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)); JwcC9 O
} 'Ad|*~
for(int i=0;i<nEndPos.length-1;i++) [G7S
{ \vp^[,SI
nEndPos = nStartPos[i+1]; s Vg89I&
} L?r\J8Ch<
nEndPos[nEndPos.length-1] = nFileLength; 89a`WV@}
} yvV]|B@sO
} js)I%Z
HQ`A.E2
s-),Pv|
//启动子线程 [OQ+&\
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; i2n66d
for(int i=0;i<nStartPos.length;i++) -SKcS#IF
{ `g:bvIV5x>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q7SRf$4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #4ii!ev
nStartPos,nEndPos,i); "Sd2VSLg
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8 qwOZ d
fileSplitterFetch.start(); :hUt7/3c
} J3AS"+]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6x"|,,&MD0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $iOkn|~<@W
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", lpHz*NZ0
nEndPos = " + nFileLength); ]0&ExD\4
// fileSplitterFetch[nPos.length-1].start(); <zE~N~;
Ve\=By-a|
@E@5/N6M
//等待子线程结束 CPS1b
//int count = 0; @2Ca]2,4
//是否结束while循环 +p#Q|o'
boolean breakWhile = false; #Mmr{4m
!K319 eE
_|%l) KO
while(!bStop) e#jkp'
{ U6Ws#e
write_nPos(); qD/X%`>Q
Utility.sleep(500); = 7TK&
breakWhile = true; =hse2f
<fm0B3i?
?IHa>f:
for(int i=0;i<nStartPos.length;i++) a]mPc^h
{ eLc@w<yB
if(!fileSplitterFetch.bDownOver) ui#K`.dn
{ (<:mCPk(~
breakWhile = false; _onEXrM
break; .qjdi`v
} E5U{.45
} K!a4>Du{
if(breakWhile) >UUT9:,plA
break; t<QSp6n""
wX!>&Gc.
iAAlld1
//count++; ;x=r.3OQy
//if(count>4) h-`*S&mZ
// siteStop(); 7,![oY[
} 37M?m$BL
iig ({b
,\cO>y@
System.err.println("文件下载结束！"); 5QoU&Hv
} OG&X7>'3I{
catch(Exception e){e.printStackTrace ();} A_vf3 *q
} }*ZOD1j
l~v BA$,
U;Ne"Jh
//获得文件长度 HLnizE
public long getFileSize() O]nZr
{ `p.O
int nFileLength = -1; aAX(M=3
try{ j;+!BKWy4
URL url = new URL(siteInfoBean.getSSiteURL()); KW~fW r8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Vg+jF!\7
httpConnection.setRequestProperty("User-Agent","NetFox"); u3>Dvl@
B- VhUS
oy)'wb~
int responseCode=httpConnection.getResponseCode(); 0f<$S$~h
if(responseCode>=400) -#ta/*TT:
{ X+*"FKm S.
processErrorCode(responseCode); qU) pBA
return -2; //-2 represent access is error 'n)]"G|
} 9se,c
jPjFp35;zb
@4Ox$M
String sHeader; JN Ur?+g
A]FjV~PB
oq>8
for(int i=1;;i++) h 'F\9t
{ v_zVhEtY
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); r^$4]@Wn
//Utility.log(in.readLine()); }8W5m(Zq9n
sHeader=httpConnection.getHeaderFieldKey(i); t*&O*T+fgy
if(sHeader!=null) C6XZZ
{ |Ir&C[QS{y
if(sHeader.equals("Content-Length")) a_pNFe
{ )ww#dJn
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); TZ]D6.mD
break; D\Nhq Vw
} cS'|c06
} v/Z!Wp1LV
else )$Erfu
break; *)2&gQ&%+
} &mM[q'V
} 0PK*ULwSN
catch(IOException e){e.printStackTrace ();} wjr1?c
catch(Exception e){e.printStackTrace ();} B[]v[q<
Q+O3Wgjy
E_aDkNT
Utility.log(nFileLength); >q:0w{.TU
jM E==)Y
)T=cd
return nFileLength; 8mCL3F
} %Q}T9%Mtj
k_2W*2'S
0;b%@_E
//保存下载信息（文件指针位置） 1w)#BYc=L
private void write_nPos() gZFtV
{ Uv(THxVh
try{ qw!_/Z3[
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5df~] -=0Y
output.writeInt(nStartPos.length); >lo,0oG
for(int i=0;i<nStartPos.length;i++) \&&jzU2
{ A&$oiLc
// output.writeLong(nPos); DL^}?Ve
output.writeLong(fileSplitterFetch.nStartPos); QsaaA MGY
output.writeLong(fileSplitterFetch.nEndPos); (Ut)APM
} +$eEZ;4
output.close(); Ol,Tw=?
