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)); UW/3{2
} 2]NAs9aZ
for(int i=0;i<nEndPos.length-1;i++) mU+FQX
{ oiv2rOFu
nEndPos = nStartPos[i+1]; 8<-oJs_o+
} {?f^
nEndPos[nEndPos.length-1] = nFileLength; 7#9'2dI
} vYSetAdv
} [ lzy &To
]EM)_:tRf
+:"6`um|
//启动子线程 A-7wkZ.H
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; I4<{R
for(int i=0;i<nStartPos.length;i++) 7 xp1\j0
{ 0"kE^=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T]nR=uK6LL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]\a\6&R
nStartPos,nEndPos,i); }&(E#*>x
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g2aT`=&Z
fileSplitterFetch.start(); l<aqiZSY
} I^M#[xA
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bL'#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }+dM1O
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", O&3r*vd
nEndPos = " + nFileLength); A)RI:?+
// fileSplitterFetch[nPos.length-1].start(); 6t_ 3%{
b>bgUDq
uq|vNLW26
//等待子线程结束 Lov.E3S6;
//int count = 0; 3%[)!zKv
//是否结束while循环 miG;]-"^
boolean breakWhile = false; -; us12SZ
z^P* :
tIxhSI^
while(!bStop) Th~3mf #
{ -Ap2NpZ"t
write_nPos(); ^fE\S5P
Utility.sleep(500); @jE d%W
breakWhile = true; } T/}0W]0
(RDa,&
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for(int i=0;i<nStartPos.length;i++) Som. qD
{ [GR|$/(z=
if(!fileSplitterFetch.bDownOver) FtFv<UV
{ G>=9gSLM
breakWhile = false; V4`:Vci Aw
break; Ms:KM{T0
} 5w,lw
} *or2
if(breakWhile) NIGB[2V(
break; mh A~eJ
'ZGT`'ri
hF{x')(#l
//count++; d`?U!?Si
//if(count>4) YW?7*go'Z
// siteStop(); {k_ PMl0G
} o%V @D'w
[!J @a
Q? <-`7
System.err.println("文件下载结束！"); ?qf:_G
} =E [4H
catch(Exception e){e.printStackTrace ();} $@[dm)M
} J ?ztn
}t@f|TX
m4Phn~>Gg
//获得文件长度 n0+g]|a AF
public long getFileSize() g[#k.CuP
{ 'DCKD4@C/
int nFileLength = -1; }b_R5U$@@
try{ lfxuc7Rdla
URL url = new URL(siteInfoBean.getSSiteURL()); Bmx(qE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C<[d
httpConnection.setRequestProperty("User-Agent","NetFox"); w8 ?Pb$Fe
mP9cBLz
qZ8|B
int responseCode=httpConnection.getResponseCode(); d98))G~W
if(responseCode>=400) b$dJ?%W
{ ]> nPqL
processErrorCode(responseCode); |MTpU@`p5
return -2; //-2 represent access is error ruZYehu1W
} =7 Jy
pT("2:)x
+"k.E x0:
String sHeader; v2/yw,
tt+>8rxF:;
.abyYVrN4?
for(int i=1;;i++) &u+yM D
{ "%{,T
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); D ?Nd;[
//Utility.log(in.readLine()); 5~@?>)TBv
sHeader=httpConnection.getHeaderFieldKey(i); Q=d.y&4%
if(sHeader!=null) Dh hG$
{ '8s>rH5[V
if(sHeader.equals("Content-Length")) +mJ :PAy4
{ XMt u"K
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); bH'S.RWp=
break; ?r{TOjn
} 4^0d)+Ff
} w+t#Yb\7
else c:=7lI
break; `%$8cZ-kr
} 7n\ThfH{
} \:]DFZ=!
