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)); +\MGlsMK@.
} ^+9i~PjL
for(int i=0;i<nEndPos.length-1;i++) 8' +I8J0l
{ AXpyia7nU
nEndPos = nStartPos[i+1]; P? LpI`f
} g<MCvC@
nEndPos[nEndPos.length-1] = nFileLength; 4% 2MY\
} ~"WN4
} k)S'@>n{u
}zHG]k,j
{OW.^UIq^
//启动子线程 @86I|cY
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; H`8}w{ft&
for(int i=0;i<nStartPos.length;i++) rh6m
{ Ert` ]s~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s C?-L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \v([,tiW%
nStartPos,nEndPos,i); `HsI)RmX
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); o,=dm@j
fileSplitterFetch.start(); I>spJ5ls
} )dI `yf
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e}W|wJ):j@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); MrpT5|t
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 76EMS?e
nEndPos = " + nFileLength); x5W. 3*
// fileSplitterFetch[nPos.length-1].start(); !a9/8U_>XF
>66v+
>/DlxYG?
//等待子线程结束 ykG^(.E
//int count = 0; YRJw,xl
//是否结束while循环 b`DPf@p^kc
boolean breakWhile = false; x=VLRh%Gvl
R8fB 8 )
LT)G"U~
while(!bStop) 9K_p4 mq
{ Xh"8uJD
write_nPos(); EB[B0e7}
Utility.sleep(500); 1WLaJ%Fv
breakWhile = true; :%"$8o*0W
psE&Rx3)
!"N-To-c
for(int i=0;i<nStartPos.length;i++) VAZ6;3@cd
{ k>72W/L^
if(!fileSplitterFetch.bDownOver) SFa~j)9'n
{ kV+O|9
breakWhile = false; ,$;pLjo6
break; :HDU\|{^
} 2<Q3-|/i
} >^%TY^7n
if(breakWhile) i@STo7=
break; %PxJnMb?
@wOX</_g
5j-?Uf
//count++; bupDnTF
//if(count>4) MbjMO"}
// siteStop(); i?CXDuL
} ^`oyf{w@
.wz.Jr`{
nn6&`$(Q~
System.err.println("文件下载结束！"); Cw&U*H
} 0?8{q{ o+
catch(Exception e){e.printStackTrace ();} >TZyax<:
} =aE!y5
{/SLDyf%Z
8K0@*0
//获得文件长度 5$L=l
public long getFileSize() cSs??i D"q
{ hQ}B?'>
int nFileLength = -1; A>W8^|l6+-
try{ p1(<F_Kta
URL url = new URL(siteInfoBean.getSSiteURL()); :I^I=A%Pe(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B]|"ePj-
httpConnection.setRequestProperty("User-Agent","NetFox"); UBvea(z-#
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P|4qbm4%O,
int responseCode=httpConnection.getResponseCode(); khtYn.eaL
if(responseCode>=400) \t\ZyPxn
{ uGH>|V9'c
processErrorCode(responseCode); %,[p[`NRYR
return -2; //-2 represent access is error H8'_.2vwX
} D\i8WU
~V<imF
V50FX}i
String sHeader; e|jmOYWG
Z 361ko}
{%Q&CQG_
for(int i=1;;i++) "]0sR
{ BX=YS)
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ^+zhzfJ
//Utility.log(in.readLine()); 6+Wkcrh
sHeader=httpConnection.getHeaderFieldKey(i); ]Sgc42hk
if(sHeader!=null) ;;g'C*_
{ j^'op|l
if(sHeader.equals("Content-Length")) f|X./J4Bl
{ ?oO<PR}y
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); n; fUwon
break; sX$EdIq
} fd} Ul
} N++jI(
else P(#by{s
break; `cBV+00YS
} Q]d3a+dK
} J}UG{RttI
catch(IOException e){e.printStackTrace ();} ,/>hWAx
catch(Exception e){e.printStackTrace ();} {(,[
k9pOY]_Y
l.Qv9Ll|b
Utility.log(nFileLength); %d/Pc4gfc
w0iv\yIRQ
HKZD*E((
