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)); u-PAi5&n
} sm5\> L3V
for(int i=0;i<nEndPos.length-1;i++) sS;6QkI"y
{ :+{G|goZ*
nEndPos = nStartPos[i+1]; z+I'N4*^
} /ylO["<Q
nEndPos[nEndPos.length-1] = nFileLength; t-Rfy`I3
} D7|[:``
} MTo<COp($
+aaj3m
O=UXe]D
//启动子线程 ehk5U,d
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ntbl0Sk
for(int i=0;i<nStartPos.length;i++) ~$n4Yuu2[
{ S9R(;
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vdw5T&Q{{C
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), D+ mZ7&L
nStartPos,nEndPos,i); l+!!S"=8)~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 's>
fileSplitterFetch.start(); &5puGnTZ
} W_l/Jpv!W
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xY9#ouF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Fb=(FQ2Y?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1BT]_ cP
nEndPos = " + nFileLength); c*2U'A
// fileSplitterFetch[nPos.length-1].start(); n%zW6}
MyB&mC7Es
H'k$<S
//等待子线程结束 Y,Dd}an
//int count = 0; I^"ouM9}Q
//是否结束while循环 }a?PBo`
boolean breakWhile = false; 85CH% I#
li'h&!|]
~_opU(;f
while(!bStop) MuXp*s3[
{ cb!mV5M-g
write_nPos(); FJ0Ity4u6
Utility.sleep(500); gU\pP,a
breakWhile = true; gY\X?
u3 k%
]j> W9n?
for(int i=0;i<nStartPos.length;i++) hkV;(Fr&z
{ {hQ0=rv<
if(!fileSplitterFetch.bDownOver) XN9s!5A<L)
{ Y~\71QE>
breakWhile = false; :T^!<W4
break; wKOljE6d
} & $E[l'
} Pyh+HD\
if(breakWhile) m,}0p
break; d 90
3FRz&FS:j
p3>(ZWPNV
//count++; )_bc:6Q
//if(count>4) '%Og9Bgd+
// siteStop(); Z9X<W`
} MzjV>.
$ N`V%<W
9U[Gh97Sf
System.err.println("文件下载结束！"); ldp x,
} Qn=3b:S-
catch(Exception e){e.printStackTrace ();} e_'/4 n
} a&:1W83
;pe1tp
PdiP5S }/
//获得文件长度 .T~<[0Ex+U
public long getFileSize() =k.:XblEe[
{ PWeCk2xH
int nFileLength = -1; sF9{(Us
try{ x/~qyX8vo
URL url = new URL(siteInfoBean.getSSiteURL()); cUW>`F(S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _)|_KQQu
httpConnection.setRequestProperty("User-Agent","NetFox"); (Z:(f~;
1Q_ C
UNLmnj;-Q
int responseCode=httpConnection.getResponseCode(); X3[gi`
if(responseCode>=400) W\]bh'(
{ =KQQS6
processErrorCode(responseCode); &Tz@lvOv%
return -2; //-2 represent access is error O-m=<Fk> D
} 8Aq [@i
5)h#NkA\J
V{!fag
String sHeader; MTBHFjXO
k3[rO}>s
)Ve-)rZ
for(int i=1;;i++) #,dNhUV#
{ W|@7I@@$"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); s5/5>a V
//Utility.log(in.readLine()); Bmx+QO
sHeader=httpConnection.getHeaderFieldKey(i); w2*.3I,~)B
if(sHeader!=null) x)evjX=q
{ A8,9^cQ]
if(sHeader.equals("Content-Length")) M)v\7a
{ n(X{|?
