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)); OidF{I*O
} wyqXD.of
for(int i=0;i<nEndPos.length-1;i++) 3Lx]-0h
{ S|U/m m
nEndPos = nStartPos[i+1]; bL`O k
} p4k*vuu>
nEndPos[nEndPos.length-1] = nFileLength; ISy\g`d`C
} &5fM8Opkd
} _<?lP$Xr
<^}{sdOyu
VH&6Tm1
//启动子线程 V,=V
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; F<wwuCbF
for(int i=0;i<nStartPos.length;i++) &lg+uK
{ !C&!Wj
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A;~u"g'z&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 52-Gk2dp
nStartPos,nEndPos,i); chE~UQ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B2UQO4[w
fileSplitterFetch.start(); (uBevU\
} fL[(;KcAa
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n GE3O#fv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ht8%A 1|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8 Zy`Z
nEndPos = " + nFileLength); ^+CTv
// fileSplitterFetch[nPos.length-1].start(); }]cKOv2
`&2AN%Xz
Y }*[Krw
//等待子线程结束 I4%&/~!
//int count = 0; Q<$I,C]
//是否结束while循环 S:qML]RO
boolean breakWhile = false; _9!_fIY
Xz`?b4i
m7z6c"?lB
while(!bStop) g0-hN%=6
{ _1w?nN'
write_nPos(); 2J;h}/!H
Utility.sleep(500); K-VNU
breakWhile = true; Jq1 Zb
:(A5,$
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for(int i=0;i<nStartPos.length;i++) !Kv.v7'N/k
{ yQ)y#5/<6
if(!fileSplitterFetch.bDownOver) "g7`Ytln
{ .@{W6 /I
breakWhile = false; 9N^&~O|1
break; Z2d,J>-
} $_,?SXM
} SdF*"]t
if(breakWhile) so h3d
break; Fxwe,
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"y@B|
//count++; |sWH!:]49
//if(count>4) "7_6iB&@<
// siteStop(); yE3g0@*
} mO$]f4}
&E.ckWf
z@hlN3dg
System.err.println("文件下载结束！"); Yrp WGK520
} qv<[f=X9|
catch(Exception e){e.printStackTrace ();} oy90|.]G
} 3{o5AsVv
+JE h7
<6k5nEh
//获得文件长度 ol^J-
public long getFileSize() P@LYa_UFsN
{ V[>MKB(
int nFileLength = -1; Y=JfV
try{ (hTe53d<S?
URL url = new URL(siteInfoBean.getSSiteURL()); o$I% 1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &-#!]T-P:E
httpConnection.setRequestProperty("User-Agent","NetFox"); `A O_e4D0i
E )D*~2o/
ws:@Pe4AF
int responseCode=httpConnection.getResponseCode(); |}paa
if(responseCode>=400) A$G>D3
{ &CW,qY,sh
processErrorCode(responseCode); Y*iYr2?;
return -2; //-2 represent access is error F3/aq+<P[
} $fSV8n;Y
-Y'Qa/:7
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String sHeader; /5:C$ik
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xMI4*4y(
for(int i=1;;i++) g1-^@&q
{ D_r&B@4w
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); hR"j[
//Utility.log(in.readLine()); CSx V^
sHeader=httpConnection.getHeaderFieldKey(i); U1<EAGo|
if(sHeader!=null) 4[t1"s~Wg
{ COJny/FT|
if(sHeader.equals("Content-Length")) f]H[uzsV
{ iTi]D2jC
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7c|8>zES:E
break; gV]]?X&
} 1t{h)fwi
} e_6VPVa
else dM"Suw
break; g+h)s!$sB
} #|76dU
} xwG=&+66
catch(IOException e){e.printStackTrace ();} uxF88$=!t
catch(Exception e){e.printStackTrace ();} /I|.^ Id|
s-]k7a2V
e,/b&j*4th
Utility.log(nFileLength); wS"[m>.{v
hmJ{'D1"
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return nFileLength; :lQl;Q -e
} ,w%cX{
%(h-cuhq
}MAvEaUd
//保存下载信息（文件指针位置） a]^hcKo4
