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)); l?Ya"C`FL
} Z-l=\ekJ
for(int i=0;i<nEndPos.length-1;i++) 8|" XSN
{ ;A*`e$
nEndPos = nStartPos[i+1]; %T~ig[GstX
} v&=gF/$
nEndPos[nEndPos.length-1] = nFileLength; tQjLOv+?=
} @~%r5pz6
} =F@Wgn,
(JM5`XwM
GSRVe/[
//启动子线程 !7kG!)40
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; O)jWZOVp >
for(int i=0;i<nStartPos.length;i++) 8p:j&F
{ /bi}'H+#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .dav8n*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), pim!.=vN/U
nStartPos,nEndPos,i); #H:7@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hy`?E6=9+
fileSplitterFetch.start(); gy_>`16K
} x= 5N3[5
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), HbxL:~:}J
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |g//g\dd
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |y2w9n0D
nEndPos = " + nFileLength); k@'#@ t
// fileSplitterFetch[nPos.length-1].start(); sPR1?:0:
MP>dW nl
v~^{{O
//等待子线程结束 $GTU$4u
//int count = 0; fe9LEM8j
//是否结束while循环 ;t|Ii8Ne
boolean breakWhile = false; ^G.B+dG@`x
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/%;mqrdk
while(!bStop) {62n7'U{
{ z&fwE$Nm
write_nPos(); yp({>{u7
Utility.sleep(500); m+Rv+_R
breakWhile = true; K[!&b0O
s[w6FXt
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for(int i=0;i<nStartPos.length;i++) IWY;="
{ "t~
if(!fileSplitterFetch.bDownOver) ;oy-#p>N%
{ ])nPPf
breakWhile = false; Y9&,t\ q
break; rl#p".4q
} BBtzs^C|
} rv|)n>m
if(breakWhile) ]{ntt}3G,
break; P7{gfiB
}#n;C{z2e
orjj'+;X
//count++; LyAn&h}
//if(count>4) ZR(x%ews
// siteStop(); Yj6*NZ*
} njWL U!
FW21 U<
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System.err.println("文件下载结束！"); lLF-{
} #g]vc_V
catch(Exception e){e.printStackTrace ();} `0Oh_8"
} T>NDSami
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!;KCU^9
//获得文件长度 *tK\R&4,4s
public long getFileSize() 5) pj]S!]-
{ Z)SY.iK.
int nFileLength = -1; s]f6/x/~
try{ &2{tF
URL url = new URL(siteInfoBean.getSSiteURL()); !Rhlf.x
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,}K7Dg^1
httpConnection.setRequestProperty("User-Agent","NetFox"); 61)-cVC
oz}+T(@O
U G~ba
int responseCode=httpConnection.getResponseCode(); }<9cL'
if(responseCode>=400) TzNn^ir=HX
{ $3s@}vLd
processErrorCode(responseCode); {/ BT9|LI
return -2; //-2 represent access is error "gDb1h)8
} =*r])Vg^
osX8eX]\
RsY3V=u
String sHeader; gk0(ANx
fmb} 2h
d~1gMz+)
for(int i=1;;i++) mqSQL}vR
{ 4\4FolsK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); lXjXqk\
//Utility.log(in.readLine()); 7~5ym15*
sHeader=httpConnection.getHeaderFieldKey(i); K>DRJz
if(sHeader!=null) Vnr[}<L
{ 8n*.).33
if(sHeader.equals("Content-Length")) <w)r`D6
{ O8j_0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )'6DNa[y
break; t+1 %RyKFB
} $Z\.-QE\
} FXi{87F2
else Y]B)'[=h
break; WZ*ws[dVI
} VCD:3U 8
} H?)w!QX
catch(IOException e){e.printStackTrace ();} Na?!;1]_
catch(Exception e){e.printStackTrace ();} fngOeLVG
vJ-q*qM1
B#.L
Utility.log(nFileLength); Y}#J4i0b*
QT>`^/]d
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return nFileLength; 2gCX}4^3b
} er!DYv
:[hgxJu+
+/)#( j@
//保存下载信息（文件指针位置） S|]X'f
private void write_nPos() 4'!c*@Y
{ ?C&z]f3(:
try{ OslL~<
output = new DataOutputStream(new FileOutputStream(tmpFile)); JU^lyi!
