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)); >*B59+1P
} p/LV^TQ
for(int i=0;i<nEndPos.length-1;i++) k`'*niz
{ _ A{F2M
nEndPos = nStartPos[i+1]; :!$+dr(d
} >ZgV8X:
nEndPos[nEndPos.length-1] = nFileLength; V#Y"0l+~
} CO,{/
} 1n6%EC|X
}{PG^Fc<P
3 Sf':N`u
//启动子线程 i;qij[W.z
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; f*xv#G
for(int i=0;i<nStartPos.length;i++) (*vBpJyz%
{ Zf??/+[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c%wztP;L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), e*I92
nStartPos,nEndPos,i); HHgv,bC!
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g#1Y4
fileSplitterFetch.start(); 6N Ogi
} Ed_Fx'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Fwvc+ a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 77+3CME{'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Wi\k&V.mE
nEndPos = " + nFileLength); ;jPiD`Kyv
// fileSplitterFetch[nPos.length-1].start(); OYmutq
IZQ*D)
"8a ?KQ
//等待子线程结束 k7sD"xR3
//int count = 0; Ut/%+r"s
//是否结束while循环 x.Ny@l%]
boolean breakWhile = false; {od@Sl
QWt3KW8)
kPAg*
while(!bStop) {+5Ud#\y
{ 5xj8^W^G9
write_nPos(); )3f\H
Utility.sleep(500); 1BP/,d |+
breakWhile = true; sS4V(:3s
t-}IKrbv
z7P~SM
for(int i=0;i<nStartPos.length;i++) Qk|+Gj
{ J5<16}*
if(!fileSplitterFetch.bDownOver) KCp9P2kv.
{ x",ktE>9
breakWhile = false; +T,A^(&t
break; b53s@7/mq
} :}#j-ZCC"
} xDS]k]/(T
if(breakWhile) 7.)_H
break; 3'0Jn6(
tef>Py
D=.Ob<m`Z
//count++; kf|J
//if(count>4) i]@k'2N
// siteStop(); NweGK
} im)r4={ 9
P{J9#.Zq&s
6V6Mo}QF s
System.err.println("文件下载结束！"); +o0yx U 7t
} qM2m!
catch(Exception e){e.printStackTrace ();} 5'`DrTOA
} Nm-E4N#'i
0;OZ|;Z
~Dw% d;
//获得文件长度 n\BV*AH
public long getFileSize() 0pH$MkQ
{ @~5Fcfmm
int nFileLength = -1; _^ n>kLd$
try{ *xj2Z,u
URL url = new URL(siteInfoBean.getSSiteURL()); VP~%,=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |942#rM
httpConnection.setRequestProperty("User-Agent","NetFox"); Z0XQ|gkH
<y7Hy&&y-
-H|!KnR
int responseCode=httpConnection.getResponseCode(); YV>&v.x0;
if(responseCode>=400) d@b2XCh<K
{ eE;j#2SEO
processErrorCode(responseCode); ' eWG v
return -2; //-2 represent access is error QvOl-Lfc
} 4N3O<)C)@
k$DRX)e
<QaUq`,
String sHeader; mjk<FXW
![]6| G&
bwszfPM
for(int i=1;;i++) ]n:R#55A
{ i3$G)W
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +t Prqv"(
//Utility.log(in.readLine()); vD/l`Ib:
sHeader=httpConnection.getHeaderFieldKey(i); 1g$xKe~]4
if(sHeader!=null) j>.1RG
{ vI48*&]wTf
if(sHeader.equals("Content-Length")) ^R(=4%8%"
{ $?[pcgv
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )U]q{0`
break; :DuEv:;v
} 6O0aGJ,H
} $j@P8<M7
else uI9+@oV
break; o>&pj
} z fy(j
} 9d=\BBNZ
catch(IOException e){e.printStackTrace ();} G_ ~qk/7mF
catch(Exception e){e.printStackTrace ();} a6It1%a+
4V mUTMY
zx+}>(U\U
Utility.log(nFileLength); ^6Yt2Bhs
VrhHcvnZ
"kIlxf3
return nFileLength; +<B"g{dLuX
} 4((p?jbC
{Dy,u%W?
