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)); s2Rg-:7
} y,/Arl}yc
for(int i=0;i<nEndPos.length-1;i++) PP*',D3
{ {)`tN&\
nEndPos = nStartPos[i+1]; r+RFDg/
} @LyCP4
nEndPos[nEndPos.length-1] = nFileLength; b}APD))*H!
} V|\dnVQ'-%
} HuI?kLfj\
x*#9\*@EI
U0m 5Rc
//启动子线程 )lhPl
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #@UzOQ>
for(int i=0;i<nStartPos.length;i++) aam6R/4
{ 0rrNVaM
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >OxSrc@A
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ` W}Bc
nStartPos,nEndPos,i); OF1fS\P<>
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); af-
fileSplitterFetch.start(); a(#aEbN?d
} <rn26Gfr
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Gnthz0\]{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); EEJ OJ<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 2kSN<jMr
nEndPos = " + nFileLength); b+#A=Z+Pr
// fileSplitterFetch[nPos.length-1].start(); y_:~
3:g~@PB
6%A_PP3Z
//等待子线程结束 A.5`+
//int count = 0; i-FsA
//是否结束while循环 b#[EkI 0@
boolean breakWhile = false; SJ8CBxA
HU1ZQkf
PZ.q
while(!bStop) WKvG|YRDq
{ zL@FN sYVM
write_nPos(); WV&grG|
Utility.sleep(500); ;RzbPlkl
breakWhile = true; vuoD~=z
#qDMUN*i
f&2f8@
for(int i=0;i<nStartPos.length;i++) ym*oCfu=
{ |aX1PC)o_
if(!fileSplitterFetch.bDownOver) L ]Y6/Q
{ 2tqj]i
breakWhile = false; <$@*'i^7Ez
break; lL;SP&
} mx=2lL`
} Ad)::9K?J
if(breakWhile) vp4NH]fJ
break; X:kr$
I3hN7
sNHxUI
//count++; YwaWhBCIF
//if(count>4) lN~V1(1B
// siteStop(); xe@11/F
} jnIf(a
E(-@F%Q
|w+N(wcJ
System.err.println("文件下载结束！"); =-%10lOI
} ?2nF1>1
catch(Exception e){e.printStackTrace ();} T=,A pa
} &rfl(&\oUi
N9cCfB\`
V.|#2gC]t
//获得文件长度 JU3to_Io
public long getFileSize() 0BrAgv"3a_
{ (~N[j;W,_W
int nFileLength = -1; E+z"m|G
try{ _?oofE:{
URL url = new URL(siteInfoBean.getSSiteURL()); @8eQ|.q]Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !]C=5~BBI
httpConnection.setRequestProperty("User-Agent","NetFox"); $(fhO
d6f+[<<
{'a|$u+
int responseCode=httpConnection.getResponseCode(); <`?V:};Q
if(responseCode>=400) H&SoVi_V
{ v}sk %f
processErrorCode(responseCode); G$A=Tu~
return -2; //-2 represent access is error h,zM*zA_
} b6UpE`\z
N~|Z@pU"
@@V{W)rl
String sHeader; iHKX#*
<7 xX/Z}M
wl/1~!
for(int i=1;;i++) ^m['VK#?
{ r(KAG"5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); N|e#&
//Utility.log(in.readLine()); ]sZ! -q'8
sHeader=httpConnection.getHeaderFieldKey(i); UvF5u(o
if(sHeader!=null) xG WA5[YV
{ Q.,2G7[ <
if(sHeader.equals("Content-Length")) x@3" SiC
{ 26ae|2?
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); z\`tnz7>$
break; Qs,4PPEg
} } 89-U
} B!1h"K5.($
else &embAqW:
break; G^Va$ike
} $.x,[R aN
} Xp[xO0
catch(IOException e){e.printStackTrace ();} 2ElZ&(RZJF
catch(Exception e){e.printStackTrace ();} h+ <Jv
PiN^/#D
qLV3Y?S!L
Utility.log(nFileLength); }<^QW't_Y
;EQ7kuJQ?