catch(IOException e){e.printStackTrace ();} <_"B}c/2$
catch(Exception e){e.printStackTrace ();} tRLE,(S,-
xU@1!%l@
_,DO~L
Utility.log(nFileLength); gzVtxDh
S4L-/<s[*
DW1@<X
return nFileLength; Kb^>X{
} ki\B!<uv
TG1P=g5h
ec`bz "1
//保存下载信息（文件指针位置） ,%A)"doaG
private void write_nPos() bRWIDPh
{ t(}/g
try{ A[RHw<
output = new DataOutputStream(new FileOutputStream(tmpFile)); GHv{
output.writeInt(nStartPos.length); p`d XqW
for(int i=0;i<nStartPos.length;i++) lwVk(l Z
{ i*X{^A73"
// output.writeLong(nPos); -M6L.gi)oJ
output.writeLong(fileSplitterFetch.nStartPos); tC^ 1}
output.writeLong(fileSplitterFetch.nEndPos); '9'l=Sh
} ( :
output.close(); A'GlCp
} 5gSylts8
catch(IOException e){e.printStackTrace ();} {1jpLdCbV^
catch(Exception e){e.printStackTrace ();} vwVVBG;t
} yB.G=90
<O.Kqk* nq
doBNghS
//读取保存的下载信息（文件指针位置） Ski G2n]
private void read_nPos() 0|ZVA+
{ :-)GNf yGz
try{ `3J':Vh
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); I6+2>CUGo
int nCount = input.readInt(); 5Q`RTn%
nStartPos = new long[nCount]; Hk@r5<{
nEndPos = new long[nCount]; XlVc\?
for(int i=0;i<nStartPos.length;i++) >W r$Y{
{ Z(p*Z,?u
nStartPos = input.readLong(); {|z#70
nEndPos = input.readLong(); ?{eY\I
} cQX:%Ix=
input.close(); )u0O_R
} Y=E9zUF
catch(IOException e){e.printStackTrace ();} Rv,82iEKs
catch(Exception e){e.printStackTrace ();} qYK4)JP
} hd5$yU5JQ
IhE9snJ[
(VyA6a8
private void processErrorCode(int nErrorCode) BBxc*alG0
{ #EJP(wXa
System.err.println("Error Code : " + nErrorCode); JT04vm4
} Y.>kO
dByjcTPA
L=RGL+f1_
//停止文件下载 f3G1r5x
public void siteStop() C,"=}z1P
{ z$|;-u|
bStop = true; B52yaG8C
for(int i=0;i<nStartPos.length;i++) @TysXx
fileSplitterFetch.splitterStop(); +oZH?N4yaM
b0 &
+Qs!Nhsq
} C`NmZwL
} =p q:m
//负责部分文件的抓取 DVh)w}v
**FileSplitterFetch.java MWs~#ReZ
*/ hk_g2g
package NetFox; @.gPJMA
F}'wH-qp
$eBQH
import java.io.*; v5T`K=qC
import java.net.*; \,R!S/R#
%G[/H.7s-
F;P5D<
public class FileSplitterFetch extends Thread { hU"F;4p
o\4CoeG
SNab
String sURL; //File URL zJY']8ah
long nStartPos; //File Snippet Start Position w>[T&0-N
long nEndPos; //File Snippet End Position $3k "WlRG
int nThreadID; //Thread's ID n(>C'<otj
boolean bDownOver = false; //Downing is over &RW`W)0;
boolean bStop = false; //Stop identical 2bLI%gg3
FileAccessI fileAccessI = null; //File Access interface r+S;B[Vd
@}DFp`~5|
>F[GVmC
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException KQ{Lt?S
{ a8Uk[^5
this.sURL = sURL; V&*D~Jq
this.nStartPos = nStart; WK==j1
this.nEndPos = nEnd; &yU>2=/T
nThreadID = id; IP ,.+:i
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @7W?8
} qSTWb%
rslvsS:
Jf_%<\ O
public void run() <bUXC@3W
{ @?Zf-.
while(nStartPos < nEndPos && !bStop) @h}`DNaZ^
{ m[:K"lZ ]2
]-:6T0JuS
w2OsLi Sv
try{ _Yq@FOu
URL url = new URL(sURL); u,o1{%O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fx)KNm8Lx
httpConnection.setRequestProperty("User-Agent","NetFox"); f*m[|0qI<X
String sProperty = "bytes="+nStartPos+"-"; /e1(? 20
httpConnection.setRequestProperty("RANGE",sProperty); sbnjy"Z%
Utility.log(sProperty); 6G of.:"f
".P){Dep$4
~.oj.[}
InputStream input = httpConnection.getInputStream(); rF] +,4
//logResponseHead(httpConnection); | -+zofx
"IFgRaP=
/t5p-
byte[] b = new byte[1024]; ]Blf9h7
int nRead; F*` t"7Lm
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &| !B!eOY
{ iZxt/}1X0
nStartPos += fileAccessI.write(b,0,nRead); exZLj0kvF
//if(nThreadID == 1) LZ<[ll#C
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~3CVxbB^<
} IQnIaZ
,T|x)"uA`
U~H?4Izl=
Utility.log("Thread " + nThreadID + " is over!"); cWa)#:JOV
bDownOver = true; U>F{?PReA?
