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)); ]*Q,~uV^|
} <P6d-+
for(int i=0;i<nEndPos.length-1;i++) H*+7{;$
{ VZ y$0*
nEndPos = nStartPos[i+1]; {^^LeUd#V
} yy&L&v'
nEndPos[nEndPos.length-1] = nFileLength; K5\l (BB
} ^U96p0H"T
} I0=L_&`)
oA7|s1
N 7Y X
//启动子线程 Zy8tI#
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; U~t!
for(int i=0;i<nStartPos.length;i++) ]VE3u_kR
{ 53pT{2]zAi
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s.n:;8RibP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), qDz[=6BF
nStartPos,nEndPos,i); x;-D}#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }UQ,B
fileSplitterFetch.start(); @LDs$"f9=
} j]]5&u/l
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qDhZC*"9#D
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); X8?@Y@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", AZA5>Y
nEndPos = " + nFileLength); @$ lX%p>
// fileSplitterFetch[nPos.length-1].start(); Z,81L3#6
:XPat93w
:nc%:z=O
//等待子线程结束 /=A@O !l
//int count = 0; rmtCCPF?0
//是否结束while循环 2Vu?Y
boolean breakWhile = false; 9 `q(_\x
m\bmBK"I
H{Lt,#
while(!bStop) RAws{<6T-
{ }[MkJ21!
write_nPos(); csxn"Dz\
Utility.sleep(500); -S&9"=v
breakWhile = true; a1u4v/Qu9
[z+YXs!N
^tWSu?9
for(int i=0;i<nStartPos.length;i++) wL^x9O|`p9
{ ; C(5lD&\5
if(!fileSplitterFetch.bDownOver) bn5O2
{ qt/6o|V
breakWhile = false; @ 'N$5
break; rOO10g
} 'zT7$ .L
} a|#pl!
if(breakWhile) &0:Gj3`
break; M"u=)CT
\u(Gj]B#"
:(tKc3z
//count++; dLwP7#r
//if(count>4) 8*&73cp
// siteStop(); Gm=&[?}
} l @@pXg3
Qz%q#4Zb
ZrA*MN
System.err.println("文件下载结束！"); kM=&Tfpj
} h4MBw=Tz~
catch(Exception e){e.printStackTrace ();} 0Js5 ' 9}H
} rg]b$tL~
@\xEK5SG
}1+2&Ps50
//获得文件长度 5J&Gc;[p
public long getFileSize() _5O~]}
{ %W|Sl
int nFileLength = -1; :?m"kh ~
try{ C=U4z|Ym
URL url = new URL(siteInfoBean.getSSiteURL()); 9f5~hBlo
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1&7?f
httpConnection.setRequestProperty("User-Agent","NetFox"); O:RN4/17
)=x4+)9
589fr"Ma,6
int responseCode=httpConnection.getResponseCode(); j \d)#+;
if(responseCode>=400) M(C}2.20
{ )`\Q/TMl5
processErrorCode(responseCode); j]5e$e{
return -2; //-2 represent access is error 7Q~W}`Qv'
} 0/fZDQH
v$(Z}Hg
{TMng&
String sHeader; qs_cC3"=%=
uGW#z_{(n
B>\q!dX3
for(int i=1;;i++) 0oBAJP
{ F{.g05^y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6cbV[!BL
//Utility.log(in.readLine()); NiE`u m
sHeader=httpConnection.getHeaderFieldKey(i); ]gv3|W
if(sHeader!=null) O*,O]Q
{ KZ^>_K&
if(sHeader.equals("Content-Length")) wc"~8Ah
{ }j2t8B^&:
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); '.S02=/
break; {Dy,|}7s
} Az#kE.8b*A
} .W2w/RayC
else \:q@I]2
break; QyZ'%T5J
} XH/!A`ZK
} D@[#7:rHL
catch(IOException e){e.printStackTrace ();} -HuIz6
catch(Exception e){e.printStackTrace ();} HJpx,NU'
?6x&A t
yGC HWP
Utility.log(nFileLength); }NdLd!
