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)); zyF[I6Gs
} w7Y>B`wm?
for(int i=0;i<nEndPos.length-1;i++) 97~*Z|#<+
{ .>bvI1
nEndPos = nStartPos[i+1]; s\#eD0|
} o])2_e5
nEndPos[nEndPos.length-1] = nFileLength; F2k)hG*|{
} xfqW~&
} itmQH\9 8
F G5e{
WeqQw?-
//启动子线程 :.%Hu9=GL
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; wD'LX
for(int i=0;i<nStartPos.length;i++) SYZS@o
{ 6yRxb(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?iQA>P9B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), f7Fr%*cO
nStartPos,nEndPos,i); 4RU/y+[o
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q9mYhT/Im
fileSplitterFetch.start(); p/GYfa dU
} AroXf#.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]'a9>o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <+2M,fq+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "Ca?liy
nEndPos = " + nFileLength); 2 - ?
// fileSplitterFetch[nPos.length-1].start(); 5qW*/
v\gCgx=%j
c7$U0JO
//等待子线程结束 )/1,Ogb%_
//int count = 0; Z-BPC|e
//是否结束while循环 K;}h u(*\]
boolean breakWhile = false; |Y42ZOK0
_8G
v4V|j<R
while(!bStop) 8LouCv(>
{ #Kp/AN5YC
write_nPos(); oztfr<cUH
Utility.sleep(500); std4Nyp
breakWhile = true; |K%nVcR=
WF{rrU:
h r!Htew4
for(int i=0;i<nStartPos.length;i++) _'lrI23I
{ Q<F-l.q
if(!fileSplitterFetch.bDownOver) _a3,Zuv
{ &%/kPF~<
breakWhile = false; ;v?!Pml2k
break; Y)=89s&t
} HBc^[fJ^-
} 8}0O @ wq
if(breakWhile) ,:!dqonn
break; ]c \gUU
4LBMhLy
i1#\S0jN
//count++; X)K3X:~L+
//if(count>4) :"aCl~cy9g
// siteStop(); YLfZ;W|6u
} =Qcz:ng
{t;{={$
b6k'`vLA
System.err.println("文件下载结束！"); v!pT!(h4
} h6dVT9
catch(Exception e){e.printStackTrace ();} TCd1JF0
} N?'V,p 0=
~X/1%
Z ?{;|Z5
//获得文件长度 B0^0d*8t|@
public long getFileSize() i-b++R/WN
{ 7xOrG],E
int nFileLength = -1; wER>a (
try{ JKkR963 O
URL url = new URL(siteInfoBean.getSSiteURL()); P*#H]Pv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yBPaGZ{f
httpConnection.setRequestProperty("User-Agent","NetFox"); `.FvuwP
h>6'M
d2x|PpmH
int responseCode=httpConnection.getResponseCode(); &.Jp,Xt)
if(responseCode>=400) ~8-Z=-
{ [kyF|3k~
processErrorCode(responseCode); C NNyz$
return -2; //-2 represent access is error mGXjSWsd
} ^]$x/1I;
kphv)a4z=
( *(#;|m
String sHeader; eoS8e$}
\wxS~T<&L
]Xur/C2A
for(int i=1;;i++) pv=g)
{ ;^Vsd\ac0
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); OgiElA.
//Utility.log(in.readLine()); "b!EtlT9
sHeader=httpConnection.getHeaderFieldKey(i); !`k{Ga
if(sHeader!=null) (o1*7_]e
{ >C`b4xQ
if(sHeader.equals("Content-Length")) +oZq~2?*S6
{ K.Tfu"6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .O{2]e$
break; LsnM5GU7
} Ocq.<#||H
} _(}{=:M?
else );wSay>%(
break; ^1vh5D
} 1@)8E`u
} C|"h]
catch(IOException e){e.printStackTrace ();} gp:,DC?(
catch(Exception e){e.printStackTrace ();} S=>54!{`x
S;[*5g6a&x
&i8AB{OU
Utility.log(nFileLength); Y. ]FVq
iw\RQ 0
G SXe=?