return nFileLength; 0kdPr:B Q0
} N?mTAF'M
KixS)sG
r|>a;nY
//保存下载信息（文件指针位置） 2po>%Cp
private void write_nPos() 1^4z/<ZWm
{ nR1QS_@{L
try{ ``p()^zT
output = new DataOutputStream(new FileOutputStream(tmpFile)); -$js5Gx1
output.writeInt(nStartPos.length); 0+P<1ui
for(int i=0;i<nStartPos.length;i++) 9OnH3
{ %8a886;2
// output.writeLong(nPos); ~@wM[}ThP$
output.writeLong(fileSplitterFetch.nStartPos); g:sn/Zug]
output.writeLong(fileSplitterFetch.nEndPos); O8drR4Pt
} SuU_psF
output.close(); `pzXh0}|
} rL/e
catch(IOException e){e.printStackTrace ();} 8I`t`C/4
catch(Exception e){e.printStackTrace ();} |3A/Og
} a*Oc:$
xF4>D!T%8
,>rr|O
//读取保存的下载信息（文件指针位置） Rr|&~%#z
private void read_nPos() <s7OY`(8
{ wtY*{m2
try{ D+ )R_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); = UT^5cl(
int nCount = input.readInt(); (ugB3o
nStartPos = new long[nCount]; 4G4[IAu_
nEndPos = new long[nCount]; :7w^2/ZGo
for(int i=0;i<nStartPos.length;i++) }(/")i4h
{ " tUS>c/
nStartPos = input.readLong(); 23AMrDF=N
nEndPos = input.readLong(); dMnJ)R
} ?Q]{P]
input.close(); Z`=[hu
} ,r-l^I3<
catch(IOException e){e.printStackTrace ();} $\ 0d9^)&
catch(Exception e){e.printStackTrace ();} UtebSQ+h\
} 1j7sJ" *
DKG%z~R*
?{OB+f}Mo
private void processErrorCode(int nErrorCode) ;QA`2$Ow
{ .%pbKi `
System.err.println("Error Code : " + nErrorCode); d }"Dp
} QKAo}1Pq
Xo{|m[,
Gs% cod
//停止文件下载 q@}eYQ=P|e
public void siteStop() >+ZG{'!j
{ JToc("V
bStop = true; ;gC.fpu
for(int i=0;i<nStartPos.length;i++) #=G[~m\
fileSplitterFetch.splitterStop(); q-g3!
+x3T^G
Sj$XRkbj:
} %ifq4'?Z
} '<A:`V9M}v
//负责部分文件的抓取 FOFZ/q
**FileSplitterFetch.java /NH9$u.g
*/ $&@L[[xl
package NetFox; 19u'{/Y"
4|9c+^%^
.%D9leiRe
import java.io.*; B~o;,}
import java.net.*; e*7nq~ B5
lAxbF
0 s-IW
public class FileSplitterFetch extends Thread { r pv`%
kXmnLxhS/
hf/6VlZ
String sURL; //File URL ~qG`~/7
long nStartPos; //File Snippet Start Position uK:?6>H
long nEndPos; //File Snippet End Position F3aOKV^
int nThreadID; //Thread's ID a5v}w7vL
boolean bDownOver = false; //Downing is over hpxqL%r
boolean bStop = false; //Stop identical aP%2CP~_P
FileAccessI fileAccessI = null; //File Access interface H WOl79-
]pZxbs&Vb
^=H. .pr
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException SxHj3,`#C
{ ~i4h.ZLj
this.sURL = sURL; _k0X)N+li
this.nStartPos = nStart; q"|,HpQ
this.nEndPos = nEnd; \a|FhhI
nThreadID = id; h@5mVTb}i
fileAccessI = new FileAccessI(sName,nStartPos);//定位 BrdHTk= Vy
} y&HfF~
f__r" N
dPdodjSu,!
public void run() GWNLET
{ { *"I4
while(nStartPos < nEndPos && !bStop) jIq@@8@o
{ Rn(vG-xQ
`h>a2
Q -!,yCu
try{ X*'tJN$
URL url = new URL(sURL); HAHv^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Oie0cz:>:
httpConnection.setRequestProperty("User-Agent","NetFox"); Mpfdl65
String sProperty = "bytes="+nStartPos+"-"; T ~9)0A"]
httpConnection.setRequestProperty("RANGE",sProperty); S1iF1X(+?X
Utility.log(sProperty); pZS0;T]W,
eY)JuJ?
