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)); |z-A;uL<
} v0apEjT
for(int i=0;i<nEndPos.length-1;i++) &3:-(:<U
{ '>@evrG
nEndPos = nStartPos[i+1]; }BzV<8F
} TMT65X!
nEndPos[nEndPos.length-1] = nFileLength; /!P,o}l7
} >E^sZmY[f-
} ri.;&
Oz-X}eM
jLM1~`&
//启动子线程 Dc}-wnga
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; q~T*R<S
for(int i=0;i<nStartPos.length;i++) !Hr~B.f7
{ &?#V*-;^
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), HX7"w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1\$xq9
nStartPos,nEndPos,i); W{*U#:Jx1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wC}anq>>
fileSplitterFetch.start(); &)T5V
} J)"2^?!&B
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l*e*jA_>:7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); a[1^)=/DM
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5.q2<a :
nEndPos = " + nFileLength); |p-, B>p!
// fileSplitterFetch[nPos.length-1].start(); to|O]h2*U2
O>IY<]x>L
`gDpb.=Y
//等待子线程结束 J4;w9[a$
//int count = 0; g~rZ=
//是否结束while循环 :54ik,l
boolean breakWhile = false; LkK%DY
O@ F0UM`!
AVF(YD<U
while(!bStop) %-/[.DYt
{ =e$<["
write_nPos(); 1~zzQ:jAZ
Utility.sleep(500); K7 -AVMY
breakWhile = true; 64fa0j~<*M
wa\Yc,R
O&RW[ml*3
for(int i=0;i<nStartPos.length;i++) *:{s|18Pj
{ |D~mLs;&
if(!fileSplitterFetch.bDownOver) RXxi7^ U
{ a` s2 z
breakWhile = false; FAX|.!US*p
break; nm`[\3R
} (y*7 gf
} >B!E 6ah
if(breakWhile) ,.A@U*j
break; >-*rtiE
7l/.fSW
7/&i'y
//count++; 6!*be|<&
//if(count>4) <2"'R(4",
// siteStop(); #>iBu:\J
} ywTt<;
sEkfmB2J/
%IL] Wz<
System.err.println("文件下载结束！"); bA!n;
} w$[&ejFb
catch(Exception e){e.printStackTrace ();} }E0~'
} :tBIo7
t~]n"zgovz
rofj&{w
//获得文件长度 `u$ Rd
public long getFileSize() VHyH't_&s
{ X'Q?Mh
int nFileLength = -1; e=Ko4Ao2y
try{ <`rmQ`(}s
URL url = new URL(siteInfoBean.getSSiteURL()); %A64AJZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P{fT5K|
httpConnection.setRequestProperty("User-Agent","NetFox"); ~"|MwR!0
`?E|frz[
M(8dKj1+
int responseCode=httpConnection.getResponseCode(); n_QSuh/Wn
if(responseCode>=400) [U]^:sV)
{ QxS]6hA
processErrorCode(responseCode); xY4g2Q J
return -2; //-2 represent access is error @+Yql
} SQ'\Kd=
,.DTJ7H+
>M~1{
String sHeader; )Q= EmZbJz
diHK
|y1O M
for(int i=1;;i++) Pt5"q3ec{T
{ A0X'|4I
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2^ uP[
//Utility.log(in.readLine()); kb3>q($
sHeader=httpConnection.getHeaderFieldKey(i); +q n[F70}
if(sHeader!=null) 3r^Ls[ey
{ S!WG|75B
if(sHeader.equals("Content-Length")) C0C2]xx{
{ bpP-wA^Hd
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K|L&mL&8
break; ;>hRj!
} B|d-3\sn
} :m.6a4vx
else &s6;2G&L$
break; b'q ru~i
} X* 4C?v
} 43wm_4C!H
catch(IOException e){e.printStackTrace ();} xmVW6 ,<?
catch(Exception e){e.printStackTrace ();} H=lzW_(
?vt#M^Q
aa2 vk)~
Utility.log(nFileLength); o8_))
d?:KEi-<7
M>qqe!c*
return nFileLength; yz}ik^T
} OSoIH`tA
.A6D&-&z
>0F)^W?