!,5qAGi0
DZb0'+jQ
return nFileLength; *H=h7ESq
} T%Zfo7
JnnxXj30,
yOb']
//保存下载信息（文件指针位置） U-f8D
private void write_nPos() ?>vkY^/
{ {BaPK&x,
try{ ;<E?NBV^
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]rg-=Y k
output.writeInt(nStartPos.length); ymqn1ja1
for(int i=0;i<nStartPos.length;i++) n: {f\
{ <4/q5*&
// output.writeLong(nPos); |q\i, }
output.writeLong(fileSplitterFetch.nStartPos); F*Yx1vj
output.writeLong(fileSplitterFetch.nEndPos); s+G(N$0U
} {`J!DFfur
output.close(); (r}StR+
} $`t2SD
catch(IOException e){e.printStackTrace ();} +#(GU9_i+M
catch(Exception e){e.printStackTrace ();} ?@Tsd@s~r
} Yc3\
o@aXzF2
_ |HA\!
//读取保存的下载信息（文件指针位置） $`0,N_C<}
private void read_nPos() M;KeY[u
{ =>A}eR1Y
try{ BZXee>3"
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t 0p
int nCount = input.readInt(); '9<8<d7?
nStartPos = new long[nCount]; r4K%dx-t
nEndPos = new long[nCount]; HyYJ"54
for(int i=0;i<nStartPos.length;i++) ,5 3`t
{ j0Os]a
nStartPos = input.readLong(); ]lE5^<<
nEndPos = input.readLong(); aSHN*tP%y
} uz=9L<$
input.close(); HoWK#Nz\
} 6ZjY-)h
catch(IOException e){e.printStackTrace ();} I,& gKgh
catch(Exception e){e.printStackTrace ();} Jiru~Vo+
} HFz;"s3lWM
BI!EmA
H,j_2JOY=
private void processErrorCode(int nErrorCode) ]f wW dtz1
{ qk0cf~gz
System.err.println("Error Code : " + nErrorCode); c@4$)68
} 7W&XcF
)RWukr+
UKB/>:R
//停止文件下载 +9<:z\B|
public void siteStop() Hf30ve}
{ uo|:n"v
bStop = true; RgM=g8}M
for(int i=0;i<nStartPos.length;i++) ~rAcT6#
fileSplitterFetch.splitterStop(); V^}$f3\B
Sb)}
5pHv5e
} ;LKYA?=/V
} Y2g%{keo
//负责部分文件的抓取 QNXS.!\P
**FileSplitterFetch.java W3%RB[s-
*/ ,&Zk63V
package NetFox; U2Ky4UFm
%y)hYLOJ
>f|0# *
import java.io.*; {5+69&:G.
import java.net.*; O%&N6U
UCTc$3
1$m{)Io2(
public class FileSplitterFetch extends Thread { 7 VYhRC-
UvqnNA
,t'"3<^Jg
String sURL; //File URL 6_tl_O7
long nStartPos; //File Snippet Start Position F2)KAIl
long nEndPos; //File Snippet End Position qB`%+<)C
int nThreadID; //Thread's ID -|=)
boolean bDownOver = false; //Downing is over -`t9@1P> =
boolean bStop = false; //Stop identical sdgI ,
FileAccessI fileAccessI = null; //File Access interface Az>r}*FGr
`P*wZKlW
,.<c|5R
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException BcQw-<veu
{ X%7l! k[
this.sURL = sURL; RYl\Q,#
this.nStartPos = nStart; `\=~ $&vjC
this.nEndPos = nEnd; ~!%G2E!
nThreadID = id; s]D1s%Mx
fileAccessI = new FileAccessI(sName,nStartPos);//定位 k6\&[BQs
} Ms+SJ5Lg
!rG-[7K
_,p/2m-Pj
public void run() 3rLc\rK
{ N5xI;UV9'
while(nStartPos < nEndPos && !bStop) dLR[<@E
{ FL0yRF5
XuU>.T$]c
xa{.hp?