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "FuOWI{in
break; -CV_yySc
} U-RR>j
} a=ye!CN^
else EQQ/E!N8l
break; 'ec G:B`S
} 'I$-h<W
} 8:#\g
catch(IOException e){e.printStackTrace ();} pe^hOzVv
catch(Exception e){e.printStackTrace ();} \YUl$d0
)m8ve)l
-,xCUG<g
Utility.log(nFileLength); jA'qXc+\
t "y[
\9;SOAv
return nFileLength; vjo@aY.x
} ?yAp&Ad
+65OR'd
#Z;6f{yWf
//保存下载信息（文件指针位置） nsT]Yxo%M
private void write_nPos() @8keLrp
{ g%C!)UbT
try{ ku2gFO
output = new DataOutputStream(new FileOutputStream(tmpFile)); s|40v@M
output.writeInt(nStartPos.length); |W't-}yf
for(int i=0;i<nStartPos.length;i++) Wp2W:JX:
{ @|I:A
// output.writeLong(nPos); R$>]7-N}
output.writeLong(fileSplitterFetch.nStartPos); K6uZ4 m;
output.writeLong(fileSplitterFetch.nEndPos); 0[A4k:
} {;:QY1QT
output.close(); 2T3TD%
} C%c}lv8;^
catch(IOException e){e.printStackTrace ();} P:~Xaz\F
catch(Exception e){e.printStackTrace ();} XOOWrK7O
} Z|78>0SAt
M.DU^-7
!T+jb\O_
//读取保存的下载信息（文件指针位置） cL+--$L
private void read_nPos() 0QzUcr)3+
{ ywQ>T+
try{ B#o/3
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); tKr.{#)
int nCount = input.readInt(); hMcSB8?
nStartPos = new long[nCount]; g(X-]/C{
nEndPos = new long[nCount]; 'eM90I%(
for(int i=0;i<nStartPos.length;i++) t1LIZ5JY
{ =1!,A
nStartPos = input.readLong(); rTJ='<hIy
nEndPos = input.readLong(); wEQ7=Gyx
} M<Gr~RKmAn
input.close(); 8`\^wG$W
} i|`b2msvd
catch(IOException e){e.printStackTrace ();} O"'.n5>:`
catch(Exception e){e.printStackTrace ();} 24Y8n
} "hE/f~\
C(w?`]Qs
R,3E_me"}
private void processErrorCode(int nErrorCode) d3nx"=Cy0I
{ t=-t xnlr<
System.err.println("Error Code : " + nErrorCode); `zRE$O
} cImOZx
F'v3caE
3Jt7IM!9[
//停止文件下载 B~%'YQk
public void siteStop() FWi c/7
{ g&79?h4UXQ
bStop = true; q5Bj0r[/o
for(int i=0;i<nStartPos.length;i++) ,5Vc
fileSplitterFetch.splitterStop(); >rbHpLm1`
fPW|)e"
ujlIWQU2mo
} '7'*+sgi$
} Mx-? &
//负责部分文件的抓取 fG *1A\t]
**FileSplitterFetch.java P4\{be>e
*/ G<F+/Oi&DX
package NetFox; >M}\_c=
| c:E)S\
EnM }H9A
import java.io.*; |*G$ilu
import java.net.*; dz3KBiq
?MW*`U
9+z5$
public class FileSplitterFetch extends Thread { S]Y3nI
TT85G&#
{2A| F{7>
String sURL; //File URL Vxr_2Kra
long nStartPos; //File Snippet Start Position \(4"kY_=
long nEndPos; //File Snippet End Position Dw%V.J/&o
int nThreadID; //Thread's ID ]"ZL<?3g
boolean bDownOver = false; //Downing is over .o27uB.
boolean bStop = false; //Stop identical z;c~(o@4
FileAccessI fileAccessI = null; //File Access interface 7o+JQ&fF;
;~A-32;Y4
xJ-(]cO'
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0 |/:m
{ S!LLC{
this.sURL = sURL; U{ZE|b.?b
this.nStartPos = nStart; 4qd =]i
this.nEndPos = nEnd; )td?t.4
nThreadID = id; |UudP?E
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [N35.O6P6u
} t;3n
G}2DZ=&>'
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public void run() wgN)*dpuI
{ P#8+GN+bF
while(nStartPos < nEndPos && !bStop) aEO``W
{ 4R c_C0O
3?}\Hw
@;6I94Bp
try{ 9_$i.@L1
URL url = new URL(sURL); T%[&[8{8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YK=o[nPmK
httpConnection.setRequestProperty("User-Agent","NetFox"); bOB<m4
String sProperty = "bytes="+nStartPos+"-"; 1WTDF
httpConnection.setRequestProperty("RANGE",sProperty); ak SUk)}e
Utility.log(sProperty); sI/]pgt2
*mvDh9v
;0Vyim)S]
InputStream input = httpConnection.getInputStream(); GlVb|O"
//logResponseHead(httpConnection); /LH# 3
@Sik~Mm_h
Gp l
byte[] b = new byte[1024]; OI8Hf3d=
int nRead; jD<fu
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) M1Frn n
{ %Voq"}}N
nStartPos += fileAccessI.write(b,0,nRead); Y=NXfTc
//if(nThreadID == 1) 0P+B-K>n
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l[,RA?i {
} `<?{%ja
ms(Z1ix^
o4[
Utility.log("Thread " + nThreadID + " is over!"); L~Hl?bK
bDownOver = true; `wMHjcUP
//nPos = fileAccessI.write (b,0,nRead); x)]_]_vX
} ytmFe!
