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)); 8''9@xz
} ?aP1
for(int i=0;i<nEndPos.length-1;i++) Rc$=+K#
{ '2;Ny23
nEndPos = nStartPos[i+1]; FRb&@(;
} mvUVy1-c
nEndPos[nEndPos.length-1] = nFileLength; jI@bTS o
} E!:.G+SEl
} cP/F|uG5
N )b|
#p11D= @[
//启动子线程 ,e}mR>i=e
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !~6'@UYo
for(int i=0;i<nStartPos.length;i++) ZE5-i@1
{ 1^n5CI|7u
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DW'0j$;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), AJJ%gxqGq
nStartPos,nEndPos,i); I^rZgp<'i
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sa\|"IkD2
fileSplitterFetch.start(); 4WBoZJ
} Om&{4a\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d;@E~~o?B]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); p,_6jdz
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", j TB<E=WC
nEndPos = " + nFileLength); F[Guy7?O
// fileSplitterFetch[nPos.length-1].start(); ~ wJ3AqNC?
s!nSE
mR!&.R?
//等待子线程结束 1{;[q3a
//int count = 0; p@!@^1j=
//是否结束while循环 >*<6 zQf
boolean breakWhile = false; USHlb#*
KoxGxHz^Y3
UH1S_:6
while(!bStop) q9g[+*9]$
{ P!>{>r4
write_nPos(); }uV?
Utility.sleep(500); L*SSv wSL
breakWhile = true; d~P<M3#>
O,V6hU/ *
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for(int i=0;i<nStartPos.length;i++) =2vMw]
{ #buV;!_!E?
if(!fileSplitterFetch.bDownOver) X+'^Sp
{ {m*V/tX
breakWhile = false; r=iMo7q
break; oZ\qT0*eb
} .5#tB*H
} iA^+/Lt
if(breakWhile) %FR^[H]
break; :<WQ;q
6Mf3)o2
Gn2bZ%l
//count++; I]WeZ,E
//if(count>4) [Q.4]K2
// siteStop(); wn A%Nh7
} zvK5Zxl
#)h ~.D{
7gdU9c/q,
System.err.println("文件下载结束！"); DS,FVh".|
} 8y4D9_{
catch(Exception e){e.printStackTrace ();} #.<F5
} hB GGs
!7"K>m<
PhI6dB`
//获得文件长度 SJ WP8+
public long getFileSize() BJ.8OU*9]S
{ 5[j!\d}U
int nFileLength = -1; UmD-7Fd
try{ ==jw3_W
URL url = new URL(siteInfoBean.getSSiteURL()); G=bP<XF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :hhE=A>X
httpConnection.setRequestProperty("User-Agent","NetFox"); v(Zi;?c
1N$gE
F#}1{$)% /
int responseCode=httpConnection.getResponseCode(); j~L1~@
if(responseCode>=400) Jr>S/]"
{ ~q_+;W.
processErrorCode(responseCode); \#+2;L
return -2; //-2 represent access is error Dy{`">a
} /@nRL
~ Dp:j*H
8$<AxNR
String sHeader; MkNURy>n&
,<P[CUD&&
q[|`&6B
for(int i=1;;i++) ,I&0#+}n
{ a6k(O8Ank3
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @<TfA>*VJ
//Utility.log(in.readLine()); ,8"[ /@
sHeader=httpConnection.getHeaderFieldKey(i); 0iZ9a/v
if(sHeader!=null) `7qp\vYL
{ n40MP5RxY
if(sHeader.equals("Content-Length")) AIxBZt7{b
{ %M,d/4=P
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); On.x~t
break; v yLAs;
} wAOVH].
