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)); M`7y>Ud
} hmC*^"C>U=
for(int i=0;i<nEndPos.length-1;i++) lnh+a7a)
{ dJ ~Zr)>
nEndPos = nStartPos[i+1]; lCIDBBjy^
} kn"q:aD
nEndPos[nEndPos.length-1] = nFileLength; !'G~k+
} C <B<o[:H
} $,fy$ Qk,S
,LhCFw{8?~
$t}<85YCQ
//启动子线程 V'G Ju
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; CMW,slC_3
for(int i=0;i<nStartPos.length;i++) DyO$P#~?
{ G2:%g(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mi,&0xDea
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9\JQ7$B
nStartPos,nEndPos,i); SA;#aj}rV
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R>/NE!q
fileSplitterFetch.start(); xY<{qHcX
} 2`?!+")
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0w=R_C)s
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); //f
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", t2>fmQIQ
nEndPos = " + nFileLength); 7Nzbz3
// fileSplitterFetch[nPos.length-1].start(); VT%:zf
k;ZxY"^
"=1;0uy]
//等待子线程结束 ;*2>ES
//int count = 0; @7oL#-
//是否结束while循环 lDxc`S
boolean breakWhile = false; :A1:
_; Y`
@-&MA)SN
while(!bStop) T{+Z(L
{ B<?wh0
write_nPos(); pkgjTXR2b
Utility.sleep(500); lIRlMLuG
breakWhile = true; "IQ/LbOqm_
=elpH^N
#V,R >0"
for(int i=0;i<nStartPos.length;i++) K/=|8+IDL
{ k8AW6oO/i
if(!fileSplitterFetch.bDownOver) n'1'!J;Q
{ yQNV@T<o
breakWhile = false; P"/G
break; n>>Qn&ym
} 9$qm>,o
} ?9{~> 4@
if(breakWhile) _)T5lEFl=
break; ml`8HXK0
FRu]kZv2
'o_:^'c
//count++; P!G858V(
//if(count>4) #S]ER907
// siteStop(); vw,rF`LjZ
} p Z: F:
TS2ZF{m
Uu 8,@W+
System.err.println("文件下载结束！"); #Lv2Zoi>G
} 6Orum/|h
catch(Exception e){e.printStackTrace ();} ~Wo)?q8UY,
} Y_woKc*
G3G#ep~)vC
!8NC# s
//获得文件长度 G 0%6ch^%
public long getFileSize() ,'xYlH3s
{ *37uy_EpV
int nFileLength = -1; L>yJ
try{ W\&8auds
URL url = new URL(siteInfoBean.getSSiteURL()); uN([*'0Cg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ZOCDA2e(j
httpConnection.setRequestProperty("User-Agent","NetFox"); t3(]YgF
J &pO%Q=b
FCi U
int responseCode=httpConnection.getResponseCode(); .sC?7O=
if(responseCode>=400) (8.Z..PH
{ }J">}j]/
processErrorCode(responseCode); TJ q~)Bm
return -2; //-2 represent access is error +t5U.No
} >Cw<BIF
&0 >Loja`^
R}^~^#
String sHeader; 6f')6X'x
"#[!/\=?:
)M6w5g
for(int i=1;;i++) Q8!)!r%
{ S4=~`$eP
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )OiT{-m
//Utility.log(in.readLine()); 'Vyt4^$%
sHeader=httpConnection.getHeaderFieldKey(i); o(DOQGl
if(sHeader!=null) I!e})Y
{ =jB08A
if(sHeader.equals("Content-Length")) [<DZ*|+
{ KD`IX-r{s
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &l3iV88
break; Oo"^%F~%
} KMI_zhyB
} z!l.:F
else .pvi!NnL-
break; &?mD$Eo
} Tyvtmx M
} ,lZB96r0
catch(IOException e){e.printStackTrace ();} ,AxdCT
catch(Exception e){e.printStackTrace ();} _%5Ro6
]]Cb$$Td
O8B\{T1
Utility.log(nFileLength); &f^,la
$5Xh,DOg
6d_'4B
return nFileLength; yzqVz_Fi*W
} s2Mb[#:a"
{ ^cV lC_
q Y#n'&
//保存下载信息（文件指针位置） ?>I;34tL(
private void write_nPos() ^h69Kr#d4
{ ZosP(Tdq
try{ j#cYS*^H
output = new DataOutputStream(new FileOutputStream(tmpFile)); N[s}qmPha
output.writeInt(nStartPos.length); -$\+' \
for(int i=0;i<nStartPos.length;i++) $0vb^
{ -r-k_6QP
// output.writeLong(nPos); ^J$2?!~
output.writeLong(fileSplitterFetch.nStartPos); 0aG ni|
output.writeLong(fileSplitterFetch.nEndPos); rg^'S1x|
} bD/~eIcWL
output.close(); 3AU;>D^5
} Kx>qz.wwI?
