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)); f1hi\p0q
} VH,k EbJ
for(int i=0;i<nEndPos.length-1;i++) DU]MMR
{ G\Toi98d*
nEndPos = nStartPos[i+1]; B58H7NH ;G
} /Eh\07p
nEndPos[nEndPos.length-1] = nFileLength; )0fQ(3oOg
} peR=J7
} .Eh~$wm
k;;?3)!
zUIh8cAoE
//启动子线程 ZUAWSJ,s
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; sB-c'`,w`
for(int i=0;i<nStartPos.length;i++) 0ydAdgD
{ eey <:n/Z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yTkYPx
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), bN<c5
nStartPos,nEndPos,i); d7$H})[^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T*-*U/
fileSplitterFetch.start(); @\u)k
} %jKR\f G
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3,3{wGvHHW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /=,^fCCN
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", roj/GZAy"
nEndPos = " + nFileLength); <MA!?7Z|
// fileSplitterFetch[nPos.length-1].start(); (RWZ[-;)
V*U"OJ%
6:ZqS~-
//等待子线程结束 w v9s{I{P
//int count = 0; e%(zjCA
//是否结束while循环 ~9h6"0K!
boolean breakWhile = false; sjWhtd[fgG
2"yzrwZ:
D#W{:_f
while(!bStop) n_.2B$JD
{ 8[(c'rl|)|
write_nPos(); s2b!Nib
Utility.sleep(500); ?n\~&n'C
breakWhile = true; @<W"$_r-
K]N^6ome
6\OSIxJZF
for(int i=0;i<nStartPos.length;i++) &"Ua"H)
{ s3/->1#i
if(!fileSplitterFetch.bDownOver) P]]9Sqo7
{ Qn[4&nUD
breakWhile = false; qECc[)B
break; onG,N1`+
} (}gF{@sn
} dm)V \?b
if(breakWhile) a%Mbq;
break; ,Xo9gn
zRsT6u
FspI[gUN,
//count++; J);1Tpm
//if(count>4) Rk2ZdNc\
// siteStop(); \EUc17
} A9p$5jt7
c c ,]
:==kC672
System.err.println("文件下载结束！"); ]bhzB
} 5(2g*I
catch(Exception e){e.printStackTrace ();} I;uZ/cZ|/
} e>uV8!u
&tLg}7?iB
s:jr/ j!
//获得文件长度 !i.`m-J*
public long getFileSize() 7bQ#M )}
{ #9#N+
int nFileLength = -1; PrDvRWM
try{ ZKAIG=l&!
URL url = new URL(siteInfoBean.getSSiteURL()); q fadsVp
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); at6f(+
httpConnection.setRequestProperty("User-Agent","NetFox"); }1N)3~
`@")R-
s-*8=
int responseCode=httpConnection.getResponseCode(); YPf&y"E&H
if(responseCode>=400) %DgU
{ 8 6?D
processErrorCode(responseCode); eZI&d;i
return -2; //-2 represent access is error }P-9\*hlm
} ,Y &Q,
JQQD~J1)E
1 (P>TH
String sHeader; vb5tyY0c
`r+e!o
v|t^th,
for(int i=1;;i++) rZ w&[ G
{ |Wi$@sWO
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); S%mN6b~{
//Utility.log(in.readLine()); +]`MdOu
sHeader=httpConnection.getHeaderFieldKey(i); _BHb0zeot
if(sHeader!=null) 9.#\GI ;
{ ;=F^G?p^
if(sHeader.equals("Content-Length")) Pt";f
{ n#,AZ&
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Zhz.8W
break; 7!<cU
} Z-Bw?_e_K
} e,`+6qP{
else r}D`15IHJ
break; 1i2jYDB"
} jW?.>(
} t#6gjfIi
catch(IOException e){e.printStackTrace ();} N''9Bt+:
