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)); ,P!D-MN$V
} Y@ObwKcG
for(int i=0;i<nEndPos.length-1;i++) SLg+H
{ n/?eZx1
nEndPos = nStartPos[i+1]; G#'Q~N
} \P5>{2i
nEndPos[nEndPos.length-1] = nFileLength; !+=Zjm4L
} g?gqkoI
} db^aL8
[Ek42%
}D Z)W0RDe
//启动子线程 w)^\_uAlS
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6SV7\,2M
for(int i=0;i<nStartPos.length;i++) Nr%(2[$ =
{ @+$cZ3,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h)^dB,~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), P3i^S_
nStartPos,nEndPos,i); }$<^wt
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _HLC>pH~#
fileSplitterFetch.start(); T0YDfo
} </|)"OD9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ))p$vU3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); =?HzNA$yh
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }'DC Q
nEndPos = " + nFileLength); TR~|c|B
// fileSplitterFetch[nPos.length-1].start(); l 4!kxXf-<
WN$R[N
AvyQ4xim+
//等待子线程结束 Xthtw*
//int count = 0; Zd8drT'@#
//是否结束while循环 IKGTsA;
boolean breakWhile = false; Y~:}l9Qs
ujiZM
hHCzj*5
while(!bStop) i3D<`\;r
{ tCX9:2c
write_nPos(); Wx}M1&d/J
Utility.sleep(500); O+p]3u
breakWhile = true; O%fUm0O d
|3S'8OeCI
P`p6J8}4
for(int i=0;i<nStartPos.length;i++) : #3OcD4
{ mm_^gQ,`
if(!fileSplitterFetch.bDownOver) Y 5Qb4Sa
{ qx Wgt(Os
breakWhile = false; ^eT@!N
break; >vHH
} "EN98^ Sl
} f( ]R/'o
if(breakWhile) m{vT_ei
break; ;0;3BH A
y*}AX%8`e~
{EOn r1
//count++; 3aEt>x
//if(count>4) Y_$^:LG
// siteStop(); TG4\%S$w
} be&6kG
mgo'MW\
NR;q`Xe-
System.err.println("文件下载结束！"); L& I` #
} =*{K@p_
catch(Exception e){e.printStackTrace ();} >BJ2v=RA
} 2^cAK t6bC
w/qQ(]n8
'&RZ3@}+
//获得文件长度 hm*Th
public long getFileSize() tU9rCL:P
{ 8o!
int nFileLength = -1; X QI.0L"
try{ Qe7"Z
URL url = new URL(siteInfoBean.getSSiteURL()); enPzy:C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h |s*i
httpConnection.setRequestProperty("User-Agent","NetFox"); dD[v=Z_
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p#ZMABlE,P
int responseCode=httpConnection.getResponseCode(); }9MW!Ss
if(responseCode>=400) |hu"5*
{ {fAh@:{@
processErrorCode(responseCode); j%6|:o3G(
return -2; //-2 represent access is error Rg%R/p)C
} 2Som0T<2
rE/}hHU
sqm%iyC=q
String sHeader; Q.j-C}a
ph Wc8[Q
PFImqojHd
for(int i=1;;i++) ODM>Z8@W/
{ E`oSi ez)
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); SlH7-"Ag
//Utility.log(in.readLine()); $=\oJ-(!@S
sHeader=httpConnection.getHeaderFieldKey(i); ;s}-X_O<
if(sHeader!=null) I>N-95
{ nG&w0de<>
if(sHeader.equals("Content-Length")) MuCQxzvkhf
{ B|$\/xO
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8r7/IGFg
break; E'S<L|A/
} Up]VU9z
} }0k"SwX
else 9b{g+lMZo
break; K9x*Sep
} !nP8ysB
} J ,Qy`Y B
catch(IOException e){e.printStackTrace ();} o=a:L^nt,
catch(Exception e){e.printStackTrace ();} b?+Yo>yF8
2:smt)f
&(z8GYBr
Utility.log(nFileLength); :kf3_?9rc
+1JZB*W
: L6-{9$
return nFileLength; =y,yQO
} \K4CbZ,.
