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)); bRfac/:}
} o4\\q66K
for(int i=0;i<nEndPos.length-1;i++) S sGb;
{ 6||zfH
nEndPos = nStartPos[i+1]; k_/*>lIZY
} 'de&9\
nEndPos[nEndPos.length-1] = nFileLength; K>N\U@@8i
} 0EKi?vP@y7
} k`_sKr]9
;M1#M:
+9<"Y6
//启动子线程 $mgW|TBXCQ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~5q1zr)E
for(int i=0;i<nStartPos.length;i++) yX0nyhq
{ *%E4,(T
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Kejp7okb
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), wQEsq<
nStartPos,nEndPos,i); d)1 d0ES
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); SFv'qDA
fileSplitterFetch.start(); 3f@@|vZF
} |6v $!wBi
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A+de;&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @>cz$##`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", UQc!"D
nEndPos = " + nFileLength); FC@h6\+a
// fileSplitterFetch[nPos.length-1].start(); ?(0=+o(`
qILb>#
C3)*Mn3%P
//等待子线程结束 xhK8Q
//int count = 0; XXPn)kmWR
//是否结束while循环 +saXN6
boolean breakWhile = false; ;-#2p^
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FUzN}"\1
while(!bStop) t-B5,,`
{ \2)D
write_nPos(); n+MWny
Utility.sleep(500); +fS<YT
breakWhile = true; <-;/,uu
,cE yV74
`,QcOkvbC
for(int i=0;i<nStartPos.length;i++) _t&`T
{ %e^GfZ
if(!fileSplitterFetch.bDownOver) 0v+-yEkw
{ l0 =[MXM4
breakWhile = false; }@x!r=O)I
break; mX 3p
} >m]LV}">O
} ;`Nh@*_
if(breakWhile) h?[|1.lJx(
break; ~-R%m
mC2K &'[
~(nc<M[
//count++; 76H>ST@G|
//if(count>4) 7-:R{&3Lm:
// siteStop(); l^F ?^kP
} dq,j?~ _}
Yw] 7@
v{d$DZUs
System.err.println("文件下载结束！"); J-#V_TzJ?
} NNt n
catch(Exception e){e.printStackTrace ();} i/j53towe
} CRBj>
Z<^;Ybw{`Z
w=pr?jt1:
//获得文件长度 FFa =/XB"
public long getFileSize() TZ *>MySiF
{ ] # VHx
int nFileLength = -1; @A4$k dJ2
try{ <O5WY37"q
URL url = new URL(siteInfoBean.getSSiteURL()); sSd/\Ap
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w4(L@1
httpConnection.setRequestProperty("User-Agent","NetFox"); FA%_jM
E\|nP~;~F9
+F-EgF+J
int responseCode=httpConnection.getResponseCode(); t0+i]lr
if(responseCode>=400) KL9k9|!p
{ Kci. ,I
processErrorCode(responseCode); WQ{[q" O
return -2; //-2 represent access is error `78Bv>[A
} z/u^
8N%nG( 0
W1 k]P.