//保存下载信息（文件指针位置） ncGt-l<9
private void write_nPos() #`]`gNB0Yg
{ Cv[_N%3[
try{ J.;!l
output = new DataOutputStream(new FileOutputStream(tmpFile)); AQ%B&Q(V1
output.writeInt(nStartPos.length); K g6hySb
for(int i=0;i<nStartPos.length;i++) GFGW'}w-
{ izDfpr}s4
// output.writeLong(nPos); m^!Kthq
output.writeLong(fileSplitterFetch.nStartPos); 0<i8 ;2KD
output.writeLong(fileSplitterFetch.nEndPos); i?wEd!=w
} T.(C`/VM
output.close(); '\B0#z3
} r4 $<,~
catch(IOException e){e.printStackTrace ();} rEHlo[7^
catch(Exception e){e.printStackTrace ();} o|G'vMph
} $^:s)Yv
Qm_IU!b
`T\_Wje(
//读取保存的下载信息（文件指针位置） 2dsXG$-W2
private void read_nPos() f9K+o-P.h
{ 7D(Eo{ue
try{ KvjsibI/Y
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); S>Z07d6&
int nCount = input.readInt(); gV}c4>v(
nStartPos = new long[nCount]; ~P7zg!p/q
nEndPos = new long[nCount]; LZtO Q__B)
for(int i=0;i<nStartPos.length;i++) &|-jU+r}B
{ |LV}kG(2
nStartPos = input.readLong(); *I:a\o~$[
nEndPos = input.readLong(); )\KU:_l
} ~xLo0EV"
input.close(); oRo[WQla
} ~4+ICCbH
catch(IOException e){e.printStackTrace ();} ]z O6ESH
catch(Exception e){e.printStackTrace ();} ;fW`#aE
} BOflhoUX
y(ceEV
23d*;ri5
private void processErrorCode(int nErrorCode) redMlHM
{ Sx:JuK@
System.err.println("Error Code : " + nErrorCode); 0fGt7 "Q
} xX?9e3(
d>gQgQ;g
r>#4Sr
//停止文件下载 frokl5L@
public void siteStop() 2BKiA[ ;;
{ kyi"U A82
bStop = true; ~|G`f\Ln"
for(int i=0;i<nStartPos.length;i++) 4|&_i)S-Y
fileSplitterFetch.splitterStop(); ::p%R@?
f AY(ro9Q(
7@R^B=pb
} LC7%Bfn!
} o2D;EUsNX
//负责部分文件的抓取 ,|g&v/WlC%
**FileSplitterFetch.java )[ QT?;
*/ qeDXG
package NetFox; 5O(U1 *
%I=/ y
wRdN(`;v
import java.io.*; EK.n $
import java.net.*; EfB.K}b^
!hFzIp
qZdA%
public class FileSplitterFetch extends Thread { IyEfisOK?
<(t{C8>g%
mlYkn
String sURL; //File URL \sAkKPI
long nStartPos; //File Snippet Start Position o@m7@$7
long nEndPos; //File Snippet End Position !K-qoBqKM
int nThreadID; //Thread's ID X$Shi *U[
boolean bDownOver = false; //Downing is over N\"Hf=Y(~
boolean bStop = false; //Stop identical mBxMDnh
FileAccessI fileAccessI = null; //File Access interface =Fc}T%
q[Tl#*P?y
:-_"[:t 5Z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -_xTs(;|8
{ SP\s{,'F-b
this.sURL = sURL; ;VzdlCZ@
this.nStartPos = nStart; wh#IQ.E-
this.nEndPos = nEnd; I<Cm$8O?
nThreadID = id; 9n49p?
fileAccessI = new FileAccessI(sName,nStartPos);//定位 GkxQEL
} "Lyb4#M
#eF,* d
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public void run() <*I*#WI&B
{ i[4!% FxB
while(nStartPos < nEndPos && !bStop) {Hie%2V
{ r $[{sW
iGSF5S
Es- =0gpK
try{ vmv6y*qU
URL url = new URL(sURL); 0 .UN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); baBPf{<
httpConnection.setRequestProperty("User-Agent","NetFox"); Q;ZV`D/FA
String sProperty = "bytes="+nStartPos+"-"; e7y,zcbv
httpConnection.setRequestProperty("RANGE",sProperty); SQ*%d.1
Utility.log(sProperty); c'XSs
xU2i&il^!