BmYX8j]
//保存下载信息（文件指针位置） }%42Ty
private void write_nPos() *#?9@0b@
{ EW`WFBjj
try{ -0NkAQrg
output = new DataOutputStream(new FileOutputStream(tmpFile)); )?LZg<<
output.writeInt(nStartPos.length); wCj)@3F
for(int i=0;i<nStartPos.length;i++) hwi_=-SL
{ pm[i#V<v
// output.writeLong(nPos); 66_=bd(9
output.writeLong(fileSplitterFetch.nStartPos); |X6R2I
output.writeLong(fileSplitterFetch.nEndPos); iorQ/(
} <KoOJMx(
output.close(); vuJEPn%
} e$rPXRf
catch(IOException e){e.printStackTrace ();} T+%P+
catch(Exception e){e.printStackTrace ();} #)S&Z><<
} 7lwFxP5QT
) <w`:wD
U5?QneK
//读取保存的下载信息（文件指针位置） t23W=U
private void read_nPos() ^L.'At
{ cveQ6 -`K
try{ *Aug7 HlS
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); p^ OHLT
int nCount = input.readInt(); [ThAvQ_$
nStartPos = new long[nCount]; |BD2=7,z
nEndPos = new long[nCount]; lJx5scN[
for(int i=0;i<nStartPos.length;i++) [.CP,Ly
{ jL'R4z
nStartPos = input.readLong(); =OTu8_ d0t
nEndPos = input.readLong(); )?6%d
} ={o)82LV
input.close(); lB#7j
} 8~Pdr]5
catch(IOException e){e.printStackTrace ();} q; C6ID`
catch(Exception e){e.printStackTrace ();} 7(|f@Y~*
} IQ xi@7%&
S{{wcH$n'i
sx'eu;S
private void processErrorCode(int nErrorCode) 3hA5"G+7
{ k6RH]Ha
System.err.println("Error Code : " + nErrorCode); z"FxKN~Z
} Z4gn7 'V
K7i@7
t7,$u-
//停止文件下载 Lnq CHe
public void siteStop() <B @z>V
{ ,TYFPulYcp
bStop = true; jQBn\^w
for(int i=0;i<nStartPos.length;i++) nmyDGuzk
fileSplitterFetch.splitterStop(); pP#|: %
F9A5}/\
:" JEC'
} \H1t<B,
} $)6M@S
//负责部分文件的抓取 8VC%4+.FF
**FileSplitterFetch.java <@0S]jy
*/ R+.kwq3CED
package NetFox; vw-y:,5`t8
h&~9?B
ocpM6b.fK
import java.io.*; J\J3'u
import java.net.*; <5G4|l
v0T?c53?
1Cw$^jd
public class FileSplitterFetch extends Thread { C@pn4[jTl
J2Qt!-
`v'yGsIV
String sURL; //File URL gQ<{NQMzvd
long nStartPos; //File Snippet Start Position )lJi7 ^,
long nEndPos; //File Snippet End Position ;*=7>"o'`
int nThreadID; //Thread's ID G6xNR
boolean bDownOver = false; //Downing is over T#vY(d
boolean bStop = false; //Stop identical Rv.IHSQUo
FileAccessI fileAccessI = null; //File Access interface vV"I}L
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2av=W
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException NiRb:F-
{ SEE:v+3|
this.sURL = sURL; NW&2ca
this.nStartPos = nStart; as!P`*@
this.nEndPos = nEnd; GXRW"4eF5
nThreadID = id; sN) xNz
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (.5Ft^3W
} Fr2F&NN`D
@3~Wukc
Y)#,6\=U
public void run() . K_Jg$3
{ <Ynrw4[)t
while(nStartPos < nEndPos && !bStop) <$C3] =2
{ (CAkzgTfc
y k\/Cf
2+*o^`%4P
try{ 05 .EI)7
URL url = new URL(sURL); O[p c$Pi
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -M4VC^_
httpConnection.setRequestProperty("User-Agent","NetFox"); U r8JG&,
String sProperty = "bytes="+nStartPos+"-"; kUr/*an
httpConnection.setRequestProperty("RANGE",sProperty); EiyHZ
Utility.log(sProperty); 6}Rb-\N
"{c@}~
-"XHN=H