return nFileLength; ISI\<qx
} 8'Z#sM^E
;^}gC}tq
FY [WdZDZ
//保存下载信息（文件指针位置） 0Ii* "?s
private void write_nPos() dyRKmLb
{ r=<Oy1m/
try{ fQ5VRpWGn
output = new DataOutputStream(new FileOutputStream(tmpFile)); C:/O]slH
output.writeInt(nStartPos.length); l@a>"\><i*
for(int i=0;i<nStartPos.length;i++) :=BFx"Y
{ }&)X4=
// output.writeLong(nPos); TC80nP
output.writeLong(fileSplitterFetch.nStartPos); /vi>@a
output.writeLong(fileSplitterFetch.nEndPos); m]8rljo
} 4tR:O#($V
output.close(); MO+g*N
} sv0)sL
catch(IOException e){e.printStackTrace ();} wR\Y+Z
catch(Exception e){e.printStackTrace ();} Kv'2^B
} \0iF <0oy
VLuhURI)
>(s)S[\
//读取保存的下载信息（文件指针位置） 31\l0Jg
private void read_nPos() Q# w`ZQX3
{ _-$"F>
try{ MzRwsf
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7t7"glP
int nCount = input.readInt(); ~ztsR;iL
nStartPos = new long[nCount]; =B g
nEndPos = new long[nCount]; a9C8Q l
for(int i=0;i<nStartPos.length;i++) bT<if@h-
{ n}MW# :eJe
nStartPos = input.readLong(); *Ppb;
nEndPos = input.readLong(); eXY*l>B
} =m.Lw
input.close(); v/{LC4BF
} luYkC@I@a
catch(IOException e){e.printStackTrace ();} XBE+O7
catch(Exception e){e.printStackTrace ();} A*jU&3#
} M=$ qus
`9BZ))Pg
=&RpW7]
private void processErrorCode(int nErrorCode) FS7 _ldD
{ .}n%gc~A
System.err.println("Error Code : " + nErrorCode); ;/w-7O:
} 45` i
.UF](
9MQ!5Zn
//停止文件下载 S)T]>Ash
public void siteStop() P` Hxj> {
{ InnjZ>$
bStop = true; Gf'qPLK0
for(int i=0;i<nStartPos.length;i++) (3Hz=k_
fileSplitterFetch.splitterStop(); u`I&&
;i*<HNQ
| +osEHC
} p|!5G&O,
} U5N/'p%)<
//负责部分文件的抓取 e&WlJ
**FileSplitterFetch.java 6%bZZTP`
*/ w&yK*nBK
package NetFox; c5x2FM z
#=mLQSiQ
yd#SB)&
import java.io.*; tHAr9
import java.net.*; P;_}nbB
t*Hr(|.
.J0s_[
public class FileSplitterFetch extends Thread { $+CKy>
iV#sMJN9
%M8m 8 )
String sURL; //File URL 7kX;|NA1
long nStartPos; //File Snippet Start Position 5}S~8
long nEndPos; //File Snippet End Position XpWcf ([
int nThreadID; //Thread's ID {~J'J$hn8
boolean bDownOver = false; //Downing is over coa+@g,w7#
boolean bStop = false; //Stop identical 4D+S\S0bk
FileAccessI fileAccessI = null; //File Access interface d:C|laZHn
1t&LNIc|^
a"7zz]XO2
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~6YTm6o
{ cu{c:z~
this.sURL = sURL; @r7ekyO8)
this.nStartPos = nStart; /Kcp9Qx
this.nEndPos = nEnd; P2la/jN
nThreadID = id; bMe/jQuL.$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 f793yCiG
} zh8\ _>+
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je_:hDr
public void run() 8t)5b.PS
{ .V~z6
while(nStartPos < nEndPos && !bStop) L=g(w$H
{ W:5uoO]=<
HRQ3v`P.