6Dr$*9
PuUon6bZ
//保存下载信息（文件指针位置） ; @[.$Q@I
private void write_nPos() 1xFhhncf
{ O"2wV +9
try{ 'vf,T4uQ"
output = new DataOutputStream(new FileOutputStream(tmpFile)); @=aq&gb
output.writeInt(nStartPos.length); 2WbZ>^:Nsk
for(int i=0;i<nStartPos.length;i++) ek+8hnkh
{ z-{"pI
// output.writeLong(nPos); z=8_%r
output.writeLong(fileSplitterFetch.nStartPos); &CPe$'FYI
output.writeLong(fileSplitterFetch.nEndPos); ]aL [
} e\|E; l
output.close(); V,"AG
} N2S!.H!Wz
catch(IOException e){e.printStackTrace ();} lHj7O&+
catch(Exception e){e.printStackTrace ();} duiKFNYN
} |)>GeE
`rOe5Zp$
-*]9Ma<wa
//读取保存的下载信息（文件指针位置） Y GcY2p<
private void read_nPos() ,XF6Xsg2
{ EC\rh](d 1
try{ &caO*R<#J}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); < 8W:ij.`
int nCount = input.readInt(); D$^7Xhk
nStartPos = new long[nCount]; !&`7
nEndPos = new long[nCount]; "78cl*sD
for(int i=0;i<nStartPos.length;i++) 4HYH\ey
{ JY,l#?lM{
nStartPos = input.readLong(); E%v[7 ST
nEndPos = input.readLong(); ">4[+'
} enfu%"(K)
input.close(); ^Qb!k/$3y
} /[)P^L`
catch(IOException e){e.printStackTrace ();} (}7o a9Q<
catch(Exception e){e.printStackTrace ();} uJAB)ti2I
} #@OKp,LJ
5x L,~"
a!6OE"?QQ
private void processErrorCode(int nErrorCode) y O9pEO|W
{ u BW
System.err.println("Error Code : " + nErrorCode); [4(A458H
} oY#XWe8Om
`S!uj <-
dT-O8
//停止文件下载 "r `6c0Z
public void siteStop() P)o[p(
{ oz5lt4
bStop = true; ]H@uuPT!
for(int i=0;i<nStartPos.length;i++) zYl+BM-j,6
fileSplitterFetch.splitterStop(); Jv$2wH
&wWGZ~T
N`mC_)
} iF2IR{h
} f\%X7.
//负责部分文件的抓取 fJN9+l
**FileSplitterFetch.java Y(;[L`"
*/ FU3IK3}
package NetFox; 3 mMdq*X5
WlJRKM2
0|3B8m
import java.io.*; r-DD*'R
import java.net.*; '{_tDboY
kJ:5msKwC
5;%xqdD
public class FileSplitterFetch extends Thread { R5YtCw]i=
FH@e:-*=
X=RmCc$:
String sURL; //File URL o0v m?CL#
long nStartPos; //File Snippet Start Position ,PtR^" Mf4
long nEndPos; //File Snippet End Position HH7gT
int nThreadID; //Thread's ID d=Ihl30m
boolean bDownOver = false; //Downing is over >L3p qK
boolean bStop = false; //Stop identical 2/W0y!qh1
FileAccessI fileAccessI = null; //File Access interface uqH! eN5
"PM:&v
]5MRp7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException p5 PON0dS
{ s`#j8>`M
this.sURL = sURL; KuAGy*:4T
this.nStartPos = nStart; 0R{R=r]
this.nEndPos = nEnd; LA(JA
nThreadID = id; JQv ZTwSI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2/NWWoKw
} B,qZwc|
V'#u_`x"D)
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public void run() gM:oP.
{ YXOD fd%L
while(nStartPos < nEndPos && !bStop) D%}o26K.C
{ 0md{e`'q:
, 0ja_
ziip*<a!_
try{ Ji:@z%osr
URL url = new URL(sURL); um4zLsd#v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MA QY/s~F
httpConnection.setRequestProperty("User-Agent","NetFox"); / S^m!{
String sProperty = "bytes="+nStartPos+"-"; ijSYQ
httpConnection.setRequestProperty("RANGE",sProperty); Rla*hc~
Utility.log(sProperty); MO+0]uh:
?n~j2-[<
lJ2/xE]
InputStream input = httpConnection.getInputStream(); atnbM:t
//logResponseHead(httpConnection); f;6d/?=~
|W[rywxx
UeTp,
byte[] b = new byte[1024]; >sY+Y22U
int nRead; %Q01EjRes
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;0{*V5A
{ 2o}FB\4^i
nStartPos += fileAccessI.write(b,0,nRead); $fG/gYvI\
//if(nThreadID == 1) b .@dUuKz-
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e;\c=J,eE
} mSp7H!
