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)); p5KNqqZZ
} U]acm\^Z
for(int i=0;i<nEndPos.length-1;i++) ZKvh]
{ #cs!`Ngb+
nEndPos = nStartPos[i+1]; N_<n$3P\?f
} >O _
nEndPos[nEndPos.length-1] = nFileLength; X]!@xlwF\
} 8vo} .JIl
} fCfY.vd5
m";gD[m
!S:@x.n@iR
//启动子线程 IFY!3^;zO
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; K"1J1>CHQ
for(int i=0;i<nStartPos.length;i++) kD>vQ?
{ [wR8q,2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >W<5$.G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), J0 P
nStartPos,nEndPos,i); PG!vn@b6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _X[c19q
fileSplitterFetch.start(); J\V(MN,
} [OcD#~drO
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), riL!]'akV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); xpM~*Gpm
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )N<!3yOz
nEndPos = " + nFileLength); >U)O@W)
// fileSplitterFetch[nPos.length-1].start(); J[l K
H/$q]i*#K
*"ShE=\p
//等待子线程结束 0u_'(Z-^2
//int count = 0; +[ zo2lBx
//是否结束while循环 To`?<]8
boolean breakWhile = false; w(D9'
{@A2jk\
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while(!bStop) ;qMlGXW*q
{ V'.|IuN
write_nPos(); @-}]~|<
Utility.sleep(500); brWt
breakWhile = true; =S,<yQJ
9o`3g@6z
u W T[6R
for(int i=0;i<nStartPos.length;i++) .Dm{mV@*T
{ 5*$Zfuf
if(!fileSplitterFetch.bDownOver) ^=G+]$8
{ 9x!y.gx
breakWhile = false; %u}sVRJ
break; vknFtpx
} BE~[%6T7
} ;"Y6&YP<
if(breakWhile) #F@7>hd1
break; M6iKl
OT i3T1&
BP$#a #
//count++; vvxj{fxb)
//if(count>4) 4(82dmKO
// siteStop(); }3 }=tN5
} ([~`{,sv
c29Z1Zs2)
1tdCzbEn+
System.err.println("文件下载结束！"); j&.BbcE45
} d}_c(
catch(Exception e){e.printStackTrace ();} 7w,FA
} L ]c9
S)yV51^B
DlI5} Jh
//获得文件长度 mI#; pO2
public long getFileSize() ]6 wi
{ ?C35
int nFileLength = -1; T*yveo&j
try{ "Ycd$`{Vgt
URL url = new URL(siteInfoBean.getSSiteURL()); <h9\A&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !$Z"\v'b
httpConnection.setRequestProperty("User-Agent","NetFox"); \<**SSN
m{c#cR
-::%9D}P|
int responseCode=httpConnection.getResponseCode(); CN(4;-so)
if(responseCode>=400) sfE8b/Z8
{ HU9y{H
processErrorCode(responseCode); c ?XUb[
return -2; //-2 represent access is error .Er/t"Qs;
} '.,.F0{x
8 -A7
VsEAo
String sHeader; JxJntsn
+_P 2S
:g#it@
for(int i=1;;i++) E e>j7k.G.
{ uW=NH;u
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &,]+>
//Utility.log(in.readLine()); D|9fHMg%
sHeader=httpConnection.getHeaderFieldKey(i); vWs c{9
if(sHeader!=null) j*d~h$[k
{ ^~ $&
if(sHeader.equals("Content-Length")) "|`9{/]
{ X>7]g670@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \*aLyyy3
break; <9a_wGs
} @l GnG
} XWpnZFjE
else C)s1' =TZ
break; GK?R76d
} 30+l0\1
} vfJk? (
catch(IOException e){e.printStackTrace ();} 4uAafQ`@H
catch(Exception e){e.printStackTrace ();} -oBas4J
yX3H&F6
)OC[;>F7
Utility.log(nFileLength); 3z92Gy5cr
% T\N@
H^;S}<pxW
return nFileLength; U^BXCu1km
} z/k~+-6O
&\|<3sd(
ok%!o+nk.