G8bc\]
try{ RuyqB>[o
URL url = new URL(sURL); 'W'['TV
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vXA+o)*#/
httpConnection.setRequestProperty("User-Agent","NetFox"); Qy0Zj$,Z
String sProperty = "bytes="+nStartPos+"-"; u={A4A#
httpConnection.setRequestProperty("RANGE",sProperty); ^j~CYzmt
Utility.log(sProperty); =CBY_
imb.CYS74
okwkMd-yW
InputStream input = httpConnection.getInputStream(); Tvp~~Dk
//logResponseHead(httpConnection); }6S~"<Ym
2bIP.M2Fs
fkKk/M>1
byte[] b = new byte[1024]; d\eTyN'rA
int nRead; tUOqF
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !*I0}I ~
{ olA 1,8
nStartPos += fileAccessI.write(b,0,nRead); -hy`Np
//if(nThreadID == 1) Dk^,iY(u
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); su2|x
} {&u`d.Lk2p
2!@ER i
79HKfG2+KB
Utility.log("Thread " + nThreadID + " is over!"); ZMp5d4y5
bDownOver = true; g>gVO@"b2
//nPos = fileAccessI.write (b,0,nRead); py-5 :g}d
} }N^3P0XjYq
catch(Exception e){e.printStackTrace ();} 76IjM4&a
} _;zIH5 H
} FaA'%P@
"UM*(&
YRU1^=v
//打印回应的头信息 %"yy8~|
public void logResponseHead(HttpURLConnection con) :t)<$dtf[
{ ]h3{MTr/
for(int i=1;;i++) 3'*}ZDC
{ $M:Ru@Du2
String header=con.getHeaderFieldKey(i); 0,{tBo
if(header!=null) "pA24Ze
//responseHeaders.put(header,httpConnection.getHeaderField(header)); yb/v?q?Fk
Utility.log(header+" : "+con.getHeaderField(header)); TyGsSc
else NzBX2
break; 0&21'K)pW
} z5tOsU
} (Ts#^qC
]=ubl!0=:
S+*%u/;l
public void splitterStop() m)\wbkC
{ 506AvD
bStop = true; sKCfI]
} <>l!
g&]n:qx
-a+oQP]O
} x<=<Lx0B;
Lb=4\ _
@Jh;YDr`A
/* ]DJ]L=T7
**FileAccess.java 5f}GV0=n
*//文件访问(定位，写) w~a_FGYX
package NetFox; iJaA&z5sr
import java.io.*; n/ m7+=]v
7eU|iDYo
yt5'2!jc
public class FileAccessI implements Serializable{ `VL<pqPP
>Y)FoHa+/
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &al\8
RandomAccessFile oSavedFile; SbYsa
long nPos; zNh$d;(O$^
.dw;b~p
.}*_NU
public FileAccessI() throws IOException _mG>^QI.
{ 1)N~0)dO
this("",0); p=jIDM'
} vVfIe5+OP
-. J@
2;`F`}BA
public FileAccessI(String sName,long nPos) throws IOException %CaF-m=Pq
{ x6iT"\MO
oSavedFile = new RandomAccessFile(sName,"rw"); ^v+7IFn
this.nPos = nPos; *Q`y'6S
oSavedFile.seek(nPos); d@QC[$qXj
} |]=s
,\CG}-v@CN
@\)a&p]a
public synchronized int write(byte[] b,int nStart,int nLen) }'c@E0"
{ z@tIC^s
int n = -1; y&(R1Y75
try{ m2r%m y
oSavedFile.write(b,nStart,nLen); 41s[p56+@
n = nLen; :G/.h[\R|
} W^T6^q5;H
catch(IOException e) Hphfqdh0`
{ Ks/Uyu. X
e.printStackTrace (); =5D@~?W ZG
} Z.{r%W{2
,]cb3nP
|$QL>{81
return n; <pp<%~_Z
} X)^&5;\`
Zt{\<5j
$?Yw{%W
} a"pejW`m
KOP*\\1 J
EwuBL6kN
/* kFZjMchm A
**SiteInfoBean.java .#wU+t>
*/ Ng;Fhv+
package NetFox; ufc_m4PN
/sa\Ze;E
vkg."G:=
public class SiteInfoBean { L\/YS;Y
=k|hH~
y|O)i I/g
private String sSiteURL; //Site's URL 9xZ?}S:d
private String sFilePath; //Saved File's Path (U@uJ
private String sFileName; //Saved File's Name S/)J<?<b
private int nSplitter; //Count of Splited Downloading File X!=*<GF)
+ug[TV
lV)SOs$
public SiteInfoBean() DNp4U9
{//nSplitter的缺省值为5 TkjPa};R
//default value of nSplitter is 5 L|pJ\~
this("","","",5); QU%'z/dip
} :eR[lR^4*
vp#r:+=
+E-f
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) WC ZDS>
{ @ZFU< e$!
