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)); sxn^1|O;m
} \QMRuR.
for(int i=0;i<nEndPos.length-1;i++) :LMLY<8>9
{ `BKV/Xl
nEndPos = nStartPos[i+1]; +m1y#|08
} p V`)
nEndPos[nEndPos.length-1] = nFileLength; N:e5=;6s
} L=-v>YL+
} 47^R
aiwKkf`\
P4dhP-t
//启动子线程 ]c$)0O\O
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; M@78.lPS
for(int i=0;i<nStartPos.length;i++) YhFd0A?]
{ S,2{^X
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bZzB\FB~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]='zY3
nStartPos,nEndPos,i); 9/I|oh_ G
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @vkO(o
fileSplitterFetch.start(); HD{2nZT
} tU>?j1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yM*f}S/ (
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); u|D|pRM-LT
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", gKWsmx!["
nEndPos = " + nFileLength); EnnE@BJ"
// fileSplitterFetch[nPos.length-1].start(); s^Rig[
X) xeq
UU"'
//等待子线程结束 jxNnrIA
//int count = 0; =^S1+B MY-
//是否结束while循环 FJ(}@U}57
boolean breakWhile = false; gj-MkeI)
%[H|3
Yl0_?.1 z
while(!bStop) ;7w4BJcq']
{ &5o ln@YL
write_nPos(); QFX )Nov];
Utility.sleep(500); aX{i
breakWhile = true; B~t[Gy
Rx%SeM2
2qxede
for(int i=0;i<nStartPos.length;i++) [$AOu0J
{ c&a.<e3mL
if(!fileSplitterFetch.bDownOver) '\I!RAZ
{ :FqHMN
breakWhile = false; QC^#ns&
break; EX9os
} 5x/LHsr=m
} yEB1gYJB
if(breakWhile) l0-zu6iw
break; sxFkpf_h
.P5OUK
Qy_! +q
//count++; 0$A7"^]
//if(count>4) ZI/Ia$O
// siteStop(); bfl%yGkd/|
} S@[B?sNj
5 i;n:&Y
qGrUS_~q*
System.err.println("文件下载结束！"); m6 @,J?X
} ]p5]n*0X
catch(Exception e){e.printStackTrace ();} 1'Y7h;\~\
} ipdGAG
k2Y *
w9Z,3J6r
//获得文件长度 yON";|*\m
public long getFileSize() H". [&VP5Z
{ CE;J`;
int nFileLength = -1; |E5\_Z
try{ Cr#Z.
URL url = new URL(siteInfoBean.getSSiteURL()); Ia!B8$$'RP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |h(05Kbk
httpConnection.setRequestProperty("User-Agent","NetFox"); Vnvfu!>(
I5mtr
;r.0=Uo9]
int responseCode=httpConnection.getResponseCode(); ?4A$9H
if(responseCode>=400) s !XJ
{ %|\Af>o4d
processErrorCode(responseCode); V~!lY\
return -2; //-2 represent access is error $9}jU#Z|hd
} 3Eu;_u_
%&Q9WMo
Wt 1]9{$
String sHeader; n1J;)VyR
SL ) ope
wJ Qm7n-+
for(int i=1;;i++) |Ta-D++]'
{ k=M_2T'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); S<nf"oy_K
//Utility.log(in.readLine()); >pRC$'Usx
sHeader=httpConnection.getHeaderFieldKey(i); v_L2>Pa.
if(sHeader!=null) {;-wXzv`
{ wJMk%N~R:
if(sHeader.equals("Content-Length")) 3<R8_p
{ T;`2t;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3GVS-?
