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)); zw]3Vg{T
} p.C1nh
for(int i=0;i<nEndPos.length-1;i++) jn$j^51`C
{ '00J~j~
nEndPos = nStartPos[i+1]; Ff<)4`J
} akC>s8tqlA
nEndPos[nEndPos.length-1] = nFileLength; :CTL)ad2
} &DLhb90
} $6!iBX@
IBET'!j4"
O:JPJ"!
//启动子线程 ({e7U17[#
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (;UP%H>
for(int i=0;i<nStartPos.length;i++) DWrbp
{ 4.Z(:g
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TV=c,*TV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,dcg?48
nStartPos,nEndPos,i); [D[D`gpjA
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Cw#V`70a
fileSplitterFetch.start(); Pbe7SRdr^
} bMmra.x4L
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l3p3tT3+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5 `=KyHi:b
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", h<Wg3o
nEndPos = " + nFileLength); b[srG6{ &
// fileSplitterFetch[nPos.length-1].start(); 76u{!\Jo/{
H&bh<KPMh
W-XpJ\_
//等待子线程结束 X+iK<F$
//int count = 0; g$w6kz_[
//是否结束while循环 ~ziexZ=N
boolean breakWhile = false; WNF9#oN|oT
:l"dYfl
kA^A mfba
while(!bStop) $<OhGk-
{ v[&'k\
write_nPos(); fHfY}BQS
Utility.sleep(500); "8HE^Po/pn
breakWhile = true; G),db%,X2
e4[) WNR
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for(int i=0;i<nStartPos.length;i++) %v4ZGtKC@
{ I4ilR$jg
if(!fileSplitterFetch.bDownOver) S}7>RHe
{ kcS6_l
breakWhile = false; GN%(9N'W
break; O2v.
} "EH,J
} 2xTT)9Tq*
if(breakWhile) .pvxh|V
break; "HC)/)Mv@
_M5Xk?e=
U3F3((EYJ
//count++; J^ ={}
//if(count>4) zu<3^=3
// siteStop(); hZN<Yd8:
} /s[DI;M$o
'qy#)F
[/ohk&
System.err.println("文件下载结束！"); /6U 4S>'(
} / Z!i;@Wf
catch(Exception e){e.printStackTrace ();} o:UXPAj
} ]0/p 7N14
X/+OF'po
a+?~;.i~
//获得文件长度 Ror2qDF
public long getFileSize() d+}kg
{ yVS\Q,:J9
int nFileLength = -1; BXhWTGiG
try{ p4>,Fwy2
URL url = new URL(siteInfoBean.getSSiteURL()); )#`H."Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -_~)f{KN@
httpConnection.setRequestProperty("User-Agent","NetFox"); rkYjq4Z@
g:gB`8w?
{$fsS&aPg
int responseCode=httpConnection.getResponseCode(); QIV%6q+*R
if(responseCode>=400) >;nS8{2o
{ HomN/wKh
processErrorCode(responseCode); Pp_V5,i\
return -2; //-2 represent access is error ',mW`ZN
} N[k<@Q?*a
hz)9"B\S
!k<:k "7
String sHeader; 8(xw?|D7
Z2p> n`D
oJY[{-qW
for(int i=1;;i++) 8A{6j
{ FA$zZs10\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); nyhMnp#<
//Utility.log(in.readLine()); ,7,;twKz
sHeader=httpConnection.getHeaderFieldKey(i); O9]\Q@M.
