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)); 8`e75%f:2
} =+K2`=y;WF
for(int i=0;i<nEndPos.length-1;i++) s68&AB
{ %E\&9,
nEndPos = nStartPos[i+1]; L0\97AF
} e;1n!_l\
nEndPos[nEndPos.length-1] = nFileLength; ?}y{tav=
} y:6&P6`dx
} os|Y=a
NdpcfZq
XUf]gQu3=
//启动子线程 ^T):\x(
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Nqih LUv
for(int i=0;i<nStartPos.length;i++) E'|@hL-jn
{ X2avo|6e
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k 7 !{p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), H-&Z+4 +Xs
nStartPos,nEndPos,i); E;[ANy4L
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V2< 4~J2:9
fileSplitterFetch.start(); m_{?py@tZ
} . zM
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dgb#PxOMH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ho3$T
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 'Xl[ y
nEndPos = " + nFileLength); 9|Z25_sS
// fileSplitterFetch[nPos.length-1].start(); 1 J3h_z6/
Ok7i^-85
rFY% fo
//等待子线程结束 oLJP@J
//int count = 0; qA4w*{JN
//是否结束while循环 yDwG,)m 4s
boolean breakWhile = false; h^{D "
&X0qH8W
Ne^md
while(!bStop) %O$4da"y
{ 5v51:g>c
write_nPos(); f0S&_gt
Utility.sleep(500); p&Usl.
breakWhile = true; qPJU}(9#B
SiN22k+
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for(int i=0;i<nStartPos.length;i++) 8mM^wT
{ JGS4r+
if(!fileSplitterFetch.bDownOver) mlolSD;7
{ 3*13XQ
breakWhile = false; v!oXcHK/
break; 4~< :Pj
} &.sfu$]
} ;Drt4fOxX
if(breakWhile) -p|@Enn
break; .Rq|F
Jf<+VJ>t
(A.%q1h
//count++; -]1F]d
//if(count>4) Isa]5>
// siteStop(); Iu`B7UOF
} *,w9#?2x
[[{y?-U
tx=~bm"*?
System.err.println("文件下载结束！"); JFw<Po,MEa
} k_)H$*
catch(Exception e){e.printStackTrace ();} ^rd]qii"
} p4k*vuu>
ISy\g`d`C
(h NSzG\
//获得文件长度 _<?lP$Xr
public long getFileSize() wgm?lfX<
{ mT8")J|2
int nFileLength = -1; :Gyv%>.
try{ ^P&)2m:s
URL url = new URL(siteInfoBean.getSSiteURL()); Z!Y ^iN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); QO;W}c:N
httpConnection.setRequestProperty("User-Agent","NetFox"); V\nQHzjF<6
-3 }
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int responseCode=httpConnection.getResponseCode(); @pueM+(L&
if(responseCode>=400) ]|cL+|':y
{ !(=bH"P
processErrorCode(responseCode); K8 Y/sHl
return -2; //-2 represent access is error j(Tt-a("z
} Xj:?V;
]d]tQPEU
u@v0I$
String sHeader; PxENLQ3a=
^cO^3=
Q`#Y_N-h+
for(int i=1;;i++) <&3qFK*9r
{ !|P>%bi
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \wY? 6#;
//Utility.log(in.readLine()); _9!_fIY
sHeader=httpConnection.getHeaderFieldKey(i); Xz`?b4i
if(sHeader!=null) m7z6c"?lB
{ g0-hN%=6
if(sHeader.equals("Content-Length")) +(d\`{A
{ <<>?`7N
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Q>y2C8rnJ/
break; vJg|}]h>L
} +'qzk>B
} !QoOL<(){
else k8E'wN
break; =k]RzeI
} <5*cc8
} eup#.#J
catch(IOException e){e.printStackTrace ();} RFyeA. N
catch(Exception e){e.printStackTrace ();} *Q bPz4,"
^J0*]k%
YKbR#DC\
Utility.log(nFileLength); y"=j[.