8j)*T9
return nFileLength; _<KUa\
} =&F~GCZ>
4L_)@n}
.(99f#2M:
//保存下载信息（文件指针位置） e2yCWolmTS
private void write_nPos() E>iN>
{ !Ahxi);a
try{ ERy=lP~gV
output = new DataOutputStream(new FileOutputStream(tmpFile)); HR;I}J 9
output.writeInt(nStartPos.length); =~>g--^U
for(int i=0;i<nStartPos.length;i++) DTlId~Dyq
{ GOOm] ]I
// output.writeLong(nPos); 6Ey@)p..E
output.writeLong(fileSplitterFetch.nStartPos); Tje(hnN
output.writeLong(fileSplitterFetch.nEndPos); (K_{a+$[
} oFGWI#]ts>
output.close(); t.#ara{
} 6Yl+IP];i
catch(IOException e){e.printStackTrace ();} pI_dV44W
catch(Exception e){e.printStackTrace ();} 2 w6iqLr?
} /;kSa}"Q
M@o^V(j
,m8mh)K?0>
//读取保存的下载信息（文件指针位置） _+X-D9j(l
private void read_nPos() ]GO=8$Z
{ mVFo2^%v
try{ .TCDv4?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); bObsj]
int nCount = input.readInt(); wr5v-_7r,
nStartPos = new long[nCount]; *%Fu/
nEndPos = new long[nCount]; _N=f&~T
for(int i=0;i<nStartPos.length;i++) 6bPl(.(3
{ {A'*3(8
nStartPos = input.readLong(); &isKU8n
nEndPos = input.readLong(); - AU{Y`j
} U(LLIyZv
input.close(); e^'|<0J
} yO}5.
catch(IOException e){e.printStackTrace ();} x[0O*ty-*<
catch(Exception e){e.printStackTrace ();} ITg<u?z_
} ~Hu!iZ2]
Xdwpn+7s
VFzIBgJ3
private void processErrorCode(int nErrorCode) 2WTOu x*
{ BNj_f
System.err.println("Error Code : " + nErrorCode); ~>HzAo9e
} C$0g2X
bAbR0)
8NiR3*1
//停止文件下载 u`&lTJgF/O
public void siteStop() {VKFw=$8
{ * k<@
bStop = true; yYaoA/0
for(int i=0;i<nStartPos.length;i++) 3%hq<
fileSplitterFetch.splitterStop(); @Ns[qn;9
1Qu@pb^
loO"[8i.k
} y$_@C8?H
} Z %Ozzp/
//负责部分文件的抓取 yIrJaS-
**FileSplitterFetch.java JhfVm*,
*/ bMGn&6QiP[
package NetFox; xM(H4.<
fx(h fz
^lAM /
import java.io.*; '3Lu_]I-
import java.net.*; FY ms]bv
z9*e%$+S
d&[RfZ`
public class FileSplitterFetch extends Thread { |1RVm?~i
%IX)+ Lp`
BBRL_6
String sURL; //File URL wWy;dma#
long nStartPos; //File Snippet Start Position Vv45w#w;
long nEndPos; //File Snippet End Position X!p`|i
int nThreadID; //Thread's ID qh:Bc$S
boolean bDownOver = false; //Downing is over sVK?sBs]
boolean bStop = false; //Stop identical qD4]7"9
FileAccessI fileAccessI = null; //File Access interface Jsysk $R
Y.\x.Hg
tqZ+2c<W3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *y!O\-\S#>
{ })H d]a
this.sURL = sURL; !:^q_q4
this.nStartPos = nStart; %'yrIR
this.nEndPos = nEnd; <;6{R#Tuh
nThreadID = id; {]< G=]'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8o$rF7.-
} ,|{`(y/v
/{\ /e"5
I I+y
public void run() l6ym <V(1p
{ ;^5k_\
while(nStartPos < nEndPos && !bStop) yGdX>h
{ ch8a
=FrB{Eu
Gv_~@MN
try{ wQSye*ec
URL url = new URL(sURL); #GE]]7:Na
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q$c6l[(g
httpConnection.setRequestProperty("User-Agent","NetFox"); ;:fW]5"R
String sProperty = "bytes="+nStartPos+"-"; e@Lxduq
httpConnection.setRequestProperty("RANGE",sProperty); FfdB%