InputStream input = httpConnection.getInputStream(); Gh<#wa['}
//logResponseHead(httpConnection); 1@F>E;YjL=
[jGE{<Je
@4Q/J$
byte[] b = new byte[1024]; F;Q'R|HQ
int nRead; u(PUbxJ V
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) WmRu3O
{ IGlM} ?x
nStartPos += fileAccessI.write(b,0,nRead); }Nma %6PfV
//if(nThreadID == 1) $+,kibk*R
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5v sn'=yN
} Cm0K-~ U
def\=WyK
~NO7@muw
Utility.log("Thread " + nThreadID + " is over!"); 3FMYs&0r4
bDownOver = true; _{GD\Ai_W
//nPos = fileAccessI.write (b,0,nRead); 8v=t-GJW
} +WguWLO"
catch(Exception e){e.printStackTrace ();} QT|\TplJt
} 8~O0P=
} B3I0H6O
>LB*5
z$Qy<_l
//打印回应的头信息 e+?;Dc-SJ\
public void logResponseHead(HttpURLConnection con) G-#rWZ&
{ ;qcOcm%
for(int i=1;;i++) _,f7D/dq
{ c(!pcB8
String header=con.getHeaderFieldKey(i); tqL2' (=
if(header!=null) A-h[vP!v|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); AXv-%k};
Utility.log(header+" : "+con.getHeaderField(header)); JM53sx4&
else Kp!A ay
break; j!@,r^(
} $8Z4jo
} klTRuU(
cqcH1aSv
'>Thn{
public void splitterStop() o?I`n*u"X
{ 8:Dkf v
bStop = true; J?1Eh14KZ
} *|gl1S
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f9O_M1=|lo
} bP%X^q~]A
ucJ8l(?Qc
u]]mbER*t#
/* ET%F+
**FileAccess.java ={jj'X9
*//文件访问(定位，写) EH'eyC-B<
package NetFox; x6vkd%fCj
import java.io.*; :]LW,Eql
uI3oPP> $
TjpAJW@-
public class FileAccessI implements Serializable{ ${97G#
Qh]k)]+*|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %2beoH'
RandomAccessFile oSavedFile; 9MbF:
long nPos; BT f
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public FileAccessI() throws IOException aLwEz}-
{ -1ci.4F&
this("",0); M-8d*#_P
} WWLf'89It
N_(-\\mq
VuH}@
public FileAccessI(String sName,long nPos) throws IOException tn|H~iF{
{ Ki /j\
oSavedFile = new RandomAccessFile(sName,"rw"); JQW7y!Z
this.nPos = nPos; .4y44: T
oSavedFile.seek(nPos); drp< f1`l8
} 6~6 vwp
d-I=xpB
=n;LP#(h?
public synchronized int write(byte[] b,int nStart,int nLen) ]=Wq&~
{ 6f+@@=Xc
int n = -1; i{r[zA]$
try{ s2#}@b6'.
oSavedFile.write(b,nStart,nLen); +}BKDEb
n = nLen; \3x+Z!
} G}nj 71=H
catch(IOException e) k7 Ne(4P
{ U:|:Y=O?Q
e.printStackTrace (); .8wF> 8
} <JW%h :\t
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%htwq]rZd
return n; R-Y 7I
} V7k!;0u v
HUel
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} !z5Ozm+}
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{$C"yksr
/* l4^MYwFR{O
**SiteInfoBean.java :6Gf@Z&+
*/ iq5-eJmq
package NetFox; /@",5U#
LE g#W
uao#=]?)
public class SiteInfoBean { =!($=9
4u1au1c
BD M"";u
private String sSiteURL; //Site's URL F*y7 4j,
private String sFilePath; //Saved File's Path X$_z"t
private String sFileName; //Saved File's Name )%hW3w
private int nSplitter; //Count of Splited Downloading File jori,"s
+Ecn
hh-sm8
public SiteInfoBean() 'Ojxzz*tT
{//nSplitter的缺省值为5 so@ijl4{Z
//default value of nSplitter is 5 -hGLGF??