break; V N<omi+4
} ,6AnuA
} 0Q4i<4 XW
else :pXY/Pa
break; W:hg*0z-*
} Y6:b
} Q@0Zh,l
catch(IOException e){e.printStackTrace ();} T:!f_mu|
catch(Exception e){e.printStackTrace ();} oGvk,mh"(
|9Pi*)E
b9RJ>K
Utility.log(nFileLength); )1, U~+JFU
(\M#Ay t)
*F;W 1TF
return nFileLength; <19A=
} NE5H\
L"Dos +
cJLAP%.L
//保存下载信息（文件指针位置） !=bGU=^
private void write_nPos() u?7^+z
{ h-+vNhH
try{ 8.ej65r*
output = new DataOutputStream(new FileOutputStream(tmpFile)); E]dc4US
output.writeInt(nStartPos.length); k3CHv=U{
for(int i=0;i<nStartPos.length;i++) }Yargj_Gn
{ S8k<}5
// output.writeLong(nPos); )o`[wq
output.writeLong(fileSplitterFetch.nStartPos); -^ R?O
output.writeLong(fileSplitterFetch.nEndPos); T%]@R4z#q
} 9}A\BhtiM
output.close(); '_B;e=v`
} MREB
catch(IOException e){e.printStackTrace ();} 4QBPN@~t
catch(Exception e){e.printStackTrace ();} a^g}Z7D'T
} wJF(&P
eZ8DW6l*
aJLc&o 8Yg
//读取保存的下载信息（文件指针位置） I3;03X<2
private void read_nPos() 7* R %zJ
{ zK>}x=
try{ IC:>60A,]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ib%'{?Q.
int nCount = input.readInt(); GJIZu&C
nStartPos = new long[nCount]; Vl/fkd,Z
nEndPos = new long[nCount]; C;0VR
for(int i=0;i<nStartPos.length;i++) B|ctauJ
{ \ 0/m$V.
nStartPos = input.readLong(); hMyN$7Z
nEndPos = input.readLong(); i hcSSUm
} }CM#jN?(
input.close(); ,wZq~;2
} :%<'('S|
catch(IOException e){e.printStackTrace ();} 1h3`y
catch(Exception e){e.printStackTrace ();} <9]J/w+
} R>hL.+l.
Ys]cJ]
M^{=&
private void processErrorCode(int nErrorCode) 2oo\SmO]
{ Nz>xilU'
System.err.println("Error Code : " + nErrorCode); C9 j{:&
} >{[
=g|5VXW5
5a|{ytP
//停止文件下载 Uf9L*Z'6il
public void siteStop() Kf#iF*
{ <6&Z5mpm$w
bStop = true; nd"$gi
for(int i=0;i<nStartPos.length;i++) JC#5CCz
fileSplitterFetch.splitterStop(); hcoZ5!LvT
M'JCT'(X
KGGJ\r6
} p\Fxt1Y@X
} S@Aw1i p
//负责部分文件的抓取 gOr%N!5
**FileSplitterFetch.java ]IH1_?HgP7
*/ p@U[fv8u
package NetFox; j!"5,~
R`M@;9I.@
F{Oaxn
import java.io.*; erOj(ce
import java.net.*; dEkAUH
EY0,Q {
h-\Ov{~
public class FileSplitterFetch extends Thread { vj|#M/3>
>z73uKA(
(9b%'@A@m
String sURL; //File URL Js^(mRv=
long nStartPos; //File Snippet Start Position +Jm[IN
long nEndPos; //File Snippet End Position "q KVGd
int nThreadID; //Thread's ID 5> !N)pA
boolean bDownOver = false; //Downing is over v6ei47-
boolean bStop = false; //Stop identical `3*QKi$
FileAccessI fileAccessI = null; //File Access interface F`1J&S;C
lYmxd8
@|{8/sOq
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException (gIFuOGi>
{ Jp= )L
this.sURL = sURL; FiSx"o
this.nStartPos = nStart; mY]o_\`
this.nEndPos = nEnd; 7~);,#[ky
nThreadID = id; 5}a.<
fileAccessI = new FileAccessI(sName,nStartPos);//定位 K"ly\$F
} WJ,?5#
7a=ul:
s>%.bAxc
public void run() t{,e{oZx
{ (}s& 84!
