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)); T"E%;'(cp)
} -i4hJC!3
for(int i=0;i<nEndPos.length-1;i++) Ev&aD
{ ^1XnnQa
nEndPos = nStartPos[i+1]; ~bfjP2 g
} R#/0}+-M
nEndPos[nEndPos.length-1] = nFileLength; Qa1G0qMEIF
} g]._J
} 5~"m$/yE
ZMch2 U8
3UJSK+d\
//启动子线程 7gt%[r M
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $oZV 54
for(int i=0;i<nStartPos.length;i++) D+*_iM6[-
{ K Z0%J5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), YTfMYH=}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), u6*mHkM
nStartPos,nEndPos,i); #F+b^WTR
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !3o]mBH8
fileSplitterFetch.start(); fJn4'Q*U
} KPa&P:R3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wr2F]1bh@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); U?ZxQj66}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `e5f69"
nEndPos = " + nFileLength); ^2mCF
// fileSplitterFetch[nPos.length-1].start(); hle@= e/n
%UCuI9
}k6gO0z
//等待子线程结束 1VG7[#Zy
//int count = 0; _i0,?U2C
//是否结束while循环 s?&UFyYb,
boolean breakWhile = false; <2PO3w?Z
`R:HMO[ow
9Oc(Gl5az
while(!bStop) !(qaudX{>k
{ 6CzN[R}
write_nPos(); It8@Cp.dU
Utility.sleep(500); <Kq!)) J'
breakWhile = true; -)E6{
YuzgR;Z
L%4Do*V&
for(int i=0;i<nStartPos.length;i++) Z'y:r2{ql
{ s=)1:jYk
if(!fileSplitterFetch.bDownOver) g]}E1H6-
{ lLuAgds`
breakWhile = false; n}q/:|c
break; X6o iOs
} ['@R]Si"!
} 5~xv"S(E}
if(breakWhile) 4+au6ABy
break; aP +)
Evq^c5n>{
S{)'1J_0
//count++; q6V\n:hKV
//if(count>4) )}T0SGY
// siteStop(); y3mJO[U0 a
} 9X87"
oz\r0:
liVj-*m
System.err.println("文件下载结束！"); Gu K!<-Oz"
} ziD+% -
catch(Exception e){e.printStackTrace ();} k0-,qM#p;X
} <>[]-Vq
q=uJ^N
mV'^4by
//获得文件长度 ?r(Bu
public long getFileSize() wfBf&Z0{
{ RQd5Q.
int nFileLength = -1; ~@EBW3>~5
try{ @m ?&7{y#?
URL url = new URL(siteInfoBean.getSSiteURL()); O:te;lQK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Xq.GvZS`
httpConnection.setRequestProperty("User-Agent","NetFox"); A*+KlhT
8J+:5b_?
F$>^pw
int responseCode=httpConnection.getResponseCode(); RyN?Sn5)
if(responseCode>=400) ;NrU|g/ksX
{ .k:Uj-&
processErrorCode(responseCode); M9dUo7
return -2; //-2 represent access is error |%7OI#t^
} N^By#Z
"%{J$o
/N\[ C"8
String sHeader; uHpSE?y/
[}=/?(5
rTLo6wI
for(int i=1;;i++) t[?O*>
{ u7ER
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *61G<I
//Utility.log(in.readLine()); agxR V
sHeader=httpConnection.getHeaderFieldKey(i); )l*6zn`z
if(sHeader!=null) Q~AK0W
{ 73'.TReK
if(sHeader.equals("Content-Length")) h**mAa0fo
{ FQ6{NMz,h
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); gjhWoZV
break; =[V
} Z\P&i#
} ,[0rh%%j
else <{b#nPc!,#
break; IBe0?F #
} $sR-J'EE!