private void write_nPos() K@lZuQ.1
{ nsWenf
try{ INZycNqm,
output = new DataOutputStream(new FileOutputStream(tmpFile)); JFe %W?}.D
output.writeInt(nStartPos.length); wb^Yg9
for(int i=0;i<nStartPos.length;i++) !\wdX7%
{ *het_;)+{
// output.writeLong(nPos); qB-9&X
output.writeLong(fileSplitterFetch.nStartPos); M^I*;{w6i
output.writeLong(fileSplitterFetch.nEndPos); J+IQvOn_|
} 46c7f*1l
output.close(); ,@"Z!?e
} =qH9<,p`H
catch(IOException e){e.printStackTrace ();} |5|^[v
catch(Exception e){e.printStackTrace ();} L|4kv
} !HyPe"`oL
6@kKr
4Eh 2sI
//读取保存的下载信息（文件指针位置） Srw ciF
private void read_nPos() N=hr%{}c
{ 4/; X-
try{ \ZiZX$
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `C 'WSr
int nCount = input.readInt(); 5&]|p'"W\
nStartPos = new long[nCount]; Oo{+W5[
nEndPos = new long[nCount]; }Th":sin},
for(int i=0;i<nStartPos.length;i++) *gRg--PY%
{ 2Eg*Yb 1
nStartPos = input.readLong(); ;4<CnC**
nEndPos = input.readLong(); nHxos`Qx
} $c4Q6w
input.close(); O<nJbsl_w
} N\XZ=t^h(
catch(IOException e){e.printStackTrace ();} 5qo^SiB.
catch(Exception e){e.printStackTrace ();} [wB-e~
} ')_Gm{A#p
$#ks`$vM
+tFm DDx=
private void processErrorCode(int nErrorCode) JF7n|o-`?
{ ;!U`GN,tH
System.err.println("Error Code : " + nErrorCode); z^=.05jB
} OH~X~n-Z
udxLHs
J{8_4s!Xt>
//停止文件下载 0&$+ CWSM
public void siteStop() 4?YhqJ
{ |eT?XT<=o
bStop = true; OMG.64DX .
for(int i=0;i<nStartPos.length;i++) R~u0!
fileSplitterFetch.splitterStop(); [OJ@{{U%
'@'~_BBZP
5Gm,lNQAv
} )yp+!\
} UEmNT9V
//负责部分文件的抓取 S%n5,vwE
**FileSplitterFetch.java (pXZ$R:
*/ Isv@V.
package NetFox; et]-;(M
rq'Cj<=Zj
"<b~pfCOQk
import java.io.*; F*QZVg+<*X
import java.net.*; sOA!Sl
I=)Hb?qT~
F[/Bp>P7
public class FileSplitterFetch extends Thread { ~?&;nTwHe
2b+cz
OD5c,IkWB
String sURL; //File URL z:f[<`,GT
long nStartPos; //File Snippet Start Position tK)E*!
long nEndPos; //File Snippet End Position *k'D%}N:
int nThreadID; //Thread's ID Bv,u kQ\CH
boolean bDownOver = false; //Downing is over m@o/W
boolean bStop = false; //Stop identical )M(;:#le
FileAccessI fileAccessI = null; //File Access interface "e62g
ZY-UQ4_|u
J$6tCFD
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException <)c/PI[j
{ vgRjd1k.\y
this.sURL = sURL; kQ4-W9u
this.nStartPos = nStart; 4$9WJ~V{
this.nEndPos = nEnd; b['Jr% "O
nThreadID = id; JmB7tRM8
fileAccessI = new FileAccessI(sName,nStartPos);//定位 O o9 ePw7
} i)fAm$8#G
5Z{i't0CQ
y7aBF13Kl
public void run() V9Bi2\s*
{ I]N?}]uZ
while(nStartPos < nEndPos && !bStop) X%Jq9_
{ ^qXc%hjg
)G6{JL-I
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try{ u50 o1^<X
URL url = new URL(sURL); zs!,PQF(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O'y8[<
httpConnection.setRequestProperty("User-Agent","NetFox"); -'btKz*9
String sProperty = "bytes="+nStartPos+"-"; 8'J"+TsOW
httpConnection.setRequestProperty("RANGE",sProperty); ]kUF>Wp
Utility.log(sProperty); n'a=@/
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B|E4(,]^
InputStream input = httpConnection.getInputStream(); t.|b285e
//logResponseHead(httpConnection); @]ydWd
``?]13XjK
(VeX[*}I
byte[] b = new byte[1024]; q_PxmPE@3v
int nRead; GZ.Xx
