
boolean bStop = false; //Stop identical sDiHXDI_m
FileAccessI fileAccessI = null; //File Access interface FT\?:wpKa
((DzUyK
X=p"5hhfn
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException c^I0y!
{ #]KgUc5B
this.sURL = sURL; 9\O(n>
this.nStartPos = nStart; ,8K'F
this.nEndPos = nEnd; 3" Vd==oK~
nThreadID = id; ,axDMMDI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _Sj}~H
} ;q#]-^
32XS`Z
^nDal':*
public void run() OOy}]uYF`
{ gp< =Gmd
while(nStartPos < nEndPos && !bStop) Jj"HpK>[
{ hol<dB
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try{ 9zKBO* p`
URL url = new URL(sURL); O+.*lo
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z>A{i?#m
httpConnection.setRequestProperty("User-Agent","NetFox"); -$4kBYC l+
String sProperty = "bytes="+nStartPos+"-"; 3(lVmfk
httpConnection.setRequestProperty("RANGE",sProperty); W"(u^}
Utility.log(sProperty); y8s=\`~PR
^7XAw: ?
}Zl"9A#K
InputStream input = httpConnection.getInputStream(); Px4/O~bLk
//logResponseHead(httpConnection); oNRG25
z-u?s`k**
v|+5:jFOqb
byte[] b = new byte[1024]; F&@|M(
int nRead; ]A:(L9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) K84&sSi
{ o)]FtL:mm
nStartPos += fileAccessI.write(b,0,nRead); 6}&^=^-
//if(nThreadID == 1) Enj_tJs
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2cnj@E:5l
} |4SW[>WT:
&IQ%\W#aY
fGu!M9qN4
Utility.log("Thread " + nThreadID + " is over!"); f$D@*33ft
bDownOver = true; e@ oWwhpE
//nPos = fileAccessI.write (b,0,nRead); *6*-WV6
} @FX{M..
catch(Exception e){e.printStackTrace ();} ju{%'D!d9
} RV!<?[
} -0|K,k
W);W.:F
cC6z,0`3
//打印回应的头信息 eqFvrESN~=
public void logResponseHead(HttpURLConnection con) ePA;:8)_j
{ G(OFr2M
for(int i=1;;i++) z\Ui8jo:;
{ 9O >z4o
String header=con.getHeaderFieldKey(i); i>GdRG&q
if(header!=null) T\3[F%?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); sc xLB;
Utility.log(header+" : "+con.getHeaderField(header)); ?y_awoBd1
else 6"%qv`.Fp
break; BlaJl[Piv
} B7 c[4
} .Ty,_3+{#p
Vipp /WV
~%P3Pp
public void splitterStop() ;X7i/DQ
{ j.& ;c'V$.
bStop = true; >h7$v~nra
} SfDQ;1?
VK4/82@5
TG]}X\c+V|
} Kq7C0)23
3j&B(aLy
Tk+DPp^
/* $c9=mjwH
**FileAccess.java )>$^wT
*//文件访问(定位，写) ,>S+-L8
package NetFox; 9.-47|-9C
import java.io.*; x u,htx
wP`sXPSmIu
UPO^V:.R4
public class FileAccessI implements Serializable{ ysth{[<5F3
5B|,S1b
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2FT-}w0;
RandomAccessFile oSavedFile; 3Uo]>BG
long nPos; ZYKd
G+C}<S}
n_;S2KM
public FileAccessI() throws IOException ,aO@.<"
{ y< ud('D
this("",0); msG3~@q
} j0?>w{e
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public FileAccessI(String sName,long nPos) throws IOException /s8/q2:
{ MCd F!{
oSavedFile = new RandomAccessFile(sName,"rw"); i* gKtjx
this.nPos = nPos; "aA_(Ydzj
oSavedFile.seek(nPos); Xq%*#)M;
} -pX|U~a[
jJ-d/"(
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public synchronized int write(byte[] b,int nStart,int nLen) oT!/J
{ :p$EiR
int n = -1; D"`[6EN[
try{ ]umZJZ#Y
oSavedFile.write(b,nStart,nLen); *o2#eI
n = nLen; -fQX4'3R
} 4@/z
catch(IOException e) $owb3g(%4
{ %09*l%,;
e.printStackTrace (); )-)pYRlO
} ,5:![
' 3VqkQ4
PC0HH
return n; O(Td:Zdp
} OaNc9c"
<vLdBfw&N
i :EO(`
} c _p[yS
ooDdV >
#!1IP~
/* IadK@?X6j
**SiteInfoBean.java ;YM]K R;
*/ ex=)H%_|
package NetFox; 1^tSn#j
zM\IKo_"
)1K! [W}t
public class SiteInfoBean { H}a)^90_
)Oo2<:"
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private String sSiteURL; //Site's URL pd7O`.3
private String sFilePath; //Saved File's Path t#{x?cF
private String sFileName; //Saved File's Name e@yx}:]h
private int nSplitter; //Count of Splited Downloading File )5'rw<:="
]*a@*0=
_ flgQ
public SiteInfoBean() i<Q& D\Pv
{//nSplitter的缺省值为5 OMi02tSm
//default value of nSplitter is 5 mDlCt_h
this("","","",5); W0U`Kt&~a
} /t$*W\PL@
niQ+EAD
i<bxc
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) B#Qpd7E+*
{ r:.6"VQu}
sSiteURL= sURL; U(P:Je
sFilePath = sPath; Z$1.^H.Db
sFileName = sName; I}rGx
this.nSplitter = nSpiltter; h&q=I.3O|?
