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)); OCUr{Nh
} kl`W\tF
for(int i=0;i<nEndPos.length-1;i++) HhpDR
{ G?ZXWu.
nEndPos = nStartPos[i+1]; ;fJ.8C
} 8RX&k
nEndPos[nEndPos.length-1] = nFileLength; uS-|wYE
} 2?5>o!C
} Qd-A.{[h
$k?>DP4
dscgj5b1~
//启动子线程 P%6~&woF
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [~^0gAlQC
for(int i=0;i<nStartPos.length;i++) <!+Az,-
{ T|p"0b A
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .h[:xYm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~`/V(r;o
nStartPos,nEndPos,i); s>en
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H.c7Nle
fileSplitterFetch.start(); /mMV{[
} K;(mC<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^"g~-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); OPi0~s
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $Y;RKe9
nEndPos = " + nFileLength); +%&yJ4-
// fileSplitterFetch[nPos.length-1].start(); G3 m Z($y
\8 ":]EU
Kgv T"s.
//等待子线程结束 @oNXZRg6
//int count = 0; 0erNc'e
//是否结束while循环 U(Zq= M
boolean breakWhile = false; 9z0p5)]n>
Z.WW(C.
>Q/Dk7#
while(!bStop) VQs5"K"
{ [e q&C_|D
write_nPos(); :U\tv[
Utility.sleep(500); qLCR] _*
breakWhile = true; N;d] 14|
u y+pP!<
#ABCDi={zA
for(int i=0;i<nStartPos.length;i++) TseGXYH
{ ~@!bsLSMU
if(!fileSplitterFetch.bDownOver) I|OoRq
{ 92c HwWZ!
breakWhile = false; %C0Dw\A*:
break; B[}6-2<>?C
} D@KlOU{<
} B1gR5p0
if(breakWhile) =v\.h=~~
break; LscGTs,
*R"/|Ka
O<I-
//count++; lFkR=!?=
//if(count>4) 7,MR*TO,
// siteStop(); G5!^*jf
} \^LFkp
<$YlH@;)`a
Lr+$_ t}r
System.err.println("文件下载结束！"); u?"Vm
} #z(]xI)"
catch(Exception e){e.printStackTrace ();} 6LZCgdS{
} +mPx8P&%
-/4P3SG/
Kq!3wb;
//获得文件长度 }b}m3i1
public long getFileSize() df=f62
{ ~~.}ah/_d
int nFileLength = -1; ta0|^KAA
try{ xG 1nGO
URL url = new URL(siteInfoBean.getSSiteURL()); @ZJS&23E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YR70BOxK
httpConnection.setRequestProperty("User-Agent","NetFox"); >_TZ'FT
Om<a<q
[;N'=]`
int responseCode=httpConnection.getResponseCode(); "7 yD0T)2
if(responseCode>=400) >~f]_puT
{ d5b% W3
processErrorCode(responseCode); N mG#
return -2; //-2 represent access is error QPx^_jA
} t-AmX)$
N+|d3X!
m~|40)
String sHeader; 0J|3kY-n>
h1RSVp+?n
"4Nt\WQ
for(int i=1;;i++) +_!QSU,@
{ \wZe] G%S
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); bD^owa
//Utility.log(in.readLine()); YUb_y^B^
sHeader=httpConnection.getHeaderFieldKey(i); RCrCs
if(sHeader!=null) *a)n62
{ mv><HqDL1
if(sHeader.equals("Content-Length")) TC('H[ ]
{ #mT"gs
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5-V pJ
break; R_KH"`q
} $qiya[&G4
} 9sP0D
else #tHK"20
break; :s,Z<^5a)g
} ~u{uZ(~
} SM'|+ d
catch(IOException e){e.printStackTrace ();} zA 3_Lx!