String sHeader; Z\?2"4H
;$WHTO(
nl qn:[BU
for(int i=1;;i++) x-"8V(
{ 1W\E`)Z}]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); m>%b4M
//Utility.log(in.readLine()); !$A/.;0$
sHeader=httpConnection.getHeaderFieldKey(i); MB!9tju
if(sHeader!=null) zcKQD)]
{ Q_U.J0
if(sHeader.equals("Content-Length")) baBBn%_V
{ W#S82
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); l%T4:p4e
break; RWc<CQcL"
} Hs*["zFc
} In?=$_p
else ;I&VpAPx
break; Nai5!_'
} ?u|@,tQ[
} CJ* D
catch(IOException e){e.printStackTrace ();} _Z23lF9
catch(Exception e){e.printStackTrace ();} $c9-Q+pZ
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>~SS^I0
Utility.log(nFileLength); r/2= nE
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7~SwNt,
return nFileLength; `PC9t)%.pV
} CmZayV
L.Qz29\
CuWJai:nQ;
//保存下载信息（文件指针位置） |@vkQ
private void write_nPos() CZ<T@k
{ HR}O:2'
try{ DsejZ&
output = new DataOutputStream(new FileOutputStream(tmpFile)); lG}#K^q
output.writeInt(nStartPos.length); H/c (m|KK
for(int i=0;i<nStartPos.length;i++) -}#HaL#'K
{ hbJ>GSoZ,
// output.writeLong(nPos); z5kAf~A
output.writeLong(fileSplitterFetch.nStartPos); }5-w,m{8/
output.writeLong(fileSplitterFetch.nEndPos); nN\H'{Wzd
} 9@lWI
output.close(); KNUK]i&L
} JVYH b 60Z
catch(IOException e){e.printStackTrace ();} ;f=m+QXU
catch(Exception e){e.printStackTrace ();} Ho>Np&
} xWxc1tT`
93>4n\
HeOdCr-PN
//读取保存的下载信息（文件指针位置） D5TDg\E
private void read_nPos() c2y,zq|H
{ r3W3;L
try{ K]hp-QK<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $"r9U|6kk
int nCount = input.readInt(); )th[fUC(
nStartPos = new long[nCount]; Q?#I{l)V(
nEndPos = new long[nCount]; J;C:nE|V
for(int i=0;i<nStartPos.length;i++) uh)S;3|
{ >2'"}np*
nStartPos = input.readLong(); w G%W{T$
nEndPos = input.readLong(); ;V xRaj?
} TmsIyDcD~
input.close(); cJ;Nh>ey
} k, HC"?K
catch(IOException e){e.printStackTrace ();} X2z<cJG|d@
catch(Exception e){e.printStackTrace ();} *.DC(2:o!
} *yu}e)(0
0NXH449I=
mQj=-\p
private void processErrorCode(int nErrorCode) }yz>(Pq
{ V ~C$|+>e
System.err.println("Error Code : " + nErrorCode); *\sPHz.
} ;2p+i/sVj
D|N4X`T`
.Q{RTp
//停止文件下载 Bqq=2lj
public void siteStop() an"&'D}U
{ Zh=arlk
bStop = true; S#7YJ7 K"N
for(int i=0;i<nStartPos.length;i++) 558P"w0"X
fileSplitterFetch.splitterStop(); d$zJLgkA
4:`D3
\^x{NV@v42
} xN1P#
} O G`8::S
//负责部分文件的抓取 ]~({;;3o-
**FileSplitterFetch.java m`/Nl<
*/ L*6'u17y
package NetFox; rbZbj#
@5Xo2}o-Q
=V^-@ji)b
import java.io.*; l8\UO<^fY
import java.net.*; \|]mClj#
N3%X>*'
2 !s&|lI
public class FileSplitterFetch extends Thread { %rzPh<>e
k }=<51c
kZ40a\9 Ye
String sURL; //File URL b 7UJ
long nStartPos; //File Snippet Start Position z p E|
long nEndPos; //File Snippet End Position apvcWF%
int nThreadID; //Thread's ID T] zEcx+e
boolean bDownOver = false; //Downing is over %FO{:@CH
boolean bStop = false; //Stop identical r|Ui1f5
FileAccessI fileAccessI = null; //File Access interface (}: s[cs
P@{x@9kI
b)LT[>f
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException L:z0cvn"
{ d1b]+AG4
this.sURL = sURL; ;cor\R
this.nStartPos = nStart; =!q% 1mP
this.nEndPos = nEnd; |>.Q U3
nThreadID = id; oQ$yr^M
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p0+^wXi)
} bSB%hFp=Cp
SmRlZ!%e
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public void run() 6Sr]<I +:
{ fab'\|Y
while(nStartPos < nEndPos && !bStop) 3H,E8>Vd
{ jvzioFCt
W(,j2pU
3/G^V'Yu
try{ }>A q<1%
URL url = new URL(sURL); ]<;,HGO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); );5o13h2
httpConnection.setRequestProperty("User-Agent","NetFox"); $#Pxf
String sProperty = "bytes="+nStartPos+"-"; ~>2uRjvkwB
httpConnection.setRequestProperty("RANGE",sProperty); k3~9;Z
Utility.log(sProperty); &m5zd$6
U7r8FLl
E5k)~P`|
InputStream input = httpConnection.getInputStream(); z _!ut
//logResponseHead(httpConnection); TdtV (
swKkY`g
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byte[] b = new byte[1024]; g3R(,IH
int nRead; ^Q6J$"Tj
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) N]<(cG&p
{ (3#PKfY+
nStartPos += fileAccessI.write(b,0,nRead); 5KCB^`|b>t
//if(nThreadID == 1) &V"oJ}M/a
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !X>u.}?g
} e+ xQ\LH
V Z(/g"9
YOCEEh?