catch(Exception e){e.printStackTrace ();} !1X^lFf;~
} 5PcN$r"P
} <P%<EgOE
x5X;^.1Fr
>qqI6@h]c
//打印回应的头信息 V[Z^Z
public void logResponseHead(HttpURLConnection con) #1-2)ZO.
{ _EusY3q
for(int i=1;;i++) |}FK;@'I6
{ rnkq.
String header=con.getHeaderFieldKey(i); .uoQ@3
if(header!=null) -&7\do<
//responseHeaders.put(header,httpConnection.getHeaderField(header)); zXEu3h
Utility.log(header+" : "+con.getHeaderField(header)); MF41q%9p
else z#j)uD
break; O(_a6s+m
} rUz-\H(-
} doX8Tq
FX yyY-(O
2 &(w\#'
public void splitterStop() 8V08>M
{ }C'H@:/
bStop = true; nt5x[xa
} m|CB')
u2FD@Xq?
0afDqvrC6
} &az :YTq
YF4?3K0F:k
#s}cK
/* ./KXElvQ%
**FileAccess.java e7$ZA#A_5v
*//文件访问(定位，写) 6m\MYay
package NetFox; QAk.~ob
import java.io.*; wnPg).
yu~o9
AeZ__X
public class FileAccessI implements Serializable{ /uNgftj
W5f|#{&L:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~vGX(8N
RandomAccessFile oSavedFile; Eq\PSa=gz
long nPos; .boBo$f
6^Q/D7U;s
rgK:ujzW!
public FileAccessI() throws IOException `"-ln'nw
{ \y^Ho1Fj
this("",0); p$:ERI
} SKUri
Il8,g+W]
MT3TWWtZ:
public FileAccessI(String sName,long nPos) throws IOException L3@upb
{ %77X/%.Y
oSavedFile = new RandomAccessFile(sName,"rw"); z2 m(<zb
this.nPos = nPos; l_MF9.z&
oSavedFile.seek(nPos); 45qSt2
} AWG;G+
bzC|aUGM
-,Oq=w*EV
public synchronized int write(byte[] b,int nStart,int nLen) U?[_ d
{ p_g#iH!*
int n = -1; 7C::%OF~7
try{ p!_3j^"{
oSavedFile.write(b,nStart,nLen); [2l2w[7Rid
n = nLen; <aPbKDF~V
} nRSiW*;R
catch(IOException e) kLfk2A;'i
{ g2|qGfl{C
e.printStackTrace (); kgl7l?|O
} &| guPZ
6 o!*bWh
+{5y,0R
return n; e{}oQK
} )<+t#5"
d OYEl<!J
->rr4xaKC
} `alQmGUZ
..=WG@>$+
c(j|xQ\pE
/* ox&PFI0Gn
**SiteInfoBean.java 937 z*mh
*/ Ht,dMt>:
package NetFox; hh1 ?/
|l#<vw wE
\$B%TY
public class SiteInfoBean { yd>b2 M
+!F+mV9
$.0l% $7
private String sSiteURL; //Site's URL Pqtk1=U
private String sFilePath; //Saved File's Path xk/osbKn
private String sFileName; //Saved File's Name 3&tJD
private int nSplitter; //Count of Splited Downloading File CBrC
A7c*qBt
<5t2+D]]}
public SiteInfoBean() kM;fxR:-
{//nSplitter的缺省值为5 u;/5@ADW
//default value of nSplitter is 5 <,:5d2mM.
