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)); <(E)M@2
} uz8eS'8
for(int i=0;i<nEndPos.length-1;i++) P0UR{tK
{ caEIE0H~
nEndPos = nStartPos[i+1]; 9^Xndo]y
} +9HU&gQ3
nEndPos[nEndPos.length-1] = nFileLength; {r&r^!K;
} &wNr2PHd#
} <@7j37,R7V
za6 hyd^
!d##q)D f?
//启动子线程 6UIS4_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; X[J<OTj`$
for(int i=0;i<nStartPos.length;i++) 8z93ETv7`
{ -dMH>e0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $;g*s?F*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ceg\lE:8
nStartPos,nEndPos,i); lR?1,yLp
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _3 !s{
fileSplitterFetch.start(); Z@q1&}D!
} )+FnwW
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3@F U-k,i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); f?.}S]u5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5+GTK)D
nEndPos = " + nFileLength); ,5 ,r.
// fileSplitterFetch[nPos.length-1].start(); 2-S}#S}2C
%YxKWZ/?
u9_?c G-
//等待子线程结束 E.#JCO|(1
//int count = 0; 1mV ' ~W
//是否结束while循环 X'd\b}Bm
boolean breakWhile = false; D*L@I@ [
nR%w5oe
tdU'cc?M
while(!bStop) ,,FhE
{ 8Ogg(uS70'
write_nPos(); Ez <YD
Utility.sleep(500); a[t"J*0
breakWhile = true; jhT/}"v
DI{Qs[
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for(int i=0;i<nStartPos.length;i++) ?(s9dS,7wZ
{ |QrVGm@2
if(!fileSplitterFetch.bDownOver) !le#7Kii
{ Lh+7z>1
breakWhile = false; )~)T[S
break; 8hV4l'Pa72
} :|l0x a
} /p-k'387
if(breakWhile) @V4nc 'o.
break; xfUV'=~(
m[ S1
:hHKm|1FE
//count++; V\Lh(zPt
//if(count>4) *<9M|H~
// siteStop(); MDpx@.A,
} ?zo7.R-Vac
s$^ 2Cuhv
vSQB~Vw8t
System.err.println("文件下载结束！"); T+V:vuK
} D<Z\6)|%I
catch(Exception e){e.printStackTrace ();} Lxa<zy~b
} 0l(G7Ju
n`Ypv{+ {%
,[n=PJVw/
//获得文件长度 7CT446
public long getFileSize() s_u! RrC
{ gd)VL}k
int nFileLength = -1; 5"#xbvRS0H
try{ &S^a_L:
URL url = new URL(siteInfoBean.getSSiteURL()); H8c -/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |$T?P*pI.
httpConnection.setRequestProperty("User-Agent","NetFox"); BQMo*I>I
q|.0Ja
@M*5q# s
int responseCode=httpConnection.getResponseCode(); ud(w0eX
if(responseCode>=400) enMHKN g
{ Zf)<)o*
processErrorCode(responseCode); <.|]%7
return -2; //-2 represent access is error -P]onD
} NS4W!o;"
T.!.3B$@]
.v) A|{:2
String sHeader; `?N|{kb
P\X$fD
_hB7;N3
for(int i=1;;i++) r^d:Po
{ AQ-R^kT
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); O sIvW'$\
//Utility.log(in.readLine()); &53LJlL Co
sHeader=httpConnection.getHeaderFieldKey(i); )q+;+J`>
if(sHeader!=null) E-rGOm" m
{ =HoA2,R)
if(sHeader.equals("Content-Length")) b<g9L4s
{ h>NuQo*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); c}7Rt|`c
break; ]T<RC\o
} :as2fO$?