} ;_yp@.,\T
catch(IOException e){e.printStackTrace ();} 7PDz ]i
catch(Exception e){e.printStackTrace ();} \X=?+| 9
} "g)@jqq:>
PXZZPW/
'g8~uP
//读取保存的下载信息（文件指针位置） MLL4nkO,`
private void read_nPos() ?mK`Wleh?
{ -?A,N,nnX
try{ ,FvBZ.4c3=
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,cR=W|6cQm
int nCount = input.readInt(); PKoB~wLH
nStartPos = new long[nCount]; K<HF!YU#I2
nEndPos = new long[nCount]; 7b,5*]oZ
for(int i=0;i<nStartPos.length;i++) FbMX?T"yH
{ Z:l.{3J$
nStartPos = input.readLong(); Yg5m=Lis
nEndPos = input.readLong(); OPp>z0p%6X
} *&b~cyC
input.close(); "#T3l^@
} >&0)d7Nu8m
catch(IOException e){e.printStackTrace ();} -5Qsc/s&
catch(Exception e){e.printStackTrace ();} 26fbBt8nP
} <$WRc\}&g
2TN+ (B#Z!
V9:h4]
private void processErrorCode(int nErrorCode) $?^#G8J
{ A^PCI*SN[
System.err.println("Error Code : " + nErrorCode); "(uEcS2<
} zG_e=
iyw"|+
<Z^t^ O
//停止文件下载 WN?1J4H
public void siteStop() 0ad -4
{ <(Ub(
bStop = true; }(AgXvRq
for(int i=0;i<nStartPos.length;i++) "Jw6.q+
fileSplitterFetch.splitterStop(); B;A^5~b
=;.#Bds
uJ<sa;
} >|jSd2_p
} ^ q]BCOfJ(
//负责部分文件的抓取 eR.ucTji
**FileSplitterFetch.java {s}@$rW
*/ >jjuWO3T
package NetFox; uX*H2"A
M9{?gM9
yW.s?3X
import java.io.*; 3 }Z[d
import java.net.*; 7Wg0-{yK4
oXG,8NOdC
SGn:f>N
public class FileSplitterFetch extends Thread { vKppXm1
H"W%+{AR
SS@F:5),
String sURL; //File URL kQXtO)
long nStartPos; //File Snippet Start Position E 5PefD\m
long nEndPos; //File Snippet End Position :70cOt~Z
int nThreadID; //Thread's ID E<;C@B
boolean bDownOver = false; //Downing is over 0IoS|P}6a
boolean bStop = false; //Stop identical #"%=7(
FileAccessI fileAccessI = null; //File Access interface e$|g
j;eR9jI$T
SEQ bw](ss
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException EeWCy5W
{ 6bCC6G
this.sURL = sURL; 4`uI)N(}*
this.nStartPos = nStart; @~Z:W<X
this.nEndPos = nEnd; lqe;lWC0Z
nThreadID = id; .Rxz;-VA
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :M(%sv</
} \:C@L&3[
}ex2tkz
:i+Tf~k{
public void run() ;Ad$Q9)EE
{ =if5$jE3
while(nStartPos < nEndPos && !bStop) 'VCF{0{H~
{ E`.dU<8HE
.x7d!t:(D
nE)?P*$3Z
try{ DWZ!B7Ts
URL url = new URL(sURL); 1QXv}36#3n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O7bTu<h=
httpConnection.setRequestProperty("User-Agent","NetFox"); "1_eZ`
String sProperty = "bytes="+nStartPos+"-"; k_.%(ZE
httpConnection.setRequestProperty("RANGE",sProperty); 9r!psRA:`)
Utility.log(sProperty); MHJH@$|]
^0ZabR'
K1a$ m2
InputStream input = httpConnection.getInputStream(); -4{sr| lm
//logResponseHead(httpConnection); `qp[x%7^
vFXih'=_
7HzO_u%H1
