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)); |:`?A3^m#
} t[L2'J.5
for(int i=0;i<nEndPos.length-1;i++) C?_t8G./_
{ U"jUMOMZ;
nEndPos = nStartPos[i+1]; W$x K^}
} pO-)x:Wg
nEndPos[nEndPos.length-1] = nFileLength; EBN]>zz
} [346w <
} Dg?Ho2ih
|V*e2w
*,Aa9wa{
//启动子线程 *X"F:7
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1tuator
for(int i=0;i<nStartPos.length;i++) /i7>&ND.r
{ % B7?l
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z.Ve#~\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), h0ZW,2?l
nStartPos,nEndPos,i); .pNq-T
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); HzFt
fileSplitterFetch.start(); kC,DW%Ls
} Mz%d_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }J4BxBuV8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -h.3M0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )aO!cQ{s
nEndPos = " + nFileLength); p]J]<QaZD
// fileSplitterFetch[nPos.length-1].start(); *axza~d
PhI{3B/
Xj(k(>7V
//等待子线程结束 )Uoe~\
//int count = 0; 9h)P8B.>M
//是否结束while循环 ' ]H#0.
boolean breakWhile = false; d<^6hF
_^,[wD
TO;]9`~;Mu
while(!bStop) aNh1e^j
{ $4fjSSB~
write_nPos(); \)s 3]/"7
Utility.sleep(500); p%i .(A
breakWhile = true; |7 W6I$Xl
WA)lk>(+
2oNPR+ -
for(int i=0;i<nStartPos.length;i++) DrYoC7
{ 4<!}4
if(!fileSplitterFetch.bDownOver) d#$i/&gE
{ ,YuWz$aF{
breakWhile = false; gJ}'O4*b
break; [~rk`
} I$sm5oL
} IcNIuv
if(breakWhile) ,4?|}xg
break; A'P}mrY
U#^:f7-$.
qy0_1xT-
//count++; ob()+p.kK
//if(count>4) P+h<{%:*
// siteStop(); P^W$qy|
} $y |6<
g\mrRZ/?
Y3F.hk}O
System.err.println("文件下载结束！"); f0s<Y
} 7G #e~,M5
catch(Exception e){e.printStackTrace ();} (/UMi,Ho
} k?*DBXJv
bJ5z??
/Gu2@m[r
//获得文件长度 "7u"d4h-:(
public long getFileSize() %EhU!K#[
{ C{Xk/Er5<
int nFileLength = -1; 0}3'h#33=
try{ _|V+["IS
URL url = new URL(siteInfoBean.getSSiteURL()); */m~m?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4%.2=
httpConnection.setRequestProperty("User-Agent","NetFox"); Gt*<?
oXOO 10
T;e(Q,!H
int responseCode=httpConnection.getResponseCode(); 6je%LHhL
if(responseCode>=400) ##\ZuJ^-
{ %b'VEd7
processErrorCode(responseCode); 61;5Yo
return -2; //-2 represent access is error JqhVD@1{
} U@ QU8
r}M4()9L
CX2q7azG
String sHeader; ,oVBgCf
\:^n-D*fX
K%#C+`Ij
for(int i=1;;i++) A>,fG9pR
{ ,,-3p#Pbw
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [t\Mu}b
//Utility.log(in.readLine()); p%qL0
sHeader=httpConnection.getHeaderFieldKey(i); @g5]w&o_
if(sHeader!=null) !ef)Ra-W
{ 2PW3S{Dt
if(sHeader.equals("Content-Length")) ^mb*w)-p?
{ 5rSth.&
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); U.9nHo{
break; \O4=mJ
} !f2>6}hE
} f3&//h8
else F?4'>ZW
break; +0042Yi
} eWs^[^c.<
} s8O+&^(U
catch(IOException e){e.printStackTrace ();} /{} ]Hu
catch(Exception e){e.printStackTrace ();} 90I3_[Ii
&BR?;LD
7im;b15j`'
Utility.log(nFileLength); 'vClZGQ1
cjpl_}'L:
d$ 7b
return nFileLength; `215Llzk;
} Sgy~Z^
=l_"M
?':'zT
//保存下载信息（文件指针位置） AYerz
private void write_nPos() mw%_yDZ{
{ $~\qoW<
try{ /!3:K<6@
output = new DataOutputStream(new FileOutputStream(tmpFile)); 7K4%`O
output.writeInt(nStartPos.length); Y5pNKL
for(int i=0;i<nStartPos.length;i++) #bH[UId[
{ sP8B?Tn1W
// output.writeLong(nPos); ,5WDYk-
output.writeLong(fileSplitterFetch.nStartPos); D/>5\da+y
output.writeLong(fileSplitterFetch.nEndPos); );LwWKa
} |U0@(H
output.close(); {S~$\4vC!
