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)); <:v+<)K
} 5l6/5
for(int i=0;i<nEndPos.length-1;i++) *y*tI}
{ 8}B
nEndPos = nStartPos[i+1]; \Fz9O-jb4
} v|%41xOsr
nEndPos[nEndPos.length-1] = nFileLength; /| v.A\:
} y|5s
} r(>S
6{y7e L3!
+ Q-b}
//启动子线程 zqeQ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Tc6cBe,
for(int i=0;i<nStartPos.length;i++) ?G,4N<]Nu
{ V)^Xz8H_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d05xn7%!{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =Zq6iMD
nStartPos,nEndPos,i); :jiuu@<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f$o^Xu
fileSplitterFetch.start(); +` Md5.w
} kamQZzPe
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S<i$0p8J;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >v:ex(y0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &h334N|4{
nEndPos = " + nFileLength); KZppQ0
// fileSplitterFetch[nPos.length-1].start(); h6h6B.\Ld
V?u#WJy/
4[gmA
//等待子线程结束 UBaXS_c\
//int count = 0; QL/KY G
//是否结束while循环 NIV}hf YF
boolean breakWhile = false; ${ {4L?7
3B1\-ry1M
24jf`1XFW
while(!bStop) 9{u8fDm!
{ tIuM9D{P
write_nPos(); pbVL|\oB}
Utility.sleep(500); L`+[mX&2B
breakWhile = true; op6]"ZV-C
'}Fe&%
%B%_[<B
for(int i=0;i<nStartPos.length;i++) >fBPVu\PA
{ ppAbG,7
if(!fileSplitterFetch.bDownOver) >yO/p(/;jR
{ 6 4_}"fU
breakWhile = false; H/D=$)3op
break; -b-a21,m>
} \o>-L\`O
} LDt6<D8,Q
if(breakWhile) |qNe_)
break; 7Nq< o5
mfraw2H
$BwWQ?lp
//count++; ea3w
//if(count>4) >XgoN\w
// siteStop(); cE\w6uBR1
} E|@C:ghG
fd)8lK[KJ"
?qjdmB|w
System.err.println("文件下载结束！"); z$1RD)TQB
} ,>j3zjf^
catch(Exception e){e.printStackTrace ();} j 3<Ci {3
} =3bk=vy
^#_gk uyd!
k1B ](@xt
//获得文件长度 gT)(RS`_)
public long getFileSize() `^)`J
{ w S
int nFileLength = -1; K"!rj.Da
try{ @M'k/jl
URL url = new URL(siteInfoBean.getSSiteURL()); u+)!C*ho
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bQaRl=:[:
httpConnection.setRequestProperty("User-Agent","NetFox"); )M8d\]
iJTG+gx
+Br<;sW
int responseCode=httpConnection.getResponseCode(); u3h(EAH>
if(responseCode>=400) P y'BMk
{ %xgP*%Sv2
processErrorCode(responseCode); ~^F]t$rz
return -2; //-2 represent access is error c~T{;
} rc=E%Qv%?
g#I`P&
LK h=jB^bT
String sHeader; ,+i^]yF3j
Zo=,!@q(
-h8mJ D%Oi
for(int i=1;;i++) c&D+=
{ 01n!T2;yW}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +R~]5Rxd
//Utility.log(in.readLine()); ?1\5X<|,
sHeader=httpConnection.getHeaderFieldKey(i); h[(YH ;Y
if(sHeader!=null) Hca(2 ]T-
{ _c]}m3/
if(sHeader.equals("Content-Length")) 2f(`HSC'
{ i;HXz`vT7
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); A+/Lt>+AS
break; xM_#FxJb
} r`"_D%kc
} 6C$+D
else ?c.\\2>|F
break; s.z)l$
} ,88B@a
} U#f*
catch(IOException e){e.printStackTrace ();} '&CZ%&(Gw
catch(Exception e){e.printStackTrace ();} h#zm+([B*
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)=)N9CRy
Utility.log(nFileLength); ~criZI/
l&H-<Z.8m
],c0nz^%BR
return nFileLength; r,eH7&P9{
} }Z <I%GT
"|6(.S+o
yK{P%oh)
//保存下载信息（文件指针位置） +9HU&gQ3
private void write_nPos() !KV!Tkx h
{ 6F^/k,(k4
try{ Pr>$m{ Z
output = new DataOutputStream(new FileOutputStream(tmpFile)); $I5|rB/4?