} i/DUB<>p6
else }5gQ dj[Y
break; CIt@xi#I
} p6{8t}
} jivGkIj!8
catch(IOException e){e.printStackTrace ();} xirZ.wjW
catch(Exception e){e.printStackTrace ();} M-f; ,>
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5DeAH;
Utility.log(nFileLength); NSh~O!pX
tjy@sO/Q
&C E){jC
return nFileLength; 1`&"U[{
} %xwdH4_
PwxRu
BG20R=p
//保存下载信息（文件指针位置） JLxAk14lc
private void write_nPos() gM#]o QOGE
{ Xpf:I
try{ X04JQLhy"
output = new DataOutputStream(new FileOutputStream(tmpFile)); DmpD`^?-L
output.writeInt(nStartPos.length); yFqB2(Dv
for(int i=0;i<nStartPos.length;i++) GA)t!Xg^
{ p?sC</R
// output.writeLong(nPos); ]OA8H[U-eA
output.writeLong(fileSplitterFetch.nStartPos); [RUYH5>Ik
output.writeLong(fileSplitterFetch.nEndPos); %wux#"8
} &p^8zEs
output.close(); .\ces2,
} @X>Oj.
catch(IOException e){e.printStackTrace ();} jUX0sRDk
catch(Exception e){e.printStackTrace ();} czp}-{4X
} |rk4,NG.
[Gb8o'
r`CsR0[
//读取保存的下载信息（文件指针位置） OM7EmMa;
private void read_nPos() u"1Zv!
{ )KD*G;<O]L
try{ 39,7N2uY
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |`6*~ciUV
int nCount = input.readInt(); H(j983
nStartPos = new long[nCount]; vqJjAls
nEndPos = new long[nCount]; ;l=ZW
for(int i=0;i<nStartPos.length;i++) +(| ,Ke
{ lK3Z}e*eXQ
nStartPos = input.readLong(); (E?X@d iu
nEndPos = input.readLong(); 3At%TA:
} %FO#j6
input.close(); gflu!C6
} LYyOcb[x
catch(IOException e){e.printStackTrace ();} .~dNzonq
catch(Exception e){e.printStackTrace ();} ;JQ;LbEn
} qm=N@@R&
EAXbbcV
1$ C\`
private void processErrorCode(int nErrorCode) \B~}s}
{ ?T <2Cl'C
System.err.println("Error Code : " + nErrorCode); u IGeSd5B
} leJ\
=6:>C9
J PK(S~
//停止文件下载 5ki<1{aVtZ
public void siteStop() )>|x2q
{ +&h<:/ V
bStop = true; #)N}F/Od^
for(int i=0;i<nStartPos.length;i++) S4FR=QuVQC
fileSplitterFetch.splitterStop(); Gg=Y}S7:
&;Jg2f%.
<^8&2wAkJ
} GY,HEe]2r
} U0X?~ 1
//负责部分文件的抓取 9s'[p'[Z
**FileSplitterFetch.java HTU?hbG(
*/ ijR,%qg
package NetFox; 7awh__@
[b6P }DW
)Cfk/OnRd
import java.io.*; ||t"}Y
import java.net.*; :N ~A7@
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public class FileSplitterFetch extends Thread { ny{Yr>:2
XIJW$CY
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String sURL; //File URL 9d_ Zdc
long nStartPos; //File Snippet Start Position f,}9~r#
long nEndPos; //File Snippet End Position rsgTd\b
int nThreadID; //Thread's ID 8\/$cP"<^
boolean bDownOver = false; //Downing is over %DR8M\d1~H
boolean bStop = false; //Stop identical aBonq]W
FileAccessI fileAccessI = null; //File Access interface R+y 9JE
)D"E]
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException B LI 9(@
{ C=>IJ'G
this.sURL = sURL; [uD G;We=
this.nStartPos = nStart; 5b5Hc Inu
this.nEndPos = nEnd; R *uwp'@
nThreadID = id; TKBW2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 VHihC]ks,
} TtKV5
3"HW{=
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public void run() H%z9VJ*!0
{ waI:w,
while(nStartPos < nEndPos && !bStop) 'Wz`P#/
{ +<1MY'>y
zt|DHVy
gONybz6]
try{ ;S.o`z1GI
URL url = new URL(sURL); Ufr,6IX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /\0g)B;]
httpConnection.setRequestProperty("User-Agent","NetFox"); }lP'bu
String sProperty = "bytes="+nStartPos+"-"; (764-iv(