output.writeInt(nStartPos.length); ]Zyur`
for(int i=0;i<nStartPos.length;i++) w[IE
{ ecCr6)
// output.writeLong(nPos); T`;%TO*Y
output.writeLong(fileSplitterFetch.nStartPos); 8(~K~q[Cr
output.writeLong(fileSplitterFetch.nEndPos); %\H|B0
} `m!j$,c.
output.close(); k=4N.*#`y
} CkdP#}f
catch(IOException e){e.printStackTrace ();} ^`)) C;
catch(Exception e){e.printStackTrace ();} PGLplXb#[S
} ~s]iy9i
RHO(?8"_
2E)wpgUc?e
//读取保存的下载信息（文件指针位置） s0k`p<q
private void read_nPos() n1VaLD
{ qT`k*i?
try{ %Ntcvp)
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); N#DYJ-~*
int nCount = input.readInt(); q(.:9A*0
nStartPos = new long[nCount]; b;cdIl!3
nEndPos = new long[nCount]; C0}IE,]
for(int i=0;i<nStartPos.length;i++) X@LRsg
{ -/g B|J
nStartPos = input.readLong(); GJtZ&H
nEndPos = input.readLong(); &'}RrW-s
} 17G'jiYH
input.close(); znaUBv_
} 8\5 T3AF
catch(IOException e){e.printStackTrace ();} [ji#U s:h
catch(Exception e){e.printStackTrace ();} b{]z wpf
} LS88.w\=S@
Zy(W^~NT
8$;=Uf,x
private void processErrorCode(int nErrorCode) ]2\VweV
{ _PlKhv}
System.err.println("Error Code : " + nErrorCode); )Ccq4i
} Z3&_
w &(|e <
l33Pm/V2?
//停止文件下载 O^^C;U@U<1
public void siteStop() qpE&go=k'
{ -2A(5B9Fq
bStop = true; _;UE9S%
for(int i=0;i<nStartPos.length;i++) %Cv D-![0
fileSplitterFetch.splitterStop(); !`M|C?b
` M3w]qJ<}
% <qw
} t`,`6@d
} .[JYj(p
//负责部分文件的抓取 <\pfIJr$
**FileSplitterFetch.java t<|NLk.
*/ I| b2acW
package NetFox; #~l(]h@ )
pt?q#EfFJ
kAC&S!n
import java.io.*; (r D_(%o
import java.net.*; T3pmVl
Ou1JIxZ)|
%]8qAtV^3j
public class FileSplitterFetch extends Thread { %+K<<iyR|
|>JS!NM I
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String sURL; //File URL Dqe^E%mc
long nStartPos; //File Snippet Start Position XAe%m^
long nEndPos; //File Snippet End Position kZerKP
int nThreadID; //Thread's ID w$`5g
boolean bDownOver = false; //Downing is over e^[H[d.WMC
boolean bStop = false; //Stop identical 1PP $XJtyD
FileAccessI fileAccessI = null; //File Access interface ~ ArP9 K"
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}C>{uXv
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _oUHJ~&,
{ 82QGS$0V
this.sURL = sURL; /(BMG/Tb
this.nStartPos = nStart; jr!?v<NoX
this.nEndPos = nEnd; Lg*B>=
nThreadID = id; CS=qj-(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (;57Vw
} 4@ML3d/
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public void run() ##V5-ZG{:
{ tP2qK_\e=
while(nStartPos < nEndPos && !bStop) $a"n1ou
{ s+EAB{w$
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9J>&29@us0
try{ nCj2N,mT
URL url = new URL(sURL); ]5$eAYq
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H+ 0$tHi
httpConnection.setRequestProperty("User-Agent","NetFox"); 6^"=dn6K
String sProperty = "bytes="+nStartPos+"-"; 3MY(<TGX
httpConnection.setRequestProperty("RANGE",sProperty); 24)(5!:"
Utility.log(sProperty); ZOQTINf
/s[l-1zW
eL\;Nf+Zp
InputStream input = httpConnection.getInputStream(); >ey\jDr#O
//logResponseHead(httpConnection); 43Qtj$F
7qg{v9|,
]jaQ[g$F
byte[] b = new byte[1024]; [I$BmGQ
int nRead; "gne_Ye.