} 4|DGQ
catch(IOException e){e.printStackTrace ();} Dh{sVRA
catch(Exception e){e.printStackTrace ();} b0"R |d[i
@mrGG F
LzJNQd'
Utility.log(nFileLength); !)TO2?,^
:p,DAt}
Zp*0%x!e
return nFileLength; K=X13As_
} NKS-G2Y<P
b py576GwA
)nJh) {4\
//保存下载信息（文件指针位置） (xhV>hsA
private void write_nPos() dGBVkb4]T
{ tcU4$%H/
try{ Af_yb`W?
output = new DataOutputStream(new FileOutputStream(tmpFile)); A/{0J\pA
output.writeInt(nStartPos.length); dk4|*l-
for(int i=0;i<nStartPos.length;i++) SRf.8j
{ G%RhNwm
// output.writeLong(nPos); mBZg(TY
output.writeLong(fileSplitterFetch.nStartPos); gw);b)&mx
output.writeLong(fileSplitterFetch.nEndPos); _f5n t:-
} 8]-c4zK
output.close(); +XN/ bT
} b".e6zev
catch(IOException e){e.printStackTrace ();} p[M*<==4
catch(Exception e){e.printStackTrace ();} F),wj8#~>-
} ON/U0V:v
fA>FU/r
2pQdDbm
//读取保存的下载信息（文件指针位置） FlQ(iv)P
private void read_nPos() }c~o3t(7`b
{ -%#F5br%
try{ "G3zl{?GP
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8o4?mhqV
int nCount = input.readInt(); S;FgS:;
nStartPos = new long[nCount]; 8h| 9;%
nEndPos = new long[nCount]; |ydOi&
for(int i=0;i<nStartPos.length;i++) X0QLT:J b
{ 9F^rXY.
nStartPos = input.readLong(); UjI-<|
nEndPos = input.readLong(); oDEvhNT
} SYsbe 5j
input.close(); !Cv:,q
} I>L@P`d
catch(IOException e){e.printStackTrace ();} ]aF!0Fln~
catch(Exception e){e.printStackTrace ();} 79JU
} YKT=0
IJt8* cw
Z#P:C":e
private void processErrorCode(int nErrorCode) -N]%)Hy
{ f~NGIlgR
System.err.println("Error Code : " + nErrorCode); p:n.:GZ=y
} D-IXO@x
0cBk/x^s
X}s}E ;v9
//停止文件下载 #^ cmh
public void siteStop() &^4E)F
{ "dO>P*k,
bStop = true; Hkck=@>8H*
for(int i=0;i<nStartPos.length;i++) UF ]g6u
fileSplitterFetch.splitterStop(); XV> )[Nd\H
P,@ :?6
NlnmeTLO5
} ADQ#qA,/
} <CnTiS#
//负责部分文件的抓取 ;=[~2*8
**FileSplitterFetch.java c/q -WEKL
*/ m|5yET
package NetFox; w0FkKJV
$J]b+Bp
X^;LiwQv
import java.io.*; BCK0fk~
import java.net.*; T+y3Ph--^
5@xl/
;%H/^b.c
public class FileSplitterFetch extends Thread { @a{1vT9b
|tkhsQ-;
*j0kb"#
String sURL; //File URL LYv$U;*+
long nStartPos; //File Snippet Start Position b\l +S2
long nEndPos; //File Snippet End Position `Ko6;s#
int nThreadID; //Thread's ID CI };$4W~
boolean bDownOver = false; //Downing is over XvIrO]F-
boolean bStop = false; //Stop identical ED+tVXyw
FileAccessI fileAccessI = null; //File Access interface eZ^-gk?
-:|1>og
{IlX@qWr
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `1eGsd,f
{ z`:uvEX0
this.sURL = sURL; JWuF ?<+k
this.nStartPos = nStart; !VJ5(b
this.nEndPos = nEnd; `V1D&}H+G
nThreadID = id; 'kz[Gh*8
fileAccessI = new FileAccessI(sName,nStartPos);//定位 V!Q1o!J
} UvtSNP&/2d
9Xv>FVG!