if(sHeader!=null) dr})-R
{ c> G@+
if(sHeader.equals("Content-Length")) 2QayM?k8
{ PZM42"[&
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :oa9#c`L
break; Dip*}8$o(w
} &" h]y?Q
} Alz~-hqQ
else vA-PR&
break; BaL]mIx
} 8wIK:
} F?4Sz#
catch(IOException e){e.printStackTrace ();} cZ< \
catch(Exception e){e.printStackTrace ();} e4.&aIC[
cY{Nos
y\[r(4h
Utility.log(nFileLength); xm^95}80yh
mm,lhIh
pm]fQuq
return nFileLength; ?`P2'i<b
} rn" pKUd
yQ[u3tI
1K[(ou'rl
//保存下载信息（文件指针位置） D4Sh9:\
private void write_nPos() nem@sB;v#
{ dlD}Ub
try{ DuNcX$%%
output = new DataOutputStream(new FileOutputStream(tmpFile)); IZ~.{UQ
output.writeInt(nStartPos.length); B8~=RmWLl
for(int i=0;i<nStartPos.length;i++) pFIecca w
{ #nEL~&
// output.writeLong(nPos); 6tdI6
output.writeLong(fileSplitterFetch.nStartPos); J}@GKNm
output.writeLong(fileSplitterFetch.nEndPos); Yx1 D)
} :s*>W$Wp4
output.close(); se,Z#H
} &O tAAE
catch(IOException e){e.printStackTrace ();} &jm[4'$ *z
catch(Exception e){e.printStackTrace ();} 9#@Zz4Ww
} Z[} $n-V
afm_Rrg[
z5EVG
//读取保存的下载信息（文件指针位置） K0<yvew
private void read_nPos() 9^zx8MRXd
{ :_H>SR:
try{ mo9$NGM&}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0w3b~RJ
int nCount = input.readInt(); ou6j*eSN
nStartPos = new long[nCount]; a8JN19}D
nEndPos = new long[nCount]; j9xXKa5
for(int i=0;i<nStartPos.length;i++) ./.=Rw
{ s.y}U5Ty?P
nStartPos = input.readLong(); 1nB@zBQu-
nEndPos = input.readLong(); 3!Bj{;A
} *V|zx#RN
input.close(); p&5S|![\
} !K\itOEP-
catch(IOException e){e.printStackTrace ();} AbZ:(+@cP
catch(Exception e){e.printStackTrace ();} 0N VI+Z$
} /{we;Ut=g
-+P7:4/
HRHrSf7
private void processErrorCode(int nErrorCode) O+FBQiv
{ /"MJkM.~E
System.err.println("Error Code : " + nErrorCode); ;+%Z@b%
} \7 Mq $d
la702)N{
oD,C<[(p
//停止文件下载 'w6hW7"L
public void siteStop() D3.VXuKn6
{ pqq?*\W&[v
bStop = true; [;@):28"
for(int i=0;i<nStartPos.length;i++) x@Vt[}e
fileSplitterFetch.splitterStop(); ~04[KG
\G3!TwC%
N 8}lt
} o^PuhVu
} CWvlr nv
//负责部分文件的抓取 R&!]Rl9hf
**FileSplitterFetch.java ^j iE9k)
*/ 4:`[qE3
package NetFox; I>Y{>S
"Q?_ EEn
m&cvU>lC
import java.io.*; DZP*x
import java.net.*; >[P%Ty);
[`9^QEj
yM|g|;U
public class FileSplitterFetch extends Thread { Nm"<!a<F
InN{^uN
2_N/wR#=&
String sURL; //File URL K @C4*?P
long nStartPos; //File Snippet Start Position , QA9k$`
long nEndPos; //File Snippet End Position ',#
int nThreadID; //Thread's ID )-#i8?y3C
boolean bDownOver = false; //Downing is over 6Ty3e|do
boolean bStop = false; //Stop identical 0@v2*\D#
FileAccessI fileAccessI = null; //File Access interface p}BGw:=
Pl?}>G
Z+,CL/
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException uAT/6@
{ ZR6&AiL(Bj
this.sURL = sURL; 94YA2_f;
this.nStartPos = nStart; ETg{yBsp
this.nEndPos = nEnd; L?Tu)<Mn
nThreadID = id; `Jqf**t
fileAccessI = new FileAccessI(sName,nStartPos);//定位 F~'sT}A*
} FR(QFt!g
,@479ZvvR3
Onyh1
public void run() i=V-@|Z
{ J7Sx!PQ
while(nStartPos < nEndPos && !bStop) [!Ao,rt?Vg
{ s"N\82z)
| F8]Xnds
IF e+B"
try{ ;xI0\a7
URL url = new URL(sURL); Y=|CPE%V
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G4O3h Y.`
httpConnection.setRequestProperty("User-Agent","NetFox"); }Wqtip:L
String sProperty = "bytes="+nStartPos+"-"; s*eyTm
httpConnection.setRequestProperty("RANGE",sProperty); +dJ&tuL:S
Utility.log(sProperty); &AJUY()8
{H'X)n$
\D ^7Z97
InputStream input = httpConnection.getInputStream(); Z"]xdOre
//logResponseHead(httpConnection); 1j+eD:d'
nqrDT1b**
N?zV*ngBS
byte[] b = new byte[1024]; _=6vW^s
int nRead; z41D^}b
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) n}f3Vrl
{ l-XnB
nStartPos += fileAccessI.write(b,0,nRead); -&$%|cyThQ
//if(nThreadID == 1) |Cu1uwy
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _E&U?>g+
} 'Z y{mq\
g4i #1V=
|K6nOX!i
Utility.log("Thread " + nThreadID + " is over!"); G$|G w
bDownOver = true; *XHj)DC;
//nPos = fileAccessI.write (b,0,nRead); 5R)[Ou.