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g)_e]&
{ |*'cF-lp6v
nStartPos += fileAccessI.write(b,0,nRead); v{jQek4
//if(nThreadID == 1) RQ'H$r.7g
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v%s`~~u%^
} (''M{n
~YRDyQ:%T
r]l!WRn
Utility.log("Thread " + nThreadID + " is over!"); aP8H`^DFX>
bDownOver = true; OZTPOz.
//nPos = fileAccessI.write (b,0,nRead); l#H#+*F
} 2GWMlI
catch(Exception e){e.printStackTrace ();} 'iGzkf}j
} $;/}?QY(
} MV\|e1B}
W'.s\e?gh
>b6-OFJx
//打印回应的头信息 k?z98 >4
public void logResponseHead(HttpURLConnection con) a(9L,v#?
{ A%D7bQ
for(int i=1;;i++) b r^_'1
{ Zuw?58RE\
String header=con.getHeaderFieldKey(i); AQ+]|XYo_
if(header!=null) _-9@qe
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?}RSwl
Utility.log(header+" : "+con.getHeaderField(header)); 6C]1Q.f;
else S`"LV $8
break; M\Z6$<H?U
} bV8!"{
} z6?)3'
YR>B_,Gl
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public void splitterStop() FcRW;e8-
{ Ircp``g
bStop = true; 9f',7i
} ZP;j9T!
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mN>h5G>a
} ~d%Pnw|
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)Jk0v_ X
/* mXUGe:e8
**FileAccess.java q@@T]V6
*//文件访问(定位，写) &/uu)v
package NetFox; &%s8L\?
import java.io.*; '{J&M|<A
<YOLxR
l411a9o
public class FileAccessI implements Serializable{ O=$~O\}b
n< ud> JIb
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~<k,#^"}X
RandomAccessFile oSavedFile; <%Ostqj
long nPos; C":o/;,1
'^Ql]% _
` bdZ/*E
public FileAccessI() throws IOException .hba*dV
{ Wt=|
this("",0); +\|Iu;w
} _`I"0.B]
F@*+{1R
LNa$ X5`
public FileAccessI(String sName,long nPos) throws IOException `X`2:@gQ
{ ,Vh{gm1
oSavedFile = new RandomAccessFile(sName,"rw"); K)-m*#H&uw
this.nPos = nPos; xw3YK!$sIF
oSavedFile.seek(nPos); 6X\ 2GC9
} =Apxdnz,
66'?&Xx'
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public synchronized int write(byte[] b,int nStart,int nLen) ~,BIf+\XF
{ :sP!p`dl
int n = -1; 3Ezy %7
try{ jWY$5Vq<H
oSavedFile.write(b,nStart,nLen); ?APeR,"V
n = nLen; 13+<Q \
} `"@g8PWe
catch(IOException e) }Y*VAnY6;
{ u_'!_T L
e.printStackTrace (); ]miy/V }5
} 2OwV^-OG
N @#c,,
EM/@T}
return n; Cz W:L&t
} T<L^N+<,{N
Pf_S[ sm
E-{^E.w1
} Cxcr/9
l%`F&8K
XO9M_*Va
/* S_T1y
**SiteInfoBean.java ]a!xUg!S
*/ 1|?05<8
package NetFox; %uoQ9lD'
X5khCLHi
}#qGqY*@LK
public class SiteInfoBean { V%_4%
m1IKVa7-\}
6sE{{,OGB
private String sSiteURL; //Site's URL !p[9{U->o;
private String sFilePath; //Saved File's Path g(Io/hyj
private String sFileName; //Saved File's Name #!$GH_
private int nSplitter; //Count of Splited Downloading File `c69?/5
K^3co
^<:sdv>Y5
public SiteInfoBean() GV^i`r^"
{//nSplitter的缺省值为5 C-?%uF
//default value of nSplitter is 5 Q3 eM2i8Y
this("","","",5); S<L.c
} W?We6.%
sz9G3artK&
<97d[/7i
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :KKa4=5L
{ 3 AHY|
sSiteURL= sURL; |hO~X~P
sFilePath = sPath; c(/VYMJZ&
sFileName = sName; shH~4<15
this.nSplitter = nSpiltter; Khe!g1=&X
-PnyZ2'Z
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} gxT4PQDy
{w8 NN-n
U^.4Hy&D
public String getSSiteURL() )OLq_':^@
{ TP}h~8 /;
return sSiteURL; R.s^o]vT
} eVR5Xar
iz~ pGkt
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public void setSSiteURL(String value) g!`3{ /4
{ AWjm~D-?