catch(IOException e){e.printStackTrace ();} Pi]19boM.
catch(Exception e){e.printStackTrace ();} xai*CY@cQ
} _f$^%?^
YB-h.1T-
;M)QwF1
//读取保存的下载信息（文件指针位置） z6*X%6,8
private void read_nPos() N@t|7~
{ wK?vPS
try{ Tj:B!>>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |S_eDjF
int nCount = input.readInt(); -[cTx[Z,
nStartPos = new long[nCount]; HMSO=)@+
nEndPos = new long[nCount]; Qk:Y2mL
for(int i=0;i<nStartPos.length;i++) 8fl`r~bqZ
{ uScMn/%
nStartPos = input.readLong(); R%?9z 8-
nEndPos = input.readLong(); Yt;MV)
} ML|FQ
input.close(); RZXjgddL
} \G*0"%!U
catch(IOException e){e.printStackTrace ();} Y$"O VC
catch(Exception e){e.printStackTrace ();} bbE!qk;hEP
} jYk&/@`Ly
Dfmjw
hb}+A=A=+
private void processErrorCode(int nErrorCode) ynthDEo
{ ? m DI#~)
System.err.println("Error Code : " + nErrorCode); E|iQc8gr&
} F(>Np2oi6
1*\o.
h2G$@8t}I
//停止文件下载 Sc;BCl{=|
public void siteStop() 4K\G16'$v
{ [_k1jHr48N
bStop = true; pH9VTM.*
for(int i=0;i<nStartPos.length;i++) \NPmym_6J
fileSplitterFetch.splitterStop(); .P8&5i)'P,
fp`;U_-&0
;ub;lh3
} V<GHpFi0
} X $jWo@
//负责部分文件的抓取 ZOh`(})hy
**FileSplitterFetch.java b,7k)ND1F
*/ EJMM9(DQ7
package NetFox; ,o86}6Ag
B38]~'8
l9{hq/V
import java.io.*; GeH#I5y
import java.net.*; g6j?,c|y
9jM}~XvV
H\ F:95
public class FileSplitterFetch extends Thread { Lt64JH^lz
(A9Fhun
0X6YdW_2X
String sURL; //File URL J')o|5S1N
long nStartPos; //File Snippet Start Position geru=7
long nEndPos; //File Snippet End Position Z^3rLCa
int nThreadID; //Thread's ID m*&]!mM"0G
boolean bDownOver = false; //Downing is over ?9 <:QE;I>
boolean bStop = false; //Stop identical I|qo+u)
FileAccessI fileAccessI = null; //File Access interface )_HA>o_?C:
y0L_"e/
c"f-3kFv
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException wr$("A(
{ oH97=>
this.sURL = sURL; ,wQ5.U,
this.nStartPos = nStart; DhKS pA
this.nEndPos = nEnd; 'j#*6xD
nThreadID = id; C0T;![/4A
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p|U?86t
} &6/[B_.
