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)); W}rLHAaDh
} 4)+L(KyB2
for(int i=0;i<nEndPos.length-1;i++) %w#8t#[,6
{ Rn5{s3?F~2
nEndPos = nStartPos[i+1]; E0aJ~A(Hv
} *4?%Y8;bF6
nEndPos[nEndPos.length-1] = nFileLength; j,CVkA*DY
} \>p\~[cxt
} *!&,)''
<)VNEy'
I.hy"y2&
//启动子线程 -PLh|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; uL9O_a;!
for(int i=0;i<nStartPos.length;i++) F%`O$uXA
{ z-G*:DfgH
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 26[m7\O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1}"Prx-
nStartPos,nEndPos,i); JHCXUT-r{
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (Qj;B)
fileSplitterFetch.start(); `i{p6-U3
} [kL`'yi
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NZ:KJ8ea"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9Je+|+s]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", h$$2(!G4
nEndPos = " + nFileLength); xa$4P [
// fileSplitterFetch[nPos.length-1].start(); e(Y5OTus
I,@ 6w
re@;6o
//等待子线程结束 rYPj3!#
//int count = 0; UB3hC`N\
//是否结束while循环 y?ypRCgO.u
boolean breakWhile = false; :[!b";pR
)kvrQ6
[J +5
while(!bStop) =} flmUv~
{ BT*{&'\/
write_nPos(); a|kEza,]
Utility.sleep(500); 6h{>U*N"&d
breakWhile = true; 8<PQ31
UIK4]cYC'
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for(int i=0;i<nStartPos.length;i++) *IIuGtS
{ qTI_'q
if(!fileSplitterFetch.bDownOver) -$ha@bCWO
{ ^|ul3_'?
breakWhile = false; \JBPZ~N3
break; - sL4tMP
} [BuAJ930#5
} 'W*ODAz6
if(breakWhile) LjPpnjU
break; ChRCsu~
I;+>@Cn(g<
y@9ifFr
//count++; oL -udH
//if(count>4) n |Q'>
// siteStop(); xew s~74L
} U)C>^ !Us
Uu~~-5
/kNSB;
System.err.println("文件下载结束！"); h=ben&m
} /PZxF
catch(Exception e){e.printStackTrace ();} ~=gpn|@b
} |SuN3B4e
51Q~/
q*7:L
//获得文件长度 )uC5
public long getFileSize() f J+
{ "GB493=v
int nFileLength = -1; %OJq(}
try{ |6 E !wW
URL url = new URL(siteInfoBean.getSSiteURL()); <8BNqbX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ah_0o_Di
httpConnection.setRequestProperty("User-Agent","NetFox"); dyVfDF
0`Y"xN`'i
] D+'Ao^'
int responseCode=httpConnection.getResponseCode(); ky I~
if(responseCode>=400) E^? 3P'%^
{ li9>zjz
processErrorCode(responseCode); $Go)Zs-bL?
return -2; //-2 represent access is error d'[]
} <`d;>r=4z
Xk}\-&C7
i Ie{L-Na
String sHeader; @6%o0p9zz
t)hi j&wzu
>r.W \
for(int i=1;;i++) @P/6NMjZ^
{ '1rO&F
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 91M5F$
//Utility.log(in.readLine()); =DwY-Ex
sHeader=httpConnection.getHeaderFieldKey(i); S@cKo&^
if(sHeader!=null) ^1;Eq>u
{ o ^""=Z
if(sHeader.equals("Content-Length")) l!j,9wz7
{ :(#5%6F
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); -YY@[5x?u
break; 2X6L'!=
} e#(X++G
} w]O,xO
else J }|6m9k!
break; > *soc!#Y
} o<Qt<*
} rY295Q
catch(IOException e){e.printStackTrace ();} Zu|qN*N4
catch(Exception e){e.printStackTrace ();} Ww=b{lUD
}A&I@2d
CvRO'
Utility.log(nFileLength); G{gc]7\=Cd
C sCH :>
i0rh{Ko
return nFileLength; F~?|d0
} :*MR$Jf
iC~ll!FA!
