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)); R<vbhB/lU
} GHo mk##0E
for(int i=0;i<nEndPos.length-1;i++) u/NcX
{ B~M6l7^?
nEndPos = nStartPos[i+1]; =p7id5"
} XL9-N?(@
nEndPos[nEndPos.length-1] = nFileLength; fQwLx
} \/C5L:|p_
} wCV~9JTJ!
u?rX:KkS
fdHFSnQ g
//启动子线程 ~]`U)Aw
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7F_N{avr
for(int i=0;i<nStartPos.length;i++) m>3\1`ZF~<
{ o?cNH
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jP0TyhM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), lauq(aD_C
nStartPos,nEndPos,i); u#`51Hr$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <>Ha<4A =E
fileSplitterFetch.start(); =(Y0wZP|
} jW4>WDN:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5y] %Cu1.u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); MttFB;Tp
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %mD{rG9
nEndPos = " + nFileLength); Gd'_X D
// fileSplitterFetch[nPos.length-1].start(); Kr<UPr
us8HXvvp{
E$&bl
//等待子线程结束 +WKN&@
//int count = 0; KfPgj
//是否结束while循环 y&eU\>M
boolean breakWhile = false; UR S=1+
~;YkR'q0_
kBnb9'.A1
while(!bStop) Rlm28
{ HuKOb4g
write_nPos(); g$vOWSI+
Utility.sleep(500); Ct zWdo.
breakWhile = true; .JJ50p
"zzb`T[8
~=t9-AF-
for(int i=0;i<nStartPos.length;i++) hs:iyr]@9
{ ie>mOsz
if(!fileSplitterFetch.bDownOver) sTep2W.9
{ 1)qD)E5&cf
breakWhile = false; }W(t>>
break; .<xD'54
} yq<W+b/
} P_H_\KsH*(
if(breakWhile) Y*O Bky
break; B52dZb
e\f\CMb
&Vu-*?
//count++; PfB9 .f{
//if(count>4) QC&,C}t,
// siteStop(); !4<A|$mQ
} k*C[-5&#
ts("(zI1E
\PFjw9s
System.err.println("文件下载结束！"); ,H<nNBv3M
} 9 g- 8u+&
catch(Exception e){e.printStackTrace ();} .u=|h3&
} g6S-vSX,
}RYPr
-}( o+!nl
//获得文件长度 DRTT3;,N
public long getFileSize() "3|OB, <;:
{ -j:yEZ4Oy
int nFileLength = -1; GU9p'E
try{ .2_xTt
URL url = new URL(siteInfoBean.getSSiteURL()); m(EVC}Y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :S7[<SwL
httpConnection.setRequestProperty("User-Agent","NetFox"); &p*rEs
84i0h$ZZo
&.#dZ}J
int responseCode=httpConnection.getResponseCode(); h?}S|>9
if(responseCode>=400) T&bB8tQk
{ hd[t&?{=
processErrorCode(responseCode); }odjaM}5Nc
return -2; //-2 represent access is error TDWD8??e
} t]iKU@3
%K7;ePu
Z!jJ93A"
String sHeader; Ke]'RfO\
qPJSVo
%K06owV(S)
for(int i=1;;i++) 0ia-D`^me
{ v6E5#pse8
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); g:U -kK!i
//Utility.log(in.readLine()); rSm#/)4A
sHeader=httpConnection.getHeaderFieldKey(i); gQ%mVJB{(
if(sHeader!=null) 8DbP$Wwi
{ Ge=\IAj
if(sHeader.equals("Content-Length")) 'WBhW5@
{ a1[J>
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); PL!dkaD^y>
break; =4U$9jo!;
} ,JTyOBB<I
} <1:I[b
else {i3=N{5b
break; Z@$'fX?~9
} )nK+`{;@!