output.writeInt(nStartPos.length); ^ iu)vED
for(int i=0;i<nStartPos.length;i++) 3g7]$}
{ 0+0Y$;<
// output.writeLong(nPos); $(&uaDYv
output.writeLong(fileSplitterFetch.nStartPos); d^'_H>x
output.writeLong(fileSplitterFetch.nEndPos); !jP[=
} 42`Uq[5Y
output.close(); r%: :q^b3
} /:!sn-(
catch(IOException e){e.printStackTrace ();} ccv
catch(Exception e){e.printStackTrace ();} 9Zx| L/\
} `c:r`Oi?
u9_?c G-
d Np%=gIj
//读取保存的下载信息（文件指针位置） H~[q<ybxr
private void read_nPos() ~&/Nl_#
{ Fmn_fW6
try{ ;zqxDl_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %~eu&\os
int nCount = input.readInt(); , wk}[MF
nStartPos = new long[nCount]; hj=n;,a9
nEndPos = new long[nCount]; V xN!Ki=
for(int i=0;i<nStartPos.length;i++) zRh)q,Dt
{ m<Gd 6V5
nStartPos = input.readLong(); s2sJJdN
nEndPos = input.readLong(); O-AC$C[d
} +fvVora
input.close(); ,-])[u
} 6heK8*.T
catch(IOException e){e.printStackTrace ();} =>*}qen
catch(Exception e){e.printStackTrace ();} F, =WfM\
} } %3;j5 ;6
o<|u4r={s
axG%@5
private void processErrorCode(int nErrorCode) }T%E;m-
{ *"|f!t
System.err.println("Error Code : " + nErrorCode); :t;\`gQoS
} J?p|Vy|9
`34+~;;Jh
TPJuS)TU9
//停止文件下载 B_!S\?}$
public void siteStop() jcePSps]
{ `[=/f=Q}
bStop = true; jxK `ShW=
for(int i=0;i<nStartPos.length;i++) fN`Prs A
fileSplitterFetch.splitterStop(); s$^ 2Cuhv
rl"yE=
1\jj3Y'i'
} D<Z\6)|%I
} ~LH).\V
//负责部分文件的抓取 g6q[ I8
**FileSplitterFetch.java wh]v{Fi'
*/ Kt#X'!9/<
package NetFox; ]{-ib:f~
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<l)I%1T_c
import java.io.*; N[=R$1\Z
import java.net.*; AQ-R^kT
Xp^71A?>
P; =,Q$e8
public class FileSplitterFetch extends Thread { S?H qrf7<
5X`m.lhUc
M/6q ^*
String sURL; //File URL _t7aOH
long nStartPos; //File Snippet Start Position ds+0y;vc
long nEndPos; //File Snippet End Position n\scOM)3
int nThreadID; //Thread's ID gdBH\K(\
boolean bDownOver = false; //Downing is over &-.2P!t
boolean bStop = false; //Stop identical CJLfpvV
FileAccessI fileAccessI = null; //File Access interface g<4@5OQKu
xirZ.wjW
~<_PjV
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException u_)'}
{ ;#2yF34gv
this.sURL = sURL; NSh~O!pX
this.nStartPos = nStart; "qY_O/Eg]]
this.nEndPos = nEnd; *Q3q(rdrp
nThreadID = id; _K>YB>W}7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;x=0+0JD
} "IdN*K
\R#OJ=F
Pu]Pp`SP
public void run() rcMSso2
{ [tz}H&
while(nStartPos < nEndPos && !bStop) i\k>2df
{ I_h&35^t
*+cW)klm
8<g9 ~L
try{ AtlUxFX0S
URL url = new URL(sURL); &p^8zEs
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &qFy$`"
httpConnection.setRequestProperty("User-Agent","NetFox"); v+`gQXJ"G
String sProperty = "bytes="+nStartPos+"-"; M,9f}V)
httpConnection.setRequestProperty("RANGE",sProperty); arj?U=zy
Utility.log(sProperty); [Gb8o'