"x O+
//保存下载信息（文件指针位置） ~8U0(n:^
private void write_nPos() gl 27&'?E*
{ Z6 E_Y?
try{ SE6c3
output = new DataOutputStream(new FileOutputStream(tmpFile)); \`R8s_S
output.writeInt(nStartPos.length); {_UOS8j7
for(int i=0;i<nStartPos.length;i++) ^Vg-fO]V
{ 1 Q*AQYVY
// output.writeLong(nPos); #@J{ )
output.writeLong(fileSplitterFetch.nStartPos); (e4#9
output.writeLong(fileSplitterFetch.nEndPos); BH0s` K"
} #'BPW<Ob
output.close(); ;*cCaB0u
} jmF)iDvjuZ
catch(IOException e){e.printStackTrace ();} U\-=|gQ'
catch(Exception e){e.printStackTrace ();} E_\V^
} cVli^*se
pj Md
g0#w 4rGF)
//读取保存的下载信息（文件指针位置） Bo8NY!
private void read_nPos() * 'Bu-1{
{ eU\XAN#@
try{ lYS*{i1^ '
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .mplML0oW
int nCount = input.readInt(); wH+| &C
nStartPos = new long[nCount]; >65\
nEndPos = new long[nCount]; A45!hhf
for(int i=0;i<nStartPos.length;i++) a#a n+JY3
{ !\!j?z=O8
nStartPos = input.readLong(); 3Scc"9]
nEndPos = input.readLong(); m .R**g
} W&v|-#7=6
input.close(); t\-|J SZ
} L;v.X'f
catch(IOException e){e.printStackTrace ();} J3$@: S'
catch(Exception e){e.printStackTrace ();} .R)uk
} g]E3+:5dk
*Tr9pq%m
!C ZFbz~:
private void processErrorCode(int nErrorCode) <u/(7H
{ gux?P2f
System.err.println("Error Code : " + nErrorCode); w-3Lw<
} e xkPu-[W
vRH2[{KQ9
nd&i9l
//停止文件下载 i&{%}==7
public void siteStop() Hwcmt!y
{ XSGBC:U)l
bStop = true; 1x8wQ/p|
for(int i=0;i<nStartPos.length;i++) N_/+B]r }T
fileSplitterFetch.splitterStop(); O=6[/oc '
qg:EN~E#
zbgGK7
} d.HcO^
} =}YX I
//负责部分文件的抓取 6"; ITU^v
**FileSplitterFetch.java | ^G38
*/ )S;3WnQ)
package NetFox; MGY0^6yK5
)_Z^oH ]<
HiBI0)N}
import java.io.*; M6GiohI_"P
import java.net.*; zrf tF2U
"Q{l])N
zRbY]dW
public class FileSplitterFetch extends Thread { JKy~'>Q
sPXjU5uq#
Ks<+@.DLTu
String sURL; //File URL ;e< TEs
long nStartPos; //File Snippet Start Position EWQLLH"h
long nEndPos; //File Snippet End Position D$@2H>.-
int nThreadID; //Thread's ID a&UzIFdB
boolean bDownOver = false; //Downing is over 4c[/%e:\-
boolean bStop = false; //Stop identical \+=`o .2
FileAccessI fileAccessI = null; //File Access interface i<):%[Q)>
yDWBrN._
_GrifGU\
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException g>k?03;
{ #Ge_3^'
this.sURL = sURL; w)B?j
this.nStartPos = nStart; y#th&YC_b
this.nEndPos = nEnd; K:GEC-
nThreadID = id; pb)kN%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +k~0&lZi
} - Ry+WS=
>239SyC-,
-/V(Z+dj
public void run() )WInPW
{ F-oe49p5e
while(nStartPos < nEndPos && !bStop) p|8ZHR+
{ EW1,&H
+I3O/=)
>^GV #z
try{ U|VL+9#hd
URL url = new URL(sURL); L`X5\D'X
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j>B*8*Ss
httpConnection.setRequestProperty("User-Agent","NetFox"); _>rM[\|X
String sProperty = "bytes="+nStartPos+"-"; ir"t@"Y;o
httpConnection.setRequestProperty("RANGE",sProperty); nO!&;E&
Utility.log(sProperty); GM?s8yZ<
|cgjn*a?M
m C`*#[
InputStream input = httpConnection.getInputStream(); $;'M8L
//logResponseHead(httpConnection); GZ,MC?W
0y+^{@lU
Mgi~j.[
byte[] b = new byte[1024]; X^K^az&L
int nRead; lWtfcU?S[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {\CWoFht>
{ &(A#F[ =0
nStartPos += fileAccessI.write(b,0,nRead); )GAlj;9A$
//if(nThreadID == 1) Wbei{3~$Y"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y_}vVHT,
} q4&! mDU
s)`(@"{
lwrh4<~\,*
Utility.log("Thread " + nThreadID + " is over!"); ybw\^t
bDownOver = true; )E*f30
//nPos = fileAccessI.write (b,0,nRead); NsP=l]
} PfRA\
catch(Exception e){e.printStackTrace ();} t!*[nfR
} GWWg3z.o"W
} vxTn
$!MP0f\q g
,;Wm>V)o
//打印回应的头信息 B=L!WGl<!