OA#AiQUR
mgeNH~%m@*
return nFileLength; KL]@y!QU
} d,j"8\@
?`?"j<4e
;kO Op@e
//保存下载信息（文件指针位置） B6tp,Np5,
private void write_nPos() 3rX5haD\
{ c!@g<<}[(
try{ 8E`rs)A
output = new DataOutputStream(new FileOutputStream(tmpFile)); .%>UA|[~:
output.writeInt(nStartPos.length); Q8.SD p
for(int i=0;i<nStartPos.length;i++) Q5'DV!0aSv
{ 6AgevyVG
// output.writeLong(nPos); 3{o5AsVv
output.writeLong(fileSplitterFetch.nStartPos); hamn9
output.writeLong(fileSplitterFetch.nEndPos); vluA46c
} ol^J-
output.close(); P@LYa_UFsN
} 56(S[
catch(IOException e){e.printStackTrace ();} XBv:$F.>$
catch(Exception e){e.printStackTrace ();} M/ @1;a@\
} Nq>74q]}n8
Ct[{>asun
xcO Si>
//读取保存的下载信息（文件指针位置） m_~!Lj[u.
private void read_nPos() :Mr_/t2(
{ xk=5q|u_-
try{ yRaB\'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); T1ZAw'6(K
int nCount = input.readInt(); b!VaEK
nStartPos = new long[nCount]; 9j458Yd4*
nEndPos = new long[nCount]; E.kGBA;a?
for(int i=0;i<nStartPos.length;i++) MH|!tkW>:
{ )24r^21.q
nStartPos = input.readLong(); `mV&[`NZ
nEndPos = input.readLong(); +5(#~
} B5"(NJ;
input.close(); !%n3_tZC
} |<&9_Aq_
catch(IOException e){e.printStackTrace ();} @K`2y'#b
catch(Exception e){e.printStackTrace ();} GD?4/HkF
} ]dB6--
Jvt| q5
HJT}v/FZ
private void processErrorCode(int nErrorCode) 7r#U^d(
{ -AcLh0pc
System.err.println("Error Code : " + nErrorCode); 0?525^
} :Rc>=)<7
@O b$w1c
_W]qV2j
//停止文件下载 L 1=HD
public void siteStop() +VSJve |
{ \vbU| a
bStop = true; g+h)s!$sB
for(int i=0;i<nStartPos.length;i++) #|76dU
fileSplitterFetch.splitterStop(); xwG=&+66
o*H j E
VH1PC
} B'\^[
} Y3G$(+i8
//负责部分文件的抓取 ]MJyBz+k
**FileSplitterFetch.java JgXP2|Y!
*/ Ld>y Fb(`
package NetFox; qCg`"/0
24Lo.
tW;?4}JR
import java.io.*; kxU<?0
import java.net.*; Vrl)[st!;I
;pu68N(B
C=L_@{^Rgb
public class FileSplitterFetch extends Thread { =E@wi?
kW>Q9Nc=V
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String sURL; //File URL ~[bS+]d!
long nStartPos; //File Snippet Start Position i{zg{$U
long nEndPos; //File Snippet End Position BG!;9Z{u
int nThreadID; //Thread's ID '3B`4W,
boolean bDownOver = false; //Downing is over F/z$jj)
boolean bStop = false; //Stop identical cRBdIDIc
FileAccessI fileAccessI = null; //File Access interface Onoi^MDy
NQzpgf|h
=qH9<,p`H
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |5|^[v
{ ^LgaMmz
this.sURL = sURL; X6s6fu;
this.nStartPos = nStart; =~Oi:+L
this.nEndPos = nEnd; "5*n(S{ks
nThreadID = id; K8CjZpzq
fileAccessI = new FileAccessI(sName,nStartPos);//定位 `WvNN>R
} (u`[I4z`
%/!n]g-
hXr`S4aJ
public void run() e6n1/TtqM
{ !l!^`c
while(nStartPos < nEndPos && !bStop) (.TkvUj`
{ i1RU5IRy|j
tX)l$oRPr
*oLAO/)n
try{ sdP% Y<eAT
URL url = new URL(sURL); gAt[kW< n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gIv :<EJ9
httpConnection.setRequestProperty("User-Agent","NetFox"); [v$_BS#u^3
String sProperty = "bytes="+nStartPos+"-"; J~7E8
httpConnection.setRequestProperty("RANGE",sProperty); v%c r
Utility.log(sProperty); O8#}2
|/K+tH
$#ks`$vM
InputStream input = httpConnection.getInputStream(); +tFm DDx=
//logResponseHead(httpConnection); JF7n|o-`?