this("","","",5); $8Gj9mw4e'
} mD,fxm{G
q oz[x
Qgq VbJP"
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2Xv$
{ mS+sh'VH
sSiteURL= sURL; 0 l+Jq
sFilePath = sPath; 1gX$U00:
sFileName = sName; k%;oc$0G-3
this.nSplitter = nSpiltter; 7<LCX{Uw
~@"H\):/
5W09>C>OC
} u_Xp\RJ
id>2G %Tx
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public String getSSiteURL() t24.u+O
{ %D`j3cEp@
return sSiteURL; n_6#Df*
} 7_L$XIa
+]e) :J
caL\ d
public void setSSiteURL(String value) $]J<^{v
{ L!Gpk)}[i
sSiteURL = value; N <M6~
} `F_R J.g*p
Y 9BKd78Y
+[[^W;<.l
public String getSFilePath() R'^J#"[
{ pR!m
return sFilePath; GFvLd:p` [
} }RUK?:lEA
cEGR?4z
XM`&/)
public void setSFilePath(String value) Y,-!QFS#
{ X:QRy9]
sFilePath = value; Axla@
} 9dva]$^:*1
6U1_Wk?
2F/oWt|w?
public String getSFileName() QvlVjDIy
{ MwaRwk;
return sFileName; FW3uq^
} D=M'g}l
(bD#PQXzm
?BU?c:"f
public void setSFileName(String value) oKPG0iM:
{ @u:q#b
sFileName = value; &pHXSU
} 8(}cbW
b.cBg.a
5 axt\
public int getNSplitter() ]<u%jTQREd
{ C-&s$5MzGb
return nSplitter; \cHFV
} _:KeSskuO
D&D-E~b^
-=qHwcId
public void setNSplitter(int nCount) O:#/To'
{ -gv[u,R
nSplitter = nCount; %Lp#2?*
} % "^CrG
} O{EbL5p
/{-J_+u*%
-`PLewvX
/* }&^1")2t
**Utility.java pbGv\SF
*/ tQ)l4Y 8
package NetFox; >KJE *X@s
A"IaFXB
S"@@BQ#mf
public class Utility { &Zo+F]3d
D 75;Y;E
\OkJX_7
public Utility() e]V7 7oc
{ YOUX
~oRT@E
H5be5
} C-/+n5J
Sre:l'.
//线程睡眠 )O>M~
public static void sleep(int nSecond) ogoEtKi
{ J4?SC+\
try{ xj JoWB
Thread.sleep(nSecond); VI)hA ^S
} 1{G@'#(
catch(Exception e) pAyUQe;X#
{ R4S))EHg
e.printStackTrace (); UK.=Y9
} e/$M6l$Q*4
} ONLhQJCb
`*cJc6
//日志 :e\M~n+y
public static void log(String sMsg) 9!6u Yf+
{ |wuN`;gc"
System.err.println(sMsg); <4N E)!#
} Or-LQ^~
a,e;(/#\7
U:8cz=#
public static void log(int sMsg) "|/q4JN)7d
{ /1.gv~`+
System.err.println(sMsg); Kj:'Ei7
} NFI~vkk'G
} 7Kti&T
6ciA|J'MR
LWV^'B_X-
/* 'r}y{`3M
**TestMethod.java G_xql_QR
*/ peVzF'F
package NetFox; #/)U0IR)
r<'B\.#tp>
%< Jj[F
public class TestMethod { +xNq8yS
I<S*"[nV
u89Q2\z~"M
public TestMethod() )Zrn?KM
{ ///xx/weblogic60b2_win.exe 'i 8`LPQ
try{ TIno"tc3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pK)!o
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); % xBQX
SiteFileFetch fileFetch = new SiteFileFetch(bean); }1NNXxQ
fileFetch.start(); ;>Z0e`=
} vH6.;j'^
catch(Exception e){e.printStackTrace ();} TU9$5l/;g
N'?#g`*KW
+<WNAmh
} Z;6?,5OSc
`(~oZbErM
8>DX :`
public static void main(String[] args) BuS[(
{ 3*eS<n[uG
new TestMethod(); E-#C#B
} b3q&CJ4|
} ty8E;['
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