sSiteURL = value; oM)h#8bq
} w]_zp?\^ }
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t'~/$=9}
public String getSFilePath() Lqp8yVO
{ S#b-awk
return sFilePath; QnI.zq V
} >?]_<:
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8LI-gp\ 2
public void setSFilePath(String value) {Rear2
{ JI/_ce
sFilePath = value; X>I)~z}9#
} a|BcnYN
$x#FgD(iI
D&ve15wL
public String getSFileName() /oL;YIoQX
{ x-'~Bu
return sFileName; XG@`ZJhU6
} J@L9p46,
S|zW^|YU
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public void setSFileName(String value) LrCk*@
{ '&FjW-`" G
sFileName = value; E"|4Y(G
} $2MAZGJV
aZk&`Jpz
y#<MVH
public int getNSplitter() npDIX
{ zD)pF1,7:8
return nSplitter; DOQc"+
} !>(RK"KWq]
OI0B:()
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public void setNSplitter(int nCount) 8CC/BOe
{ oW$s xS
nSplitter = nCount; }Z`(aDH
} -z:&*=
} Kv{8iAB#c
}4>JO""
D\~e&0*
/* _ OaRY]
**Utility.java }#v{`Sn%^C
*/ ,&YTj>
package NetFox; Zw] ?.
y\F=ui
=6=_/q2
public class Utility { %5
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r,N[)@
public Utility() nW+YOX|+
{ a45ss7
^# A.@
~/IexQB&
} Y& ] 8 {
?G08[aNR
//线程睡眠 {^Pq\h;
public static void sleep(int nSecond) x3e]d$
{ RiO="tX'
try{ gcJF`H/iNK
Thread.sleep(nSecond); -@IL"U6
} \Xt)E[
catch(Exception e) Ze!92g
{ [rreFSy#@
e.printStackTrace (); np WEop>
} uO >x:*^8
} 'FzN[% K"
sl/)|~3!8
//日志 )~rB}>^Z
public static void log(String sMsg) i_F$&?)
{ QfQ\a%cc
System.err.println(sMsg); }t>q9bZ9z
} y1BgK>R
|*,jU;NI
Gqyue7;0,
public static void log(int sMsg) ~E=\t9r
{ kA7(CqUW
System.err.println(sMsg); ]=D5p_A(
} {6xPdUhw
} m&R"2t_Z
s6=YV0w(
LQ-6vrbs
/* j1$<]f
**TestMethod.java WA LGIW
*/ =V|Nn0E
package NetFox; :w?7j_p#
WwW^[k (X
~4)Y#IxL
public class TestMethod { }#=Od e
[.q(h/b
vZajT!h
public TestMethod() 'H FKBp
{ ///xx/weblogic60b2_win.exe j[P8
try{ aQcN&UA@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); kd;'}x=5yP
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Zj-BuE&@f
SiteFileFetch fileFetch = new SiteFileFetch(bean); A1*4*
fileFetch.start(); agaq`^[(P
} 7CrpUh
catch(Exception e){e.printStackTrace ();} o@dy:AR
5a(<%Q <"
wq4nMY:#
} '1]7zWbW
;IC'Gq
KtTza5aF
public static void main(String[] args) kb|eQtH
{ bZ#X9fT
new TestMethod(); 'Kis hXOn]
} JJl7JwSTW
} +$(0w35V5
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