} 1=!2|D:C)i
catch(IOException e){e.printStackTrace ();} _F^NX%
catch(Exception e){e.printStackTrace ();} +&J1D8
bxBndxl
7 n^1H[q
Utility.log(nFileLength); n!lE|if
~DB:/VSmu
f.E{s*z>
return nFileLength; :O?3lj)
} 9;`hJ!r
F&3:]1
HzuG- V
//保存下载信息（文件指针位置） 1|>bG#|
private void write_nPos() v:>sS_^
{ "d M-3o<
try{ ~3-+~y=o~
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2 '$nz
output.writeInt(nStartPos.length); w_LkS/
for(int i=0;i<nStartPos.length;i++) 1:./f|m
{ Ys?0hd<cn
// output.writeLong(nPos); YG*}F|1
output.writeLong(fileSplitterFetch.nStartPos); 300[2}Y]
output.writeLong(fileSplitterFetch.nEndPos); :`<MlX
} Ywcgt|
output.close(); uaCI2I
} at2)%V)
catch(IOException e){e.printStackTrace ();} 04}c_XFFE
catch(Exception e){e.printStackTrace ();} $?LegX
} 1Vz3N/AP%?
{W%XSE
XB:E<I'q!3
//读取保存的下载信息（文件指针位置） jxYze/I
private void read_nPos() c`\qupnY
{ }wJH@'0+
try{ u%OLXb
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )]\-Uy$x
int nCount = input.readInt(); fj9&J[
nStartPos = new long[nCount]; kn`O3cW/
nEndPos = new long[nCount]; w7\ \m9
for(int i=0;i<nStartPos.length;i++) e. E$Ej]w
{ , 0?_? GO
nStartPos = input.readLong(); >rYMOC~
nEndPos = input.readLong(); OL@$RTh
} 'c >^Aai
input.close(); @Yw42`>!s
} \vpX6!T
catch(IOException e){e.printStackTrace ();} Zl.,pcL
catch(Exception e){e.printStackTrace ();} -f?,%6(1
} Le,;)Nd
k? ,/om1
tU>7jo[-p
private void processErrorCode(int nErrorCode) F9r|EU#;
{ )L_@l5l
System.err.println("Error Code : " + nErrorCode); sn'E}.uhXH
} vJX0c\e
e Dpt1
{ / ,?3
//停止文件下载 v[jg|s&6"
public void siteStop() Lg-!,Y
{ wzY{ii
bStop = true; ~;t/VsgGW
for(int i=0;i<nStartPos.length;i++) [?XP[h gd
fileSplitterFetch.splitterStop(); \GK]6VW
F8\JL %
\J-D@b;
} fd&>p
} g?u=n`k]\
//负责部分文件的抓取 FU)=+m
**FileSplitterFetch.java :8]y*j
*/ I(z16wQ
package NetFox; *-E'$
F^?DnZs
E7I$GD
import java.io.*; IUD@Kf]S
import java.net.*; [&lH[:Y#
o;OEb
p]7IoO -@
public class FileSplitterFetch extends Thread { |!CAxE0d$B
:xY9eq=
0aJcX)
String sURL; //File URL f7;<jj;w7
long nStartPos; //File Snippet Start Position #W4 "^#2
long nEndPos; //File Snippet End Position T5dnj&N ]
int nThreadID; //Thread's ID 0u +_D8G
boolean bDownOver = false; //Downing is over `:Oje
boolean bStop = false; //Stop identical jZiz 0[
FileAccessI fileAccessI = null; //File Access interface L08lkq,
%Vk77(
WM ]eb, 8q
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8KsPAK_
{ NC sem
this.sURL = sURL; #1WCSLvtV
this.nStartPos = nStart; E9' 2_e
this.nEndPos = nEnd; z00,Vr^m
nThreadID = id; ~{pds
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "kjSg7m*:
} l]~IZTC
:*YnH&
n(sseQ|\
public void run() \Qf2:[-V0
{ W<$!H V$
while(nStartPos < nEndPos && !bStop) |FSp`P
{ F'T.-lEO_d
X3?RwN:P
!x")uYf
try{ =VV><^uzdY
URL url = new URL(sURL); $KP&#;9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y~Mu~/s
httpConnection.setRequestProperty("User-Agent","NetFox"); k:N/-P&+
String sProperty = "bytes="+nStartPos+"-"; UtRwZ(09
httpConnection.setRequestProperty("RANGE",sProperty); iV!V!0- @
Utility.log(sProperty); B`)bo}h
b,>>E^wd!
