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)); Fl`U{03
} %YR&>j k
for(int i=0;i<nEndPos.length-1;i++) GLf!i1Z
{ r9ulTv}X
nEndPos = nStartPos[i+1]; Dj\nsc@e3
} h.EI(Ev"GN
nEndPos[nEndPos.length-1] = nFileLength; H,(vTthd
} r!Eh}0bL
} ~q ^o|?
A6]:BuP;c
jqaX|)8|$
//启动子线程 m'"r<]pB*4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Skt-5S#
for(int i=0;i<nStartPos.length;i++) wMVUTm
{ $?56 i4
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n4{%M
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +9Tc.3vQ
nStartPos,nEndPos,i); =dGp&9K,fw
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ve d]X!
fileSplitterFetch.start(); <st<oR'
} roQI;gq^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kSz+UMC-7:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Tw-NIT)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^C'S-2nGH
nEndPos = " + nFileLength); KqGb+N-@
// fileSplitterFetch[nPos.length-1].start(); ~[Tcl
DkWp
J+P<zC
//等待子线程结束 tW UI?\
//int count = 0; <U3X4)r
//是否结束while循环 @vl$[Z|
boolean breakWhile = false; !8G)`'
NVMn7H}>
B'yjMY![
while(!bStop) M@.l# [@U
{ Q5ASN"_
write_nPos(); Q4cCg7|0
Utility.sleep(500); :+"4_f0
breakWhile = true; MqZ"Js
e}uK"dl(
@AZNF+ \W$
for(int i=0;i<nStartPos.length;i++) ,iyy2
{ !,`'VQw$
if(!fileSplitterFetch.bDownOver) I/(U0`%
{ uz!8=,DFw
breakWhile = false; ({E,}x
break; d'';0[W)
} }k }=e
} nYx /q
if(breakWhile) o ]*yI[\
break; x {NBhq(4
!/p|~K
k?fz @H8D(
//count++; j#//U2VdN
//if(count>4) TQ(q[:>
// siteStop(); %tVU Rj
} FDl/7P`b(
C'I&<
sx#O3*'>1
System.err.println("文件下载结束！"); 76w[X=Fv
} 5sJ>+Rg
catch(Exception e){e.printStackTrace ();} )h]+cGM
} 7z;2J;u`n
k{+cFG\C&
q9vND[BQ
//获得文件长度 4FaO+Eo,8
public long getFileSize() Z|_V ;*
{ #f#6u2nF\
int nFileLength = -1; x:)H Ii q/
try{ +^BThrB
URL url = new URL(siteInfoBean.getSSiteURL()); 1J!v;Y\\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p(RF
httpConnection.setRequestProperty("User-Agent","NetFox"); B!+c74
9Kd=GL_
y[i}iT/~
int responseCode=httpConnection.getResponseCode(); c[-N A
if(responseCode>=400) D/E5&6
{ AOg'4
processErrorCode(responseCode); 8xlj,}QO\
return -2; //-2 represent access is error p6j-8ggL
} .eN"s'
#mU\8M,
AW r2Bv
String sHeader; |5vJ:'`I
w%\ nXJ
_#K|g#p5
for(int i=1;;i++) }n&nuaj
{ 25OQY.>bE
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +t,b/K(?]