//保存下载信息（文件指针位置） ;<@6f@
private void write_nPos() A5<Z&Y[
{ iLcadX
try{ %C0O?q
output = new DataOutputStream(new FileOutputStream(tmpFile)); E:=KH\2f
output.writeInt(nStartPos.length); )+4}Ix/q
for(int i=0;i<nStartPos.length;i++) E(kpK5h{
{ SoU'r]k1x
// output.writeLong(nPos); Pl&`&N;
output.writeLong(fileSplitterFetch.nStartPos); yVQz<tX|
output.writeLong(fileSplitterFetch.nEndPos); YzW7;U S
} "UGj4^1f
output.close(); r5fkt>HZ
} 3H#/u! W
catch(IOException e){e.printStackTrace ();} #r)1<}_e#
catch(Exception e){e.printStackTrace ();} ugCS &
} h?3l
Ny,A#-?
)-KE4/G
//读取保存的下载信息（文件指针位置） m_02"'
private void read_nPos() \}QuNwc
{ 2$zq (
try{ a& aPBv1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); afiK!0col2
int nCount = input.readInt(); vLFaZ^(
nStartPos = new long[nCount]; OMI!=Upz
nEndPos = new long[nCount]; i2a"J&,6O
for(int i=0;i<nStartPos.length;i++) L_1_y, 0N
{ [2 w<F[
nStartPos = input.readLong(); ]q[
nEndPos = input.readLong(); \*!%YTZ~
} 9'#.>Q>0=j
input.close(); e$+f~~K
} a05:iFoJ
catch(IOException e){e.printStackTrace ();} *R\/#Y|
catch(Exception e){e.printStackTrace ();} -b\V(@5
} \.;ct
yX.5Y|A<
ElR&scXi__
private void processErrorCode(int nErrorCode) +<WRB\W
{ NU&^7[!yl
System.err.println("Error Code : " + nErrorCode); KR+BuL+L
} 4B8Se
Y:!/4GF
]VG84bFm
//停止文件下载 ?~JxO/K
public void siteStop() MRg\FR2>1
{ T19rbL_
bStop = true; u~- fK'/!|
for(int i=0;i<nStartPos.length;i++) QB3d7e)8>
fileSplitterFetch.splitterStop(); }d3N`TT
t#pqXY/;D
eIUuq&(
} i=X*
} A6UdWK
//负责部分文件的抓取 a}qse5Fr
**FileSplitterFetch.java N[x@j)w-`
*/ YUVc9PV)Ws
package NetFox; 56=K@$L {F
RnA&-\|*
Bw]L2=d
import java.io.*; 9p\Hx#^
import java.net.*; 7hN6IP*so
Dj ]Hgg
mj~N]cxB
public class FileSplitterFetch extends Thread { y }&4HrT&
<% 7P
}y-;>i#m=g
String sURL; //File URL | 2.e0Z]k
long nStartPos; //File Snippet Start Position j`|^s}8t
long nEndPos; //File Snippet End Position Ld}(*-1i
int nThreadID; //Thread's ID cbu nq"
boolean bDownOver = false; //Downing is over NM1cyZ
boolean bStop = false; //Stop identical C*EhexK,}
FileAccessI fileAccessI = null; //File Access interface 2 ]DCF
7Z`Mt9:Ht
N[bR&#p
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException eC^0I78x
{ @W1WReK]f
this.sURL = sURL; 3r-VxP 5n
this.nStartPos = nStart; [}p
this.nEndPos = nEnd; _/jUs_W
nThreadID = id; Ku0H?qft(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .kbr?N,'
} 0/SC
L* khj3;
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public void run() B3cf] S%
{ AFINm%\/0
while(nStartPos < nEndPos && !bStop) ~X~xE]1o|U
{ iz9\D*or
}c35FM,
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try{ cVB|sYdf
URL url = new URL(sURL); k_K,J6_)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e+F}9HR7
httpConnection.setRequestProperty("User-Agent","NetFox"); j(Fa=pi
String sProperty = "bytes="+nStartPos+"-"; zM_DE
httpConnection.setRequestProperty("RANGE",sProperty); x5fgF;
Utility.log(sProperty); rb *C-NutE
J})$
wuIsO;}/9
InputStream input = httpConnection.getInputStream(); c_qcb7<~.