byte[] b = new byte[1024]; %{g<{\@4(;
int nRead; hl?G_%a
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |]sh*<:?,
{ !8M]n
nStartPos += fileAccessI.write(b,0,nRead); q-O=Em<*
//if(nThreadID == 1) @#$5_uU8\(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }8Tr M0q8
} TyVn5XHl^
[f,; +Ze
I5PI;t+
Utility.log("Thread " + nThreadID + " is over!"); E'zLgU)r`
bDownOver = true; {H{u[XR[z
//nPos = fileAccessI.write (b,0,nRead); 4% )I[-sH
} >AI65g
catch(Exception e){e.printStackTrace ();} `8xt!8Z$
} <z+5+h|^
} 4`Qu+&4J
\zCT""'i
1TeYA6 t
//打印回应的头信息 xG i,\K\:
public void logResponseHead(HttpURLConnection con) +@>K]hdr
{ hOjy$Z
for(int i=1;;i++) uc4#giCD
{ (;-< @~2
String header=con.getHeaderFieldKey(i); dq[X:3i
if(header!=null) X}C}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); q_K8vGm4e
Utility.log(header+" : "+con.getHeaderField(header)); *^+8_%;1
else z)N8#Y~vn
break; CU'$JF
} jt5en;AA[
} $/sIdFZi
#wn`choT'
f/Cf2 K
public void splitterStop() ,x#5.Koz
{ >.^/Z/[.L
bStop = true; G`3/${ti
} e7rD,`NiV
&0A^_Z .nA
. Z 93S|q
} ?QuD:vck
!Wn^B|
^p3"_;p)h
/* GSck^o2{
**FileAccess.java Bg.~#H
*//文件访问(定位，写) BVAxeXO
package NetFox; 8XFs)1s[
import java.io.*; aYc*v5QN3
'a8{YT4
x,)|;HXm
public class FileAccessI implements Serializable{ Rs*]I\
P_Rh& gkuK
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Z{<&2*
RandomAccessFile oSavedFile; |^: A,%>
long nPos; R'M=`33M
3.[ fTrzJ
[=f(u wY>g
public FileAccessI() throws IOException pGS!Nn;K2
{ >/W
this("",0); s.VtmAH
} S.G"*'N
`cu W^/c
-B+Pl*
public FileAccessI(String sName,long nPos) throws IOException r1vF/yt(
{ 2VB|a;Mo
oSavedFile = new RandomAccessFile(sName,"rw"); =8`!Ph@(
this.nPos = nPos; &1ZqC;
oSavedFile.seek(nPos); Xyz w.%4c
} {jK:hQX
VuU{7:
F]fBFDk
public synchronized int write(byte[] b,int nStart,int nLen) per$%;5E"
{ NQ9/,M
int n = -1; w$`[C+L
try{ Oh&k{DWE$
oSavedFile.write(b,nStart,nLen); G(Ky7SZ
n = nLen; yJ0q)x sS
} T09'qB
catch(IOException e) EFk9G2@_
{ @,9cpaL3
e.printStackTrace (); 6Fe$'TP
} 9 SBVp6'
_ Vo35kA
GW;\3@o
return n; *)8!~Hs
} 79yF {
:(?F(Q^
u]<_6;_
} H1fKe=$1
o<\uHr3
g><*qd?t
/* 8*7,qX
**SiteInfoBean.java O]1aez[
*/ p7Xe[94d^
package NetFox; 23iMG]J&
Y9w^F_relL
^C|N
public class SiteInfoBean { yh'uH
N!Cy)HnS\w
UVUoXv)N
private String sSiteURL; //Site's URL "<Q,|Md
private String sFilePath; //Saved File's Path vIQu"J&fE
private String sFileName; //Saved File's Name ?]]7PEee*
private int nSplitter; //Count of Splited Downloading File 3[UB3F4K
Qw@_.I
T4e-QEH
public SiteInfoBean() +\yQZ{4'@
{//nSplitter的缺省值为5 ~2L]K4Z^
//default value of nSplitter is 5 C?h}n4\B^?