9+Np4i@
Cio 1E-4
public void run() 'OITI TM
{ -*1d!
while(nStartPos < nEndPos && !bStop) f,U.7E
{ ;17E(tl
)|ju~qbf
P)Jgs
try{ L+b6!2O,
URL url = new URL(sURL); u-QB.iQ+s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ha]VWt%}
httpConnection.setRequestProperty("User-Agent","NetFox"); ]E5o1eeg
String sProperty = "bytes="+nStartPos+"-"; xQ f*
httpConnection.setRequestProperty("RANGE",sProperty); BtkOnbz8X
Utility.log(sProperty); 3#3n!(
`V}q-Zdy
t%d Z-Ym
InputStream input = httpConnection.getInputStream(); 0yk]o5a++
//logResponseHead(httpConnection); h0g8*HY+}
^9v4OUG
l!D}3jD
byte[] b = new byte[1024]; ~[t[y~Hup
int nRead; zfJT,h-{
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) b6,iZ+]
{ Z@4Arfl
nStartPos += fileAccessI.write(b,0,nRead); `'DmDg
//if(nThreadID == 1) 5AFJC?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); is?{MJZ_
} .YtKS
w'>pY
R$R*'l
Utility.log("Thread " + nThreadID + " is over!"); !z\h|wU+
bDownOver = true; j*|VctM
//nPos = fileAccessI.write (b,0,nRead); =/@D8{pU
} <$D`Z-6
catch(Exception e){e.printStackTrace ();} sA+ }TNhq
} /:cd\A}
} ju8>:y8
1KU! tL
Cwv9 a^
//打印回应的头信息 hZ|z|!g0
public void logResponseHead(HttpURLConnection con) yl'u'-Zb6
{ Ki;*u_4{
for(int i=1;;i++) g_;\iqxL
{ /J]5H
String header=con.getHeaderFieldKey(i); jk;j2YNPw
if(header!=null) 1.}d.t
//responseHeaders.put(header,httpConnection.getHeaderField(header)); A @i
Utility.log(header+" : "+con.getHeaderField(header)); tm|ZBM
else z<MsKD0Q
break; tR#OjkvX
} '+@=ILj>
} akmkyrz'&
$zUP?Gq!
KqHyG
public void splitterStop() em y[k
{ bTI|F]^!
bStop = true; ?e%ZOI
} lt/1f{v[:
1y:-N6
W8G,=d}6
} FUiRTRIYe
Pd8![Z3
8=!D$t\3
/* 0-B5`=yU
**FileAccess.java XgZD%7
*//文件访问(定位，写) 4j*
package NetFox; u2tfF
import java.io.*; lqy Qf$t
y#`tgJ:
G?yLo 'Ulo
public class FileAccessI implements Serializable{ irZ])a
49eD1h3'X[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |44Ploz2b
RandomAccessFile oSavedFile; M$wC=b
long nPos; R7%#U`Q^A
+V2F#fI/
\UA[
public FileAccessI() throws IOException (|2t#'m
{ ."g`3tVK
this("",0); B.=FSow
} .7J#_*NV
RTYvS5G
<3nMx^
public FileAccessI(String sName,long nPos) throws IOException )Om*@;r(
{ ~-k9%v`
oSavedFile = new RandomAccessFile(sName,"rw"); jVi) Efy
this.nPos = nPos; td$E/h=3
oSavedFile.seek(nPos); IYv`IS"
} x5pdS:
_T60;ZI+^
'B|JAi?
public synchronized int write(byte[] b,int nStart,int nLen) ?d*z8w
{ @@f"%2ZR[
int n = -1; GC-5X`Sq
try{ .e#w)K
oSavedFile.write(b,nStart,nLen); x[p|G5
n = nLen; KR}?H#%
} 9+|$$)
catch(IOException e) Q3'llOx
{ +w`2kv
e.printStackTrace (); w?L6!)oiz
} b1I]>\
PrqlTT}Px
aj='b.2)
return n; &$+AXzn
} ,~U>'&M;
x>K Or,f
4Z3su^XR
} 6jaEv#
KYm0@O>;
&C_j\7Dq
/* cVv=*81\
**SiteInfoBean.java `bq<$e
*/ }RF(CwZr(
package NetFox; phXGnm
rI{; IDV
Z-%\ <zT
public class SiteInfoBean { ic:zsuEm
G[PtkPSJ
ScOK)nL"
private String sSiteURL; //Site's URL 38B2|x