while(nStartPos < nEndPos && !bStop) 0sH~H[ap
{ {$>.I
6n~)R
5F!i%{XQvm
try{ 4*inN~cU
URL url = new URL(sURL); {R"mvB`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^=8/Iw
httpConnection.setRequestProperty("User-Agent","NetFox"); -2'+GO7G
String sProperty = "bytes="+nStartPos+"-"; %Y,Ru)5}
httpConnection.setRequestProperty("RANGE",sProperty); PXML1.r$Q
Utility.log(sProperty); +hX=
|kD69 }sG
nM *}VI
InputStream input = httpConnection.getInputStream(); AMASh*
//logResponseHead(httpConnection); iP@FXJJ
[WV&Y,E
mg" _3].j
byte[] b = new byte[1024]; `jyyRwSoe
int nRead; 0|C !n+OK
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g<7Aln}Nl\
{ R0mkEM
nStartPos += fileAccessI.write(b,0,nRead); ";7/8(LBZ
//if(nThreadID == 1) X|D-[|P
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6uKP BL@,
} h<bhH=6~
u~>G8y)k9O
G/#m.=t
Utility.log("Thread " + nThreadID + " is over!"); q8n@fi6
bDownOver = true; n5;@}Rai
//nPos = fileAccessI.write (b,0,nRead); U| ?68B3
} y%x:~.
catch(Exception e){e.printStackTrace ();} W*DKpJy
} s {^wr6B
} 2-jXj9kp`
&#KN"uPW
&5XEjY>@
//打印回应的头信息 4jGN:*kZ
public void logResponseHead(HttpURLConnection con) 587;2
{ 5#s],h
for(int i=1;;i++) s:_a.4&Y
{ U_;="y
String header=con.getHeaderFieldKey(i); vVIND
if(header!=null) 0pG +yec
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )=`DEbT
Utility.log(header+" : "+con.getHeaderField(header)); U@CAQ?
else ofw&?Sk0
break; H_Va$}8z
} kjB'WzZ8
} 9Kgyt
KUK.;gG*Z
&/-MUKN
public void splitterStop() ,zr,>^v
{ jSH.e?
bStop = true; H9i7y,[*
} !]Qk?T~9-
;\6@s3
J/:U,01
} S=.%aB
V6'u\Ch|
S'W,AkT
/* cruBJZr*
**FileAccess.java aXG|IN5 *m
*//文件访问(定位，写) HFTeG4R
package NetFox; qY'+@^<U;
import java.io.*; !8T04988j
,4`Vl<6
_`O",Ff
public class FileAccessI implements Serializable{ 6R^32VeK($
`LLmdm 6i
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 a5saN5)H
RandomAccessFile oSavedFile; 5c(g7N
long nPos; (aC=,5N
F?"Gln~;
%'_:#!9
public FileAccessI() throws IOException KK1?!7
{ =+Odu
this("",0); AXte&l=M
} )=X g
*PV7s
Y?7GFkIP$
public FileAccessI(String sName,long nPos) throws IOException 'J-a2oiM(
{ MzgP@tB
oSavedFile = new RandomAccessFile(sName,"rw"); q5hE S
this.nPos = nPos; tKcC{
oSavedFile.seek(nPos); MUv#8{+F'/
} ]+m2pEO
Vy[xu$y
8#tuB8>
public synchronized int write(byte[] b,int nStart,int nLen) 8Dtpb7\o
{ ,Eh]Zv1AE
int n = -1; SCe$v76p#
try{ @Lf&[_
oSavedFile.write(b,nStart,nLen); vqQ)Pu?T
n = nLen; ,%N[FZ`|
} \}W3\To_
catch(IOException e) 7RBEEE`)
{ j$XaO%y)
e.printStackTrace (); D}X6I#U'/
} &0y`Gt
=Hn--DEMg
cuumQQ
return n; %Cqp88]
} eD2eDxN2
BY[7`@
@R%qP>_
} IzUpkwN
-P|claO0
4lc|~Fj++
/* ^xNzppz`]C
**SiteInfoBean.java !03JA9lo
*/ Dt(D5A
package NetFox; ];6955I!
