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)); CWG6;NT6m
} wHv]ViNvXE
for(int i=0;i<nEndPos.length-1;i++) #9fWAF
{ |R@~-Ht
nEndPos = nStartPos[i+1]; ~h=X8-D
} uV hCxUMQ
nEndPos[nEndPos.length-1] = nFileLength; ZBG}3Z
} G633Lm`ri
} ;HBCUe<_
#:|+XLL
9F- )r'
//启动子线程 ?$Wn!"EC8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Z!&Rr~i <
for(int i=0;i<nStartPos.length;i++) [;.`,/
{ _l], "[d
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), a=$t&7;,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), gx:;&4AD
nStartPos,nEndPos,i); ).HDru-2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *tX{MSYW
fileSplitterFetch.start(); 9Sq%s&
} 5P hX"7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hv$m4,0WB
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); f8<o8*`7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", R%H$%cnj
nEndPos = " + nFileLength); b7\ cxgRq
// fileSplitterFetch[nPos.length-1].start(); \zkw2*t
$hVYTy~}
)|<_cwz
//等待子线程结束 4YMX|1wd)
//int count = 0; )Vk6;__
//是否结束while循环 0Hw-59MK
boolean breakWhile = false; xf>z@)e
|nk3^;Yf
"SoHt]%#
while(!bStop) 5ZPzPUa8~
{ b2^AP\: k
write_nPos(); ^t*x*m8
Utility.sleep(500); !lmWb-v%36
breakWhile = true; /_-;zL
'QH1=$Su
b2&V
for(int i=0;i<nStartPos.length;i++) ;C/bJEgdd
{ +~U=C9[gj
if(!fileSplitterFetch.bDownOver) O0*e)i8
{ ZRUhAp'<qj
breakWhile = false; "$5\,
break; `}no9$l~
} Hj1 EGCA
} 7ji=E";.w
if(breakWhile) rspayO<]3
break; ]AS"z<
FM5e+$>@
ql&*6KZ"
//count++; [rOaM$3|
//if(count>4) zN_:nY>
// siteStop(); mN5 8r"!J
} $O:w(U
68'>Zbelb
QI[}(O7#6
System.err.println("文件下载结束！"); |__=d+M'
} QldzQ%4c\
catch(Exception e){e.printStackTrace ();} r\9TMg`C
} ftavbNR`W
n1:v HBM@\
/WnE:3G
//获得文件长度 ]y)Q!J )Q
public long getFileSize() Q7o5R{.oJ
{ N 6O8Wn
int nFileLength = -1; dd7 =)XT+
try{ 2#/p|$;Ec'
URL url = new URL(siteInfoBean.getSSiteURL()); qJT0Y/l:(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YY4-bNj[p
httpConnection.setRequestProperty("User-Agent","NetFox"); b}zBn8l
VLg EX4
*Wb=WM-.
int responseCode=httpConnection.getResponseCode(); )yb+M ez
if(responseCode>=400) M`,XyIn
{ =j /hl
processErrorCode(responseCode); IdRdW{o
return -2; //-2 represent access is error FFGqa&
} bYh9sO/l
zyN (4
EZ(^~k=I
String sHeader; g"!\\:M
-lRhz!E]
[~k]{[NJ
for(int i=1;;i++) (%Oe_*e}Y
{ ^2M!*p&h
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); vh>{_ #
//Utility.log(in.readLine()); DcV<y-`'1
sHeader=httpConnection.getHeaderFieldKey(i); azb=(l-
if(sHeader!=null) af+}S9To
{ 8h?X!2Nq
if(sHeader.equals("Content-Length")) 26:evid
{ q:HoKJv4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ew^ @Aq
break; dNVv4{S
} s"0b%0?A
} o;-<|W>
else 2neRJ
break; ]?9[l76O7
} %XXkVK`
} #Y,A[Y5jX
catch(IOException e){e.printStackTrace ();} .Tm- g#
catch(Exception e){e.printStackTrace ();} bv\ A,+
Zy wK/D
?SUQk55w
Utility.log(nFileLength); T2Z[AvNXFk
<e6=% 9
I Ru$oF}
return nFileLength; }NX\~S"
} z-0:m|=yH
H$-$2?5
o|287S|$
//保存下载信息（文件指针位置） C?QfF{!7
private void write_nPos() t,vTAq.))