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wFp~
} ` %l&zwj>
f@h2;An$w
['?^>jfr
public String getSSiteURL() 48:liR
{ xSdN5RN
return sSiteURL; K_Z+]]$#
} Z~:/#?/
@|E;}:?u
R !Fx)xj
public void setSSiteURL(String value) ZRX^^yN
{ F68},N>vr@
sSiteURL = value; /G{&[X<4U
} 8NxUx+]
4bPqmEE
Kq8(d`g}
public String getSFilePath() sC!1B6:
{ >,kL p|gA
return sFilePath; bG"6pU
} KUlB2Fqi
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{qY3L8b
public void setSFilePath(String value) ?<Z)*CF)
{ A\Lr<{Jh
sFilePath = value; H]VsOr
} V/@[%w=
fYb KmB
<=$rU232}
public String getSFileName() $^] 9
{ VtD@&N
return sFileName; D7EXqo
} K<RmaXZ
0BT;"B1
)o86lH"z
public void setSFileName(String value) P_kaIPP
{ f%vHx,
sFileName = value; =_K%$y*
} IES41y<
8y-e+
*iPs4Es-
public int getNSplitter() ,:c:6Y^
{ gkSGRshf
return nSplitter; LQ~LB'L
} 9cl{hdP{
Z@<q/2).|
}m9S(Wal
public void setNSplitter(int nCount) f:n]Exsy
{ _e;N'DZ
nSplitter = nCount; O\LjtMF
} mipi]*ZfXE
} FAH[5VDr%
"ugX /r$_
5JO[+>
/* zC<'fT/rG
**Utility.java M|1eqR%x-?
*/ N5[_a/
package NetFox; ~l;yr @
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s4!|v`+$M
public class Utility { nrxjN(9V%+
#&;m<%
cjCE3V9X
public Utility() zG&WWc`K
{ [6Uudiw
QWU5-p9e8
bv.EM
} ON:LPf>"-
8yY"x ['
//线程睡眠 71K\.[ =-
public static void sleep(int nSecond) Q,[rrG;?@
{ }~7H2d);-
try{ R tXF
Thread.sleep(nSecond); }T?i%l
} >:3xi{
catch(Exception e) e-nWD
{ ##SLwrg
e.printStackTrace (); $xKg }cO
} i n[n Aa
} 9itdRa==
dL1~]Z y
//日志 _Ym&UY.u#
public static void log(String sMsg) dM);LT8@
{ M>`?m L
System.err.println(sMsg); Hj}g1"RA
} MsN2A6|33
Z\ "Kd
?AqrlR]5
public static void log(int sMsg) BZ]&uD|f
{ @t{{Q1
System.err.println(sMsg); yVbg,q'?
} @ef//G+Z"
} |NphG|
~EM#Hc,
=Bcux8wA#6
/* jldcvW
**TestMethod.java yb@X*PW/z
*/ SL?%/$2g=O
package NetFox; }'@tA")-)
*#X+Gngo
I v 80,hW
public class TestMethod { z|t.y.JX
}w|=c>'_}
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public TestMethod() :epitpJ
{ ///xx/weblogic60b2_win.exe e8WPV
try{ +lY\r +;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :Su5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); OF<[Nh\.
SiteFileFetch fileFetch = new SiteFileFetch(bean); -y7l?N5F>
fileFetch.start(); ex;Yn{4
} s+OvS9et_
catch(Exception e){e.printStackTrace ();} NKIkd
.HH,l
S4@117z5
} ~|$) 1
$=;bccIob
%j 9vX$Hj
public static void main(String[] args) W#oEF/G
{ ;DT"S{"7
new TestMethod(); >o=axZNa
} (_s!,QUe
} D9@<#2-
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