} whm tEY
else c.{&~
break; V-ouIqnI
} Gxa.<E^k
} &P{p\v2Y
catch(IOException e){e.printStackTrace ();} c'#J{3d
catch(Exception e){e.printStackTrace ();} HFx"fT
\y )4`A
$E,DxDT
Utility.log(nFileLength); %FWfiFV|<
8~Hs3\Hp
3&nc'
return nFileLength; .nF
} BvW gH.OX
Cz);mOb%M%
Vv)E41
//保存下载信息（文件指针位置） s>``- ]3
private void write_nPos() fQ.>G+0I>
{ zu*G4?]~h
try{ D:vUy*
output = new DataOutputStream(new FileOutputStream(tmpFile)); v?TJ!o
output.writeInt(nStartPos.length); cTaD{!zm5
for(int i=0;i<nStartPos.length;i++) *n_4Rr
{ MHyl=5
// output.writeLong(nPos); UG'U D"
output.writeLong(fileSplitterFetch.nStartPos); ^?]H$e
output.writeLong(fileSplitterFetch.nEndPos); S=amjcC
} HeifFJn
output.close(); jsaCnm>&
} Bt7v[Ot
catch(IOException e){e.printStackTrace ();} J+NK+,_*M
catch(Exception e){e.printStackTrace ();} )$4DH:WN
} gI5nWEM0{
U@5Z9/n{
to|9)\
//读取保存的下载信息（文件指针位置） ViT 5Jn7
private void read_nPos() i6:yNb ='
{ _";pk _
try{ ~[y+B0I3
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); UBHQzc+,
int nCount = input.readInt(); F-,{+B66
nStartPos = new long[nCount]; bCe-0!Q
nEndPos = new long[nCount]; _1c_TMh}9
for(int i=0;i<nStartPos.length;i++) SfL`JNi)
{ =?Md&%j
nStartPos = input.readLong(); E(LE*J
nEndPos = input.readLong(); Byj~\QMD|
} [gp:nxyfQm
input.close(); y+afUJT
} F/>Pvq]
catch(IOException e){e.printStackTrace ();} yZ0ZP
catch(Exception e){e.printStackTrace ();} (b}7Yb]#c
} u`@FA?+E1
RAbq_^Q
(+ anTA=
private void processErrorCode(int nErrorCode) |6^ K
{ aBi:S3 qk
System.err.println("Error Code : " + nErrorCode); B&N&eRAE
} mxA )r5sx
!z 5d+ M
xU<lv{m`D
//停止文件下载 $i>VI
public void siteStop() q#3X*!)
{ a\_,_psK
bStop = true; yvisoZX
for(int i=0;i<nStartPos.length;i++) 82!GM.b
fileSplitterFetch.splitterStop(); ScoHtX3
Nb/%>3O@
nn%xN\~<
} H H3
} 9W$)W
//负责部分文件的抓取 4:g:$s|SE[
**FileSplitterFetch.java c (8J
*/ jloyJ@ck
package NetFox; 3[Iw%% q
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x's-UO"^
import java.io.*; Uk\U*\.
import java.net.*; ,0~TvJS
mDfWR
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public class FileSplitterFetch extends Thread { X-FHJ4
oH"N>@Vl
e*s{/a?,
String sURL; //File URL ZE`{J=,
long nStartPos; //File Snippet Start Position oyw1N;K
long nEndPos; //File Snippet End Position J[wXG6M
int nThreadID; //Thread's ID L9oZ7o
boolean bDownOver = false; //Downing is over &_j4q
boolean bStop = false; //Stop identical musxX58%
FileAccessI fileAccessI = null; //File Access interface !F)oX7"
Kjw\SQ)2~
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException V}qmH2h
{ UXHFti/A<
this.sURL = sURL; --kK<9J7
this.nStartPos = nStart; 6~>k]G
this.nEndPos = nEnd; 4PQWdPv;
nThreadID = id; 2_X0Og8s[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 y9)",G!
} |3m%d2V*hF
o:<3n,T
e.V){}{V
public void run() &)-?=M
{ &=bI3-
while(nStartPos < nEndPos && !bStop) q=6Y2Q
{ zn|}YovY+
J~.kb k
G\%hT5^
try{ 6! 'Xo:p
URL url = new URL(sURL); -S@:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +F|[9o z
httpConnection.setRequestProperty("User-Agent","NetFox"); e{&gF1"[
String sProperty = "bytes="+nStartPos+"-"; ;rgsPVbVf
httpConnection.setRequestProperty("RANGE",sProperty); QUf_fe!,|
Utility.log(sProperty); kx[8#+P
&bQ^J%\
2uVm?nm
InputStream input = httpConnection.getInputStream(); ZV;yXLx|
//logResponseHead(httpConnection); ?9+;[X
mLE`IKgd]
7~'@m(9e
byte[] b = new byte[1024]; ?L^ Gu ]y
int nRead; X!Q"p$D4(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 16vfIUtb
{ J++D\x#@
nStartPos += fileAccessI.write(b,0,nRead); uypD`%pC
//if(nThreadID == 1) bX,Z<BvbF
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5 *_#"
} ']Z8C)tK
Cb.Aw!