catch(Exception e){e.printStackTrace ();} -;Cl0O%
e|"`W`"-
Y]B2-wt-
Utility.log(nFileLength); l: 1Zq_?v;
,)S|%tDW
~?[%uGI0h
return nFileLength; y5|`B(
} WvUe44&^$
NrNbNFfo
%$!}MxUM
//保存下载信息（文件指针位置） ?G0=\U< o,
private void write_nPos() 1UyI.U]
{ A;Xn#t ,(K
try{ p&:RSO
output = new DataOutputStream(new FileOutputStream(tmpFile)); + :iNoDz
output.writeInt(nStartPos.length); :HMnU37m W
for(int i=0;i<nStartPos.length;i++) A5!f#
{ /3'-+bp^=
// output.writeLong(nPos); uDQ d48>
output.writeLong(fileSplitterFetch.nStartPos); uJF,:}qA
output.writeLong(fileSplitterFetch.nEndPos); HMrS::
} _4xX}Z;
output.close(); Tx`;y|
} "eZNci
catch(IOException e){e.printStackTrace ();} 0&2TeqsLh)
catch(Exception e){e.printStackTrace ();} MFiX8zwhx+
} |v[{k>7f
M:Xswwq
iN<&
//读取保存的下载信息（文件指针位置） pRPz1J$58
private void read_nPos() \96?OCdr
{ D0lgKQ
try{ `:-{8Vo7
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); L*D-RYW
int nCount = input.readInt(); z"=#<C
nStartPos = new long[nCount]; C;G~_if4PR
nEndPos = new long[nCount]; WnvuB.(@3
for(int i=0;i<nStartPos.length;i++) efl6U/'Ij
{ pWO,yxr:
nStartPos = input.readLong(); o*'J8El\y^
nEndPos = input.readLong(); l?pZdAE
} ,DXNq`24
input.close(); &>*fJ
} wu/]M~XwI
catch(IOException e){e.printStackTrace ();} |9~{&<^X
catch(Exception e){e.printStackTrace ();} F1w~f <
} jiC;*]n
daGGgSbh
C8-4 m68"
private void processErrorCode(int nErrorCode) kNd[M =%
{ \m*?5]m;
System.err.println("Error Code : " + nErrorCode); m9wV#Ldu
} mI@E>VCV[
st+X~;PX*
)$#ov-]
//停止文件下载 ;jo,&C
public void siteStop() `:}GE@]
{ |A8xy#
bStop = true; 4F??9o8}
for(int i=0;i<nStartPos.length;i++) )l\BZndf
fileSplitterFetch.splitterStop(); H}dsd=yO
do+HPnfDzU
tceQn ^|<
} 5m=3{lBi
} *&% kkbA
//负责部分文件的抓取 8ooj)
**FileSplitterFetch.java qyP@[8eH
*/ TStu)6%`
package NetFox; TsfOod
P%ev8]2
#J\ 2/~
import java.io.*; b U-Cd
import java.net.*; \3O#H
[JO'ta
4%KNHeaN
public class FileSplitterFetch extends Thread { 600-e;p
BN|+2D+S
#T99p+O
String sURL; //File URL I}kx;!*b
long nStartPos; //File Snippet Start Position oz(<e
long nEndPos; //File Snippet End Position Y"K7$+5#\
int nThreadID; //Thread's ID dSS_^E[{
boolean bDownOver = false; //Downing is over `Ft.Rwj2:m
boolean bStop = false; //Stop identical BYqDC<Fq
FileAccessI fileAccessI = null; //File Access interface qCc'w8A
4IG'Tm
/H:'(W_b;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,}=x8Xxr
{ @Vr?)_0
this.sURL = sURL; Hh(_sewo
this.nStartPos = nStart; /IxMRi=
this.nEndPos = nEnd; 4["$}O5
nThreadID = id; qg 4:Vq
fileAccessI = new FileAccessI(sName,nStartPos);//定位 l$}h1&V7
} CD +,&id
I8Y[d$z
2(\~z@g
public void run() CGbW]D$@
{ `-hFk88
while(nStartPos < nEndPos && !bStop) VWI|`O.w
{ "o*F$7D!