catch(Exception e){e.printStackTrace ();} kM6 Qp
NbobliC=
e.>P8C<&
Utility.log(nFileLength); hgmCRC
W^Yxny
D9df=lv mD
return nFileLength; ~[ jQ!tz
} K9[UB
H}!r|nG
EnR}IY&sI
//保存下载信息（文件指针位置） _t$sgz&
private void write_nPos() !if
{ pmM9,6P4@
try{ b}f~il
output = new DataOutputStream(new FileOutputStream(tmpFile)); SBpL6~NW
output.writeInt(nStartPos.length); \zY!qpX<
for(int i=0;i<nStartPos.length;i++) O^.#d
{ > I?IPQB
// output.writeLong(nPos); 8}[).d160
output.writeLong(fileSplitterFetch.nStartPos); XX@ZQcN
output.writeLong(fileSplitterFetch.nEndPos); T%Lx%Qn
} .>S!ji
output.close(); do%&m]#;
} eRYK3W
catch(IOException e){e.printStackTrace ();} .H|-_~Yx|
catch(Exception e){e.printStackTrace ();} *|0 -~u%q
} j.Hf/vi`z
+0&/g&a\R
`A>@]d
//读取保存的下载信息（文件指针位置） +TJCLZ..
private void read_nPos() M{@(G5
{ =(Mch~
try{ g(052]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); f 2.HF@
int nCount = input.readInt(); q'DW~!>qX
nStartPos = new long[nCount]; BLttb
nEndPos = new long[nCount]; Wri<h:1
for(int i=0;i<nStartPos.length;i++) bsX[UF
{ pkzaNY/q
nStartPos = input.readLong(); .]u/O`c]
nEndPos = input.readLong(); ZH8,KY"
} ?}0,o.
input.close(); |N2#ItBbW
} Za9qjBH
catch(IOException e){e.printStackTrace ();} t!XwW$@
catch(Exception e){e.printStackTrace ();} vt8By@]:
} n[z+<VGwC
Z~CjA%l
+2{Lh7Ks
private void processErrorCode(int nErrorCode) JI}'dU>*U:
{ khe}*y
System.err.println("Error Code : " + nErrorCode); u[YGm:}
} L_T5nD^D
)2.Si#
M-71 1|eGI
//停止文件下载 e= AKD#
public void siteStop() wj,=$RX
{ +whDU2 "
bStop = true; q1,~
for(int i=0;i<nStartPos.length;i++) py4 h(04u
fileSplitterFetch.splitterStop(); A&VG~r$
KPF1cJ2N
w>gYx(8b
} xpt:BBo
} v+XJ*N[W
//负责部分文件的抓取 (HVGlw'`
**FileSplitterFetch.java vzM^$V
*/ .]^?<bG
package NetFox; ueudRb
G[=c Ss,
pP_LR ks}
import java.io.*; b=vkiO`2
import java.net.*; t_^4`dW`
)pa]ui\t
~}P,.QQ
public class FileSplitterFetch extends Thread { &ncvGDGi
]G\}k
AH^/V}9H
String sURL; //File URL s AkdMo
long nStartPos; //File Snippet Start Position r@V!,k#S
long nEndPos; //File Snippet End Position rp$'L7lrX
int nThreadID; //Thread's ID V`- 9m$
boolean bDownOver = false; //Downing is over :X=hQ:>P
boolean bStop = false; //Stop identical >7|VR:U?B
FileAccessI fileAccessI = null; //File Access interface Ac@VGT:9
s[jTP(d)8
jp,4h4C^)
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException K0~rN.C!0
{ ?4,T}@P
this.sURL = sURL; 1?}T=)3+$
this.nStartPos = nStart; A^g(k5M*
this.nEndPos = nEnd; dN q$}
nThreadID = id; &~CI<\o P
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ];m_4
} LVGe]lD
Xvu(vA
]M=&+c>H~
public void run() aN?zmkPpov
{ /: "1Z]@
while(nStartPos < nEndPos && !bStop) <)9y{J}s:
{ )`:UP~)H
]Ze1s02(
)7F/O3Tq
try{ 0kh6@y3
URL url = new URL(sURL); M%HU4pTW#o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I9Xuok!0>=