//Utility.log(in.readLine()); 4 ?BQ&d
sHeader=httpConnection.getHeaderFieldKey(i); eX"%b(;s
if(sHeader!=null) e`0C0GaP
{ XNa{_3v
if(sHeader.equals("Content-Length")) q?LOtN? o
{ 1`?o#w
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); j& 7>ph
break; r%;|gIky
} t`6]eRR
} ;}Jv4Z
else {gzQ/|}#z-
break; CG%bZco((
} ,[ 2N3iH
} 7FH-l(W
catch(IOException e){e.printStackTrace ();} =Z.0-C>W
catch(Exception e){e.printStackTrace ();} ?eTZ>o.p/
}C @xl9S"
[7><^?t V
Utility.log(nFileLength); diXWm-ZKL
,It0brF
.M:&Aj)x16
return nFileLength; ZW;Ec+n_K
} Qy9_tvq X
w yxPvI`
|r+ x/,2-
//保存下载信息（文件指针位置） 4]1/{</B|
private void write_nPos() 76T7<.S
{ ~;oXLCL0})
try{ SXsszb:_
output = new DataOutputStream(new FileOutputStream(tmpFile)); _!2lnJ4+5
output.writeInt(nStartPos.length); |4DN2P
for(int i=0;i<nStartPos.length;i++) N@PuC>
{ E#P#{_BR^
// output.writeLong(nPos); w#1BHx
output.writeLong(fileSplitterFetch.nStartPos); }h1BAKg
output.writeLong(fileSplitterFetch.nEndPos); {eU>E/SQ
} p@78Xmu?q
output.close(); ,xU#uyB
} vs8[352
catch(IOException e){e.printStackTrace ();} E0qJ.v
catch(Exception e){e.printStackTrace ();} 3sV$#l P
} =RUy4+0>F
F+Kju2
HxK'u4I
//读取保存的下载信息（文件指针位置） 7s%D(;W_Mo
private void read_nPos() 3z0Bg
{ \2u7>fU!
try{ KF&8l/f
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9(fh+
int nCount = input.readInt(); O$z"`'&j#
nStartPos = new long[nCount]; -)%\$z
nEndPos = new long[nCount]; $/^Y(0
for(int i=0;i<nStartPos.length;i++) 3q4VH q
{ DvhFCA}z
nStartPos = input.readLong(); 1[OY-G
nEndPos = input.readLong(); MVMJl">
} :[l}Bb,
input.close(); $-DW+|p.?^
} zji9\
catch(IOException e){e.printStackTrace ();} eLT3b6'"?
catch(Exception e){e.printStackTrace ();} ty!DMg#
} 6\l F
t_ CMsp
nGGw(6c%>
private void processErrorCode(int nErrorCode) mqeW,89
{ ();Z,A
System.err.println("Error Code : " + nErrorCode); 2L^/\!V#
} >W+,(kAS
e}O&_j-
VXCB.C"
//停止文件下载 53/$8=
public void siteStop() 0qR#o/~I
{ W+u@UJi
bStop = true; @j\;9>I/
for(int i=0;i<nStartPos.length;i++) ;|T|*0vY[
fileSplitterFetch.splitterStop(); Z^]Oic/0Oa
u9:sj
oG22;
} euY+jc%
} K:XXtG
//负责部分文件的抓取 yq, qS0Fo
**FileSplitterFetch.java &T-:`(
*/ <Y /3U
package NetFox; DaH4Br.2
:M;|0w*b
L7- JK3/E
import java.io.*; %D-!<)z
import java.net.*; N]8/l:@
qKXg'1#E)
1grcCL q
public class FileSplitterFetch extends Thread { -DGuaUU
F+c8 O
?b d&Av
String sURL; //File URL /slCK4vFc
long nStartPos; //File Snippet Start Position H1~9f{
long nEndPos; //File Snippet End Position CWZv/>,%
int nThreadID; //Thread's ID Z3zD4-p$_
boolean bDownOver = false; //Downing is over !]"M]tyv\
boolean bStop = false; //Stop identical ZLaht(`+
FileAccessI fileAccessI = null; //File Access interface 6k')12~'
v3~`1MM
T#E,^|WEk
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException M+-odLltw
{ `-s]dq
this.sURL = sURL; c(Xm~ 'jeH
this.nStartPos = nStart; .4 NcaMj
this.nEndPos = nEnd; 1OY 5tq
nThreadID = id; z xgDaT
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &B8x0 yi
} 0I)eYksh
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Cjt].XR@
public void run() j~rW 2(
{ Q&$2F:4f&
while(nStartPos < nEndPos && !bStop) Y}}1]}VIK