Utility.log(sProperty); 6 Rl[M+Q
[OW <<6
Do/R.Mgy*
InputStream input = httpConnection.getInputStream(); YV<y-,Io
//logResponseHead(httpConnection); |oi+|r
#wI}93E
?T/]w-q>
byte[] b = new byte[1024]; YQn<CjZ8af
int nRead; "XR=P> xk
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) wlT8|
{ STp9Gh-
nStartPos += fileAccessI.write(b,0,nRead); L~Gr,i
//if(nThreadID == 1) #h5lz%2g
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); QQM:[1;RT
} kAQ(8xV
"lI-/G
V4:/LNq_]
Utility.log("Thread " + nThreadID + " is over!"); Io1j%T#ZT
bDownOver = true; 7nek,8b
//nPos = fileAccessI.write (b,0,nRead); HIXAA?_eh=
} P:"R;YCvE
catch(Exception e){e.printStackTrace ();} YYv0cV{E
} apo)cR
} An{>39{
/MGapmqV9
]JrD@ Vy
//打印回应的头信息 ~U0%}Bbh
public void logResponseHead(HttpURLConnection con) Qt>K{ >9Cf
{ l88=
for(int i=1;;i++) 2R[v*i^S
{ a!9'yc
String header=con.getHeaderFieldKey(i); b=,BLe\
if(header!=null) mn7I# ~
//responseHeaders.put(header,httpConnection.getHeaderField(header)); R2,9%!iiX
Utility.log(header+" : "+con.getHeaderField(header)); ]n!V
else Mu\V3`j
break; T/_u;My;
} =AIFu\9#a`
} QK]P=pE'C
Vu:ZG*^
;W,* B.~
public void splitterStop() [';o -c"!
{ hdPGqJE
bStop = true; %Mda<3P
} (S~kyU!)0
cx\E40WD
qGk.7wf%
} * Gg7(cnpw
;m]V12
GV0\+A"vD
/* AxH;psj
**FileAccess.java 6}^x#9\
*//文件访问(定位，写) J,=K1>8s
package NetFox; ?Mjs[|
import java.io.*; uY]';OtG
\p4*Q}t
$*C }iJsF
public class FileAccessI implements Serializable{ w2s`9
WLUgiW(0$
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 U%h.l
RandomAccessFile oSavedFile; C'JI%HnQ
long nPos; TO6F
U,WOP7z
N[_T3(
public FileAccessI() throws IOException 7{#p'.nc5
{ $--8%gh dG
this("",0); q8{Bx03m6
} TGJz[Ny
Wg|6{'a
REh"/d
public FileAccessI(String sName,long nPos) throws IOException 8W&1"h`
{ K*@?BE
oSavedFile = new RandomAccessFile(sName,"rw"); k79OMf<v
this.nPos = nPos; -wn-PB@r
oSavedFile.seek(nPos); +~5Lo'^
} o?a2wY^_
L4po1
/@`"&@W'
public synchronized int write(byte[] b,int nStart,int nLen) G8repY
{ 6s@!Yn|?
int n = -1; v}DNeIh~
try{ vPnS`&
oSavedFile.write(b,nStart,nLen); MXA?rjd0
n = nLen; y" =?l
} 4@{;z4*`
catch(IOException e) D$FTnY
{ H:G``Vq;0m
e.printStackTrace (); D <iG*I
} (%^C}`|EA
nAP*w6m0j
K_MEd1l
return n; so`\e^d
} Xe4
3o rSk
Hcf"u&%
} gW~YB2 $
s)\PY
4-bM90&1t
/* b'O/u."O
**SiteInfoBean.java [r2V+b.C
*/ >l0Qd1
package NetFox; =d;a1AO{&
{L$$"r,
dw6ysOR@
public class SiteInfoBean { zTue(Kr
nk!uO^
6PsT])*>DE
private String sSiteURL; //Site's URL xhALJfv
private String sFilePath; //Saved File's Path 5YrzOqg=
private String sFileName; //Saved File's Name ~=yU%5 s@
private int nSplitter; //Count of Splited Downloading File }oD^tU IK
61_PSScSY
Ja1`S+
public SiteInfoBean() `@y~JNf!
{//nSplitter的缺省值为5 TFHYB9vV
//default value of nSplitter is 5 @kSfF[4H
this("","","",5); .nY}_&
} K-'uE)
4l0>['K&{
W(62.3d~}?