} {rz>^
catch(Exception e){e.printStackTrace ();} 'r6cVBb}
} s* @QT8%
} p0
}!Xf&c{7{
QP'qG@j[:
//打印回应的头信息 FXcc1X/
public void logResponseHead(HttpURLConnection con) . c#90RP
{ *Gf&q
for(int i=1;;i++) 3Sk5I%
{ ~0av3G
String header=con.getHeaderFieldKey(i); $tEdBnf^ca
if(header!=null) e#K rgUG
//responseHeaders.put(header,httpConnection.getHeaderField(header)); y(V&z"wk[
Utility.log(header+" : "+con.getHeaderField(header)); YcPKM@xo
else ]Qh[%GD
break; 6Q?BwD+>
} C+DG+_%V*S
} SlR7h$r'
QziN]
O}e|P~W
public void splitterStop() hkkF1 h
{ X>3iYDe
bStop = true; | pF5`dX
} !Jk(&.
i-|/2I9%
]r"31.w(
} ~W2:NQ>i
#($k 3OA
@?'t@P:4
/* &19lk
**FileAccess.java 2,rY\Nu_
*//文件访问(定位，写) A9NOeE
package NetFox; Tnzco
import java.io.*; 8XLxT(YFIs
n ;Ql=4
t-3v1cv"
public class FileAccessI implements Serializable{ Z'7 c^c7_
\]tq7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 p.6$w:eV
RandomAccessFile oSavedFile; n's2/9x
long nPos; IKNFYe[9e
DLwC5Iir
s!8J.hD'I
public FileAccessI() throws IOException S3%.-)ib
{ d A_S"Zc
this("",0); tJ(c<:zD
} hP'~
*7:u-}c!
u|_ITwk
public FileAccessI(String sName,long nPos) throws IOException N7RG5?
{ 3&drof\{
oSavedFile = new RandomAccessFile(sName,"rw"); @p9e:[
this.nPos = nPos; ZuF4N=;
oSavedFile.seek(nPos); ,d9%Ce.$2
} ,H#qgnp
!`O_VV`/@
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public synchronized int write(byte[] b,int nStart,int nLen) >#"jfjDuR
{ V7KtbL#
int n = -1; j. ks UJ
try{ X:xC>4]gG'
oSavedFile.write(b,nStart,nLen); z[0LU]b<
n = nLen; Q KcF1?