>wNE!Oa*B
L@_IGH
try{ q-KN{y/
URL url = new URL(sURL); P2_JS]>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lo,?mj%M
httpConnection.setRequestProperty("User-Agent","NetFox"); Q6`oo/
String sProperty = "bytes="+nStartPos+"-"; ^;Nu\c
httpConnection.setRequestProperty("RANGE",sProperty); QNLkj`PL/
Utility.log(sProperty); vh"zYl`
>Yl?i&3n
'%. lY9D
InputStream input = httpConnection.getInputStream(); !}9k @=[
//logResponseHead(httpConnection); I%h9V([
HH&`f3
W=M]1hy
byte[] b = new byte[1024]; KA0Ui,q3
int nRead; w[^s)1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1,p7Sl^h
{ |>gya&
nStartPos += fileAccessI.write(b,0,nRead); ^+Ie
//if(nThreadID == 1) #VgPg5k.<
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Dr^#e
} +#"CgZ]
[;7&E{,C
$A`D p{e"
Utility.log("Thread " + nThreadID + " is over!"); Xjt/ G):L
bDownOver = true; =nh/w#
//nPos = fileAccessI.write (b,0,nRead); &y[Od{=
} j="{^b
catch(Exception e){e.printStackTrace ();} *T$`5|
} +?),BRCce
} DBWe>Ef(
m*6C *M
+t({:>E
//打印回应的头信息 Ko]A}v\]
public void logResponseHead(HttpURLConnection con) jqPQ=X
{ ]E .+)>
for(int i=1;;i++) 8`EzvEm
{ $VvL
String header=con.getHeaderFieldKey(i); JQP7>W
if(header!=null) ?\L@Pr|=Dr
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~c%H3e>Jcq
Utility.log(header+" : "+con.getHeaderField(header)); -fI-d1@
else L~%@pf>
break; zqh.U@
} (|(#~o]40t
} _Jn-#du
T\eOrWt/
>V2Tr$m j
public void splitterStop() +/'3=!oyd
{ UiqHUrx
bStop = true; oyZ}JTl(Q
} OGw =e{
IP~*_R"bM
]x8^s
} AifnC4
I'{-T=R-q
l~kxt2&
/* (, Il>cR4
**FileAccess.java p&/}0eL y
*//文件访问(定位，写) I,OEor6%R(
package NetFox; L=nyloz,0
import java.io.*; LE%3.. !
4:GVZR|-
|_@ '_
public class FileAccessI implements Serializable{ 5(R ./
1K.i>]}>
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Q%o:*(x[O
RandomAccessFile oSavedFile; *~~ >?
long nPos; u )cc
o(Yj[:+m
T$RVz
public FileAccessI() throws IOException -$WU-7`
{ 59A@~;.F
this("",0); -\O%f)R
} H3"90^|,@
B~K@o.%
1|_jV7`Mz
public FileAccessI(String sName,long nPos) throws IOException jHBzZ!<
{ r8x<-u4
oSavedFile = new RandomAccessFile(sName,"rw"); x?v/|
this.nPos = nPos; Z+!._uA
oSavedFile.seek(nPos); %;$zR}
} 8R<2I1xn2
;L (dmx?
MwMv[];I
public synchronized int write(byte[] b,int nStart,int nLen) ^}vLZA
{ Q^}6GS$
int n = -1; 9aky+
try{ [+<lm 5t
oSavedFile.write(b,nStart,nLen); f mu `o-
n = nLen; FMMQO,BU
} .G8+D%%.
catch(IOException e) ANh7`AUuO
{ wPdp!h7B~N
e.printStackTrace (); [9dW9[Z+!
} ,$BbJQ5
O}5mDx
{}!`v%z
return n; &Jw]3U5J
} -8H0f-1
(`<X9w,
f'._{"
} w ryjs!
M|IR7OtLV
VX#4Gh,~N
/* faH113nc
**SiteInfoBean.java fR[kjwX)<1
*/ naE;f)
package NetFox; sTeW4Hnp
SKO*x^"eU
,?s3%<\2
public class SiteInfoBean { $*a'[Qot#
80=6B
(ns>z7
private String sSiteURL; //Site's URL do0;"O0 (
private String sFilePath; //Saved File's Path |]FJfMX
private String sFileName; //Saved File's Name pV`?=[h9
private int nSplitter; //Count of Splited Downloading File MD`1KC_m
Ovu!G q
[AgS@^"sf5
public SiteInfoBean() 6bj.z
{//nSplitter的缺省值为5 GddP)l{uCF
//default value of nSplitter is 5 gYb}<[O!