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public void run() Jt3]'Nr04@
{ c88I"5@[bD
while(nStartPos < nEndPos && !bStop) cF7efs8u
{ ;P{HePs=)
_26~<gU8
wSMP^kG
try{ /5y*ZIq]e
URL url = new URL(sURL); ]^63n/Twj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >,Zf3M
httpConnection.setRequestProperty("User-Agent","NetFox"); V>`xTQG
String sProperty = "bytes="+nStartPos+"-"; vl'2O7
httpConnection.setRequestProperty("RANGE",sProperty); %0z&k!P
Utility.log(sProperty); SbLx`]rI
#$GDKK
:$`"M#vMX
InputStream input = httpConnection.getInputStream(); `]{/(pIgW;
//logResponseHead(httpConnection); fA]b'8
)aOPR|+
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byte[] b = new byte[1024]; Y!8Ik(/~i
int nRead; -2dk8]KB]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) cG"+n@\
{ H ',Nt
nStartPos += fileAccessI.write(b,0,nRead); Fj`6v"h
//if(nThreadID == 1) u5,\Kz
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w1je|Oil
} `~bnshUk
2^}E!(<
*[(}rpp M
Utility.log("Thread " + nThreadID + " is over!"); y3 R+060\3
bDownOver = true; L;7x2&
//nPos = fileAccessI.write (b,0,nRead); 0t-!6
} @@,l0/
catch(Exception e){e.printStackTrace ();} 1HF=,K+
} Ri}n0}I
} $LLy#h?V]
>^8=_i !
=c-,uW11[
//打印回应的头信息 1?6;Oc^
public void logResponseHead(HttpURLConnection con) [HKTXF{n
{ f\ wP}c'
for(int i=1;;i++) <4gT8kQ$x
{ .."=
String header=con.getHeaderFieldKey(i); D=w5Lks
if(header!=null) _oB!-#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @c<*l+Qc
Utility.log(header+" : "+con.getHeaderField(header)); )>]~Y
else Wb_'X |"u
break; Wgt[ACioN
} OIuEC7XM^C
} C>d_a;pX
z8SrZ#mg
/mb?C/CI
public void splitterStop() A{5^A)$
{ *20$u% z2
bStop = true; <_S>-;by
} l@x/{0
,Qgxf';+$
>Jl(9)e
} gg>O:np8
DA5kox&cU
Z\{"/( Hi
/* `g2DN#q[0
**FileAccess.java `wJR^O!e
*//文件访问(定位，写) 6]=R#d 7U
package NetFox; ,qS-T'[v,(
import java.io.*; Hoaf3 `n
):@XMECa
#Z'r;YOzs
public class FileAccessI implements Serializable{ d66 GO];"
73kF=*m
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,;aELhMZ
RandomAccessFile oSavedFile; *(%]|z}]m
long nPos; 87Sqs1>cw
cr{;gP
+ht -Bl
public FileAccessI() throws IOException <<zYF.9L]
{ KaJCfu yp
this("",0); w`kn!k8
} Tl.dr
_H:mBk,,
zj ;'0Zu
public FileAccessI(String sName,long nPos) throws IOException Y<'T;@
{ 6!|-,t><
oSavedFile = new RandomAccessFile(sName,"rw"); 2]Nc@wX`p
this.nPos = nPos; CS;bm`8a
oSavedFile.seek(nPos); f$G{7%9*
} jl;%?bx
iRo/~(
""GeO%J8
public synchronized int write(byte[] b,int nStart,int nLen) Jww LAQ5
{ !TJCQ[Aa}
int n = -1; v !~lVv&
try{ oUMY?[Wp
oSavedFile.write(b,nStart,nLen); O@@=ZyYwc
n = nLen; GXV<fc"1
} WD=#. $z$
catch(IOException e) N`FgjnQ`
{ "XWrd[Df
e.printStackTrace (); CNCWxu
} Cv@ZzILyoK
K&zp2V
uyt]\zVT
return n; ]] R*sd*
} ?0>% a$`
S]kY'(V(*
J2\%rb,
} F;5S2:a@Z
g$c\(isY;
YQb43Sh`
/* ;naD`([
**SiteInfoBean.java _lrCf
*/ >wiW(Ki}
package NetFox; I:4m]q b
$F|3VQ~
[whX),3>
public class SiteInfoBean { l6^IX0&p
f;<qGM.#|
4{?Djnh
private String sSiteURL; //Site's URL Y#9dVUS
private String sFilePath; //Saved File's Path EV}c,*);y
private String sFileName; //Saved File's Name oe<9CK:?>
private int nSplitter; //Count of Splited Downloading File "*E#4e[
Rf)lFi
*.X!AJ;M=O
public SiteInfoBean() P4xQ:$2!