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -']Idn6
{ IfH/~EtX
sSiteURL= sURL; fhg'4FO
sFilePath = sPath; 1!zd#TX
sFileName = sName; )7NK+k
this.nSplitter = nSpiltter; /K2[`+-
=o~mZ/ 7=M
c6jVx_tt.
} `"~GqFwy~
|ghyH
KEy8EB
public String getSSiteURL() 5Y;&L!T
{ /\e_B6pF<
return sSiteURL; [#!Y7Ede
} /sYr?b!/<6
8}BM`@MG
1#L%Q(G
public void setSSiteURL(String value) P:Q&lnC
{ dOaOWMrfdf
sSiteURL = value; [m! P(o
} e>_a (
sC"w{_D@*4
6# bTlmcg
public String getSFilePath() otaRA
{ ?yG[VW
return sFilePath; "Pc}-&
} JV,h1/a("
8yIBx%"4MH
7Tp+]"bL
public void setSFilePath(String value) 3Z~_6P^ +N
{ }S*]#jr&
sFilePath = value; iYiTkq
} &CQ28WG X
:/gHqEC24
#HP-ne; #
public String getSFileName() Jr'a_(~
{ `#ff`j|a
return sFileName; jBEW("4R
} aQHR=.S]X
;eo}/-a_Xw
CY=lN5!J
public void setSFileName(String value) I\Y N!
{ ]*MVC/R,
sFileName = value; %O!xrA{
} F7<u1Rx]
3;jxIo$,
'PrBa[%
public int getNSplitter() GfSD%"
{ h}tC+_"D
return nSplitter; {ZdF6~+H(!
} WNeBthq6
*oLDy1<
G'Wp)W;])\
public void setNSplitter(int nCount) ]>Dbta.27
{ Xn~\Vb
nSplitter = nCount; rosD)]I7
} 'pUJREb
} 8mOGEx
o/&K>]8M
gKQs:25
/* iW2\;}y
**Utility.java fVZ92Xw B
*/ ^?0'\Z
package NetFox; W8x&:5Fc)3
'5Kj"aD%
+2tFX
public class Utility { 3_9CREZCl
0)zJG |
y5KeUMcu
public Utility() }tBw<7fe
{ <5Ll<0
+BO kHXk1
-awG14%
} ' -9=>
O> _ F
//线程睡眠 qnQ".
public static void sleep(int nSecond) y8C8~-&OK
{ 'C`Ykjf
try{ 4*o?2P$Q
Thread.sleep(nSecond); IMM+g]#e
} @d^DU5ats>
catch(Exception e) RO3q!+a$/
{ |Vlx:
e.printStackTrace (); G{,DoCM5WL
} pd`m//G
} CAx eJ`Q
r9!s@n
//日志 9Nna-}e?W
public static void log(String sMsg) uzmYkBv
{ d@$bPQQ$,
System.err.println(sMsg); m<k6oev$
} $0OOH4
b>i5r$S8G
S[hyN7sI
public static void log(int sMsg) +e.w]\}
{ 8QL=%Pv
System.err.println(sMsg); .v}|Tp&k
} /ece}7M
} IG\Cj7{K^
aO(iKlZ$
t,r:='
/* z Fj|E
**TestMethod.java 8D@Jd
*/ Sp?e!`|8
package NetFox; /:{4,aX2
RL\?i~'KH
<}'=@a
public class TestMethod { L<iRqayn
9c*B%A8J
Bxw(pACf
public TestMethod() oP4+:r)LKD
{ ///xx/weblogic60b2_win.exe f52P1V]
try{ fI<d&5&g
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); gs/ocu
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &%@O V:C
SiteFileFetch fileFetch = new SiteFileFetch(bean); '/X]96Ci7
fileFetch.start(); Ac*J;fI
} $%'3w~h`
catch(Exception e){e.printStackTrace ();} KZ#\ >
`jr?I {m;
RjgJIVm(
} h~CLJoK<
H[OgnnM
TXyiCS3
public static void main(String[] args) 0b n%L~KU
{ goF87^M
new TestMethod(); v@M^ukk'}
} dkDPze9l
} -/Wf iE
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