{ <~%t$:
try{ zw:/!MS
output = new DataOutputStream(new FileOutputStream(tmpFile)); u2`xC4>c
output.writeInt(nStartPos.length); 8g5V,3_6
for(int i=0;i<nStartPos.length;i++) |Odu4 Q
{ .Y/-8H-3v
// output.writeLong(nPos); m(3);)d
output.writeLong(fileSplitterFetch.nStartPos); T~Yg5J
output.writeLong(fileSplitterFetch.nEndPos); W<gD6+=8
} TJ2/?p\x
output.close(); Tj,Nmb>Q7'
} g+Ph6W
catch(IOException e){e.printStackTrace ();} 6dT|;koWbm
catch(Exception e){e.printStackTrace ();} 2_olT_#
} :2q ?>\
W:ixzpQ
pa] TeH
//读取保存的下载信息（文件指针位置） gv` h-b
private void read_nPos() |z7dRDU}]
{ q lY\*{x4
try{ Z oTNm
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); urxqek
int nCount = input.readInt(); *Pb.f
nStartPos = new long[nCount]; pB'x_z
nEndPos = new long[nCount]; Q}uG/HI
for(int i=0;i<nStartPos.length;i++) O`[]xs
{ UIw?;:Y
nStartPos = input.readLong(); s4IKSX
nEndPos = input.readLong(); ip5u_Xj?
} "X?LAo
input.close(); !\w\ ]7ls
} @dhH;gt.I
catch(IOException e){e.printStackTrace ();} ~M[>m~8
catch(Exception e){e.printStackTrace ();} S1>Z6
} WRMz]|+}4
/2:Q6J
cJq<9(
private void processErrorCode(int nErrorCode) |\p5mh
{ !`h~`-]O
System.err.println("Error Code : " + nErrorCode); :+pPrGj"
} bVmvjY4
(j`l5r#X#/
ArdJ."
//停止文件下载 8c?8X=|D7
public void siteStop() Alh?0Fk3)
{ '?L%F{g/9
bStop = true; ) hPVX()O!
for(int i=0;i<nStartPos.length;i++) s{%fi*
fileSplitterFetch.splitterStop(); KH)pJG|NY
3z$\&& BR
@S}|Ccfc_
} g&aT!%QvX+
} W,'3D~g8
//负责部分文件的抓取 o;'4c
**FileSplitterFetch.java fsb=8>}63}
*/ Pu/lpHm|
package NetFox; +wjlAqMQ
]J~g'">
0eaUorm)
import java.io.*; ^AH-+#5
import java.net.*; wO\!xW:
@>9A$w$H|a
v*gLNB,ZH
public class FileSplitterFetch extends Thread { H.;yLL=
?ZM^%]/+
Kk56/(_S
String sURL; //File URL cl#OvQ
long nStartPos; //File Snippet Start Position `i{4cT8:
long nEndPos; //File Snippet End Position <W9) Bq4
int nThreadID; //Thread's ID 6g5]=Q@U:
boolean bDownOver = false; //Downing is over GfQ^@Tl
boolean bStop = false; //Stop identical !%)L&W_
FileAccessI fileAccessI = null; //File Access interface ]LY^9eK)>{
V'$oTZ`
m4\g o
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ma`w\8a
{ ;C6O3@Q
this.sURL = sURL; IM2/(N.%
this.nStartPos = nStart; -q|*M:R
this.nEndPos = nEnd; | )S{(#k
nThreadID = id; |<7i|J
fileAccessI = new FileAccessI(sName,nStartPos);//定位 T7X!#j"\
} EXH!glR[$
2tlO"c:_/
@YbZ8Uc
public void run() Hm<M@M$aG
{ 2w;G4
while(nStartPos < nEndPos && !bStop) +;5Wp$M\
{ PH{c,
4jPwL|#
{K6Kx36
try{ 's/27=o
URL url = new URL(sURL); \Z8Y(]6*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (O<abB(
httpConnection.setRequestProperty("User-Agent","NetFox"); 1pl2;!