private String sFilePath; //Saved File's Path 4> K42m
private String sFileName; //Saved File's Name VD*6g%p
private int nSplitter; //Count of Splited Downloading File zpn9,,~u
"Fr.fhh'~
iQ67l\{R
public SiteInfoBean() |d2SIyUc
{//nSplitter的缺省值为5 _;S-x
//default value of nSplitter is 5 0D.Mke )
this("","","",5); fUWG*o9
} ,L2ZinU:
n`_{9R
>b}o~F^J
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [\eeDa
{ ktXM|#
sSiteURL= sURL; N{!i=A
sFilePath = sPath; Vr)S{k-Q
sFileName = sName; KfEx"94
this.nSplitter = nSpiltter; dES"@?!^
5DU6rks%
y-b%T|p9
} 9.M4o[
,2oWWsC7
eb{nWP
public String getSSiteURL() Tk[ $5u*,
{ oH?b}T=9jz
return sSiteURL; 9rX&uP)j^#
} O/(`S<iip
]jQutlg|
x8B}ZIbT9
public void setSSiteURL(String value) Mx?d
{ net@j#}j-
sSiteURL = value; &m7]v,&
} ~vhE|f
p`dU2gV
x_}:D *aI
public String getSFilePath() |^I0dR/w:
{ 2,oKVm+
return sFilePath; NiEUW.0
} W(Fv l
tY<4%~%X
U}[d_f
public void setSFilePath(String value) H2\;%K 2
{ |A~jsz6pI
sFilePath = value; uAq~=)F>,
} ZU4nc3__
\)904W5R
[b%D3-}'
public String getSFileName() SM#]H-3
{ U$.@]F4&
return sFileName; 65P0,b6"OT
} /t57!&
2;`1h[,-^
/9*B)m"
public void setSFileName(String value) (N6i4 g6
{ xh,qNnGGi
sFileName = value; kx{{_w
} @})|Z}~
IqHV)A
wk D^r(hiH
public int getNSplitter() bHYy}weZ
{ rQs)O<jl
return nSplitter; #4%]o%.
} %P/Jq#FE.
Oc#syfO
]i)c{y
public void setNSplitter(int nCount) BwGfTua
{ K`WywH3-
nSplitter = nCount; . B9iLI
} drP=A~?&:
} *b}HNX|
3?9IJ5p
py!|\00}
/* `Bp.RXsd*
**Utility.java ,/%=sux
*/ ^7U G$A
package NetFox; &*,#5.
HxV=F66"
XGWSdPJLr
public class Utility { *boR`[Ond
Qf+\;@
.CABH,Po:
public Utility() xb~yM%*c
{ 5h-SCB>P
F=e8IUr
HGs $*
} D6Ui!
:D6 ON"6
//线程睡眠 u(>^3PJ+
public static void sleep(int nSecond) !qh]6%l
{ Smn;(K
try{ Uw. `7b>B
Thread.sleep(nSecond); 8,4"uuI
} { ]{/t-=
catch(Exception e) VU(v3^1"
{ EF[@$j
e.printStackTrace (); {_[N<U:QT&
} W0@n/U
} %COX7gV
eK?MKe
//日志 t7Iv?5]N
public static void log(String sMsg) HZC"nb}r4
{ x.!V^HQSN
System.err.println(sMsg); ZF9z~9
} ]?kZni8j_
2\MT;;ZTZ
4K#>f4(U`g
public static void log(int sMsg) xQ-<WF1i
{ *xxx:*6rk;
System.err.println(sMsg); KE5kOU;
} q]ku5A\y
} kWMl
p Z|V 3
x_N'TjS^{
/* (l~AV9!m:
**TestMethod.java RUnSCOdX
*/ _?m(V=z>
package NetFox; Eex~xiiV
x:NY\._
S]e|"n~@
public class TestMethod { _~l5u8{^6
WdH$JTk1
;>EM[u
public TestMethod() >=I|xY,
{ ///xx/weblogic60b2_win.exe #4Rx]zW^%
try{ TCwFPlF|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); o4F2%0gJ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); s^G.]%iU
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6 6EV$*dRL
fileFetch.start(); n?!">G
} &WuN&As!Z
catch(Exception e){e.printStackTrace ();} C\Wmq [
}_M~2L?i
~?Qe?hB
} 9iIhte.
Z*]9E^
8yR.uMI$/
public static void main(String[] args) <sGVR5NR
{ K( c\wr\6
new TestMethod(); ,i?nWlh+
} b7?uq9
} r"3=44St
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