public void logResponseHead(HttpURLConnection con) U4fv$gV
{ 1W{oj
for(int i=1;;i++) \t&! &R#
{ #IvKI+"
String header=con.getHeaderFieldKey(i); 6XF Ufi+
if(header!=null) 2[ofz}k]r)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Eu'E;*-f
Utility.log(header+" : "+con.getHeaderField(header)); vj%"x/TP
else v_EgY2l(
break; $f0u
} cZ|*Zpk
} &qG/\
yuBRYy#E|%
5\C(2naf
public void splitterStop() Tp?IK_
{ |ymW0gh7o$
bStop = true; *3`R W<Z
} x _>1x#
K~,!IU_QG
#o/;du
} Ie/_gz^
9 da=q
hS8M|_
/* #$xtUCqX
**FileAccess.java _>\33V-?b
*//文件访问(定位，写) E> GmFw
package NetFox; /~u^@@.
import java.io.*; mc%. 8i
yO7y`;Q(sF
dxAGO(
public class FileAccessI implements Serializable{ Es7 c2YdU
:XFQ}Cl
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 3WF]%P%
RandomAccessFile oSavedFile; S1Y,5,}
long nPos; Z,2?TT|p
8(Te^] v#
W7WHDL^
public FileAccessI() throws IOException Ebs]]a>PO
{ &,%n
this("",0); 1a(\F7
} a5/, O4Q
wi7Br&bGi
w/o^OjwQ
public FileAccessI(String sName,long nPos) throws IOException Xydx87L/-e
{ ,Ohhl`q(
oSavedFile = new RandomAccessFile(sName,"rw"); y4jiOhF<d
this.nPos = nPos; BedL `[,
oSavedFile.seek(nPos); vw!7f|Pg ~
} k{;?>=FH!
f\cTd/?Ju
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public synchronized int write(byte[] b,int nStart,int nLen) C('D]u$Hdk
{ wsB-( 0-
int n = -1; 9_5>MmiB
try{ J&~I4ko]
oSavedFile.write(b,nStart,nLen); L]z8'n,
n = nLen; s3JzYDpy
} <tbs,lcw;
catch(IOException e) 4h!yh2c..
{ jRC{8^98
e.printStackTrace (); ]lfufjj
} ,0h{RZKw
PU.j(0
h\@X!Z,
return n; {ObY1Y`ea
} n]#YL4j
k8stXW-w
b*h:e.q
} F~eYPaEKy!
83V\O_7j
6)YckxN^
/* &&<l}E
**SiteInfoBean.java G2wSd'n*y
*/ igTs[q=Ak
package NetFox; h& 4#5{=
tE-bHu370
-V2`[k
public class SiteInfoBean { 2<J2#}+\
-2}ons(
YR\(*LJL
private String sSiteURL; //Site's URL Cd^1E]O0{
private String sFilePath; //Saved File's Path x4kQGe(
private String sFileName; //Saved File's Name GL0P&$h
private int nSplitter; //Count of Splited Downloading File U+B{\38
$ZyOBxI
zp9lu B
public SiteInfoBean() ~u0<c:C^
{//nSplitter的缺省值为5 (bI/s'?K
//default value of nSplitter is 5 M<l<n$rYS
this("","","",5); )g8Kicox5
} Xl<*Fn?