rQJoaP+\q
Utility.log("Thread " + nThreadID + " is over!"); 2 O%UT?R
bDownOver = true; UWI5/R
//nPos = fileAccessI.write (b,0,nRead); N*fN&0r
} 8J} J;Ga
catch(Exception e){e.printStackTrace ();} U|=y&a2Rb
} eo!z>9#.
} sZc<h]L(g
$3>|RlxYA
k.%F!sK
//打印回应的头信息 =B 9U
public void logResponseHead(HttpURLConnection con) <3HJkcYGz
{ *h UrE
for(int i=1;;i++) a^BD55d?
{ $\H>dm
String header=con.getHeaderFieldKey(i); Ap/WgVw;
if(header!=null) sMZ \6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); "LYob}_z
Utility.log(header+" : "+con.getHeaderField(header)); VrpYBU
else (U)=t$=o
break; nP.d5%E
} }U9e#>ex
} ?S"xR0 *
ws=y*7$y
;k>{I8L~
public void splitterStop() u!(|y9p
{ .$Y[>9
bStop = true; '?\Hm'8
} DGcd|>q
E>&dG:3no
m|!sY[!
} Ab2VF;z :
l1@:&j3h
)[A}h'J)
/* s;bqUY?LD
**FileAccess.java Q,>AT$|
*//文件访问(定位，写) sviGS&J9h
package NetFox; ~!@a
import java.io.*; p0Vw@R=
\!_ >ul
56fcifXz@
public class FileAccessI implements Serializable{ )9}z^+TH
EM"YjC)F
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 U@H SU%H
RandomAccessFile oSavedFile; m$]?Jq
long nPos; tYnNOK*|
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~#wq sm
public FileAccessI() throws IOException #fQStO
{ =h4XsV)rO
this("",0); dD=dPi#
} xand%XNv
h9No'!'!
l/SbJrM*
public FileAccessI(String sName,long nPos) throws IOException U`xjau+
{ d>2>mT$U
oSavedFile = new RandomAccessFile(sName,"rw"); ]2?t$"G8
this.nPos = nPos; )8yNqnD
oSavedFile.seek(nPos); E#J+.&2
} tip\vS)
ZZ#S\*
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public synchronized int write(byte[] b,int nStart,int nLen) ri6_u;Ch
{ 60Y&)UR
int n = -1; m+zzhv1
try{ kA fkQy(~
oSavedFile.write(b,nStart,nLen); I U/gYFT
n = nLen; rlgp1>89
} b3W@{je
catch(IOException e) YeT[KjX
{ woQYP,
e.printStackTrace (); s~,Ypo?
} 0X.pI1jCO
!M6*A1g5
L'.7V ~b{
return n; aH*)W'N?
} LNtBYdB`pK
u`3J2,.
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} W-2,QVp%
-b8Vz}Y
UO>ADRs}
/* 2/3,%5j_
**SiteInfoBean.java m\RU|Z
*/ b 'jZ4{+W
package NetFox; *MglX<
g?qm >X
^fa+3`>
public class SiteInfoBean { wknX\,`Q
L TzD\C'
0"#'Z>"
private String sSiteURL; //Site's URL ( $A0b
private String sFilePath; //Saved File's Path R5(<:]
private String sFileName; //Saved File's Name Kf/1;:^
private int nSplitter; //Count of Splited Downloading File /I(IT=kp
cia'h_w
D6fry\
public SiteInfoBean() Bvb.N$G
{//nSplitter的缺省值为5 g1UP/hNJ\8
//default value of nSplitter is 5 jvv3;lWDL.
this("","","",5); }rRf4te
} ..'k+0u^
qbrY5;U
ya.!zGH
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )RG@D\t,
{ FxeDjAP
sSiteURL= sURL; ~gg(i"V
sFilePath = sPath; =:Ahg 9
sFileName = sName; l+`f\},
this.nSplitter = nSpiltter; Z]OXitt7
D+.< kY.