this("","","",5); kex4U6&OQB
} ?VVtEmIN
7S+_eL^
_4H 9rPhf
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Reci:T(_
{ a?&{eMEe}
sSiteURL= sURL; }s i{
sFilePath = sPath; &,~0*&r0
sFileName = sName; <*I%U]
this.nSplitter = nSpiltter; ^=kUNyY
HjG!pO{
l!UF`C0g
} \Nd8,hE
hbfTv;=z
+JQ/DNv
public String getSSiteURL() 24;F~y8H
{ ]!l]^/.
return sSiteURL; Y*oT(
} H$GJpXIb
-U'3kaX5<
:f1Q0klwP
public void setSSiteURL(String value) v8=7
{ ,D#ssxV
sSiteURL = value; ="X2AuK%1$
} Z*,Nt6;e
mWhQds6
'L$%)`;e
public String getSFilePath() w=]id'`?q
{ yffg_^fR
return sFilePath; @0js=3!2
} 19V
H\W/;Nn
9UF^h{X
public void setSFilePath(String value) wLX:~]<xl
{ ^Yu<fFn
sFilePath = value; _G9vsi
} oUXi4lsSc
ZY NHVR
p%MH**A
public String getSFileName() /"$A?}V
{ ?"23XKe
return sFileName; + Xc s<+b
} VG,O+I'^z
|Dz$OZP
u7L!&/6On
public void setSFileName(String value) >\J({/ #O
{ O+ ].'
sFileName = value; Pr|:nJs
} $_bhZnYp7
/da5"
?f}lYQzM
public int getNSplitter() POZ5W)F(
{ W ='c+3O6
return nSplitter; *CsRO
} bU3e*Er
8v eG^o
7t8[M(
public void setNSplitter(int nCount) k(<:
{ Sxn#
nSplitter = nCount; 7bC1!x*qw
} ?<_yW#x6
} K chp%
?ykQ]r6a<
tXlo27J
/* 1Z. D3@
**Utility.java 4$HU=]b6Tf
*/ ~3,>TV
package NetFox; .TI=3*`G
8oAr<:.=
$>Y2N5
public class Utility { l'Oz-p.@
2.xA' \M
nu'r`
public Utility() 1=R6||8ws
{ CJn{tP
LYYz =gvZl
=IbDGw(
} `>.^/SGu>?
U^AywE]
//线程睡眠 q\0CS>.
public static void sleep(int nSecond) 4V2}'/|[
{ 2h_XfY'3pX
try{ g>L4N.ZH_v
Thread.sleep(nSecond); Z>9uVBE02
} huPAWlxT
catch(Exception e) aicvu(%EE
{ gL)l)}#
e.printStackTrace (); MM+x}g.?
} 8mrB_B5
} ]g/:lS4
ef !@|2
//日志 {>x6SVF
public static void log(String sMsg) he/WqCZg
{ !xqy6%p
System.err.println(sMsg); NVt612/'7y
} EISgc {s
z' oK 0"
!06 !`LT
public static void log(int sMsg) %A]?5J)Bi
{ E.ugr])
System.err.println(sMsg); bSG}I|
} %3Ba9Nmid
} [9hslk
g?TPRr~$9
MXVQ90
/* pZVT:qFF
**TestMethod.java ][gr(-68
*/ D7X8yv1
package NetFox; &3@{?K
IdHydY1
?.A~O-w
public class TestMethod { HITw{RPrW
){D6E9
V:YN!
public TestMethod() *6C ]CS
{ ///xx/weblogic60b2_win.exe l0 Eh?
try{ ZqONK^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); PU& v{gn
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %oee x1`=
SiteFileFetch fileFetch = new SiteFileFetch(bean); -2D/RE7|
fileFetch.start(); GBh$nVn$
} nfj8z@!
catch(Exception e){e.printStackTrace ();} ls;!Og9
5]c\{G
80'!XKSP
} =yR$^VSY
.=kXO{>
|.ZYY(}
public static void main(String[] args) cs-wqxTX[$
{ ?W27 h
new TestMethod(); /s/\5-U7q
} zUQn*Cio e
} iNlY\67sW
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