httpConnection.setRequestProperty("User-Agent","NetFox"); ye&;(30Oq
String sProperty = "bytes="+nStartPos+"-"; nlP;nlW
httpConnection.setRequestProperty("RANGE",sProperty); ~ljXzD93Z
Utility.log(sProperty); 0J9x9j`&j
lA]8&+,ZM
jcOcWB|
InputStream input = httpConnection.getInputStream(); 1}x%%RD_
//logResponseHead(httpConnection); K?;DMUSY\
afVT~Sf{
(QEG4&9
byte[] b = new byte[1024]; +7Gwg
int nRead; @ Y+oiB~Y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) -w2/w@&
{ 01]f2.5
nStartPos += fileAccessI.write(b,0,nRead); K-v#.e4
//if(nThreadID == 1) us-L]S+lm
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q9"96({\@
} .v K-LHs
pK*TE5]
E GU2fA7x
Utility.log("Thread " + nThreadID + " is over!"); ytImB`'\
bDownOver = true; (PLUFT
//nPos = fileAccessI.write (b,0,nRead); ?<!|
} cuX)8+
catch(Exception e){e.printStackTrace ();} !$JT e
} #a#F,ZT
} KlEpzJ98
7CysfBF0g
-7ep{p-
//打印回应的头信息 sJZiI}Xc
public void logResponseHead(HttpURLConnection con) >4TO=i
{ i-1op> Y
for(int i=1;;i++) t@(HF-4~=
{ %{W6PrY{
String header=con.getHeaderFieldKey(i); 1MFbQs^
if(header!=null) -).C
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )0`C@um
Utility.log(header+" : "+con.getHeaderField(header)); hN_]6,<\
else X|dlt{Gf
break; yi[x}ffdE
} Rq-ZL{LR7
} -"x$ZnHU
]Wup/o
W/N7vAx X
public void splitterStop() 5xiEPh
{ ).O)p9
bStop = true; UMi~14& ;
} W?&%x(6M
tQVVhXQ7
=pNY eR_[
} UKGPtKE<
*~`(RV
h[ ZN+M
/* CpN>p.kM
**FileAccess.java Wwo0%<2y
*//文件访问(定位，写) e-;}366}
package NetFox; JF]JOI6.e
import java.io.*; WH\d| 1)
A/(a`"mK|'
t20K!}D_
public class FileAccessI implements Serializable{ TeQV?ZQ#}
7zMr:JmV
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %T[]zJ(
RandomAccessFile oSavedFile; BtZyn7a
long nPos; sW$XH1Uf#
0RfZEG)
[g,}gyeS(
public FileAccessI() throws IOException \V:^h[ad
{ z:O8Ls^\T
this("",0); >_} I.\X
} }H2R3icE
qs6aB0ln
iZ%yd-
public FileAccessI(String sName,long nPos) throws IOException %<5'=t'|-U
{ |Tw~@kT@
oSavedFile = new RandomAccessFile(sName,"rw"); AA_%<zK
this.nPos = nPos; 7)m9"InDI
oSavedFile.seek(nPos); 1C.VnzRnJ
} :UdF
}Z>)DN=+
Bvj0^fSm
public synchronized int write(byte[] b,int nStart,int nLen) 2%1hdA<
{ rqq1TRg
int n = -1; )u">it+
try{ *hrd5na
oSavedFile.write(b,nStart,nLen); +\'tE~V
n = nLen; L];b<*d
} rQXzR
catch(IOException e) X&zis1A<
{ E`q_bn
e.printStackTrace (); YIE<pX4Q7)
} 9uY'E'm*
Tw% 3p=
6~{C.No}
return n; zDp2g)
} Z)!C'cb
J4utIGF
:N@^?q{b
} B!yr!DWv
3T 9j@N77
-&f$GUTJ
/* |{;G2G1[
**SiteInfoBean.java q4q6c")zp
*/ ijcm2FJcG
package NetFox; fM}#ON>Z
+p^u^a
neh(<>
public class SiteInfoBean { -di o5a
mmsPLv6
wBzC5T%,
private String sSiteURL; //Site's URL ]9L oZ)
private String sFilePath; //Saved File's Path fVwUe _Y