\5UwZx\
Z'c{4b`N
byte[] b = new byte[1024]; WS6pm6@A*!
int nRead; z[:UPPbW
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) K$_Rno"
{ lk8g2H ,
nStartPos += fileAccessI.write(b,0,nRead); MK"PCE5^i6
//if(nThreadID == 1) zh7#[#>t
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f&=y\uP]
} 1Y iUf
NQS@i'W=g
7MIu-x|
Utility.log("Thread " + nThreadID + " is over!"); !%b.k6%>w
bDownOver = true; Pe@M_ r
//nPos = fileAccessI.write (b,0,nRead); Qd"{2>
} 41 sClC"
catch(Exception e){e.printStackTrace ();} ~J1;Z0}#
} |0:&dw?*!
} g0t$1cUR
WtF
I,dH\]^h=
//打印回应的头信息 )%p.v P'p
public void logResponseHead(HttpURLConnection con) o_
{ `=b)fE
for(int i=1;;i++) 0JTDJZOz@#
{ "(j.:jayd
String header=con.getHeaderFieldKey(i); <]I[|4J 7
if(header!=null) -Si'[5@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); U1(<1eTyu
Utility.log(header+" : "+con.getHeaderField(header)); \.p{~Hv
else | ZBv;BW
break; V#jFjObTN
} {'dpRq{c|
} |aef$f5
rqk1 F~j|
Ro :/J
public void splitterStop() CpHF3o`Z6
{ H?tonG.^(
bStop = true; <V)T_
} R?3^Kx
S N_!o2F2
^S!^$d*
} 3XY;g{`=q
n,sl|hv2U
)qs>Z?7
/* X~XpX7d!
**FileAccess.java 4"72
*//文件访问(定位，写) *=i|E7Irg
package NetFox; -E~pCN(E
import java.io.*; ~6!{\un
Y%!3/3T
g+BW~e)
public class FileAccessI implements Serializable{ :NJb<%$
*IWO ,!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 z VleJ!d
RandomAccessFile oSavedFile; @F)51$Ld
long nPos; un|+YqLf
)@)wcf!b
FNlzpCT~L
public FileAccessI() throws IOException 6LZ(bP'd;
{ ]CyWL6z
this("",0); ^sIxR*C[v
} {M:Fsay>p
5|YpkY
dn/0>|5OF(
public FileAccessI(String sName,long nPos) throws IOException n[4F\I>
{ }R5>ja0
oSavedFile = new RandomAccessFile(sName,"rw"); g2L^cP>2
this.nPos = nPos; <)c/PI[j
oSavedFile.seek(nPos); {U8Sl.
} 9ui_/[K
QXx<Hi^ /
nTO,d$!Kp
public synchronized int write(byte[] b,int nStart,int nLen) 4$9WJ~V{
{ -1t"(v
int n = -1; xZAc~~9tD
try{ L?!*HS7m
oSavedFile.write(b,nStart,nLen); Fy^*@&
n = nLen; x,YC/J
} /CX_@%m}e=
catch(IOException e) HRO:U%
{ Aat_5p
e.printStackTrace (); =*0<.Lo':
} @8X)hpHf
^t4T8ejn
-U;2 b_
return n; uPbvN[~t
} Ut4cli&cC
VS0 &[bl
l6ayV
} --E_s/
1~\YJEsb}d
=$3]%b}
/* 8Z{&b,Y4L
**SiteInfoBean.java b%<-(o/
*/ bL\ab
package NetFox; +O P8U]~
"PH}\Dl=
O#}T.5t
public class SiteInfoBean { 8Wx>,$k
/Zw^EM6c
3'WJx=0?