//nPos = fileAccessI.write (b,0,nRead); cyQBqG
} =a$Oecg?
catch(Exception e){e.printStackTrace ();} }k7'"`#?"
} ->gZ)?Fqy
} ] fwZAU
{(tHk_q
Ri)uq\E/#
//打印回应的头信息 S3Y2O x
public void logResponseHead(HttpURLConnection con) 8-Me.2K
{ |"]PCb)!
for(int i=1;;i++) I=IjdwbH
{ wK!~tYxP
String header=con.getHeaderFieldKey(i); h|)vv4-d|
if(header!=null) lV6dm=k
//responseHeaders.put(header,httpConnection.getHeaderField(header)); PsnGXcj
Utility.log(header+" : "+con.getHeaderField(header)); ke%pZ7{u
else 8P2 J2IU
break; Riry_
} O!&,5Dy
} F9flSeN
wtH~-xSB|
XP3xJm3
public void splitterStop() uQ/h'v
{ l]6%lud8_
bStop = true; _}gtcyx
} v }\,o%t^
*%gF2@=r8F
)rm4cW_
} ;\{`Ci\
f_=~H<j!
,S&z<S_
/* rwf^,r"r
**FileAccess.java 6b=q-0yj
*//文件访问(定位，写) L'Q<>{;Ig
package NetFox; =,V|OfW
import java.io.*; v=?2S
5@!st
{38bv.3'
public class FileAccessI implements Serializable{ o{WyQ&2N
n<7q`tM#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 v)X\GmW7w
RandomAccessFile oSavedFile; W+=o&V
long nPos; *d*,Hqn
hdma=KqZ(
<q2?S
public FileAccessI() throws IOException (k?7:h
{ oBQm05x"
this("",0); L.'}e{ldW
} h2Bz F
fV\]L4%
DN] v_u+}
public FileAccessI(String sName,long nPos) throws IOException )>a B
{ I5ZqBB
oSavedFile = new RandomAccessFile(sName,"rw"); {XCf-{a]~
this.nPos = nPos; 9KuD(EJS
oSavedFile.seek(nPos); quxdG>8
} * ?Jz2[B
r@G#[.*A>
CH#k(sy
public synchronized int write(byte[] b,int nStart,int nLen) %;"@Ah
{ c1XX~8
int n = -1; f!_ ctp
try{ SU.ythU2,c
oSavedFile.write(b,nStart,nLen); K9Hqq7"%
n = nLen; sW@krBxMv
} %;xOB^H^
catch(IOException e) 9&]M**X
{ F>hZ{
e.printStackTrace (); 0Q5^C!K
} !ZXUPH
pv)`%<
#I*QX%(H#
return n; TFQ!7'xk)
} /8'S1!zc
5 `/< v^
rf&M!d}!