this("","","",5); c*N>7IF,
} gc[BP>tl\
#[ TOe
(kFg2kG
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) VQ(l=k:}2
{ %h^ f?.(:
sSiteURL= sURL; sqE? U*8.-
sFilePath = sPath; =hq+9 R8=
sFileName = sName; .ZVADVg\
this.nSplitter = nSpiltter; )ePQN~#K}
1c19$KHu
(O`2$~mIM
} tGVC"a
3j}@}2D
g7g^iLU
public String getSSiteURL() /s|4aro
{ EpdSsfDP
return sSiteURL; w\`u|f;Aq
} ;cfmMt!QWJ
}0f"SWO>
;%V)lP"o
public void setSSiteURL(String value) ]<g`rR7}
{ xa]e9u%
sSiteURL = value; )a0%62
} %5rC`9^
GX-V|hLaGX
|b^+= "
public String getSFilePath() !eE;MaS>
{ @eOD+h'
return sFilePath; :+*q,lX8
} x_VD9
!]*Cwbh. u
9hn+eU
public void setSFilePath(String value) n4%ZR~9WH
{ kACgP!~/1
sFilePath = value; Z\. n6
} Y5,[udF:O
Md[M}d8
6)j4-
public String getSFileName() /|MHZ$Y9w?
{ h}$g}f%$+
return sFileName; /;{E}`
} K~6,xZlDWM
F)n^pT
kVeR{i<*(
public void setSFileName(String value) R!Lh~~@{(
{ vOQ 3A%/
sFileName = value; oo4aw1d
} %<]4]h
@]F1J
;U)xZ _Ew~
public int getNSplitter() tPqWe2
{ EJ@&vuDd$
return nSplitter; DV{0|E
} 0aM&+j\q}
Qo$j'|lD
B9(@.
public void setNSplitter(int nCount) JEh(A=Eu>
{ 1Wr,E#+C
nSplitter = nCount; euiP<[|h=
} `~k`m{4.a
} {$xt.<
{3`cSm6c
$H8B%rT]
/* 6"YcM:5~
**Utility.java FKBI.}A?!'
*/ d+o.J",E
package NetFox; G$mAyK:
!*e1F9k
~J:]cy)Q
public class Utility { <q.Q,_cW
E< Y!BT[X
~YRG9TK
public Utility() )lZoXt_3
{ NH'Dz6K5
0PD=/fh[
mgE r+
} ]_(J8v
e);`hNLih
//线程睡眠 IqAML|C
public static void sleep(int nSecond) Qg]+&8!*
{ LU $=j
try{ alH6~
Thread.sleep(nSecond); yu>)[|-
} g{^~g
catch(Exception e) @1N.;]|
{ 9? y&/D5O
e.printStackTrace (); tj4/x7!
} %<0'xJ%%Q
} v`@M IOv
FBxg^g%PB@
//日志 B~B,L*kC2
public static void log(String sMsg) ezb*tN!
{ 1ixBwnp?
System.err.println(sMsg); A{p_I<
} v{SZ(;
]P/i}R:
%xrldn%
public static void log(int sMsg) h S)lQl:^
{ 8]mRX~
System.err.println(sMsg); ,N1pww?
} d$^@$E2f
} -tIye{
UD=[::##
2HO2
/* [y~kF?a
**TestMethod.java S!rVq,| d
*/ ,FwpHs $A
package NetFox; (mplo|>
D#P]tt.Z
NL,6<ZOon,
public class TestMethod { CG;+Z-"X
7g$*K0m`
)t((x
public TestMethod() @?>5~
{ ///xx/weblogic60b2_win.exe Oyb0t|do+
try{ osc A\r
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %(|-+cLW+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); PhAD:A
SiteFileFetch fileFetch = new SiteFileFetch(bean); +/ {lz8^,
fileFetch.start(); |8tKN"QG
} ,Wtgj=1!.
catch(Exception e){e.printStackTrace ();} c/^l2CJ0
qI>,PX
&c}2[=
} LP !d|X
HQwrb HS
#0?3RP
public static void main(String[] args) ;66{S'*[
{ n0G@BE1Y=
new TestMethod(); \r9E6LLX'
} I:w+lchAMe
} [kTckZv
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