this("","","",5); NE1n9
} %vZTD+i
9()d7Y#d/`
I%Yeq"5RB
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) WW&agr
{ +k<0:Fi
sSiteURL= sURL; Zai:?%^
sFilePath = sPath; #<k L.e[
sFileName = sName; G<_<j}=
this.nSplitter = nSpiltter; Q&k1' nT5
-L6YLe%w
N0POyd/rL
} D_D76
y~'h/tjM@=
\YZ7
public String getSSiteURL() qPvWb1H:
{ 2vLV1v$,q
return sSiteURL; L8WYxJ k
} S!@h\3d8{
g7-*WN<
W)z@>4`Bb
public void setSSiteURL(String value) ">|G^@|:A
{ 1.S?(1e"
sSiteURL = value; E/:mO~1< c
} M!D&a)\
U-6pia/o
62D UF
public String getSFilePath() g[%^OT#
{ u$%;03hJ
return sFilePath; pcC/$5FQ
} Wq"5-U;:w
B ?%g@d-;
O}Mu_edM
public void setSFilePath(String value) 5z=.Z\M`8
{ Pz77\DpFi
sFilePath = value; ~\]lMsk+
} Ss$/Bh>hN
EU,f;H
e{6I-5`|,#
public String getSFileName() ygo4.
{ A}l+BIt
return sFileName; ui .riD[,O
} Q| _e=
,u@Vi0
]Dd}^khv
public void setSFileName(String value) ur@"wcl"V
{ Ucqn3&
sFileName = value; dVKctt'C
} /JGET
4 >`2vb
/73ANQ"
public int getNSplitter() C &~s<tcn
{ hYSzr-)
return nSplitter; F~Sw-b kSf
} #KgDOCQH
3IyNnm=u
0Bn35.K
public void setNSplitter(int nCount) 0=erf62=
{ w'Vm'zo
nSplitter = nCount; .EB'n{zxd
} IZSJ+KO
} D3(rD]c0{
3`+Bq+
EFdo-.Ax
/* CY</v,\:#
**Utility.java ,~nrNkhp
*/ Cw$7d:u
package NetFox; r-8fvBZ5
(CR]96n
kD\7wz,ui
public class Utility { h#~\-j9>
Qk[YF
08MY=PC~R
public Utility() (,XbxDfM
{ d9Uv/VGp
N_liKhq
ESyb34T`
} bB+ 4
TJ_pMU
//线程睡眠 qx f8f
public static void sleep(int nSecond) VXP@)\!
{ r>_40+|&
try{ |E?,hTRe5
Thread.sleep(nSecond); 4r tNvf5`
} zXZXp~7)
catch(Exception e) KJYcP72P
{ HaA2y
e.printStackTrace (); t$EL3U/(
} +aZcA#%
} (b#4Z
?8!\VNC.
//日志 &[W53Lqa
public static void log(String sMsg) w<SFs#Z
{ JuD&121N*
System.err.println(sMsg); :v B9z
} |7)oX
F&u)wI'
wB+X@AA
public static void log(int sMsg) ;2}wrX
{ ZbfpMZ g
System.err.println(sMsg); $i|d=D&t
} wzf
} pB:/oHV
0Z1';A3
A/sM ?!p>_
/* &HB!6T/
**TestMethod.java | {Tq/
*/ lnQY_~s
package NetFox; IBYSI0
a98J_^n
TOw;P:-
public class TestMethod { {wh, "Ok_
GQ\;f
gaWJzK Yc_
public TestMethod() 7-VP)|L#G
{ ///xx/weblogic60b2_win.exe *X\J[$!
try{ :6jh*,OHZl
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1!W'0LPM
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); iI Dun Ih
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^tY _ q
fileFetch.start(); Y2aN<>f
} 8}K4M(
catch(Exception e){e.printStackTrace ();} #<DS-^W!
W|(U}PrC
jidRh}>a=
} ![&9\aH
^l{q{O7U$
F$@(0c
public static void main(String[] args) _sK{qQxvM=
{ |_mN:(3
new TestMethod(); zuS4N?t`p
} %[x PyqX
} qFXx/FZ
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