NX/)Z&Fx:
!7|9r$
Utility.log("Thread " + nThreadID + " is over!"); G*V 7*KC
bDownOver = true; Jx7^|A
//nPos = fileAccessI.write (b,0,nRead); yQ2[[[@k@
} xrd^vE
catch(Exception e){e.printStackTrace ();} =,9'O/br
} TR7TF]itb
} ywBo9|%T
X:bgY
)]Rr:i9n
//打印回应的头信息 I>|?B(F
public void logResponseHead(HttpURLConnection con) Ue%5 :Sdr
{ ]C^*C|
for(int i=1;;i++) QJ'C?hn
{ Nzt1JHRS
String header=con.getHeaderFieldKey(i); )`0 j\
if(header!=null) }3e+D
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B 8,{jwB
Utility.log(header+" : "+con.getHeaderField(header)); j'cS_R
else M3;B]iRQD
break; h<q``hn>
} ~KvCb3~X
} K>~l6
*O2j<3CHf
Nr4Fp`b8
public void splitterStop() bR`5g
{ b[vE!lJEq
bStop = true; &{)<Q(g
} 4S(G366
'!>9j,BJ
QPy h.9:N
} v]JET9hY
W3i<Unq
#y\O+\4e
/* NT6jwK.?)?
**FileAccess.java [[T7s(3
*//文件访问(定位，写) jMT[+f
package NetFox; wXNng(M7
import java.io.*; 'm0WPS/6E
<?7CwW
/X8a3Eqp9
public class FileAccessI implements Serializable{ U<6)CW1;
2d[tcn$;h]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 l6zAMyau5
RandomAccessFile oSavedFile; besc7!S
long nPos; f:j:L79}
2e6P?pX~2
_0[z xOI
public FileAccessI() throws IOException za>%hZf\
{ 8;M,l2pmR{
this("",0); Dw=L]i :0v
} cg )(L;
^|/<e?~I
Z%#e* O0
public FileAccessI(String sName,long nPos) throws IOException c[J 2;"SP
{ W *0!Z:?
oSavedFile = new RandomAccessFile(sName,"rw"); 2<7pe@c98
this.nPos = nPos; /}u:N:HA%
oSavedFile.seek(nPos); $y;w@^
} H_g]q
h`Jc%6o
&"u(0q
public synchronized int write(byte[] b,int nStart,int nLen) Wv>`x?W
{ ,WdSJ BK'a
int n = -1; =Vh]{y~$
try{ Fpo}UQQbc
oSavedFile.write(b,nStart,nLen); L^u|=9
n = nLen; [voc_o7AI
} wgDAb#Zuk
catch(IOException e) VK4UhN2
{ VI3fvGHat{
e.printStackTrace (); '>[ZfT
} HF*~bL
}P=FMme{F(
ko.%@Y(=
return n; !B[Y?b:
} 2w8YtM3+"z
6n:X p_yO
[/ CB1//Y
} 4PC'7V=S
gISA13
5i$P$ R
/* AU*]D@H
**SiteInfoBean.java /3+E-|4s
*/ G>Bgw>#_
package NetFox; yR F+
vU/sQt8
%to.'R
public class SiteInfoBean { [)IaXa
<-d-. 8
v&sp;%I6=
private String sSiteURL; //Site's URL 823y;
private String sFilePath; //Saved File's Path >iJxq6!