Jz4;7/
InputStream input = httpConnection.getInputStream(); D9H%jDv
//logResponseHead(httpConnection); 8>G5VhCm~o
ex#-,;T
<`WDNi$Y
byte[] b = new byte[1024]; l9]nrT1Hy
int nRead; V$wbmz
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g:.LCF
{ -'}#j\
nStartPos += fileAccessI.write(b,0,nRead); _>a`dp.19
//if(nThreadID == 1) yRi5t{!V
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mo9(2@~<
} @HTs.4
/eT9W[a
mE;^B%v
Utility.log("Thread " + nThreadID + " is over!"); /3.;sS]B
bDownOver = true; He$v'87]
//nPos = fileAccessI.write (b,0,nRead); )Y&B63]B
} RD0*]4>]
catch(Exception e){e.printStackTrace ();} KMG}VG
} 0}YadNb7
} +U<.MVOo.
belBdxa{"
LN)yQ-
//打印回应的头信息 ~c55LlO>
public void logResponseHead(HttpURLConnection con) ~Y{]yBGoF
{ Lr20xm
for(int i=1;;i++) {3SK|J`
{ Q,:h`%V
String header=con.getHeaderFieldKey(i); +vH#xc\'
if(header!=null) R%~~'/2V
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #V)l>
Utility.log(header+" : "+con.getHeaderField(header)); W9{;HGWS
else =jA.INin4
break; }O+S}Hbwy
} :#\jx
} ]<ay_w;
I?nU+t;
6kMEm)YjT
public void splitterStop() ,S m?2<
{ _dECAk &b
bStop = true; C^LxJG{L5
} 4]E1x l
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R6`mmJ+'
} 9':Hh'
S|;}]6p
Q);}1'c
/* 5z_Kkf?o
**FileAccess.java @+_pj.D
*//文件访问(定位，写) xSO5?eR"u
package NetFox; ~[kI![
import java.io.*; d|`8\fq
fOKAy'
=*.S<Ko)
public class FileAccessI implements Serializable{ z =\ENG|x#
0C3Y =F
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Q<DXDvL
RandomAccessFile oSavedFile; >s!k"s,
long nPos; qG2P?DR
e|>@ >F]K
QxuU3#l
public FileAccessI() throws IOException 4#t=%}
{ r[^O 7
this("",0); nEP3B'+
} _mQj=
/1m+iM^V
E(z|LS*3
public FileAccessI(String sName,long nPos) throws IOException kpy)kS
{ dj4a)p|YN
oSavedFile = new RandomAccessFile(sName,"rw"); @HE?G
this.nPos = nPos; BlM(Q/z
oSavedFile.seek(nPos); U]B-B+-
} arS@l<79
5E 9R+N
>I0 a$w
public synchronized int write(byte[] b,int nStart,int nLen) YG5mzP<T
{ {$pi};
int n = -1; D(Q]ddUi'
try{ naA8RD5/
oSavedFile.write(b,nStart,nLen); sO!m,pK(
n = nLen; |9BX ~`{
} c>T)Rc
catch(IOException e) LF)wn-C}
{ 0bD\`Jiv,
e.printStackTrace (); `,Y3(=3Xe?
} rmFcSolt,f
0-uVmlk=/
\IEuu^
return n; |oePB<N
} \@T;/Pj{[
sPl3JP&s
{qU;>;(
} h0A%KL
&" 5Yt&{
91nB?8ZE6,
/* yn20*ix{
**SiteInfoBean.java *y` (^kyS
*/ kw7E<aF!
package NetFox; U'~]^F%eyu
DMSC(Sz
ka{!' ^
public class SiteInfoBean { Mhb~wDQl
k9NHdi7&2
[r9HYju=
private String sSiteURL; //Site's URL : w>R|]
private String sFilePath; //Saved File's Path R((KAl]dL
private String sFileName; //Saved File's Name i=hA. y`
private int nSplitter; //Count of Splited Downloading File NO/5pz}1
l<(jm{q?u
<(xro/
public SiteInfoBean() 'F:Tv[qx
{//nSplitter的缺省值为5 gNkBHwv
//default value of nSplitter is 5 3Tc90p l*t
this("","","",5); FBOgaI83G
} Z^%HDB9^
0Pt%(^
(h[. Ie
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) cK\?wZ| Y
{ QF22_D<.}J
sSiteURL= sURL; 0HQTe>!