//logResponseHead(httpConnection); -- i&"
\'; t*
;# R3k
byte[] b = new byte[1024]; nIV.9#~&
int nRead; ;w+:8<mM}a
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5Cc6, ]
{ Dm|gSv8d,
nStartPos += fileAccessI.write(b,0,nRead); y$j1?7
//if(nThreadID == 1) <ELziE~>V
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BcZEa^^~os
} %z-dM` i
f[JI/H>
d s|8lz,
Utility.log("Thread " + nThreadID + " is over!"); ?jNF6z*M6
bDownOver = true; qeQC&U y;
//nPos = fileAccessI.write (b,0,nRead); fuNl4BU
} P[rAJJN/E
catch(Exception e){e.printStackTrace ();} 2I]]WBW#:
} rV8(ia
} |'U,/
";)r*UgR{B
rPiiC/T.`
//打印回应的头信息 lFiq<3Nk
public void logResponseHead(HttpURLConnection con) ER~T'-YMS
{ E6'8Zb
for(int i=1;;i++) 3AdP^B<
{ x1 ;rb8
String header=con.getHeaderFieldKey(i); &5kZ{,-eM
if(header!=null) @9_nwf~X4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); q4sl=`L5Sp
Utility.log(header+" : "+con.getHeaderField(header)); (MgL"8TS
else ur/Oc24i1n
break; 3E<aiGU
} y\F`B0#$
} O%YjWb
@DfkGm[%
(@%XWg
public void splitterStop() "C:rTIH
{ $"Y3mD}?L
bStop = true; \3%W_vU_
} +Fk4{p
C+/Eqq^(
NniX/fk
} a);O3N/*I
{ A:LAAf[6
H/^~<U#p
/* _, \y2&KT
**FileAccess.java (g%JK3
*//文件访问(定位，写) 5*JV )[
package NetFox; {[Uti^)m%
import java.io.*; 6PiEa(
CCuxC9i7
Rz`@N`U
public class FileAccessI implements Serializable{ v\fzO#vj
gXq!a|eH
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 kk 8R
RandomAccessFile oSavedFile; t*o7,
long nPos; r> Fec
o{9?:*?7
Z -pyFK\
public FileAccessI() throws IOException jmRhAJV
{ kjx>
this("",0); c*.G]nRc
} D",A$(lG
xM%H~(
hX0RET
public FileAccessI(String sName,long nPos) throws IOException nURvy}<r
{ y!S^xS
oSavedFile = new RandomAccessFile(sName,"rw"); VKT@2HjNT`
this.nPos = nPos; V)2"l"Kt
oSavedFile.seek(nPos); +7Sf8tg\
} zTkFX67)
3sS=?q
NV&;e[z
public synchronized int write(byte[] b,int nStart,int nLen) U^B"|lc:[
{ K{|w 43>D
int n = -1; !$D&6M|C8l
try{ Xf6fH O
oSavedFile.write(b,nStart,nLen); 40 A&#u9o
n = nLen; UE"7
} HvAE,0N
catch(IOException e) j?=VtVP
{ H9sZR>(^
e.printStackTrace (); $b4*/vMr
} cE^kpnVq|<
:[L{KFQU
cL?\^K)
return n; D._{E*vg
} U%Dit
j -#E?&2
0xN!DvCg>.
} (2: N;
: @s8?eg
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/* XxhsPFv
**SiteInfoBean.java YQN.Ohtv*F
*/ *f{7
package NetFox; g+igxC}2z
/d[Mss
>g=^,G}y
public class SiteInfoBean { TKK,Y{{
1d`cTaQ-
K-Re"zsz
private String sSiteURL; //Site's URL 8098y,mQe
private String sFilePath; //Saved File's Path bi+9R-=&
private String sFileName; //Saved File's Name KCE=|*6::|
private int nSplitter; //Count of Splited Downloading File 5n:nZ_D
]Fxku<z7|
HHZ`%
public SiteInfoBean() -48`#"xy
{//nSplitter的缺省值为5 ya#RII']
//default value of nSplitter is 5 iA]DE`S
this("","","",5); n4Vwao/9x
} 64SW
H4W1\u
[Uswf3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) S[Vtq^lU
{ |0lLl^zp
sSiteURL= sURL; kPWBDpzN
sFilePath = sPath; :RHm*vt
sFileName = sName; I<sfN'FpT
this.nSplitter = nSpiltter; TFo}\B7
)GK+
en%J!<&W{K
} >#INEO
x9h?e`
;r3}g"D@
public String getSSiteURL() )Q~C4C-j
{ ~H7!MC~K
return sSiteURL; H*GlWgfG
} w:v=se"U
N=q#y@L
<o2,HTWNPS
public void setSSiteURL(String value) ti}f&w ICJ
{ Zgy7!AF!