;8MQ'#
Qo3Enwap=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -XnIDXM
{ Xajt][
sSiteURL= sURL; R>Ox(MG
sFilePath = sPath; ,\+N}F^
sFileName = sName; XkUwO ]
this.nSplitter = nSpiltter; L"1AC&~u
X<Xiva85
$rQ7"w J
} dlZ2iDQ%
Zonn
"-:g.x*d
public String getSSiteURL() H^o_B1
{ mIrN~)C4\
return sSiteURL; +:aNgO#e8
} ]T5\LNyN
2V; Dn$q
Uv<nJM
public void setSSiteURL(String value) W4P\HM>2
{ *e:I*L
sSiteURL = value; \AI-x$5R*
} /i_FA]Go
fO#nSB/ 8
W%&s$b(
public String getSFilePath() /Trbr]lWy
{ 4%<wxrod
return sFilePath; #_3ZF"[zq
} /={N^8^=x
NTK9`#SA
%)d7iT~M
public void setSFilePath(String value) 3 Sf':N`u
{ LtUw
sFilePath = value; GKUjtPu
} *(wxNsK
:T@} CJ
g%ys|
public String getSFileName() jc!V|w^
{ iW9
return sFileName; nu|,wE!i
} M djxTr^
=l] lwA-
;1_3E2E$
public void setSFileName(String value) F]N?_ bo
{ 9G7Brs:
sFileName = value; b o_`P3
} $Dv5TUKw
Y>8JHoV
Ck m:;q
public int getNSplitter() Ne3YhCC>
{ %'X7T^uE
return nSplitter; WD kE 5
} Cd6th F)
8y[Rwa
k1P'Q&Na
public void setNSplitter(int nCount) pnL[FMc
{ fb[lL7
nSplitter = nCount; XW2ZQMos1
} k3Puq1H
} >xF&>SDC
/74h+.amg
7&]|c?([4
/* H_| re
**Utility.java PAC=LQn&
*/ CQ{{J{pU"
package NetFox; KP>1%ap6
Z@*!0~NH=4
DH i@ujr
public class Utility { !4Sd^"
^;[_CF_
%z.d;[Hs
public Utility() :>H{?
{ JFNjc:4{0
FGm!|iI
cT&lkS
} 6iHY{WcDj
B*tQ0`
//线程睡眠 xwHE,ykE
public static void sleep(int nSecond) Fo~q35uB
{ t56PzT'M
try{ 7A$mZPKh
Thread.sleep(nSecond); 2#/sIu-L
} ,C_MB1u
catch(Exception e) ]ab q$Y'
{ 9q[[ ,R
e.printStackTrace (); @LS%uqs
} [T/S/@IT
} "&;X/~j
7*WO9R/
//日志 RjrQDh|((
public static void log(String sMsg) ;WrG\R/|
{ +Oo-8f*
System.err.println(sMsg); 0&\71txrzg
} 1g$xKe~]4
+;oR_]l
F/:%YR;
public static void log(int sMsg) WOeLn[
{ v5?ct?q
System.err.println(sMsg); 9.#")%_p
} WqCj;Tj|
} LFYSur8
G$CSZrP.
FBzsM7]j
/* t.bM]QU!1
**TestMethod.java N1x~-2(
*/ G"Ey%Q2K
package NetFox; YOvhMi
28-z
Bw[#,_
public class TestMethod { "st+2#{
{CTJX2&
^i3!1cS
public TestMethod() q,;wD1_wG
{ ///xx/weblogic60b2_win.exe W58%Zz4a
try{ ?Ho>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +-5YmN'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); iorQ/(
SiteFileFetch fileFetch = new SiteFileFetch(bean); DC_k0VBn
fileFetch.start(); AOV{@b(
} $_\x}`c~.
catch(Exception e){e.printStackTrace ();} ]<Q&
wMCgLh\wi
cBZJ
} Y\4B2:Qd9
Q0ba;KPm
)%8st'
public static void main(String[] args) V<ilv<
{ 2nL*^hhh
new TestMethod(); W}%[i+
} )vuIO(8F#
} t"MrrK>T
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