sFilePath = sPath; b&d4(dk
sFileName = sName; *iyc,f^w
this.nSplitter = nSpiltter; jR+kx:+
NSR][h_
cFq2 6(e
} \JCpwNT{P
H =&K_
V^>< =DNE
public String getSSiteURL() Hq?dqg'%~
{ g:6`1C
return sSiteURL; ;RQ}OCz9}8
} u?>8`]r
64<*\z_
q$`>[&I~)
public void setSSiteURL(String value) 9/I xh?
{ ^ ]+vtk
sSiteURL = value; wS >S\,LV
} [L ' >
6JRFYgI
}}"|(2I
public String getSFilePath() ZXIz.GFy+
{ ",Fvv
return sFilePath; Sogt?]HB$
} vTWm_ed+^
8.7lc2aX
\>{;,f
public void setSFilePath(String value) ~\<L74BB
{ 6['o^>\}f
sFilePath = value; S/l6c P
} #>sIXY
g;7u-nP
tDMNpl
public String getSFileName() )M"xCO3a
{ >LPIvmT4D?
return sFileName; ~8-xj6^
} 3BF3$_u)o
CAN1~
nV8iYBBym
public void setSFileName(String value) J: I@kM
{ h}DKFrHW;-
sFileName = value; S&D8Rao5
} N&|,!Cu
SDk^fTV8x
{M\n
public int getNSplitter() ;0uiO.
{ l|;]"&|_]c
return nSplitter; %J9+`uSl
} .S* sGauM
aB`jFp-
T#[#w*w/
public void setNSplitter(int nCount) R D?52\
{ PY&mLux%
nSplitter = nCount; m3&b)O7
} ,"YTG*ky
} JBLh4c3
6fCHd10!
M 5`hMfg
/* 8==_43
**Utility.java F6>oGmLy
*/ 0Fsa&<{6?
package NetFox; k-)Ls~#+
2h)Qz+|7
Y_~otoSoY
public class Utility { (Ap?ixrR_
)#`&[9d-
bU/YU0ZIT
public Utility() 'T;;-M3*
{ wyLyPJv
/Ba/gq0j
*>xCX
} 6` Aw!&{
s%RG_"l
//线程睡眠 OGG9f??
public static void sleep(int nSecond) +*aC \4w
{ e{*yV#Wl
try{ ;<nJBZB9u
Thread.sleep(nSecond); @Qp#Tg<'
} vcaPd}nf
catch(Exception e) `}rk1rl6
{ K6|R ;r5e{
e.printStackTrace (); 8NTE`l=>/
} JU)k+:\a
} z*9 ke
JY~CMR5#.O
//日志 s#(%u t
public static void log(String sMsg) *M$'dLn
{ MT$)A:"
System.err.println(sMsg); 8Dn~U:F/?
} 4=N(@mS
Yb1Q6[!
a>Zp?*9
public static void log(int sMsg) sk AF6n
{ 62K#rRS
System.err.println(sMsg); bfy=
} !/=.~B
} zJ@^Bw;A^@
ntW1 )H'o
LC\U6J't1
/* Z9Z\2t
**TestMethod.java MIb[}w=
*/ G^eXJusOv
package NetFox; KKWvV4u
EBr?>hl
xV=Tmu6l
public class TestMethod { Mz\l C)\B
,_Kr}RH
<y&&{*KW8m
public TestMethod() %E"Z &_3{
{ ///xx/weblogic60b2_win.exe ;|:R*(2
try{ *%E\mu,,c
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); c]/S<w<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); H8 xhE~'t
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0sTR`Xk
fileFetch.start(); qdxaP% p2
} ''3I0X*!
catch(Exception e){e.printStackTrace ();} q%dbx:y#
?-)v{4{s
P%N)]b<c*
} qB&Je$_uh
dP`B9>r
sRqecG(n
public static void main(String[] args) uL^`uI#I
{ 7!\zo mx
new TestMethod(); |=MhI5gsx
} vo%"(!
} IDL0!cF
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