} Qgi:q
catch(IOException e){e.printStackTrace ();} } 4^UVdz
catch(Exception e){e.printStackTrace ();} EeJ]> 1
} m#p^'}]!;
exvsf|
Reo0ZU>
//读取保存的下载信息（文件指针位置） 3~'F^=T.Y
private void read_nPos() sP!qv"u
{ aKZD4;
try{ 06 1=pV$CJ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); N<%,3W_-_
int nCount = input.readInt(); } U.B$4Q
nStartPos = new long[nCount]; r8$TT\?~
nEndPos = new long[nCount]; +UtK2<^:o
for(int i=0;i<nStartPos.length;i++) =uTV\)
{ ?i"FdpW
nStartPos = input.readLong(); Ckp=d
nEndPos = input.readLong(); ^DOcw@Z6HC
} \h4y,sl
input.close(); e^TF.D?RS
} .S;/v--F
catch(IOException e){e.printStackTrace ();} ]Re<7_xt
catch(Exception e){e.printStackTrace ();} 8!fwXm
} hpu(MX\
DQ$/0bq
<}%*4mv
private void processErrorCode(int nErrorCode) P8f-&(
{ E%N]t} }[
System.err.println("Error Code : " + nErrorCode); Heu@{t.[!D
} mUxD.;P
2_C.-;!
^8)d8?}
//停止文件下载 (XQG"G%U6W
public void siteStop() ;a"Ukh
{ K"61i:F
bStop = true; 1A`u0Y$g
for(int i=0;i<nStartPos.length;i++) V'B 6C#jT
fileSplitterFetch.splitterStop(); Nnw iH
yI)2:Ca*
K""04Ew*pV
} AF !_!qc;
} eJ'ojc3
//负责部分文件的抓取 D? ($R9t
**FileSplitterFetch.java 9TLP(
*/ o<y7Ut
package NetFox; pH%K4bV)8
'E9jv4E$n
=0Mmxd&o=M
import java.io.*; (DU{o\=
import java.net.*; VQyDd~Za
sx;1V{|g
e=U7w7(s9
public class FileSplitterFetch extends Thread { /dAIg1ra
W$W7U|Z9y+
" 1Bn/Q
String sURL; //File URL s$Mj4_p3l
long nStartPos; //File Snippet Start Position ZHT.+X:_
long nEndPos; //File Snippet End Position uAP|ASH9T
int nThreadID; //Thread's ID `WVQp"m
boolean bDownOver = false; //Downing is over UU_k"D~
boolean bStop = false; //Stop identical XX =A1#H
FileAccessI fileAccessI = null; //File Access interface UX6-{ RP
KM6r}CDHs
C..O_Zn{g
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +Fk.B@KT,
{ wS4zAu
this.sURL = sURL; U;_;_
this.nStartPos = nStart; p8Pvctc
this.nEndPos = nEnd; +XsY*$O
nThreadID = id; KF.?b]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 v^vEaB
} qhogcAvE
(g 8K?Q
h /on
public void run() `O[M#y%*E
{ {2,V3*NF
while(nStartPos < nEndPos && !bStop) E0YXgQa
{ KjLj
F](kU#3"S
:Z<-J`
try{ {pVD`#Tl[
URL url = new URL(sURL); J &c}z4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !=a8^CV
httpConnection.setRequestProperty("User-Agent","NetFox"); T^"d%au
String sProperty = "bytes="+nStartPos+"-"; e|`&K"fnq
httpConnection.setRequestProperty("RANGE",sProperty); 2D "mq~V
Utility.log(sProperty); _r&#Snp
)UWE.oBI
doG&qXw
InputStream input = httpConnection.getInputStream(); Od!j+.OY<
//logResponseHead(httpConnection); l?ofr*U&-x
vsc&$r3!5{
&cZD{Z
byte[] b = new byte[1024]; En1pz\'
int nRead; xD1w#FMlQs
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) x;ujR<
{ sC/T)q2
nStartPos += fileAccessI.write(b,0,nRead); \i{=%[c
//if(nThreadID == 1) BONM:(1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /QTGZb
} __)9JF
" 4s,a
Ix"uk6 h
Utility.log("Thread " + nThreadID + " is over!"); ?!Y2fK=h0