} Cfu=u *u
qoMfSz"(
V@-)\RZm
/* ;3eKqr0
**SiteInfoBean.java }f}}A=
*/ 5VW|fI
package NetFox; xg@NQI@7
7V7zGx+Z7
?/hZb"6W
public class SiteInfoBean { 8hanzwoJ:
!D^c3d
`{v?6:G:Q
private String sSiteURL; //Site's URL BqK(DH^9N
private String sFilePath; //Saved File's Path !~i' -4]
private String sFileName; //Saved File's Name Z~
private int nSplitter; //Count of Splited Downloading File 4'1m4Ugg
/b#l^x:j
Ta=s:trP
public SiteInfoBean() @@G6p($
{//nSplitter的缺省值为5 /#NYi,<{X
//default value of nSplitter is 5 Q n)d2-<
this("","","",5); (.Y/
} T#@lDpO
y[};J vk
K>:]Bx#F7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) k;W@LfP
{ OHrY(I6
sSiteURL= sURL; x3+oAb@o/
sFilePath = sPath; I?#85l{>
sFileName = sName; 9p* gU[
this.nSplitter = nSpiltter; n"Veem[_4g
Fh|#u:n
DE$q+j0P
} g^Yl TB
g]~h(mI
"ICC B1N|
public String getSSiteURL() Fzlozx1y[
{ YUU-D(
return sSiteURL; G6P)C##ibn
} ji1HV1S
{PU!=IkTS
'wasZ b<^
public void setSSiteURL(String value) UB`ToE|Ii
{ m><w0k?t
sSiteURL = value; N7r_77%m0
} `$LWmm#
:e1o<JgPt
~5 N)f UI\
public String getSFilePath() -/C)l)V}
{ T VmH
return sFilePath; ^[E'1$D
} Ox!U8g8c
lH^^77"4Qo
%.v{N6
public void setSFilePath(String value) p^kUs0$GS
{ 85:NFa@J
sFilePath = value; N{SQ(%V
} ^$>XW\yCs
~[o4a'
Qp,DL@mp>8
public String getSFileName() `N//A}9
{ cLa]D[H
return sFileName; pL=d% m.W
} mMx;yZ
)4U>!KrY
w.\w1:d
public void setSFileName(String value) [S]S^ej*8
{ tY${M^^<J
sFileName = value; vr^~yEr
} {#P`^g
x&Vm!,%:1
AmPMY:1i"
public int getNSplitter() 0kQPJWF
{ jxaD&4Fs8
return nSplitter; X[s8X!#
} =h6 sPJ
b !@Sn/
9Ya<My
public void setNSplitter(int nCount) keW~ NM
{ PP~rn fE
nSplitter = nCount; 0_P}z3(M
} anw}w!@U
} #PDf,^
HjqB^|z
)0vU k
/* _\PNr.D8
**Utility.java o}Odw;
*/ -4w=s|#.\
package NetFox; n~V4nj&_T
1(zsOeX
H7Uli]e3
public class Utility { ,t{,_uPJY
)3YtIH_
4h!f/aF'
public Utility() ,/&'m13b/L
{ l.\re"Q
ECdvX0*a
Tu{&v'!j6
} :WI.LKlo~
pMg3fUIM
//线程睡眠 zsU=sTsL
public static void sleep(int nSecond) |6UtW{2I/
{ \$aF&r<R
try{ 9`jcC-;iv
Thread.sleep(nSecond); fJ\sguZ
} ^_t%kmL`
catch(Exception e) x^|Vaf
{ IEjP<pLe
e.printStackTrace (); x83 !C}4:
} Nw&!}#m
} hmx= 35
<H1`
//日志 n,eJ$2!J
public static void log(String sMsg) YSJy`
{ F/m^?{==~*
System.err.println(sMsg); -LDCBc"
} *#%9Rp2|
PkE5|d*,
I)q,kP@yY
public static void log(int sMsg) _LAS~x7,
{ HkV1sT
System.err.println(sMsg); IX: 25CEI2
} w{~+EolK
} ms($9Lv/
~^u16z,
Wk:hFHs3
/* ^JI o?R
**TestMethod.java i,V;xB2
*/ nJRS.xs
package NetFox; mS#zraJn5
ccCzu6
%N;!+ ;F_g
public class TestMethod { Z3k(P
/vY_Y3k#
[s9O0i" Y
public TestMethod() 5qg2Zc~
{ ///xx/weblogic60b2_win.exe +jg9$e"
try{ JOjoiA
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5Zmw} M
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); oLWJm
SiteFileFetch fileFetch = new SiteFileFetch(bean); i{!T&8
fileFetch.start(); xD&^j$Em
} Lb{e,JH
catch(Exception e){e.printStackTrace ();} *Ype>x{
nf1#tlIJd
IchCACK
} U.AjYez
pA{ 5V9
*Nyev]8
public static void main(String[] args) r'CM
{ r1ws1 rr=
new TestMethod(); Q0Nyqhvi
} 8Qh#)hiW!
} $Vc~/>
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