{ </9c=GoJ
BDL[C<d(
(eT9N_W
try{ c-~i=C]
URL url = new URL(sURL); &6GW9pl[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9u^za!pE
httpConnection.setRequestProperty("User-Agent","NetFox"); U2Siw
String sProperty = "bytes="+nStartPos+"-"; ZdhA:}~^E
httpConnection.setRequestProperty("RANGE",sProperty); )fuAdG
Utility.log(sProperty); 4,`t9f^:
j0cB#M44
FKtCUq,:
InputStream input = httpConnection.getInputStream(); CW@EQ3y0
//logResponseHead(httpConnection); W)2k>cS
KVC18"|f
4\U"e*
byte[] b = new byte[1024]; 9nd,8Nji
int nRead; N+UBXhh
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 4fL>Ou[YuX
{ \J~@r1
nStartPos += fileAccessI.write(b,0,nRead); OS~Z@'Eg
//if(nThreadID == 1) BMzS3;1_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d^Cv9%X
} 8N<2RT8W
.4z_ohe
^6UE/4x!y
Utility.log("Thread " + nThreadID + " is over!"); fob.?ID-;
bDownOver = true; &)Vuh=
//nPos = fileAccessI.write (b,0,nRead); T~lHm
} _y[B/C,q
catch(Exception e){e.printStackTrace ();} #cl|5jm+m#
} IjPtJwW`A
} Y,KSr|vG
q\s>Oe6$
1N.weey}W
//打印回应的头信息 27JZwlzZ
public void logResponseHead(HttpURLConnection con) i:R_g]
{ i1qmFvksl
for(int i=1;;i++) b5 AP{ #
{ 2ak*aI
String header=con.getHeaderFieldKey(i); =VSUE Pq
if(header!=null) CrGDo9JdvT
//responseHeaders.put(header,httpConnection.getHeaderField(header)); U4NA'1yo
Utility.log(header+" : "+con.getHeaderField(header)); + VhD]!
else N@? z&urQi
break; R"`<ZY6(Ou
} 0$R}_Ok
} Nk\/lK\
I~M@v59C
?DM!=.]
public void splitterStop() AbMf8$$3SH
{ k _Bz@^J
bStop = true; D<4cpH
} .L3D]
k+u L^teyS
(ap,3$hS
} ;:~-=\
l\bgp3.+
c_6~zb?k+m
/* h],l`lT1\
**FileAccess.java }(UU~V
*//文件访问(定位，写) >s%m\"|oh
package NetFox; H1ox>sC
import java.io.*; UDgUbi^v|D
G$iC@,/
{@67'jL
public class FileAccessI implements Serializable{ I|P#|0< 2
;0 9~#Wop
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ftqeiZ 2
RandomAccessFile oSavedFile; D14i]
long nPos; LyT[
pTcN8E&Unz
D7,{p2<2T
public FileAccessI() throws IOException d/I*$UC
{ 4q`e<!MP)q
this("",0); UNescZ
} }C{wGK+o[
7,D6RP(b
>KCnmi
public FileAccessI(String sName,long nPos) throws IOException FJ V!B&
{ pM_oIH'8:
oSavedFile = new RandomAccessFile(sName,"rw"); -* piC(
this.nPos = nPos; {#TZFB
oSavedFile.seek(nPos); X2C&q$8
} } |? W
a.G;s2>
s#C~HK
public synchronized int write(byte[] b,int nStart,int nLen) 05[k@f$n
{ b~EA&dc
int n = -1; mRD'@n
try{ _*dUH5
oSavedFile.write(b,nStart,nLen); gO]jeO
n = nLen; af;~<oa
} 5wy3C
catch(IOException e) MN. $a9m
{ N:e5=;6s
e.printStackTrace (); 5|bc*iqU
} C1SCV^#
$n9Bp'<
S5xum_Dq
return n; OOX[xv!b
} De:| T8&
M@78.lPS
Z'4oE )
} S,2{^X
bZzB\FB~
Y.v. EZ
/* $]S*(K3U~
**SiteInfoBean.java C.q4rr
*/ `l`)Cs;a
package NetFox; J^<}fRw
Ga#5xAI{a
4ROuy+Ms'
public class SiteInfoBean { gKWsmx!["
e?)ic\K
-k"5GUc|
private String sSiteURL; //Site's URL t7qY!S (
private String sFilePath; //Saved File's Path NE2P "mY
private String sFileName; //Saved File's Name DE_<LN
private int nSplitter; //Count of Splited Downloading File kF29~
7c aV-8:
qA5PIEvdq
public SiteInfoBean() 1o%E(*M4I
{//nSplitter的缺省值为5 kB $?A8Olu
//default value of nSplitter is 5 %Y*]eLT>
this("","","",5); ,f?+QV\T.