httpConnection.setRequestProperty("RANGE",sProperty); 82*nC!P3E
Utility.log(sProperty); o3OtG#g2
6(0ME$
j|Hyv{sM
InputStream input = httpConnection.getInputStream(); $4ZjNN@
//logResponseHead(httpConnection); e"O c
Z]\VOA>
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byte[] b = new byte[1024]; l1I\khS
int nRead; aoP=7d|K/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) QxI^Bx
{ <tx`#,
nStartPos += fileAccessI.write(b,0,nRead); r(6$.zx
//if(nThreadID == 1) a 0+W-#G
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D@ 4sq^|2
} B9h'}460H
2{;~Bgd
r&_bk Y%
Utility.log("Thread " + nThreadID + " is over!"); VkJBqRzBOa
bDownOver = true; ;5PBZ<w
//nPos = fileAccessI.write (b,0,nRead); sf5F$
} ~,O&A B
catch(Exception e){e.printStackTrace ();} cy @",z
} %-J}m
} ;:A/WU.^
3s B9t X
.TpM3b#r
//打印回应的头信息 /=IBK`
public void logResponseHead(HttpURLConnection con) &~{0@/
{ I:Q3r"1
for(int i=1;;i++) cfhiZ~."T
{ _k O<|ev
String header=con.getHeaderFieldKey(i); \;bDDTM
if(header!=null) 8qF OO3c\V
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @h)Z8so
Utility.log(header+" : "+con.getHeaderField(header)); Nm4 h
else '?)<e^
break; :F`-<x/
} c>.=;'2
} `m+o^!SGe
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~A$y-Dt'
public void splitterStop() .6HHUy
{ $3)Z>p
bStop = true; e.VR9O]G
} q:ah%x[
s)9d\{
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} 6O\a\z
h"ZR`?h
-a\[`JHi
/* !}I+)@~\w
**FileAccess.java ={[9kR i
*//文件访问(定位，写) Ce`#J6lT
package NetFox; #Pr w2u
import java.io.*; )y"8Bx=x4
T7#}&>
,%<ICusZ
public class FileAccessI implements Serializable{ ZZ2vdy38
JS2h/Y$
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 y*H rv
RandomAccessFile oSavedFile; HVH<S
long nPos; 7v]9) W=y
8d1r#sILI
, G9{:
public FileAccessI() throws IOException >eM>Y@8=
{ A3eus
this("",0); b`& :`
} RcpKv;=iB
,,+iPGa<
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public FileAccessI(String sName,long nPos) throws IOException Yc p<N>)
{ P TMJ.;
oSavedFile = new RandomAccessFile(sName,"rw"); s~>0<3{5
this.nPos = nPos; W'"p:Uhq
oSavedFile.seek(nPos); B0$ge"FK9
} UiQF4Uc"
\$W\[s4I
qW 2'?B3<
public synchronized int write(byte[] b,int nStart,int nLen) Mem1X rBH
{ e]zd6{g[m
int n = -1; ~ya@ YP]';
try{ EK2mJCC|
oSavedFile.write(b,nStart,nLen); Aq;WQyZ2
n = nLen; 'y%*W:O
} jeWI<ms
catch(IOException e) 5fY7[{2
{ Ng|c13A=
e.printStackTrace (); fjh,e
} 4zhg#
<*[D30<
mRT$@xa]J
return n; ^{g('BQx
} "Ta"5XW
iCIU'yI
Ye]-RN/W
} [yx8?5
%_. fEFy07
\'.|7{Xu
/* s6(bTO.
**SiteInfoBean.java `G "&IQ8.
*/ l|sC\;S
package NetFox; cm17hPe`}n
K+3+?oYKH
}e]tn)
public class SiteInfoBean { |32uC3?o
2g HRfTF
EYSBC",
private String sSiteURL; //Site's URL :CGh$d] +
private String sFilePath; //Saved File's Path Ci$?Hm9n
private String sFileName; //Saved File's Name bsv!z\}
private int nSplitter; //Count of Splited Downloading File ]S7>=S
NudY9~
yn|U<Hxl~H
public SiteInfoBean() @M!nAQ8hY
{//nSplitter的缺省值为5 @&f~#Xe
//default value of nSplitter is 5 E-v^eMWX
this("","","",5); IN?6~O p
} ~nRbb;M
RC~C}
E~ +g6YlT
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ub9,Wd"^
{ T;sF@?
sSiteURL= sURL; &Y jUoe
sFilePath = sPath; aSt:G*a"
sFileName = sName; MeDlsO
this.nSplitter = nSpiltter; CPci 'SO
g_;4@jwTP"
:vJ1Fo!