Y>W$n9d&G2
} [;~:',vHQf
1$mxMXNsJ
S{wR Z|8U
public String getSSiteURL() 5G @
{ nE;^xMOK!
return sSiteURL; jd ]$U_U(
} _sLSl;/t
#y;TSHx/
YD>5zV%!D
public void setSSiteURL(String value) =)QtE|p,77
{ ,6TF]6:
sSiteURL = value; KT'Ebb]
} G4O $gg
YNHQbsZUI,
V}=%/OY?
public String getSFilePath() Q5Yy \M
{ 1V?)T
return sFilePath; _%M+!Ltz
} "MS}@NLUW
3%HF"$Gg
)\K;Ncp[
public void setSFilePath(String value) TgC8EcLr
{ j<,Ho4v}_
sFilePath = value; B"; >zF
} [k<"@[8)
cl\Gh
R{6~7<m.
public String getSFileName() 9c pjO
{ Ebk9[=
return sFileName; 8nV#\J9
} (g(.gN]
}253Q!f
vH[G#A~4
public void setSFileName(String value) Wb)>APL
{ FR57F(31
sFileName = value; m%$GiNs}
} g#W/WKvM
1UHlA8w7Q
yiT)m]E d
public int getNSplitter() 1&7~.S;km
{ /Ko{S_3<I
return nSplitter; }^b7x;O|
} ='rSB.$Ctk
xbTvv>'U
f52*s#4}
public void setNSplitter(int nCount) (Ci{fY6`
{ PQ0l<]Y
nSplitter = nCount; Jm#mC
} JkfVsmc<{h
} b '9L}q2m
@gc|Z]CV
I38j[Xk
/* 31cC*
**Utility.java ezz;NH
*/ tMy<MO)Ei
package NetFox; 7>@g)%",
{e/6iSpT
)NjxKSiU@
public class Utility { <w1#3Mu'
(>)f#t[9J
bdxmJ9a:R
public Utility() 1s"/R
{ th4yuDPuA
RJ63"F $
Fv!KLw@
} @lO(QpdG
_T^+BUw
//线程睡眠 }#bX{?f
public static void sleep(int nSecond) +`(,1L1
{ {K,KIj"
try{ Vi:<W0:
Thread.sleep(nSecond); 6xC$R q
} zZh\e,*
catch(Exception e) OS{j5o
{ USrBi[_ci\
e.printStackTrace (); }i\U,mH0_&
} QRw/d}8l
} J;R1OJs S
y5!fbmf
//日志 Xlp$xp"
public static void log(String sMsg) ;*AKeI2
{ 15)y]N={^
System.err.println(sMsg); nyRQ/.3
} iH;IXv,b3
$TK<~3`
I<}<!.Bc!
public static void log(int sMsg) 6~O9|s^38w
{ m.':5
System.err.println(sMsg); }z|@X KA#
} }iBFo\vU
} o 00(\ -eb
O)EA2`)E
A])+Pe
/* 6$*\%
**TestMethod.java ^:Hx.
*/ yr"BeTrS.
package NetFox; V!XT=Ou?6
#|ILeby
na)-'
public class TestMethod { 1{0 L~
!$1'q~sO
9irT}e
public TestMethod() 9cMQ51k)E
{ ///xx/weblogic60b2_win.exe %7vjYvo>
try{ lBN1OL[N
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); B*c@w~E
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ynQ+yW74Z
SiteFileFetch fileFetch = new SiteFileFetch(bean); Q}qw`L1
fileFetch.start(); O3];1ud
} ("!P_Q#
catch(Exception e){e.printStackTrace ();} E{B8+T:3
{<J(*K*\Jo
&'{?Y;A
} *41 2)zEy
~REP@!\r^
QswbIP/>:'
public static void main(String[] args) $6Az\Iu *
{ ^W)h=49PN
new TestMethod(); 6%Ws>H4@|
} A."]6R<
} |OarE2
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