sSiteURL= sURL; NX5NE2@^qH
sFilePath = sPath; uom~,k$|
sFileName = sName; /ar/4\b
this.nSplitter = nSpiltter; _!'sj=n]q
4}>1I}!k
\&)k{P>=
} V9r58hbVT
{I~[a#^
?ybX&V
public String getSSiteURL() Pln*?o
{ jy2@t*
return sSiteURL; B$kp\yL
} g"&e*fF
~hxo_&
r1!]<=&\
public void setSSiteURL(String value) WKB@9Vfju
{ /naGn@m5u
sSiteURL = value; 7IV:X _y
} y9'F D5\s
;th]/ G
!YJ^BI
public String getSFilePath() /qalj\ud
{ ^FZ7)T
return sFilePath; t1h2ibO
} TPeBb8v8D
{cF>,T
OJH:k~]0!
public void setSFilePath(String value) 6"UL+$k
{ dS[="Set
sFilePath = value; H@R2mw
} xw%'R-
%hqhi@q#
GOeYw[Vh
public String getSFileName() U~Ai'1?xz
{ $={WtR
return sFileName; [va7+=[1=
} ie+746tFW
#:?MtVC
$3C$])k
public void setSFileName(String value) UIl^s8/
{ ~jqh&u$(
sFileName = value; =*u:@T=d5
} Gr a(DGX
~"ij,Op,3
3M&IMf,/@
public int getNSplitter() <(%cb.^c=N
{ w'b|*_Q4Q
return nSplitter; [@_zsz,`L
} 7:_\t!]
jt/ |u=
RL;>1Q,H
public void setNSplitter(int nCount) `xO&!DN
{ ]&D;'),
nSplitter = nCount; U.@j!UrZ
} yfD)|lK
} D(]])4
N>A*N,+
xedbr
/* /N>bEr4w
**Utility.java 3C8W]yw/s
*/ cP~?Iz8nD
package NetFox; 1jhGshhp
1K;i/
Je6=N3)
public class Utility { X|WAUp?
4IIXzMOa
Yjr6/&ML
public Utility() `[+nz rLkO
{ y/}>)o4Q
F;IG@ &
t7%!~s=,M
} f'\NGL
B0:[3@P7
//线程睡眠 F<UEipe/N
public static void sleep(int nSecond) ~!,Q<?
{ <p'~$vK
try{ 9%?'[jJ
Thread.sleep(nSecond); h69: Tj!
} \c! LC4pE
catch(Exception e) FH'jP`
{ \sIRV}Tk}N
e.printStackTrace (); [Q/')5b
} Ge|& H]W
} 1{-W?n
_cZ`7]Z
//日志 S"iQQV{)Z
public static void log(String sMsg) {)t6DH#
{ *6)u5
System.err.println(sMsg); %^l77:O
} m4@y58n=
d8b'Gjwtw
R0y@#}JH
public static void log(int sMsg) Bu'PDy~W,
{ / 4K*iq
System.err.println(sMsg); EX[X|"r
} >a]4}
} 1:%m >4U
<[^nD>t_
yiUJ!m
/* >NN|vj
**TestMethod.java #4{f2s[j6
*/ (WK$ )f
package NetFox; [UI4YZu}
|n;gGR\
YZCPS6PuE
public class TestMethod { O,_2djd
NA`3
P'D~Y#^
public TestMethod() Y"mD)\Bw?
{ ///xx/weblogic60b2_win.exe hnM|=[wM
try{ O\L(I079
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #ZIV>(Q\H
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N1Y*IkW"
SiteFileFetch fileFetch = new SiteFileFetch(bean); R0fZ9_d7}
fileFetch.start(); v&U'%1|
} }Kq5!XJV9C
catch(Exception e){e.printStackTrace ();} eb:mp/
/|y3M/;F
}[PbA4l.g
} Nh41o0
V|{ )P@Q
#kX=$Bzk
public static void main(String[] args) joifIp_
{ =MG
new TestMethod(); )\uy 0+b
} :H<u@%
} {"e/3
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