} FJ] ?45
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B3Daw/G
public String getSSiteURL() (y5]]l
{ @cB6,iUr
return sSiteURL; S7(tGD
} s|D[_N!|
&Ivf!Bgm{Z
-+fW/Uo
public void setSSiteURL(String value) k{J\)z
{ cv"Bhql
sSiteURL = value; JQDS3v=1$
} z-JYzxL9
'J8Ga<s7C
n8Rsle`a
public String getSFilePath() `%_(_%K
{ ?/}-&A"
return sFilePath; _rz7)%Y'#$
} Odr<fvV,>
8+Abw)]s
gB])@O%/
public void setSFilePath(String value) qo7jrY5G
{ 6r)B|~,OA
sFilePath = value; yX%NFXD
} <Y)Aez
l0lvca=;
/)<Xoa
public String getSFileName() ~(}nd
{ uJU;C.LX
return sFileName; +Uxtxl'
} IHwoG(A~<
q0KGI/5s4+
bKQ_{cR
public void setSFileName(String value) BHpj_LB-P
{ 7_`_iymR
sFileName = value; >6gduD!6I
} lyw)4;wt\
gg@Ew4L&
I[KAW"
public int getNSplitter() r#(*x 2~,
{ 4[rX\?^e
return nSplitter; Lklb
} ,U.|+i{
<~ ?LU^
4F,RlKHBl
public void setNSplitter(int nCount) ^%NjdZuDO
{ [<.dOe7|
nSplitter = nCount; 8gJg7RxL
} LCMn9I
} p4@0Dz`Q
;CDa*(e
y4,t=Gq7^
/* KouIzWf.
**Utility.java H](TSt<Q"
*/ s]Z++Lh<{
package NetFox; V(M7d>N5G
&IP`j~b
3bagL)'iz
public class Utility { l}W"> yQ0
naM=oSB(
-# /'^O+%
public Utility() =xr2-K)e
{ m6o o-muAr
C,$7fW{?
xG|lmYt76
} gW^0A)5
OySn[4`(i
//线程睡眠 e?<$H\
public static void sleep(int nSecond) &XB1=b5
{ {CQI*\O
try{ lh-zE5;
Thread.sleep(nSecond); nQ;M@k&9eV
} ZmS ]4WM<
catch(Exception e) bq z*90
{ K Vnz{cx`
e.printStackTrace (); -;o0)DwZ
} -932[+
} (S8hr,%n
mV|Z5=f
//日志 CJt(c,!z
public static void log(String sMsg) 6JD~G\$
{ ^]9.$$GU\A
System.err.println(sMsg); 95*=&d
} t]+h.
vlPViHF.
g3c,x kaO
public static void log(int sMsg) }VqCyJu&{
{ `86})xz{
System.err.println(sMsg); wj\kx\+
} @VnK/5opS
} rhC x&L
z`!f'I--!
0>yuBgh
/* w%~Mg3|
**TestMethod.java -NUA
*/ in2m/q?
package NetFox; DYTC2
<1E5[9 q
_@O.EksY3r
public class TestMethod { 8i^d*:R
.s>.O6(^%
4d%QJ7y
public TestMethod() @|fT%Rwho<
{ ///xx/weblogic60b2_win.exe c Sktm&SP
try{ 5 &s<&h
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *_eY +\j
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); XyD*V;.E
SiteFileFetch fileFetch = new SiteFileFetch(bean); (4IH%Ez){
fileFetch.start(); `FmRoMW9+
} du&9mOrr
catch(Exception e){e.printStackTrace ();} 6,(S}x YDZ
R!2E`^{Wl
K*N8Vpz(
} #4F0o@Z
]EEac
$`_xP1bUT
public static void main(String[] args) #{zF~/Qq
{ T26'b .
new TestMethod(); v8\pOI}c
} uOb}R
} *u!l"0'\
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