Q(x/&]7=V
InputStream input = httpConnection.getInputStream(); 0g#xQzE
//logResponseHead(httpConnection); Y+5aT(6O
bGxHzzU}
`v)ZOw9&
byte[] b = new byte[1024]; lAkg47i
int nRead; aj<r=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) FuG;$';H75
{ ?P/73p
nStartPos += fileAccessI.write(b,0,nRead); 7R5+Q\W
//if(nThreadID == 1) 1\g r ;b
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `O`MW} c
} )jh~jU?c@
e\!Aoky
:#D~j]pP
Utility.log("Thread " + nThreadID + " is over!"); bCiyz+VyJn
bDownOver = true; *;U<b
//nPos = fileAccessI.write (b,0,nRead); 4[)tO-v:Y
} 7`&6l+S|
catch(Exception e){e.printStackTrace ();} JEF;Q
} x~K79Mya
} #7KR`H
tYhcoV
g{f7} gTG
//打印回应的头信息 !7p&n3dz
public void logResponseHead(HttpURLConnection con) \ _?d?:#RD
{ T1'\!6_5
for(int i=1;;i++) 5=R]1YI~$
{ GInw7
String header=con.getHeaderFieldKey(i); ZZi|0dG4;
if(header!=null) RE1M4UV.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); PKQ.gPu6*@
Utility.log(header+" : "+con.getHeaderField(header)); "8~PfLJ+
else 3eB)X2~
break; ?]o(cz
} L\V`ou
} amQTPNI
^]Z@H/]H
KLG29G
public void splitterStop() YOUB%N9+
{ =|2F?
bStop = true; X#zp,7j?
} 0& ?L%Y
M27H{}v
u4bVp+
} qh6rMqq
}0iHf'~DH*
Xz9[0;Q
/* >?6HUUQ
**FileAccess.java JpxQS~VX
*//文件访问(定位，写) \xcf<y3_
package NetFox; KP7 {
import java.io.*; wuW{2+)B
8H`L8: CM
&gUa^5'#
public class FileAccessI implements Serializable{ ;--D?Gs]Qr
>(.Y%$9"E
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7|GSs=
RandomAccessFile oSavedFile; 1N<n)>X4
long nPos; >0uj\5h)I]
`6;$Z)=.
]2 $T 6
public FileAccessI() throws IOException X4Pm&ol
{ lxr;AJ(
this("",0); j(k}NWPH
} b*/Mco 9O
#=;vg
/Gn0|]KI
public FileAccessI(String sName,long nPos) throws IOException USS%T<Vk
{ X*:,|
oSavedFile = new RandomAccessFile(sName,"rw"); E0yx @Vx
this.nPos = nPos; [rL 8L6,!
oSavedFile.seek(nPos); D@:'*Z(
} _pDfPLlY&
dCo3VF"u
yH>C7M7t
public synchronized int write(byte[] b,int nStart,int nLen) gXM+N(M-
{ xA`j:zn'j
int n = -1; FCWk8/
try{ pjs4FZ`Pd;
oSavedFile.write(b,nStart,nLen); 0s\ -iub=d
n = nLen; X8-x$07)
} ?~(#~3x
catch(IOException e) @|bJMi
{ mx UyD[|
e.printStackTrace (); s`0IyQXVU
} !l Egta[Ql
sFnR;
Y*\N{6$2
return n; h+A+>kC5
} L]u^$=rI
`w`F-ke]I
;(A-
} scYqU7$%T
6:6A"A
YDj5+'y
/* Jb^{o+s53
**SiteInfoBean.java 29VX-45
*/ xplV6q`
package NetFox; Wq"-T.i
]f&f_"D
e+D]9wM8
public class SiteInfoBean { IV1Y+Z )
Dln1 R[
9%"`9j~H>
private String sSiteURL; //Site's URL 1uCF9P ai
private String sFilePath; //Saved File's Path >tx[UF@P@
private String sFileName; //Saved File's Name SM2N3"\
private int nSplitter; //Count of Splited Downloading File }p?67y/
|lg jI!iK
}L&LtW{X
public SiteInfoBean() 3bR%#G%
{//nSplitter的缺省值为5 ^SKHYo`,,N
//default value of nSplitter is 5 )rt%.`
this("","","",5); SMJRoK3
} E`<ou_0N@q
{K6Z.-.`
R/*"N'nH-%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &43c/TSb
{ #z<#oC5
sSiteURL= sURL; EtaKo}!A}
sFilePath = sPath; ! K_<hNG&
sFileName = sName; E_DQ.!U!o
this.nSplitter = nSpiltter; odC"#Rb
Xo]2iQy
<lWj-+m
} &1?6Q_p6c
s=F[.X9lp
G6}&k[d5%
public String getSSiteURL() DwZRx@
{ URg;e M#
return sSiteURL; LME&qKe5
} 'bz&m(!