[)jNy_4
/FC HF#yK
public class SiteInfoBean { hLuv
;n*|AL7(
|94o P>d
private String sSiteURL; //Site's URL Nb !i_@m%s
private String sFilePath; //Saved File's Path 0&I*)Zt9x
private String sFileName; //Saved File's Name X"q[rsB
private int nSplitter; //Count of Splited Downloading File 52Lp_M
>lQa"F=
6s~B2t:Y
public SiteInfoBean() : -#w
{//nSplitter的缺省值为5 l-v m`-_#
//default value of nSplitter is 5 uI?Z_
this("","","",5); zng.(]U/?H
} 9DM,,h<`
>2pxl(i
6.KEe^[-
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #|Lsi`]+
{ M@h"FuX:
sSiteURL= sURL; T!y 9v5
sFilePath = sPath; Lhux~,EH
sFileName = sName; _L~ 3h
this.nSplitter = nSpiltter; bsU$$;
KU(BY}/ ^
E%D.a=UX,
} inO;Uwlv
`4xQ#K.-
p~8O6h@J
public String getSSiteURL() ^Ld5<
{ @M<qz\ [
return sSiteURL; X,3\c:
} !\1)?&y9j
[[<TW}
8+gp"!E
public void setSSiteURL(String value) D>W&#A8&y
{ `3VI9GmQ
sSiteURL = value; >I~Q[
} #\Y`?
P,)D0i
d@{12hq
public String getSFilePath() l]wLQqoO
{ ,qp8Rg|3j
return sFilePath; D-C]0Jf3
} ;4b=/1M'
\ Xh C
0<@['W}G
public void setSFilePath(String value) \7qj hA@
{ vI(LIfe;
sFilePath = value; 1I69O6"
} g7hI9(8+
A. tGr(r
%SIll
public String getSFileName() UTu~"uCR
{ 5ta;CG
return sFileName; T>(X`(
} oVHe<zE.
j96}E/gF
M"s:*c_6
public void setSFileName(String value) C&qo$C
{ :PN%'~}n
sFileName = value; rWNe&gFM
} DN=W2MEfc
af@a /
!})Y9oZc8
public int getNSplitter() ESoC7d&.K{
{ 9fbbJ"I+
return nSplitter; sDg1nKw(
} ZEDvY=@a
5p~5-_JX
}[!=O+gO
public void setNSplitter(int nCount) Yh!k uS#<
{ ;Q vQ fV4
nSplitter = nCount; J^#g?RHN>m
} \/ri|fm6l#
} @ls/3`E/5E
X8*~Cf73u
T<Y*();Zo
/* L{IMZ+IB2|
**Utility.java MRo_An+
*/ #=)>,6Zw
package NetFox; 5$:9nPAH
g&w~eWpk
f0^s<:*
public class Utility { KfVsnL_
=c,7uB
32aI0CT
public Utility() SnUR?k1
{ -:r<sv$
y?r`[{L(lA
w1zMY:9
} Ug0c0z!b
&|'yqzS3
//线程睡眠 WB'1_a
public static void sleep(int nSecond) ydY(*]
{ HWFTI /]
try{ 6/g 82kqpk
Thread.sleep(nSecond); 54WX#/<Yik
} 2)$-L'YS
catch(Exception e) FaWc:GsfB
{ byt$Wqdl
e.printStackTrace (); 4IY|<
} ->IZZ5G<
} lJfk4 -;M
NB^Al/V@
//日志 /|&4&$
public static void log(String sMsg) bxO/FrwTj{
{ BL>~~
System.err.println(sMsg); iC!6g|]X
} @U?&1.\
WO!OaC?+B,
&'Nzw2
public static void log(int sMsg) {gu3KV
{ E^{!B]/oP
System.err.println(sMsg); |9FrVO$M
} f9y+-GhaD
} !L9]nO 'BL
e9Gu`$K
Us#/#-hJ
/* ]D,_<Kk
**TestMethod.java "+&pd!\
*/ tfm3IX
package NetFox; ?5};ONjN
Tu}EAr
NZ8X@|N
public class TestMethod { hG<[F@d
K(lVAKiP]
Q*'OY~
public TestMethod() w<]-~`K
{ ///xx/weblogic60b2_win.exe <ycR/X
try{ b9T6JS j
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); d9jD?HgM(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); GCw4sb4~w
SiteFileFetch fileFetch = new SiteFileFetch(bean); !OPHS^L
fileFetch.start(); OfA+|xT&
} &~B8~U4%
catch(Exception e){e.printStackTrace ();} \3K7)o^
\4<|QE
&0G9v
} 2w+4B4
~FXq%-J
R/E6n &R
public static void main(String[] args) '?_~{\9<
{ xA2I+r*o
new TestMethod(); DaGny0|BB
} =^{MyR7
} {=gJGP/}_
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