bDownOver = true; Rf7py)
//nPos = fileAccessI.write (b,0,nRead); F`'e/
} ^/c&Ud
catch(Exception e){e.printStackTrace ();} NX$$4<A1
} 2OEOb,`
} 1'M<{h<sP
e%"L79Of6)
/z6NJ2jb
//打印回应的头信息 >pr{)bp G
public void logResponseHead(HttpURLConnection con) A2]N :=
{ y2&G0y
for(int i=1;;i++) ,_p_p^Ar\4
{ 'R= r9_%
String header=con.getHeaderFieldKey(i); b bX2D/
if(header!=null) G.1pg]P!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \#
Utility.log(header+" : "+con.getHeaderField(header)); +\SbrB P
else (m})V0/`
break; #}l}1^$
} ACc.&,!IZ
} #|)GarDG
bNj| GIf
|>Kf_b Y#
public void splitterStop() XswEAz0=
{ &H<-joZ)Z\
bStop = true; h$y1"!N(
} }fUV*U:3
$wAVM/u&
4>gkXfTF
} 5Tkh6s
RR*<txdN
*[k7KG2_U
/* Cj,fP[p#7
**FileAccess.java U5%EQc-"P
*//文件访问(定位，写) 9-I;'
package NetFox; -(@dMY
import java.io.*; {])F%Q_#cD
3T%WfS+
iE0A-;:5
public class FileAccessI implements Serializable{ 32:q'
-%NT)o
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 hT#[[md"
RandomAccessFile oSavedFile; O\-cLI<h2
long nPos; 7?dB&m6W
KzG8K 6wZ
*4dA(N\k"
public FileAccessI() throws IOException \|L@
{ !Yz~HO,u+
this("",0); fYl$$.
} m&EwX ^1-
0,{Dw9W:
g< M\zD
public FileAccessI(String sName,long nPos) throws IOException ]+{Cy\*kR
{ ==l p\
oSavedFile = new RandomAccessFile(sName,"rw"); X)$3sTj
this.nPos = nPos; p9y "0A|
oSavedFile.seek(nPos); h)~KD%
} #db8ur3?
eh&?BP?
/#GX4&z
public synchronized int write(byte[] b,int nStart,int nLen) j]6Z*AxQ
{ &Ru|L.G`
int n = -1; g~S>_~WL
try{ eo24I0`N
oSavedFile.write(b,nStart,nLen); k*\WzBTd
n = nLen; !=_:*U)-'
} =\eM -"r
catch(IOException e) y4tM0h
{ O$V 6QJ
e.printStackTrace (); v[q2OWcL
} ;$wS<zp6
N4}j,{#
k3da*vwE
return n; }5z6b>EI9a
} - /]ro8V$
.9#4qoM'
)O#]Wvr
} 4L85~l
mVcpYyD|k
5wmH3g#0
/* rbHrG<+7zO
**SiteInfoBean.java {OL*E0
*/ 4_ztIrw
package NetFox; s/Fc7V!;
$]<CC`
Mc#uWmc 7
public class SiteInfoBean { lbZ,?wm
dE7 kd=.o
7[rn ,8@
private String sSiteURL; //Site's URL UeIu -[R
private String sFilePath; //Saved File's Path >0k7#q}O
private String sFileName; //Saved File's Name 7hZCh,O
private int nSplitter; //Count of Splited Downloading File bae .?+0[
Z3<>Z\6D
#UG|\}Lp
public SiteInfoBean() ZSuUmCm
{//nSplitter的缺省值为5 QrDzfe[
//default value of nSplitter is 5 Kn SXygT
this("","","",5); QXY-?0RO#
} };o6|e:2E
*]nha1!S
7L|w~l7R~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) pk%I98! Jy
{ Qw!cd-zc
sSiteURL= sURL; ({zt=}r,
sFilePath = sPath; 8xJdK'
sFileName = sName; MCD]n
this.nSplitter = nSpiltter; =;-/( C
`re]Q0IO
0}2Uj>!i
} LyH8T'C~
p%EU,:I6
6a[D]46y,2
public String getSSiteURL() Q^$IlzG7i
{ [yM{A<\L
return sSiteURL; T8h.!Vef
} sesr`,m.,
:~3sW< PR
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public void setSSiteURL(String value) 2+M(!FHfy
{ ck>|p09q'9
sSiteURL = value; 5V!L~#
} TS^(<+'
jz QmYcd
m3C&QdjRp
public String getSFilePath() JryDbGc8
{ kbJ/7
return sFilePath; mq`N&ABO!K
} v%n'_2J =^
M`Jj!