private String sSiteURL; //Site's URL l;^Id#N
private String sFilePath; //Saved File's Path BL1$~0
private String sFileName; //Saved File's Name EhDKh\OY5
private int nSplitter; //Count of Splited Downloading File .}gGtH,b3
y]$%>N0vLX
B|E4(,]^
public SiteInfoBean() v-u53Fy
{//nSplitter的缺省值为5 7+wy`xi
//default value of nSplitter is 5 EJ7}h?a]U_
this("","","",5); ^eke,,~
} L+y}hb r
7i?"akr4
cp.c$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) iev02 8M
{ \k\ {S2SU
sSiteURL= sURL; GZ.Xx
sFilePath = sPath; 3>X]`Oj7y
sFileName = sName; A*tG[)
this.nSplitter = nSpiltter; %9ef[,WT
KEF"`VTB@
KSsv~!3Yf
} O>UG[ZgW
&u) R+7bl,
#&zNYzI
public String getSSiteURL() }gw \w?/
{ 'J(rIH3U
return sSiteURL; $<R\|_6J
} M6J~%qF^
$g? ]9}p
. 7WNd/WG
public void setSSiteURL(String value) W@<(WI3
{ e<wA["^
sSiteURL = value; C-Y~T;53
} 4%#Y)zo.e
V<&x+?>S
x {Z_rD
public String getSFilePath() A.nU8
{ >*/\Pg6^
return sFilePath; q~_DR4xZ
} It$'6HV~Sb
# +OEO
ph*9,\c8
public void setSFilePath(String value) qRk&bF/
{ ;tK%Q~To
sFilePath = value; t"[xx_i
} [Q(FBoI|
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m$b5Vqq
public String getSFileName() LLp/ SWe
{ /[ _aw&W}Z
return sFileName; ]o}g~Xn
} :E ]Ys
epw*Px
8nCw1
public void setSFileName(String value) J^t-pU
{ .W4P/Pw'
sFileName = value; -|s w\Q
} N.r8dC
f.Wip)g
FvX<(8'#a
public int getNSplitter() PuyJ:#a
{ ko-|hBNv
return nSplitter; |C;8GSw>|F
} uL!QeY>k\
hp ?4w),
.!#0eAT
public void setNSplitter(int nCount) nymF`0HYe1
{ KVQ^-^
nSplitter = nCount; zx<:1nF,]
} 8%C7!l q
} S#km`N`
@\{L%y%a0
aMaICM
/* @E Srj[
**Utility.java gumT"x .^
*/ QH~;B[->
package NetFox; +fh@m h0[
c3S}(8g5.
!4"(>Rnw
public class Utility { QH z3
X/< zxM
~SKV%
public Utility() 'OrGt_U
{ !e>+O^
)Z4ilpU,
r7dwj
} z4CqHS~%
T'VZ=l[
//线程睡眠 &6ymGo
public static void sleep(int nSecond) EI+RF{IKh
{ Ep>} S
try{ jh7-Fl`
Thread.sleep(nSecond); I8ZBs0sfF{
} B{}<DP.
catch(Exception e) 1f3c3PJ
{ [)efh9P*
e.printStackTrace (); S($8_u$U
} q!L@9&KAQ
} Jd]kg,/
pl#2JA8
//日志 tVI6GXH
public static void log(String sMsg) 244[a] %&;
{ 4gR;,%E\TO
System.err.println(sMsg); aMU0BS"
} .wH`9aq;5@
<'y}y}%
rdQKzJiX=U
public static void log(int sMsg) P8&BtA
{ |DUWB;
System.err.println(sMsg); uU$YN-
} #)3luf3G
} HB|R1<t;HB
7~zd % o
|B{@noGX
/* MUQj7.rNa
**TestMethod.java + *xi&|%
*/ =1MVF
package NetFox; H18.)yHX
LyRbD$m
"O}u2B b
public class TestMethod { ;?h+8Z/{
K*!qt(D&
`;~A
public TestMethod() ?hC,49
{ ///xx/weblogic60b2_win.exe {>v5~G
try{ gT-"=AsxZQ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); \iP=V3
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); NIo!WOi
SiteFileFetch fileFetch = new SiteFileFetch(bean); Uf}u`"$F
fileFetch.start(); 0jJ:WPR
} &~Hx!]uc
catch(Exception e){e.printStackTrace ();} n0a|GZyO]
!"d"3coQ?
SH1S_EQ<
} FF5|qCV/z
IGnP#@`5]
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public static void main(String[] args) n^lr7(!6
{ luWr.<1
new TestMethod(); urbSprdF
} W9D~:>^YP
} <5 )F9.$
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