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) e1a8>>bcI
{ yT<6b)&*&
nStartPos += fileAccessI.write(b,0,nRead); kj_o I5<'
//if(nThreadID == 1) 4DaLt&1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ST'M<G%4E
} !K:
TtA6N8G
T:$a x
Utility.log("Thread " + nThreadID + " is over!"); J8Bz|.@Q
bDownOver = true; \q9wo*A
//nPos = fileAccessI.write (b,0,nRead); Wj0=cIb
} A/eZnsk
catch(Exception e){e.printStackTrace ();} ;{mKt%#
} q~_DR4xZ
} ._2#89V
-Lh\]
=.197)e
//打印回应的头信息 R5PXX&Q
public void logResponseHead(HttpURLConnection con) $80TRB#
{ jI})\5<R
for(int i=1;;i++) MDkcG"O
{ -Zs.4@GH
String header=con.getHeaderFieldKey(i); pW{Q%"W
if(header!=null) @Z9X^Y+u^h
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Cu*+E%P9`
Utility.log(header+" : "+con.getHeaderField(header)); ko-|hBNv
else 2d1Z;@x
break; b EB3#uc
} 1Pya\To,m
} (9gL
RsTz3]`yv
xi5G?r
public void splitterStop() C(N' +VV_
{ GWb=X cx
bStop = true; \YXzq<7
} H&$L1CrdL
wm1`<r^M.
1!N|a< #
} `^3N|76Y
uJxT)m!/
"AN*2)e4
/* kwI[BF
**FileAccess.java Z5x&P_.x[
*//文件访问(定位，写) RCZ"BxleU
package NetFox; >* Ag0.Az
import java.io.*; ]iI2
f\p#3IwwH
@k+&89@G
public class FileAccessI implements Serializable{ AW{"9f4
_E\Cm
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7+(on
RandomAccessFile oSavedFile; |DUWB;
long nPos; >z #^JR\6
azK7kM~
?nf!sJ'm
public FileAccessI() throws IOException !841/TRb
{ +8xC%eE
this("",0); !=uaB.
} *'i9
e4h9rF{Cxn
-uk}Fou
public FileAccessI(String sName,long nPos) throws IOException u; ]4ydp
{ gWK[%.Jnw
oSavedFile = new RandomAccessFile(sName,"rw"); 8]@$7hy8
this.nPos = nPos; G'#f*) f
oSavedFile.seek(nPos); \\R$C
} _^%DfMP3i\
-- >q=hlA
$@Bd}35 J
public synchronized int write(byte[] b,int nStart,int nLen) 4Tdp;n\F
{ Mg"e$m
int n = -1; @PL.7FM<v
try{ M)qb6aD0
oSavedFile.write(b,nStart,nLen); l('@~-Zy
n = nLen; mz>GbImVD~
} SH1S_EQ<
catch(IOException e) @ajt D-_2
{ [_BQ%7DU
e.printStackTrace (); Svicw`uX0
} -~_[2u^3
,K WIuCU;
.QvH7
return n; @S<6#zR
} uh<e-;vU
[d?tf
m7#v2:OD+
} e,K.bgi
=w5]o@
PDgd'y
/* '.B5CQ
**SiteInfoBean.java (=-6'23q)
*/ Q"vhl2RX
package NetFox; I/B*iW^
Ee3-oHa
,{C hHnJ%#
public class SiteInfoBean { <B&vfKO^h
14pyHMOR
vojXo|c
private String sSiteURL; //Site's URL e"(SlR
private String sFilePath; //Saved File's Path 8=MNzcA }
private String sFileName; //Saved File's Name PjG^L FX
private int nSplitter; //Count of Splited Downloading File H~NK:qRzK
-UoTBvObAm
]r\FC\n6e
public SiteInfoBean() :Tcvj5
{//nSplitter的缺省值为5 BUs={"Pa
//default value of nSplitter is 5 PcQ\o>0")
this("","","",5); E[ttamU
} HO_!/4hrU
egmNX't6f5
yz<$?Gblz
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =5;tB
{ &_$0lIDQ
sSiteURL= sURL; r_hs_n!6
sFilePath = sPath; tMiy`CPh
sFileName = sName; 3GL,=q
this.nSplitter = nSpiltter; 3y%,f|ju
LC,6hpmh
5X73@Aj
} Y#t9DhzFWo
$@HW|Y
5AK@e|G$w
public String getSSiteURL() z2lT4SAv+
{ }X/>WiGh:
return sSiteURL; 6rMXv0)
} `t"7[Zk
gHtflS
c'INmc I|
public void setSSiteURL(String value) DkEf;P
{ qjsEyro$-
sSiteURL = value; t"Bp# U1
} TbD $lx3>
T#\=v(_NR
5\Rg%Ezl
public String getSFilePath() T/PmT:Qg`
{ }9V0Cu1
return sFilePath; Px3I+VP
} P(UY}oU
>K<cc#Aa
UX'q64F!