} MA/"UV&M(
catch(IOException e) <{-(\>f!9
{ B $ y44
e.printStackTrace (); i5>J
} 4z-,M7iP
clR?< LO
V1CSXY\2
return n; &<fRej]v
} 5tgILxSK
PJSDY1T
\@ WsF$
} *`S)@'@:(
C>k;MvqO
j]ln :?\
/* yp^[]Mz=
**SiteInfoBean.java 2EqsfU* I
*/ {'=Nb 5F
package NetFox; >zfZw"mEP
E |GK3/
n_xa)
public class SiteInfoBean { TYJnQ2m
C9z~)aL}7
YjIED,eRv
private String sSiteURL; //Site's URL _/z)&0DO
private String sFilePath; //Saved File's Path cV=_GE
private String sFileName; //Saved File's Name yTq(x4]
private int nSplitter; //Count of Splited Downloading File xj00eL
[-:<z?(n4
3>@qQ_8%~
public SiteInfoBean() \$~oH3m&
{//nSplitter的缺省值为5 MLv.v&@S
//default value of nSplitter is 5 G|6|;
this("","","",5); zoJkDr=jn
} "6*Kgf2G
xJH9qc ME
q$u\ q.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) l~Wk07r3
{ bh;b` 5
sSiteURL= sURL; i6g[E4nk
sFilePath = sPath; Cf1wM:K|8
sFileName = sName; ixJ20A7
this.nSplitter = nSpiltter; = "hY{RUa
eI=Y~jy
yY@s(:
} jO3u]5}.6
oN6*WNtJ
(h@yA8>n
public String getSSiteURL() X5oW[
{ l]klV+9t
return sSiteURL; 2Fp]S a
} J:-TINeB
v YmtpKNj%
k.%W8C<Pa
public void setSSiteURL(String value) +q_lYGTiO
{ zs]/Y2
sSiteURL = value; <}Wy;!L
} ,w/mk$v
%_@5_S
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public String getSFilePath() k4AE`[UE
{ t ]I(98pY
return sFilePath; @01D1A
} A7,$y!D
)}it,<
}vxH)U6$q
public void setSFilePath(String value) m[Ac'la
{ !wb~A0m
sFilePath = value; xdBZ^Q
} 5bznM[%xO
d @kLLDP
LX?r=_\
public String getSFileName() 0*:hm%g
{ }v$=mLy
return sFileName; eN?P) ,
} UE#Ni 5
aaD$'Y,<>B
JQh s=Xg
public void setSFileName(String value) Jx ;"a\KD
{ ):\{n8~
sFileName = value; RWPdS
} )w 8lusa
,vdP #:
ch8w'
public int getNSplitter() wrb& ta
{ (yTz^o$t|
return nSplitter; c+i`Zd.m<
} cxJK>%84
I/b8
$\@ V4
public void setNSplitter(int nCount) ,t&-`U]AX
{ ~md|k
nSplitter = nCount; ^FMa8;'o
} .rB;zA;4S)
} ]3y5b9DuW
&MQt2aL
*u4X<oBS*
/* kRXg."b(
**Utility.java ~$ qJw?r
*/ '>mb@m
package NetFox; f]A6Mx6
)?IA`7X
)~mc1U`b
public class Utility { [ EID27P
H!>oLui
.&}4
public Utility() 95 .'t}
{ 3XlnI:w=
MMr7,?,$
hYv 6-5_
} <J}9.k
|QTqa~~B
//线程睡眠 8EEQV}4
public static void sleep(int nSecond) IS4K$Ac.
{ W#\};P
try{ Z#:@M[HH{
Thread.sleep(nSecond); m'"VuH?^
} 2CgIY89O
catch(Exception e) 6')SJ*|yS
{ @>nk^l
e.printStackTrace (); M-K@n$k
} KdMA58)
} 2xdJ(\JWM
-qP[$Q
//日志 fQ_8{=<-&X
public static void log(String sMsg) lnSE+YJ>
{ '*;eFnmvs:
System.err.println(sMsg); |{IU<o x
} u2O^3rG-
`b`52b\6S
c%/&@vs7
public static void log(int sMsg) UVmyOC[Y{
{ d?y\~<
System.err.println(sMsg); d#:J\2V"R
} SWO!E
} 2|>wY%
yx;R#8;b.
UkbQ'P+oS
/* R/cq00g
**TestMethod.java Jd2Y)
*/ 'yRv~BA
package NetFox; mf_'| WDs
m9w ;a
I%C:d#p
public class TestMethod { I"<. h'
]sP9!hup
[#6Esy8|
public TestMethod() F8;4Oj
{ ///xx/weblogic60b2_win.exe s^R2jueR
try{ E^W*'D
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >P"/nS"nn
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); x2c*k$<p
SiteFileFetch fileFetch = new SiteFileFetch(bean); A?k,}~
fileFetch.start(); JU1; /3(
} #&c;RPac!6
catch(Exception e){e.printStackTrace ();} HFWm}vA:
&:f'{>3z
#(J}xz;
} 7{F9b0zwk
7#.PMyK9
kGiw?~t=%
public static void main(String[] args) !Ocg
{ tU/NwA"
new TestMethod(); a(T4WDl^
} <G?85*Nv_
} 6-}e-H
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