5]upfC6
~zG)<S"q
public void setSSiteURL(String value) hayJgkZ'
{ }!R*Q`m
sSiteURL = value; -2>s#/%
} o 9/,@Ri\5
c5b}q@nH
,\cV,$
public String getSFilePath() i$Kx@,O8t
{ CCol>:8{P
return sFilePath; W5= j&&|!
} EhM=wfGKw
bgKC^Q/F
FI.F6d)E$
public void setSFilePath(String value) Us!ZQ#pP
{ G &NK
sFilePath = value; ZfH>UHft
} 8ih_S2Cd
D7JrGaF{
$u'"C|>8
public String getSFileName() ;UM(y@
{ S50}]5K
return sFileName; VltM{-k^
} 6)ln,{
wet[f{c
kGo2R]Dd[
public void setSFileName(String value) _$5DK%M}
{ w,vnpdT
sFileName = value; .UQ|k,,t
} doHE]gC2Uz
qe&B$3D|
_*%K!%}l=
public int getNSplitter() X[1D$1Dvw
{ -N wic|
return nSplitter; OuEcoIK
} ]@<VLP?
KYJP`va6k
*<y9.\zY<
public void setNSplitter(int nCount) DB-79U%W
{ .5o~^
nSplitter = nCount; /|P{t{^WM
} G9LWnyQt
} Sw,*#98
58HA*w
6Aq]I$
/* !rAH@y.l
**Utility.java adIrrK
*/ X' 5R4j
package NetFox; ;CF:cH*
,>7dIJqzw
Ky,upU
public class Utility { uax0%~O\
Fpn*]x
2|& S2uq
public Utility() F0z7".)
{ S`zu.8%5
OUF%DMl4
Ys}^hy
} zEtsMU
'@hUmrl
//线程睡眠 `x#S.b
public static void sleep(int nSecond) K-#d1+P+
{ _.V5-iN
try{ YX-j|m|
Thread.sleep(nSecond); U'(zKqC
} EYj~Xj8_
catch(Exception e) Uoe;=P@
{ ]bh%pn
e.printStackTrace (); JN+7oh]u
} 5;" $X 1{
} [>54?4{|.
;5[OS8
//日志 |TMn
public static void log(String sMsg) Z^%a 1>`
{ 6P717[
System.err.println(sMsg); U!r8}@
} Sv/P:r _
hN!;Tny
T*%GeY [
public static void log(int sMsg) 9]lI?j]o
{ 'vVWUK956
System.err.println(sMsg); T%6JVFD
} \}=T4w-e
} 7AT8QC`u
WXmfh
o [V8h@K)
/* wods
**TestMethod.java :FS5BT$=
*/ "0jwCX Cu
package NetFox; ^-q{:lx
o^X3YaS)
EniV-Uj\D
public class TestMethod { sGhw23
}M%3
"%D"h
public TestMethod() $%DoLpE>
{ ///xx/weblogic60b2_win.exe )GVTa4}p
try{ ZwsQ}5
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i;C` .+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \ .#Y
SiteFileFetch fileFetch = new SiteFileFetch(bean); K |=o-
fileFetch.start(); H%Vf$1/TF
} z;oia!9z
catch(Exception e){e.printStackTrace ();} K\%\p$ZD
tkHmH/'7
DmuQE~DV
} _xh)]R
)r{Wj*u
,}'8. f
public static void main(String[] args) , p}:?uR
{ "}xIt)n%;
new TestMethod(); SJP3mq/^K
} RN)XIf$@_
} Q >[>{N&\
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