03WLVP@
InputStream input = httpConnection.getInputStream(); woctnT%"Q/
//logResponseHead(httpConnection); nN=o/zd
-R^OYgF
u~|D;e
byte[] b = new byte[1024]; ?R 4sH
int nRead; =*VKp{5=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) p[Pa(a,B7
{ N3D{t\hg
nStartPos += fileAccessI.write(b,0,nRead); )jM' x&Vg
//if(nThreadID == 1) X=i^[?C
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e/pZLj]M
} tevB2'3^
PdUlwT?8C
:x36^{7
Utility.log("Thread " + nThreadID + " is over!"); OJ (ho&((
bDownOver = true; Ow0-}Im~
//nPos = fileAccessI.write (b,0,nRead); p;[">["
} xWwQm'I2}
catch(Exception e){e.printStackTrace ();} Hm>M}MF3
} G:W4<w
} u&q RK>wLa
.?L&k|wX-
.eg?FB'7
//打印回应的头信息 d|^cKLu
public void logResponseHead(HttpURLConnection con) uSeRn@
{ h]wahExYP
for(int i=1;;i++) 5pF4{Jd1
{ ze+_iQ5
String header=con.getHeaderFieldKey(i); 6qW/Td|g
if(header!=null) q5jLK)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0y>]68D
Utility.log(header+" : "+con.getHeaderField(header)); YVzcV`4w(
else 1o&]=(
break; [0M2`x4`
} k<1BE^[V
} c-|~ABtEpX
&d"c6il[
AqPE.mf
public void splitterStop() zh5$$*\
{ C$9+p@G6
bStop = true; ,QDS_u$xi&
} r-27AJu
LaI(
koiQJdK
} gk"0r\Eq
L*;XjacI]
4 1w*<{Lk
/* e(;1XqLM
**FileAccess.java z:RclDm
*//文件访问(定位，写) t<_Jx<{2
package NetFox; _R&}CP
import java.io.*; !ke_?+8sY
l>l)m-;O
>C6wm^bl
public class FileAccessI implements Serializable{ 0FA N9u2
$D`~X`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 G#V}9l8Q
RandomAccessFile oSavedFile; -JL
long nPos; \,:3bY_d
^%)H;
Y)?dq(
public FileAccessI() throws IOException "`b"PQ<x
{ n5nV461U
this("",0); @,Je*5$o"
} #41fRmzC
kOv2E]
[;bZQ6JR
public FileAccessI(String sName,long nPos) throws IOException ( K5w0
{ I\NiA>c
oSavedFile = new RandomAccessFile(sName,"rw"); Q.5C$I
this.nPos = nPos; h'{}eYb+
oSavedFile.seek(nPos); +&LzLF.bK
} Va^AEuzF
Sq9I]A
\/rK0|2A
public synchronized int write(byte[] b,int nStart,int nLen) Gp=X1 F
{ B;SN}I
int n = -1; ;B%NFvG
try{ ztSP4lW
oSavedFile.write(b,nStart,nLen); )Fc`rY
n = nLen; ]Lc:M'V#
} P4"Pb\o*
catch(IOException e) B7:8%r/
{ *gu4%
e.printStackTrace (); |aH;@V
} j@4 yRl ^
]Y#$!fIx
Ri$wt.b
return n; Qo*,2B9R L
} JCjQR`)
]+1?T)<!
6S-1Wc4
} X#l]%IrW!
b9M.p*!