String sProperty = "bytes="+nStartPos+"-"; Ld'EABM
httpConnection.setRequestProperty("RANGE",sProperty); u<J2p?`\&`
Utility.log(sProperty); QDl)92z
%j!z\pa
'II vub#q
InputStream input = httpConnection.getInputStream(); ^$ZI>L0+
//logResponseHead(httpConnection); "&s9cO.H
Z@8MhJ
Ty(yh(oYF`
byte[] b = new byte[1024]; W=!F8g|Qz
int nRead; W=(MsuirO
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +KYxw^k}"7
{ Udg& eEF
nStartPos += fileAccessI.write(b,0,nRead); qLu8!|QT
//if(nThreadID == 1) }b<87#Nb9R
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ArLz;#AOn
} ejDCmD
wZ}n3R,
u_hE7#i
Utility.log("Thread " + nThreadID + " is over!"); yDDghW'\WU
bDownOver = true; `8qT['`#R
//nPos = fileAccessI.write (b,0,nRead); 20S9/9ll
} ;N9n'Sq4
catch(Exception e){e.printStackTrace ();} _-YL!oP
} @5JLjCN
} 'bbV<?):
nDwq!LEx%5
,Uv{dG
//打印回应的头信息 {EZFx,@t
public void logResponseHead(HttpURLConnection con) Gl dH SCy
{ c g3Cl[s
for(int i=1;;i++) /[p?_EX@
{ oR!n bm
String header=con.getHeaderFieldKey(i); &! 5CwEIF
if(header!=null) ?nj"Ptzs
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +6i7,U
Utility.log(header+" : "+con.getHeaderField(header)); MLEIx()
else JuKk"tr~RB
break; zWP.1 aA&
} 9 kTD}" %2
} QfKR pnj(o
"Yc^Nc
L5i#Kh_
public void splitterStop() !- Cs?
{ 8T!fGzHx
bStop = true; 5&GQ=m
} p3>Q<
mdmZ1:PBM
YMd&To0s
} JMl, N
%5( EkP
.Bm^3A
/* EIy]qAE:f
**FileAccess.java 35-DnTv
*//文件访问(定位，写) H-nFsJ(R!c
package NetFox; ^!-E`<jW8
import java.io.*; tU-#pB>H
%N?W]vbra
\#IJ=+z
public class FileAccessI implements Serializable{ d&$.jk8 2
Y`E{E|J
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Xs.$2
RandomAccessFile oSavedFile; &mO/u=u
long nPos; 6&/ Ew4 e
P@o,4\;K
y^0HCp{
public FileAccessI() throws IOException {+9^PC_hm;
{ cQUH%7m
this("",0); fwar8 i1
} C.Wms}XA
i`ZHjW~`
?[NTw./'7A
public FileAccessI(String sName,long nPos) throws IOException QI :/,w
{ mfp`Iy"}+
oSavedFile = new RandomAccessFile(sName,"rw"); dvrvpDoE.
this.nPos = nPos; 5Xq.=/eX
oSavedFile.seek(nPos); 8k*
} hSLwiX~
9~Y)wz
'>S8t/
public synchronized int write(byte[] b,int nStart,int nLen) tDuUAI54
{ CBz(hCaI
int n = -1; f6dE\
try{ cN[q)ts
oSavedFile.write(b,nStart,nLen); CguU+8]
n = nLen; zO7lsx2=
} OoU'86)
catch(IOException e) OLd$oxKR
{ 3=G5(0
e.printStackTrace (); y~#R:&d"
} 7#~m:K@
(<g;-pZH%
Np5/lPb1
return n; =%#$HQ=
} /4f 5s#hR
pRDON)$
leX7(Y;!a7
} C4X{Ps\
}.Na{]<gh
C7c|\T
/* oto wvm
**SiteInfoBean.java zwniS6R1
*/ k8t Na@H
package NetFox; 0W<nE[U
hD9'`SQ
X&;]
public class SiteInfoBean { $ uIwRG <
\CEnOq
6LF^[b/u
private String sSiteURL; //Site's URL #u]_7/(</`
private String sFilePath; //Saved File's Path 2Xq!'NrS
private String sFileName; //Saved File's Name x:&L?eOT
private int nSplitter; //Count of Splited Downloading File S:B-nI
ngH~4HyT
c?3F9w#
public SiteInfoBean() \qK}(xq[
{//nSplitter的缺省值为5 xhVq
//default value of nSplitter is 5 JQvQm|\nc
this("","","",5); NXG}0`QVT
} OrKT~JQVC&
6jy n,GU
j}x O34
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e>i8=U`;
{ {1-CfQ0 8
sSiteURL= sURL; =QxE-)v
sFilePath = sPath; +h\W~muR
sFileName = sName; kAe-d
this.nSplitter = nSpiltter; I!i#=
z6>ZV6(d2^
#t9=qR~"
} rc{[\1 -N
l4BO@
%imBGh
public String getSSiteURL() S|5lx7
{ HDae_.