try{ lhBAT%U\
URL url = new URL(sURL); J10&iCr{r*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iqsR]mab
httpConnection.setRequestProperty("User-Agent","NetFox"); W3R43>$
String sProperty = "bytes="+nStartPos+"-"; nwDGzC~y<
httpConnection.setRequestProperty("RANGE",sProperty); $)=`Iai
Utility.log(sProperty); C]na4yE8
H87k1^}HV
!D/W6Ic@
InputStream input = httpConnection.getInputStream(); v|3mbApv
//logResponseHead(httpConnection); C9>^!?>
!!~r1)zN
G=kW4rAk
byte[] b = new byte[1024]; NZwi3
int nRead; Ov.oyke4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) J*^ i=y
{ D8$4PT0u
nStartPos += fileAccessI.write(b,0,nRead); .9<euPrz
//if(nThreadID == 1) dzV2;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @%^h|g8>Fu
} "|PX5
~C?)- ]bF
KHeeB`V>J
Utility.log("Thread " + nThreadID + " is over!"); 7!6v4ZA
bDownOver = true; y+Bxe)6^V
//nPos = fileAccessI.write (b,0,nRead); )cm^;(#pV
} )R"UX:Q>
catch(Exception e){e.printStackTrace ();} zzT4+wy`
} ,V;HMF.
} bGlr>@;-r
(!Fu5m=<8
LftGA7uGJ)
//打印回应的头信息 zq|NltK
public void logResponseHead(HttpURLConnection con) ]l
{ SUsdX[byb
for(int i=1;;i++) _0Y?(}
{ #aKUD
String header=con.getHeaderFieldKey(i); JPg^h
if(header!=null) \e%%ik,<
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _) UnHp_^
Utility.log(header+" : "+con.getHeaderField(header)); un)PW&~E
else UGoB7TEfn
break; h6;zAM}
} W"tGCnd
} #smfOGSd
58o&Dv6?
|HwEwL+
public void splitterStop() Xl>ZnI];
{ -L wz T
bStop = true; w@a|_?
} ')(U<5y)
: TqeVf
X*&Thmee
} 9]I{GyH
mCQ:<#
~/2OK!M
/* B}N1}i+
**FileAccess.java r(zn1;zl
*//文件访问(定位，写) t&_X{!1X"w
package NetFox; &(|x-OT
import java.io.*; GP`sOPr
Ejyo oO45
/2$d'e
public class FileAccessI implements Serializable{ vxrqUjK7
Mh}vr%0;)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _93:_L
RandomAccessFile oSavedFile; `9acR>00$
long nPos; <2OXXQ1
o ethO
RE08\gNIt
public FileAccessI() throws IOException dl3}\o_
{ :_o^oi7G
this("",0); oZi{v]4
} U/h@Q\~U
STPRC&7;
*lQa^F
public FileAccessI(String sName,long nPos) throws IOException CKC5S^Mx
{ A5sz[k
oSavedFile = new RandomAccessFile(sName,"rw"); J58S8:c
this.nPos = nPos; +HG*T[%/
oSavedFile.seek(nPos); P4 #j;k4P
} KD--w(4
`A8ErfA
sR)jZpmC(
public synchronized int write(byte[] b,int nStart,int nLen) 9d!mGnl
{ nt%p@e!,
int n = -1; Hv%$6,/*v
try{ V$dhiP z
oSavedFile.write(b,nStart,nLen); BW"24JhF"
n = nLen; pfFHuS~
} |ZOdfr4uW
catch(IOException e) 9xFI%UOb#
{ t~8H~%T>v
e.printStackTrace (); vD(:?M
} + 7wMM#z
p+b$jKWQ
Hk=HO|&<XB
return n; *<X*)A{C
} |n~,{=
Mu6DTp~k
-]QP#_
} er3`ITp:dp
<*oV-A
'c3'eJ0
/* B|'}HBkP
**SiteInfoBean.java Tf('iZ2+
*/ wNmC1HOh
package NetFox; T>J ,kh
#G=AD/z
eL{$=Um
public class SiteInfoBean { DD`DU^o<
FwD q@Oj
^$[iLX
private String sSiteURL; //Site's URL YWL7.Y>%5
private String sFilePath; //Saved File's Path 8i)9ho<