Utility.log("Thread " + nThreadID + " is over!"); $.G 7Vt
bDownOver = true; 9U8M|W|d
//nPos = fileAccessI.write (b,0,nRead); S,Y|;p<+^
} c}(WniR-"
catch(Exception e){e.printStackTrace ();} *@U{[J
} K,b M9>}
} 3DU1c?M:
Ndmt$(b
Z>[7#;;
//打印回应的头信息 2*#|t: (c
public void logResponseHead(HttpURLConnection con) f5jl$H.
{ +mQ5\14#
for(int i=1;;i++) =L6#=7hcl
{ Bo 35L:r|
String header=con.getHeaderFieldKey(i); L@}PW)#
if(header!=null) 7)66e
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0-2|(9 Kc
Utility.log(header+" : "+con.getHeaderField(header)); b}e1JPk}!
else h$cm:uks
break; R4?>C-;
} $a(-r-_Fi]
} Zk3Pv0c
sZ;|NAx)
D6 B-#u!M
public void splitterStop() mxc)Wm<4
{ ys_2?uv
bStop = true; Nw;qJ58@
} 1{}p_"s>
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SI(f&T(
} |,8z"g
-<iP$,bq72
@[GV0*yz$
/* 6j#JhcS+
**FileAccess.java d2\!tJm
*//文件访问(定位，写) >{#JIG.
package NetFox; %#6@PQ[R.
import java.io.*; fFQ|dE;cF
K$E3RB_F
"oP^2|${
public class FileAccessI implements Serializable{ z;OYPGvkw
Rr) 5[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +WX/4_STV
RandomAccessFile oSavedFile; }gp@0ri%5
long nPos; B(Sy.n
[&x9<f6
`lhw*{3A
public FileAccessI() throws IOException AGBV7Kk
{ G0FzXtu)q
this("",0); %mI0*YRma
} 'yo@5*x7
iFI74COam
#]#9Xq
public FileAccessI(String sName,long nPos) throws IOException x*7@b8J
{ Q>niJ'7WF
oSavedFile = new RandomAccessFile(sName,"rw"); j,IRUx13f
this.nPos = nPos; Hv,|XE@Y
oSavedFile.seek(nPos); Ufr@j` *
} ~.a"jYb7A}
ggso9ZlLu+
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public synchronized int write(byte[] b,int nStart,int nLen) 4GYi'
{ 1 ZdB6U0
int n = -1; %6K7uvTq
try{ t)SZ2G1r
oSavedFile.write(b,nStart,nLen); |IxHtg3>6{
n = nLen; OL'Ito
} P.~UUS
catch(IOException e) =8FvkNr
{ W4$o\yA]
e.printStackTrace (); n#_B4UqW%
} u{1R=ML
Ky3mzw|
2& Q\W
return n; WMbkKC.{J
} qF)J#$4;6
u?').c4
awLvLkQb{
} pEyZH!W
I&PJ[U#~a
[4KQcmJc#
/* u@a){A(P
**SiteInfoBean.java y\Wn:RR1[
*/ _H]\
package NetFox; @T1G#[C~t
"Ih3
UpoSC
public class SiteInfoBean { -@Ap;,=
GwWK'F'2
d0J/"<
private String sSiteURL; //Site's URL B-I4(w($
private String sFilePath; //Saved File's Path .)E#*kLWR
private String sFileName; //Saved File's Name L!f~Am:#
private int nSplitter; //Count of Splited Downloading File vHaM yA-
Bfb~<rs[
.1QGNW
public SiteInfoBean() ,0'GHQWz$
{//nSplitter的缺省值为5 %G?@Hye3
//default value of nSplitter is 5 gC7!cn
this("","","",5); `Fqth^RK?p
} G':3U
5Ds[?