return sSiteURL; .WPR}v,.Z
} ]&tr\-3
kl{OO%jZ
vS,G<V3B
public void setSSiteURL(String value) v%PWr5]
{ ^zluO
sSiteURL = value; fKK-c9F
} Xe^=(| M
A%2M]];%X
JI#Enh!Lv
public String getSFilePath() L|xen*O
{ &.bR1wX
return sFilePath; *U^\Mwp
} "GC]E8&>H
u g$\&rM>
Z=5}17kA
public void setSFilePath(String value) YPJx/@Z`
{ uP'w.nA&2
sFilePath = value; -~GJ; Uw
} +Gwe%p Q
EvardUB)
p(&o'{fb
public String getSFileName() Y`_X@Q
{ {*r$m>HpM
return sFileName; <}'B-k9
} VNEZBy"F
zxmI/]3+/
3[O =2
public void setSFileName(String value) nm|m1Z+U
{ 3Os3=Ix
sFileName = value; O.8m%ZjD
} )Ai%wCzw*
F p=Q$J|
gm\o>YclS
public int getNSplitter() 48NXj\L[y
{ 6!D
return nSplitter; oHFDg?Z`
} Z.OrHg1
W[Ew6)1T
AT'$VCYC(
public void setNSplitter(int nCount) +jZg%$Q!#
{ N#!1@!2BN
nSplitter = nCount; 9^*YYK}%
} ='||BxB
} GyM%vGl 3
v.&*z48
}eRG$)'
/* kvVz-PJy
**Utility.java rQ@o
*/ nZ+5@( *
package NetFox; Zgf||,
bRe*(
Saq>o.
public class Utility { Dj&bHC5%
?-&D'
c5+lm}R?
public Utility() yacGJz^f=
{ <>/MKMq!
^* v{t?u
"X}F%:HL
} *H<g9<Dn
QgM_SY|Rj
//线程睡眠 ~g6[ [
public static void sleep(int nSecond) c'TLD!^hB
{ =WRU<`\
try{ R6o<p<fTh
Thread.sleep(nSecond); ]8nm9qmF<
} BU{V,|10a
catch(Exception e) tpzdYokh>
{ RKb3=} *C
e.printStackTrace (); m)2hl~o_
} (G!J==
} q x }fn/:
0c6AQP"=V
//日志 -t#a*?"$w
public static void log(String sMsg) }ucg!i3C
{ 5!{g6=(
System.err.println(sMsg); vszAr( t
} *K)53QKlE
3t6'5{
yk6UuI^/
public static void log(int sMsg) #{cpG2Rs
{ =zGz|YI*?
System.err.println(sMsg); Rk0rHC6[
} Y[]t_o)
} {NqGWkGt*b
5F?g6?j{
9f[[%80
/* hRcJ):Wyb
**TestMethod.java A'R sy6
*/ }H^^v[4
package NetFox; ^K[tO54
q)i(wEdUZ
`g1~ya(MC
public class TestMethod { ?kefRev<#h
I+Cmj]M s0
Ci:QIsu*
public TestMethod() na; ^/_U@
{ ///xx/weblogic60b2_win.exe yKhzymS}T
try{ @= 9y5r
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 64s;6=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _( Cp
SiteFileFetch fileFetch = new SiteFileFetch(bean); $^ 3 f}IzA
fileFetch.start(); v>PHn69PU
} e-t`\5b;
catch(Exception e){e.printStackTrace ();} {<BK@U
,gD i)]
}TLC b/+
} bcs(#
_9 O'
py4_hj\v
public static void main(String[] args) &NnMz9
{ -*r';Mz;
new TestMethod(); E/ )+hK&
} 5E|2S_)G
} Z:Am\7 I
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