{//nSplitter的缺省值为5 ? Xb8B5
//default value of nSplitter is 5 j]uL9\>
this("","","",5); |{ E\ 2U
} T%
ys+ AY^/
GCn^+`.h1t
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `:hEc<_/
{ 1]wx Ru
sSiteURL= sURL; ?!R Z~~d
sFilePath = sPath; C5Fk>[fS
sFileName = sName; >k gL N
this.nSplitter = nSpiltter; |D `r o
J7FCW^-`3
~)';[Ha
} 5l"/lGw
W`}C0[%VW
f>LwsP
public String getSSiteURL() l+e L:C!
{ S+03aJNN#
return sSiteURL; ''+6qH-.|]
} iNn]~L1
|a7W@LVYD
?}y{tav=
public void setSSiteURL(String value) y:6&P6`dx
{ }cov"o
sSiteURL = value; vYT%e:8)q
} Nqih LUv
YzTmXwuA5
F`W8\u'db
public String getSFilePath() 739J] M
{ E;[ANy4L
return sFilePath; V2< 4~J2:9
} m_{?py@tZ
. zM
dgb#PxOMH
public void setSFilePath(String value) ;J"b%~Gn
{ 9|Z25_sS
sFilePath = value; 1 J3h_z6/
} gv7(-I
k)VoDxMKK
L B:wo.X
public String getSFileName() U#=Q`
{ K OZHz`1!
return sFileName; H{Zfbb
} W'f{u&<
Ey5E1$w%&
Z:Hk'|q}I
public void setSFileName(String value) A"wor\(
{ YQU#aOl
sFileName = value; ET;=o+\d
} m2!y;)F0
gwvy$H
Q+d9D1b
public int getNSplitter() pNY+E5
{ !{@!:m3w
return nSplitter; d|UK=B^x
} o$k1&hyH
IuJj;L1
0~qnwe[g}
public void setNSplitter(int nCount) %<x2=#0
{ /\=syl
nSplitter = nCount; L;a>J
} -]1F]d
} }@-4*5P3
B(<;]
:Oz! M&Ov
/* -rYOx9P4
**Utility.java *,w9#?2x
*/ 'je=.{[lWt
package NetFox; 7<W7pXDp
<VB;J5Rv
xngK_n
public class Utility { $_N<! h*\
sxq'uF(K
$0[T=9q <+
public Utility() MjIp~?*
{ tOn_S@/r
y993uP
16q"A$
} ]=5nC)|
,U_p6TV5
//线程睡眠 T\g%.
public static void sleep(int nSecond) RIXUzKLO
{ FsrGI (x?
try{ cwK6$Ax
Thread.sleep(nSecond); @pueM+(L&
} b"-eQb
catch(Exception e) p#:.,;
{ ps:|YR
e.printStackTrace (); U0}]3a0
} 4%#C _pE9
} :cv_G;?
86J7%;^Xa
//日志 E}S)uI,gn
public static void log(String sMsg) H]a;<V9[
{ &M$s@FUY
System.err.println(sMsg); O9>&E;`5
} (;^VdiJ
o,a3J:j]
$j(2M?.>#
public static void log(int sMsg) > <WR]`G
{ g0@i[&A@{
System.err.println(sMsg); `$|!h-"
} 9;3f`DK@2k
} [([?+Ouy
y>zPsc,
mZ9+.lm
/* {5}UP@h
**TestMethod.java 0*?~I;.2m$
*/ q=8I0E&q
package NetFox; yw'b^D/
^Xjh?+WM
OyVdQ".
public class TestMethod { 1-C 2Y`
KL]@y!QU
g0w<vD`<g
public TestMethod() $0rSb0[
{ ///xx/weblogic60b2_win.exe W2Y%PD9a
try{ XjpFJ#T*$A
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); AtNu:U$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); e-Z+)4fH
SiteFileFetch fileFetch = new SiteFileFetch(bean); b?U!<s.
fileFetch.start(); %H\i}}PTe
} CA[-\>J7y
catch(Exception e){e.printStackTrace ();} aagN-/mgm
Cs$wgm*
=VkbymIZ4y
} pNFL;k+p}
h@$M.h@mcG
@;m7u
public static void main(String[] args) /YYI 4
{ wkm;yCF+
new TestMethod(); SEm3T4dfzf
} ,ZyTYD|7
} <F!On5=W*
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