private String sFileName; //Saved File's Name f::Dx1VcX
private int nSplitter; //Count of Splited Downloading File 'yth'[
B *vM0
H]!"Zq k
public SiteInfoBean() >p/`;Kq@
{//nSplitter的缺省值为5 51u0]Qx;fm
//default value of nSplitter is 5 Bt#N4m[X*|
this("","","",5); ^{{qV
} \9d$@V
u>$t'
X8|EHb<
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) bcR_E5x$
{ % nIf)/2g
sSiteURL= sURL; OB7hlW
sFilePath = sPath; r>\bW)e
sFileName = sName; 2tLJU Z1
this.nSplitter = nSpiltter; eQ"E
hcc/=_hA
-&;TA0~;
} {!`4iiF
M;NX:mX9
6RM/GM
public String getSSiteURL() C?Ucu]cW
{ X.V~SeS
return sSiteURL; __@BUK{q
} YP9^Bp{0
ccnK#fn v
[Yyk0Qv|4
public void setSSiteURL(String value) l@\FWWQ
{ Tr|JYLwF
sSiteURL = value; FqifriLN
} i?gSC<a
&R siVBA
q =Il|Nb>
public String getSFilePath() ':}\4j&{E
{ w*!aZ,P
return sFilePath; fLVAKn
} ^GX)Z~
`kr?j:g
]{kPrey
public void setSFilePath(String value) HqTjl4ai
{ Q^I\cAIB
sFilePath = value; nd(S3rct&
} ,PZ ge
BC]?0 U
x:7IIvP
public String getSFileName() 8D].MI^
{ <1pEwI~
return sFileName; +)?J#g
} E e]-qN*8
B;WCTMy}
KU;9}!#
public void setSFileName(String value) d1kJRJ
{ xCKRxF
sFileName = value; 0g\(+Qg^
} WKU=.sY
SB7c.H,
d\Zng!Z'
public int getNSplitter() &0f,~ /%Z
{ dTtSUA|V7"
return nSplitter; 2JFpZU"1
} I0a<%;JJW
&OBkevg
MW{8VH6+
public void setNSplitter(int nCount) vFsLY
{ ETLD$=iS
nSplitter = nCount; oRzi>rr
} c|1&lYal;
} Ev P{p
i?~3*#IpD
!Uc T RI
/* VD:/PL
**Utility.java qCO/?kW
*/ 0;ji65
package NetFox; C-[1iW'
tl].r|yl
d| {r5[&
public class Utility { %IRi1EmN8
o]:9')5^
4&f3%eTi
public Utility() Rh |nP&6
{ Z<phcqEi8
bTu9;(
C $JmzrE
} "nWw;-V}}
ERt{H3eCcJ
//线程睡眠 #,.Hr#3nI
public static void sleep(int nSecond) N?>vd*
{ `@ FYkH
try{ jSAjcLR
Thread.sleep(nSecond); AK#1]i~
} '=6\v!
catch(Exception e) ;\l,5EG
{ {_Gs*<.
e.printStackTrace (); ZW}_Qs
} mQ=#nk$~g
} L:8q8i
IMfqiH)
//日志 )/EO&F
public static void log(String sMsg) 'ah[(F<*@e
{ \G3rX9xG
System.err.println(sMsg); X|8c>_}
} m9A!D
Bw{I;rW{2
-GgA&dh
public static void log(int sMsg) YDFyX){
{ (khL-F
System.err.println(sMsg); ~= -RK$=
} F3N6{ysK#
} d:{O\
e!r-+.i(
AvHCO8h|
/* @gtQQxf"
**TestMethod.java pBPl6%C.X-
*/ !3v1bGk
package NetFox; 2"S}bfrX
xjUtl
N&V`K0FU
public class TestMethod { O<e{
d'I"jZ
'Qo*y%{@5
public TestMethod() L~>i,
{ ///xx/weblogic60b2_win.exe Y5d\d\e/
try{ f4Rf?w*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2T TdH)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); BRYHX.}h\A
SiteFileFetch fileFetch = new SiteFileFetch(bean); TBrPf-Xr
fileFetch.start(); Fr$5RAyg
} 2wgg7[tGi
catch(Exception e){e.printStackTrace ();} pU7lnS[
v<:R#
I)W`sBL
} ~3S~\0&|
-B\HI*u
zkdetrR
public static void main(String[] args) :#~j:C|
{ ++#5
new TestMethod(); {GcO3G#FZ
} ,i@:5X/t
} Z87|Zl
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