private String sFileName; //Saved File's Name z|\n^ZK=
private int nSplitter; //Count of Splited Downloading File #er% q:
^1_CS*
"akAGa!V+
public SiteInfoBean() Zx7aae_{
{//nSplitter的缺省值为5 c6SXz%'k
//default value of nSplitter is 5 jINI<[v[
this("","","",5); )UyJ.!Fly
} '6L@l
U=5~]0g
OU!."r`9
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) z";(0%
{ W{~ y< `D
sSiteURL= sURL; s^Xs*T@~h
sFilePath = sPath; \r [@A3O
sFileName = sName; d]N_<@tx9
this.nSplitter = nSpiltter; Jm"W+! E
Hx!eCTO:*
7U2B=]<e-
} |I{3~+E h
{CNJlr@z
'%o^#gJp
public String getSSiteURL() z#GSt ZT
{ m!=5Q S3Z
return sSiteURL; e>bARK<
} ~ H/ZiBL@
=YD<q:n4
ukRmjHbLf
public void setSSiteURL(String value) Mc$rsqDz
{ E[4 vUnm-
sSiteURL = value; L!,@_
} =d]}7PO~
( GoPXh
}}k*i0
public String getSFilePath() 5u3KL A
{ ?Mn~XN4F_
return sFilePath; {dn:1IcN
} 2b-g`60<
u6| IKZ
4;eD}g
public void setSFilePath(String value) JAT%s %UC
{ @AK&R~<
sFilePath = value; @]p{%"$
} =K}T; c
PZlPC#E-
bm4Bq>*=U
public String getSFileName() kE|x'(x
{ T8Q_JQ
return sFileName; Hi*|f!,H?
} };<?W){!H
gQJLqs"F
bbDm6,
public void setSFileName(String value) iyXd"O
{ &xGpbJG
sFileName = value; #M5d,%?+#[
} 5?([jAOf
H4j1yD(d
5(E&jKn&
public int getNSplitter() 4jZB%tH
{ 4^ U%` 1
return nSplitter; F^S]7{
} 69apTx
ck3+A/ !z
fNfa.0s
public void setNSplitter(int nCount) AjoIL
{ oN%zpz;OR
nSplitter = nCount; 6a_U[-a9;
} {<-wm-]mo
} DiTpjk]c`
S\Le;,5Z
l-S0Gn/'X
/* ~*<`PDO?
**Utility.java 9Oo`4
*/ t%0c$c
package NetFox; Lo5pn
$)BPtGMGo
\sfc!5G
public class Utility { '>n&3`r5
hw*u.46
[Q J
public Utility() zufsmY4P
{ h.KgHMV`
y,6kL2DM
*[*q#b$j
} }xi?vAaTl
V{w &RJ
//线程睡眠 )Q>Ao.
public static void sleep(int nSecond) c_?^:xs:d
{ ,2+d+Zuh
try{ -Fu,oEj{*
Thread.sleep(nSecond); kM&-t&7
} $5&~gHc,
catch(Exception e) "*N#-=MJF
{ b{{ H@LTW
e.printStackTrace (); 56.JBBZZ
} P1B=fgT
} >VQLC&u(
svb7-.!
//日志 PAtv#)h
public static void log(String sMsg) <>Dw8?O
{ Z P6p>?DQ
System.err.println(sMsg); <t*<SdAq>`
} Vsw:&$
d_0(;'
Uxik&M
public static void log(int sMsg) ( ^@i(XQ
{ p]/[ji
System.err.println(sMsg); r|jM;
} ~K99DK.
} 9c }qVf-i
4cM0f,nc+
a?8)47)
/* $Bl51VjN
**TestMethod.java UnYb}rF#%
*/ O>a1S*mxP
package NetFox; WBkx!{\z
r]DU
aR('u:@jHi
public class TestMethod { -)3+/4Q(
bZ OCj1
-1d*zySL
public TestMethod() T!>hPg
{ ///xx/weblogic60b2_win.exe )b>misb/
try{ F4WX$;1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); V45adDiZ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /x$JY\cq`
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6w{_+=T
fileFetch.start(); fjl9*
} ->.9[|lIg
catch(Exception e){e.printStackTrace ();} ",Vx.LV
RWo7_XO
I"x|U[*B
} /j4G}
Mx`';z8~
aX6}:"R2C
public static void main(String[] args) ;' vkF
{ 2nCc(F&+?
new TestMethod(); XM*5I4V
} G/~gF7
} % XZ&(
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