[[0u|`T/
eN]9=Y~-K
InputStream input = httpConnection.getInputStream(); PeB7Q=d)K1
//logResponseHead(httpConnection); fnO>v/&B
GZqy.AE,
>*goDtTjp
byte[] b = new byte[1024]; V> @+&q
int nRead; ZC:7N{a
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _0e;&2')
{ 8d"Ff
nStartPos += fileAccessI.write(b,0,nRead); =ET|h}I
//if(nThreadID == 1) ZncJ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); },G5!3
} iyf vcKO
.qk_m-o
-eoXaP{[
Utility.log("Thread " + nThreadID + " is over!"); jAb R[QR1%
bDownOver = true; EAXbbcV
//nPos = fileAccessI.write (b,0,nRead); dJD8c2G
} OB5`a,5dI
catch(Exception e){e.printStackTrace ();} BO)Q$*G~JD
} .:=G=v=1
} "_T8Km008
i"o %Gc
LL^WeD_Y
//打印回应的头信息 ]728x["(19
public void logResponseHead(HttpURLConnection con) i_6 Y6
{ f& >[$zh
for(int i=1;;i++) #Z]l4d3{T
{ `8D}\w<eI
String header=con.getHeaderFieldKey(i); _B5v&#h(.
if(header!=null) 0'0GAh2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); bs=x>F
Utility.log(header+" : "+con.getHeaderField(header)); 8C>\!lW"
else {:0TiOP5x
break; +Q+>{HK
} E1-BB
} 0B?t:XU,
ij+)U`
Q9h;`G 7t
public void splitterStop() DqGm
{ &;]KntxB
bStop = true; XIJW$CY
} U^.kp#x#
2Ub!wee
HJeZm
} rsgTd\b
%DR8M\d1~H
2/m4|
/* .>Fy ]Cqoh
**FileAccess.java )D"E]
*//文件访问(定位，写) E\Et,l#|LY
package NetFox; xaG( 3
import java.io.*; 7I`8r2H
5b5Hc Inu
4V9S~^v|
public class FileAccessI implements Serializable{ VHihC]ks,
lOuO~`,J
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 70BLd(?
RandomAccessFile oSavedFile; n3Q Rn^
long nPos; _^ny(zy(
EYD24
;S.o`z1GI
public FileAccessI() throws IOException \7U'p:h=U
{ O4.`N?Xq
this("",0); iu+r=sp
} |s$w i>7l
rCp'O\@S
V>Vu)7
public FileAccessI(String sName,long nPos) throws IOException +9!=pRq
{ j|Hyv{sM
oSavedFile = new RandomAccessFile(sName,"rw"); $WS?/H0C
this.nPos = nPos; #Li6RSeW
oSavedFile.seek(nPos); O-jpS?@
} 'BOMFp7c
_(%;O:i
{GP#/5$=
public synchronized int write(byte[] b,int nStart,int nLen) #<*=)[
{ =dM'n}@U
int n = -1; a 0+W-#G
try{ vnS;T+NZSC
oSavedFile.write(b,nStart,nLen); EYXHxo
n = nLen; ;xxu,
} r&_bk Y%
catch(IOException e) L }L"BY3$
{ aF]cEe
e.printStackTrace (); ews{0
} cy @",z
[wv;CUmgc
p38RgEf
return n; fIwG9cR
} '74*-yd
>o,l/#z
>,}SP;
} fuao*L]
e` {F7rd:
*1c1XN<7
/* 6h9Hf$'
**SiteInfoBean.java # ;3v4P
*/ *aaK_=w
package NetFox; ]b'"l
cl1>S3
eB2a1<S&@
public class SiteInfoBean { ~;/}D0k$x
$3)Z>p
dk>qTY+j5
private String sSiteURL; //Site's URL - xKa-3
private String sFilePath; //Saved File's Path ,LftQ1*;
private String sFileName; //Saved File's Name 6O\a\z
private int nSplitter; //Count of Splited Downloading File X-k$6}D
n&\DJzW\#
|kK_B :K
public SiteInfoBean() Bm4fdf#A]
{//nSplitter的缺省值为5 $*q^7ME
//default value of nSplitter is 5 HyGu3
this("","","",5); 8'|_O
} '9XSz?