public void setSFilePath(String value) e'sS",o*
{ ]XASim:A
sFilePath = value; +Ks3
} _<GXR ?
PXG@]$~3
h$XoR0
public String getSFileName() v|KGzQx$.*
{ nsM.`s@V
return sFileName; *a^wYWa
} `An p;el
RBfzti6
/BN=Kl]
public void setSFileName(String value) 3 Q~0b+k
{ w9StW94p
sFileName = value; <J>k%,:B
} d)3jkHYEjj
eE_$ADEf
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public int getNSplitter() ]T{v~]7:{
{ k8!:`jG
return nSplitter; 2*< PmKI
} G?,"AA;
(+6N)9rj`/
MJ$.ST
public void setNSplitter(int nCount) jZQ{XMF
{ P'o]#Az
nSplitter = nCount; ^ p7z3ng
} ]4r&Q4d>O
} c_>AbF{
]a`"O
xLb=^Xjec
/* (5A8#7a
**Utility.java 8;"9A
*/ }ikN
package NetFox; \mTi@T!&
7|yEf
BnfuI
public class Utility { V(XZ7<& {
^G 'n z
4\ |/S@.
public Utility() z7z9lDS
{ ,@fx[5{
Ly/
Q3Z?Z;2aR
} Mnk-"d
#|3,DZ|)F
//线程睡眠 UCup {pDp
public static void sleep(int nSecond) \D};0#G0&
{ aI=Q_}8-
try{ NcHU)
Thread.sleep(nSecond); ao0^;
} (.iwD&
catch(Exception e) 8_ascvs5
{ Wsp c;]&
e.printStackTrace (); 7z$bCO L=S
} W9oWj7&h
} s(ap~UCOw
$BT[fJ'k
//日志 '@ p464
public static void log(String sMsg) {2QP6XsJ
{ ;y{(#X#
System.err.println(sMsg); ?S9vYaA$
} "LH!Trl@k
jt(GXgm
*wsZ aQ
public static void log(int sMsg) 4<vi@,s
{ *>`6{0,9
System.err.println(sMsg); {;th~[
} WMW=RgiW\
} '/9q7?[E!
;;m;f^]}
DSWmQQ
/* @v:Eh
**TestMethod.java \YFM5l;IU
*/ OHW|?hI=[
package NetFox; QN?EI: q=
xG(iSuz
QoZZXCU
public class TestMethod { s&'FaqE
z;?j+ZsdH
00s)=A_
public TestMethod() XPZ8*8JL
{ ///xx/weblogic60b2_win.exe @H3x51PT(m
try{ kwqY~@W
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `iN\@)E
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); K3UN#G)U
SiteFileFetch fileFetch = new SiteFileFetch(bean); C@\5%~tW+
fileFetch.start(); @$t\yBSK
} ?Bl/bY$*h
catch(Exception e){e.printStackTrace ();} H'7s`^- >I
B[6k [Vs
9:GP~oI j
} wr=KAsH<
4e;$+!dlV
%3|/t-US
public static void main(String[] args) H3`.Y$z
{ [)dIt@Y&j
new TestMethod(); ?E(X>tH
} `u R`O9)e
} 1c429&-
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