Q'f!392|
/* 1WGcv O)<
**SiteInfoBean.java V=<OV]0
*/ Pn)^mt
package NetFox; ^;J@]&[ ~
A;e[-5@
zCrDbGvqF`
public class SiteInfoBean { @@L@r6
(p1y/"Xh
ahagt9[,:F
private String sSiteURL; //Site's URL (!h%) _?.l
private String sFilePath; //Saved File's Path sOc<'):TK
private String sFileName; //Saved File's Name 7U#`^Q}
private int nSplitter; //Count of Splited Downloading File f_`gUMf
mZ;W$y SO
OrXx0Hn
public SiteInfoBean() 7%p[n;-o&
{//nSplitter的缺省值为5 i ! wzID
//default value of nSplitter is 5 y'(bp=Nq
this("","","",5); tw.2h'D
} >QwZt
1:-^*
__U;fH{c
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) F$kLft[:
{ TGnyN'P|
sSiteURL= sURL; #q{i<E 07
sFilePath = sPath; Dp:u!tdbeg
sFileName = sName; =}S*]Me5
this.nSplitter = nSpiltter; VKtrSY}6T
8'=8!V
>n,RBl
} 5#~ARk*?a
SB#YV
wAHW@q9CK
public String getSSiteURL() .r9-^01mG
{ 28l",j)S
return sSiteURL; ],ow@}
} ,BM6s,\
9*!C|gC9Ia
<v<TsEI
public void setSSiteURL(String value) nQ\ +Za==
{ q7}$F]UM"
sSiteURL = value; "hRw_<
} vkmTd4g
@kR/=EfS
V1R=`
public String getSFilePath() .e2qa
{ ien >Ou
return sFilePath; @:$zReS2
} |CME:;{T
lf3:Z5*&>
#4h_(Y
public void setSFilePath(String value) l6b3i v,
{ vt`hY4
sFilePath = value; -#]?3*NO
} jEBZ"Jvb
F^kH"u[
1gp3A
public String getSFileName() C3fSSa%b
{ ;I'pC?!y
return sFileName; jKV,i?
} 7&G[mOx0
bK `'zi
]a|3"DP5
public void setSFileName(String value) /ZAS%_as
{ -Z&6PT7
sFileName = value; #84pRU~
} D$k40Mz
~ei\~;n\@
^6v ob
public int getNSplitter() ^ri?eKy.-g
{ )i&9)_ro
return nSplitter; t?^C9(;6
} sMAc+9G9k
htbN7B(
dbGW`_zQ4
public void setNSplitter(int nCount) }?B=R#5
{ \nV|Y=5
nSplitter = nCount; T2# W=P
} %-@`|
} Wt+aW
PezUG{q(
>b;fhdd:4
/* E^S[8=
**Utility.java jnFCtCB
*/ {N+N4*
package NetFox; Vm]ltiTVk
P>%\pCJ])
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public class Utility { -A}*Aa'\
8XwAKN:f
uV<I!jyI
public Utility() 2U,O e9
{ gkS#=bv9e@
| ]`gps
U6qv8*~
} uAT01ZEm
,)A^3Q*
//线程睡眠 jh.W$.Oq
public static void sleep(int nSecond) [X:mmM0gd
{ 07-S%L7Z
try{ hd1H
Thread.sleep(nSecond); VAf~,T]Ww
} '01H8er
catch(Exception e) |i-Qfpn
{ xKKL4ws
e.printStackTrace (); 2A@9jl s
} ~1YL
} 9&5\L
06 gE;iT
//日志 5,>1rd<B
public static void log(String sMsg) 'Omi3LXfDT
{ ^\ &:'$f+8
System.err.println(sMsg); ]H7_bix
} j.4oYxK!s/
cA ;'~[
W?{:HV
public static void log(int sMsg) }AG$E}~/
{ Lys4l$J]
System.err.println(sMsg); =flgKRKk.r
} ~,yHE3B\G
} jzc/Olb
p8y_uNQE
/zn|?Y[
/* PPT"?lt*&
**TestMethod.java )NZ6!3[@
*/ I,Q"<?&
package NetFox; >L/Rf8j&
aR.1&3fE
9"R]"v3BA
public class TestMethod { O!='U!X@P
9}kN9u
BR\%aU$u
public TestMethod() +NPk9jn
{ ///xx/weblogic60b2_win.exe 35Nwx<
try{ (+>~6SE
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); OxX{[|!`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .z+?b8Q\
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?_[xpK()
fileFetch.start(); zLXmjrC
} %JDG aG'
catch(Exception e){e.printStackTrace ();} CFqoD l
-yeQQ4b
S{j|("W"[
} a&)0_i:r
Pgg6(O9}B^
c"t1E-Nsk
public static void main(String[] args) BQ[1,\>
{ ` =dD6r
new TestMethod(); PaV[{CD
} &oiX/UaY
} gs 8w/
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