o_R_
\9N )71n(
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) m4x8W2q
{ mZ0'-ax
sSiteURL= sURL; /ht-]Js$G
sFilePath = sPath; NnTAKd8
sFileName = sName; D&*'|}RZ
this.nSplitter = nSpiltter; B x-"<^<
JrNqS[c/
":W$$w<
} @5tGI U;1
v\3$$T)
/ei(Q'pc[
public String getSSiteURL() u`?v-
{ S pIdw0
return sSiteURL; ;GV~MH-F
} K'U8ft*_
e]zd6{g[m
Z# o;H$
public void setSSiteURL(String value) ^t}8E2mq
{ bvF-F$n%F
sSiteURL = value; t .-%@,s
} "|nh=!L
Ng|c13A=
12LGWhDp
public String getSFilePath() EZJ[+ -Q;
{ ;i-<dAV8B
return sFilePath; *_@t$W
} "Ta"5XW
'n/L1Fn
[ XBVES8
public void setSFilePath(String value) U#g,XJ
{ w^E$R
sFilePath = value; s6(bTO.
} 'mYUAVmSC#
k] iyx
):Pzsz7
public String getSFileName() RN"Ur'+
{ -jk-ve
return sFileName; OJT%?P%@{
} ;5&=I|xqe
|32uC3?o
\\Te\l|L
public void setSFileName(String value) `h='FJ/!
{ r^T+I3
sFileName = value; W0k7(v)
} a/TeBx#yG
NudY9~
Lk2;\D>
public int getNSplitter() Ctx{rf_~
{ ]/[$3rPwZ
return nSplitter; `=P=i>,
} c1ptN
bBY7^k
,b9!\OWDF
public void setNSplitter(int nCount) :0'vzM
{ khVfc
nSplitter = nCount; % 8P8h%%Z
} ZmAo9>'Kg
} MnTqWC90
:vJ1Fo!
o?/fObV@(
/* bkS-[rW
**Utility.java tqXCj}mR
*/ V6kJoSyde
package NetFox; dmPAPCm%y
W%@0Ym`7
,'%*z
public class Utility { FZ5 Ad&".@
,m[#<}xXA
[7Liken
public Utility() &0RKNpwg
{ ;4k/h/o1#
-\~HAnh
@Px_\w
} "{x+ \Z\
!|~yf3
//线程睡眠 ,SH^L|I
public static void sleep(int nSecond) -=GmI1:=$4
{ L0>7v
try{ K'oy6$B
Thread.sleep(nSecond); Oid;s!-S6
} t/J|<Ooj?
catch(Exception e) C&f{LpB`
{ q"VC#97`
e.printStackTrace (); 2#X>^LH
} IHwoG(A~<
} +6s6QeNS8
JZ)w
//日志 8iC9xSH[%
public static void log(String sMsg) #D^(dz*
{ V-ONC
System.err.println(sMsg); IgEVz^W?h
} 9#1Jie$
o3Z<tI8-V
Lklb
public static void log(int sMsg) WDF6.i ?
{ J<MuWgx&
System.err.println(sMsg); Nt~G {m
} rw%OA4>
} P\&n0C~
=\gK<Xh
m%U$37A1
/* x,Z:12H0
**TestMethod.java vz^=o'
*/ $KPf[JvQ
package NetFox; TNlS2b1
!RwMUnp
Q+p9^_r
public class TestMethod { "@L|Z6U(
R<Ct{f!
ggUw4w/e
public TestMethod() V3$zlzSm,
{ ///xx/weblogic60b2_win.exe ~vKDB$2
try{ P(B&*1X
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pt%Y1<9Eh?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); wp<f{^ et
SiteFileFetch fileFetch = new SiteFileFetch(bean); USV;j%U4*
fileFetch.start(); RY]jY | E
} YbJB.;qK
catch(Exception e){e.printStackTrace ();} ;RS^^vDm
Vo9FlYj
NW~`oc)NS
} 9^@#Ua
6OZn7:)Y
p*|Ct
public static void main(String[] args) K}QZdN']
{ /U=?D(>x
new TestMethod(); =~'y'K]
} &Y-jK<
} QxiAC>%K
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