private String sFileName; //Saved File's Name bz&9]%S<
private int nSplitter; //Count of Splited Downloading File 'o_ RC{k2"
84(jg P
d6W&u~
public SiteInfoBean() J_ h\tM
{//nSplitter的缺省值为5 acpc[^'
//default value of nSplitter is 5 <!u(_Bxw/
this("","","",5); DL_M#c`<
} $~EY:
hO3C _}
.<P@6Jq
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) aBF<it>
{ sx9[#6~{Y
sSiteURL= sURL; (_q&QI0{
sFilePath = sPath; )P/~{Ci:T&
sFileName = sName; -mZ{.\9
this.nSplitter = nSpiltter; +c'I7bBr
L'BzefU;04
5OFb9YX
} 'bef3P9`
zpcm`z
4.&et()}
public String getSSiteURL() `O=LQ m`
{ <>1*1%m
return sSiteURL; z:$TW{%M
} Bsz;GnD|r
"jl`FAu)q
c_2kHT
public void setSSiteURL(String value) 8j%lM/ v
{ LD5E
sSiteURL = value; cW $~86u"C
} )\0c2_w>
XN'X&J
fI(H :N
public String getSFilePath() I=`efc]T
{ ~R W6;
return sFilePath; =HvLuVc
} Yc'7F7.<6
(aH_K07
Y6@A@VJ
public void setSFilePath(String value) vCNYqa)m:
{ gs|%3k|
sFilePath = value; 'uOp?g'7
} `Tf<w+H
:!EOg4%i
QPa&kl
public String getSFileName() ]pA}h.R#-
{ >&9Iy"
return sFileName; {z%%(,I
} <BN)>NqM
U`"nX)$
L``K. DF
public void setSFileName(String value) _zO,VL
{ "|"bo5M:
sFileName = value; 'x10\Q65[
} ]urcA,a
f;%4O'
*K\/5Fzl
public int getNSplitter() Hca)5$yL
{ x2TCw
return nSplitter; 2S8/ lsB
} D`.CXFI+U
B: uW(E
o0Hh&:6!M
public void setNSplitter(int nCount) _B|g)Rdv
{ 8DLMxG
nSplitter = nCount; n/UyMO3=
} p<6pmW3
} 4S.%y7d\
+B'9!t4 2
A\.M/)Qo
/* s\Cl3
**Utility.java <OW` )0UX
*/ J]|-.Wv1
package NetFox; /gHRJ$2|Sx
-]PW\}w1
f.'o4HSj
public class Utility { zYj8\iER
A0WQZt!FEN
+]|J
public Utility() mnXaf)"
{ w];t]q|
#, vN
R{6.O+j`
} oc-7gz)
JT<Ia
//线程睡眠 "Rs^0iT7>
public static void sleep(int nSecond) }kXF*cVg
{ T0RgCU IV
try{ 6576RT
Thread.sleep(nSecond); NCSb`SC:
} Ra_6}k
catch(Exception e) mKnkHGM
{ ]Wv\$JXI
e.printStackTrace (); n2Ycq&O
} kRE^G*?
} S)$ES6]9/
n&[U/`o
//日志 -\>Bphu,y
public static void log(String sMsg) ;Cyt2]F
{ t_@%4Wn!1L
System.err.println(sMsg); }N4=~'R
} %qfEFhRC
~`mOs1d
Yw+_( 2 9=
public static void log(int sMsg) Ty#L%k}-t
{ t91v%L
System.err.println(sMsg); N9:xtrJ]_J
} Z:9"7^+
} "2qp-'^[c
uj;-HN)6
P7"g/j""
/* bv$)^
**TestMethod.java M.!U;U<?
*/ o& $Fc8bH
package NetFox; oe4Fy}Y_;
aeE9dV~
i~.L{K
public class TestMethod { A^ t[PKM"
G4MNcy
i v&:X3iB
public TestMethod() cq %=DZ
{ ///xx/weblogic60b2_win.exe hq$:62NYg
try{ e/F=5_Io
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); m/%sBw\rx
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =f{V<i~q
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4 K{4=uU
fileFetch.start(); &d9tR\}
} %nP13V]
catch(Exception e){e.printStackTrace ();} +;pdG[N
lJu2}XRiU
~%k<N/B
} Iz!Blk
^cDHyB=v4d
!YsLx[+
public static void main(String[] args) -GDX#A-J
{ xv9SQ,n<
new TestMethod(); *ukugg.
} X@5!I+u\L
} 'X"@C;q
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