SL" ;\[uI
public void setSFilePath(String value) QMea2q|3$
{ %_;q<@9)
sFilePath = value; \u?z:mV
} ;W]NT4p
Y$uXBTR`y/
{>tgNW>)
public String getSFileName() h@=H7oV7k
{ 1dh_"/
return sFileName; d|k6#f-E
} BoYWx^VHx^
Q%KH^<
!SEHDRp
public void setSFileName(String value) $'btfo4H
{ LbOjKM^-
sFileName = value; &>\E >mJ
} `Jhu&MWg
~z#Faed=a
A^ $9[_
public int getNSplitter() A\ds0dUE
{ !;.i#c_u
return nSplitter; } R!-*Wk
} >DVjO9Kf
u4bPj2N8I
(2(I|O#
public void setNSplitter(int nCount) htk5\^(X
{ 85Zy0l
nSplitter = nCount; ]^$&Ejpe#
} =;!C7VS
} V9z/yNo
ke_Dd?
|B<+Y<)f^
/* 6f,#O8]#5
**Utility.java PeEf=3
*/ VFz(U)._
package NetFox; NlXHOUw)u
<^6|ZgR
zRN_`U
public class Utility { li;Np5P
+RQlMAB
vS%o>"P
public Utility() (.4mX t
{ wG[X*/v
,2q LiE>
9Slx.9f
} Bm2"} =
= zW}vm }
//线程睡眠 Q+'mBi}
public static void sleep(int nSecond) +!Q<gWb
{ ]u 4
try{ KZUB{Y^)
Thread.sleep(nSecond); fw kX-ON
} "f/lm 2<
catch(Exception e) U1G"T(;s:
{ \M(0@#-$C
e.printStackTrace (); (Em^qN
} uq~$HXdc
} Cp=DdmR
>Pj ?IE6
//日志 ?ORG<11a
public static void log(String sMsg) dPgN*Bdv
{ }/q]:3M|
System.err.println(sMsg); ~c~N _b
} *>,8+S33r{
TbbtD"b?
Cfqgu;m
public static void log(int sMsg) XcB!9AIO
{ PB00\&6H
System.err.println(sMsg); z}&w7O#
} :5IbOpVM
} IoWh&(+KdH
b!Pz~faXD
T#%r\f,l0
/* |n3fAN
**TestMethod.java {^zieP!
*/ H"lq!C`
package NetFox; xR `4<
$\?BAkx
3*C9;Q}
public class TestMethod { dlkxA^
r(-`b8ZE
|2w,Np-
public TestMethod() 7.7P>U
{ ///xx/weblogic60b2_win.exe " UaUaSg#
try{ l?GN& u
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); w:%3]2c
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 'k[d&sR
SiteFileFetch fileFetch = new SiteFileFetch(bean); OhMnG@@
fileFetch.start(); &U/7D!^X
} :4RD.l
catch(Exception e){e.printStackTrace ();} uj#bK 7
yop,%Fe
tDn{;ED<
} ~5LlIpf36|
GBnf]A,^@
Xm,w.|dx
public static void main(String[] args) iV<4#aBg
{ &L6xagR7M
new TestMethod(); eT8(O36%
} ~nO]R
} %6Wv-:LY
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