} E\dJb}"x %
aX{i
B~t[Gy
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Rx%SeM2
{ =E10j.r
sSiteURL= sURL; [$AOu0J
sFilePath = sPath; c&a.<e3mL
sFileName = sName; -TU^*
this.nSplitter = nSpiltter; 97SOa.@
X6<%SJC
2UJjYrm
} `M.\D
0s'H(qE,_
B #zU'G*Y
public String getSSiteURL() 2E*h,Mo
{ hk.Zn.6A'
return sSiteURL; =#|K-X0d=
} T99\R%
}{(J*T
W2W4w
public void setSSiteURL(String value) tEE4"OAy
{ #<EMG|&(
sSiteURL = value; X4{O/G
} qGrUS_~q*
r; pS_PV
]p5]n*0X
public String getSFilePath() t0-)\kXcA
{ NT&skrzW
return sFilePath; N^;rLrm*
} Gbrc!3K2
,3~[cE<4
nOj0"c
public void setSFilePath(String value) asd3J
{ %MH!L2|
sFilePath = value; B9i<="=p
} O|I)HpG;
$2'Q'Mx[gd
! uX0G4
public String getSFileName() |];f?1
{ }{S f*
return sFileName; 3:~ *cU
} bj$VYS"kY
1Q>D^yPI[
Y `ySNC
public void setSFileName(String value) E@%9u#
{ Tw+V$:$$
sFileName = value; tX@G`Mr(
} R7Z7o4jg
"B3&v%b
\~~y1.,U.
public int getNSplitter() sm9/sX!
{ u-%|ZSg
return nSplitter; !Un&OAy.!
} _Z{EO|L
P'Diie
~H~iKl}|7
public void setNSplitter(int nCount) [,86||^
{ dDxb}dx8
nSplitter = nCount; 5g\>x;cc
} :N>n1tHL;A
} ayK?\srw
9_ru*j\
!)-)*T
/* g;mX{p_@
**Utility.java A8oTcX_
*/ o<Y[GW1pg
package NetFox; :HW\awv
PPMAj@B}V
>^N{
public class Utility { &8xwR
3<R8_p
lGZf_X)gA^
public Utility() V(c>1xLlz
{ =%Z5"];
A\:u5(
|zCT~#
} 4157!w'\y
/(jG9RM
//线程睡眠 6i`Y]\X~#
public static void sleep(int nSecond) >Sc/E}3
{ "%E<%g
try{ KbTd`AIL
Thread.sleep(nSecond); unD.t
} M,we9];N
catch(Exception e) Q@0Zh,l
{ 3]wV 1<K
e.printStackTrace (); KJ#SE|
} oGvk,mh"(
} e~P4>3
pgipT#_K
//日志 ?(R!BB
public static void log(String sMsg) A!uO7".E
{ VqL#w<A%
System.err.println(sMsg); "J"RH:$v
} (\M#Ay t)
Mfinh@K,
l?<DY$H 0
public static void log(int sMsg) 'dvi@Jx
{ J|=0 :G
System.err.println(sMsg); v9 *WM3
} L"Dos +
} dKJ-{LV
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!=bGU=^
/* ;}KT 3Q<^
**TestMethod.java [MXyOE
*/ 5hj _YqQ7
package NetFox; ;FnU[Q`M#L
C/#?S=w`4
;6}> Shs
public class TestMethod { 1uco{JX<S
K3xt,g
w:nLm,
public TestMethod() FxdWJ|rN9D
{ ///xx/weblogic60b2_win.exe /1h ${mo~
try{ d.xT8l}sS
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Y. Uca<{.[
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); w`I+4&/h
SiteFileFetch fileFetch = new SiteFileFetch(bean); DI0Wk^m
fileFetch.start(); a&Z;$
} K,5_{pj
catch(Exception e){e.printStackTrace ();} ^I:f4RWo
~A03J:Yc7
/{>_'0
} :j&-Lc
e4LJ3y&z"
p1!-|Sqq
public static void main(String[] args) e:+[}I)
{ !uW;Ea?
new TestMethod(); aJLc&o 8Yg
} ~B\O{5W
} `l?(zy:R
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