[@$ SLl^Y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]:%DDlRb
{ ?G{0{c2
sSiteURL= sURL; >t+ ENYb
sFilePath = sPath; &61U1"&$R
sFileName = sName; lZzW- %K
this.nSplitter = nSpiltter; )@]%:m!ER
7w )?s@CD
d<c29Y
} Omd;
ss^a=?~
.G/Rh92
public String getSSiteURL() ~!uX"F8Xl
{ +.cpZqWn3
return sSiteURL; }n)0}U5;0
} fy+5i^{=
g-3^</_fZ
+'F;\E
public void setSSiteURL(String value) Ir;JYY!0?
{ Lg4|6.Ez|P
sSiteURL = value; /R&`]9].s
} !Uiq3s`1T
?XKX&ws
O:BdZ5 b
public String getSFilePath() qI'pjTMDY
{ (Jp~=6&lKf
return sFilePath; @ZEBtM%.O
} =DwLNyjU4
YNr5*P1
N:G]wsh
public void setSFilePath(String value) 082}=Tsx
{ Xj, %t}
sFilePath = value; We6eAP/Z
} ED0cnr\yG
:.PA(97xb
V#G)w~
public String getSFileName() <4{m99
{ z|s(D<*w
return sFileName; WcmX"{
} ^y,h0?Z9
aEf3hB*~
fW= N
public void setSFileName(String value) p22AH%
{ Q#MB=:0{
sFileName = value; LhG\)>Y%
} {S0-y
av'DyNW\
~[=<Os
public int getNSplitter() S1|5+PPs
{ $f@YQN=
return nSplitter; ?N4FB*x
} zJXK:/
2poo@]M/
}u#3hYa
public void setNSplitter(int nCount) Jp jHbG
{ d&3"?2IQ
nSplitter = nCount; [aSuEu?mC
} @x `X|>&
} y;o - @]
2ZxhV4\
1zRYd`IPoq
/* [%k8l~ 6
**Utility.java si&du
*/ #WjQ'c:
package NetFox; $:I{
?j&hG|W9<z
<zCWLj3
public class Utility { 9!AvsC9
_l{~O
|GMo"[
public Utility() G=y~)B}
{ }NDl~5
2G.y.#W
_DxHJl
} cs6oD!h
ti61&)(
//线程睡眠 0"7+;(\1Rk
public static void sleep(int nSecond) 2hV -h
{ ?|,:;^2l1
try{ :uo)-9_
Thread.sleep(nSecond); =`x }9|[
} /mwUDf6x
catch(Exception e) b |:Y3_>
{ "{8j!+]4i
e.printStackTrace (); JuZkE9C,${
} Mbc&))A
} -sJ1q^;f@
!aSj1 2J
//日志 Oj-\
public static void log(String sMsg) ?Uq"zq
{ ;6@sC[
System.err.println(sMsg); HGAi2+&
} s(py7{ ^K
'goKYl#1Q
{|>'(iqH"w
public static void log(int sMsg) +yI$4MY
{ Muwlehuq
System.err.println(sMsg); Cu`
} # fqrZ9:@
} TG;[,oa
Q z(n41@`
kNK0KL
/* A6[FH\f
**TestMethod.java 3IRur,|'
*/ /"J 6``MV
package NetFox; NCh-BinK@
;8oe-xS\+
X$KTsG*
public class TestMethod { %|JiFDjp
JPF6zzl)
*rTg>)
public TestMethod() &|Wqzdo?#
{ ///xx/weblogic60b2_win.exe tN<X3$aN
try{ /=YNkw5
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "gy&eR>
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); cFc(HADM`r
SiteFileFetch fileFetch = new SiteFileFetch(bean); (rFiHv5
fileFetch.start(); 6D Xja_lp
} S'5)K
catch(Exception e){e.printStackTrace ();} /e"iYF
WzstO}?P(
,KJHYm=Q
} ^mn!;nu
0GxJja
;N#}3lpLqg
public static void main(String[] args) g"748LY>=p
{ T; tY7;<
new TestMethod(); N&
} 7;|"1H:cmw
} >3p~>;9sc
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