sSiteURL = value; XJc ,uj7
} P`tyBe#=
\Fq1^ 8qa
Sg_O?.r
public String getSFilePath() 9YAM#LBTWi
{ *-6?
return sFilePath; iM"asEU
} D'<$ g
Cpe#[mE
+N7"EROc
public void setSFilePath(String value) ^}hJL7O'
{ z4bN)W )p
sFilePath = value; ![ a
} dIvy!d2l
pp<E))&R
o OQ'*7_
public String getSFileName() ewpig4
{ vmLpmxS
return sFileName; fa4=h;>a+
} 5} G:D
yWNOG 2qAP
0t+])>
public void setSFileName(String value) 7|Xe&o<n
{ g>_OuQ|c
sFileName = value; b;*c:{W)
} _H8*ReFG
Zb"jB$58
0iV;g`%
public int getNSplitter() Yh$fQ:yi\&
{ Ia#"/`||
return nSplitter; <*_o0;h|
} d+0^u(gc!8
nZxSMN0]
+mLD/gK`
public void setNSplitter(int nCount) 7k'gt/#up
{ &sdx`,
nSplitter = nCount; 6Kp}_^|z
} @`S.@^%7fO
} w:Ra7ExP
$R?@L
IkQe~;Y
/* _$5@uL{n"^
**Utility.java `w+1C&>^[
*/ 4vLw?_".
package NetFox; >L=;"+B0U&
e8-ehs>
T<6GcI>A
public class Utility { l#$TYJi
NV6G.x
_4v"")Xe
public Utility() !VRo*[yD@
{ TM-Fu([LMV
AuXs B
jM@?<1
} V'I T1~
!3V{2-y$-
//线程睡眠 )b0];&hw]
public static void sleep(int nSecond) 7h`^N5H.q
{ 8SZK:VE@
try{ `;cz;"
Thread.sleep(nSecond); !D;c,{Oz
} ?A&%Cwj
catch(Exception e) G|*G9nQ
{ XXm'6xD-
e.printStackTrace (); bcn7,ht
} bb1f/C%
} JD*8@N
G\ex^&M
//日志 , D"]y~~I5
public static void log(String sMsg) (:n|v%
{ (v^Z BM_
System.err.println(sMsg); "mA1H]r3
} mX;H((
Cfv]VQQE
p/&HUQQk
public static void log(int sMsg) P0 b4Hq3
{ ({ k7#1 h8
System.err.println(sMsg); X}W)3v
} ^1 ;BiQ
} P,ydt
^V.'^=l
h/?6=D{
/* SY T$3|a
**TestMethod.java ;MPKJS68@
*/ S3y246|4
package NetFox; ]2$x|#Gg}
O|e}
x*q35K^PE
public class TestMethod { V:Mk)8Gf|
`tVy_/3(9
UP8{5fx'
public TestMethod() U=QA e
{ ///xx/weblogic60b2_win.exe w & P&7
try{ ]\dHU.i
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); t^U^Tr
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); SiTeB)/
SiteFileFetch fileFetch = new SiteFileFetch(bean); M1{(OY(G
fileFetch.start(); s[X B#)H4
} x.UaQ |F
catch(Exception e){e.printStackTrace ();} 328L)BmW
V|: qow:F
Z&Pu8zG /m
} lDN?|YG
q3+8]-9|5
D/:3RZF
public static void main(String[] args) %*K;np-q{
{ 1tGgDbJU
new TestMethod(); MI*Sq\-i
} !y[3]8Xxv
} u"Y]P*[k
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