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)); 'Y"q=@Ei9
} vkR"A\:
for(int i=0;i<nEndPos.length-1;i++) g?@(+\W
{ *4(.=k
nEndPos = nStartPos[i+1]; {h@R\bU
} ruE.0VI@
nEndPos[nEndPos.length-1] = nFileLength; )O7Mfr
} msoE8YK&tg
} uNx3us-
Za01z^
yr;oq(&N
//启动子线程 Z)?"pBv'
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fwl RwH(
for(int i=0;i<nStartPos.length;i++) E|^a7-}|
{ ZGp8$Y>r
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~KX!i 8+X
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }Rt<^oya*
nStartPos,nEndPos,i); s}HTxY;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8o4 vA,
fileSplitterFetch.start(); v.Q)Obyn
} TAGqRYgi
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &_-~kU1K^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >)VrbPRuA
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 2&Efqy8}DZ
nEndPos = " + nFileLength); ?^@;8m
// fileSplitterFetch[nPos.length-1].start(); s'K0C8'U
+"d{P,[3J
I.( 9{
//等待子线程结束 =RQ>q
//int count = 0; K):)bL(B
//是否结束while循环 7tt&/k?Q
boolean breakWhile = false; e1'_]
rP>5OLP
^Nc\D7( l
while(!bStop) xwz2N5
{ &t6L8[#yd
write_nPos(); _ :][{W#
Utility.sleep(500); `#l_`j=r$
breakWhile = true; -EL"Sv?
]*v%(IGK
pWQ?pTh
for(int i=0;i<nStartPos.length;i++) q=6M3OnS>
{ ~w!<J-z)
if(!fileSplitterFetch.bDownOver) Cjwg1?^RZ
{ g4~{#P^i
breakWhile = false; :/1WJG:!
break; Q04N
} g/T`4"p[H
} +i K.+B
if(breakWhile) t(s']r
break; 5$9j&&R
Pu}2%P)p
`[`eg<xj
//count++; b9"Q.*c<Z^
//if(count>4) jI y'mGaG
// siteStop(); Q4Cw{2r
} G2em>W_n
"\e9Y<
*VL-b8'A<
System.err.println("文件下载结束！"); TT29LC@
} %3~jg
catch(Exception e){e.printStackTrace ();} _\u'~wWl
} :@n e29,}
6rR}qV,+{
-1U]@s
//获得文件长度 1 "4AS_Q
public long getFileSize() 2.2 s>?\
{ |qZ4h7wL
int nFileLength = -1; $@DXS~UQA
try{ !$&K~>`
URL url = new URL(siteInfoBean.getSSiteURL()); U?.VY@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n.Ekpq\
httpConnection.setRequestProperty("User-Agent","NetFox"); ,@GI3bl
jagsV'o2
=G*<WcR
int responseCode=httpConnection.getResponseCode(); m}8c.OJ>K`
if(responseCode>=400) ! 5]/2
{ ]Wfnpqc^
processErrorCode(responseCode); hGzj}t W8d
return -2; //-2 represent access is error 0naegy?,
} l$z-'
C !uwD
a N_M
String sHeader; ,Y}HP3
.,feRK>3
&Tl3\T0D
for(int i=1;;i++) ;B!&( 50e
{ [{'` |
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +AXui|mn
//Utility.log(in.readLine()); +jQW6k#
sHeader=httpConnection.getHeaderFieldKey(i); @0+@.&Z
if(sHeader!=null) 3M/kfy
{ k`xPf\^tf
if(sHeader.equals("Content-Length")) Dy0RZF4_
{ i?||R|>;"'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); joYj`K
break; 7)<&,BWc
} NouT~K`'
} 1[mX_ }K
else v-g2k_o|
break; `Y8F}%i[
} q,kdr)-
} yA=#Ji
catch(IOException e){e.printStackTrace ();} rr9N(AoxW
catch(Exception e){e.printStackTrace ();} KN_3]-+B
U H `=
a$"3T
Utility.log(nFileLength); w8$8P
qK,rT*5=
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return nFileLength; 8,=,'gFO
} #sN]6
#8rLB(
>pUR>?t"
//保存下载信息（文件指针位置） CKy' 8I9
private void write_nPos() =`99ez+y
{ FL9Dz4
try{ 2I>X]r.S!1
output = new DataOutputStream(new FileOutputStream(tmpFile)); MBp%TX!
output.writeInt(nStartPos.length); "! m6U#^
for(int i=0;i<nStartPos.length;i++) $CRu?WUS]'
{ 9x23## s
// output.writeLong(nPos); xrf z-"n4
output.writeLong(fileSplitterFetch.nStartPos); S sGb;
output.writeLong(fileSplitterFetch.nEndPos); 6||zfH
} /*i[MB
output.close(); ?s6v>#H%
} u{o3
catch(IOException e){e.printStackTrace ();} &M&*3
catch(Exception e){e.printStackTrace ();} RG0kOw0
} -LhO </l
#;z;8q
ACctyGd
//读取保存的下载信息（文件指针位置） O,x[6P54P
private void read_nPos() e?,n>
{ xG/B$DLn
try{ `zwXfY,%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); kZ>_m&g
int nCount = input.readInt(); X@RS /
nStartPos = new long[nCount]; [+ Kjun_
nEndPos = new long[nCount]; ,K 8R%B
for(int i=0;i<nStartPos.length;i++) 2Jo|]>nl}u
{ kNR -eG
nStartPos = input.readLong(); Qzt'ZK
nEndPos = input.readLong(); ~}pc&jz>q
} _Dr9 w&;<
input.close(); _(l?gj
} L7;8:^ v
catch(IOException e){e.printStackTrace ();} qILb>#
catch(Exception e){e.printStackTrace ();} C3)*Mn3%P
} N:x--,2
[MhKR }a
w;W# 'pE
private void processErrorCode(int nErrorCode) ]l>LU2 sx
{ k<Qhw)M8
System.err.println("Error Code : " + nErrorCode); {bHUZen
} !K*(# [
,sI<AFI
x{4{.s%+:
//停止文件下载 Bs)'Gk`1
public void siteStop() 0Un?[O
{ oq${}n<
bStop = true; 3>M%?d
for(int i=0;i<nStartPos.length;i++) 4PjC[A*
fileSplitterFetch.splitterStop(); lonV_Xx
:e1kpQ
V^Y'!w\LGI
} ,.9k)\/V
} BX\/Am11
//负责部分文件的抓取 s|IY t^
**FileSplitterFetch.java 6~c#G{kc
*/ 5C0![$W>
package NetFox; iR?}^|]
6S`0<Z;;/
cX7 O*5C
import java.io.*; ]-8WM5\qJM
import java.net.*; )Zf1%h~0r
I+=+ ,iXhB
TZ&X0x8
public class FileSplitterFetch extends Thread { CRBj>
TyDh\f!w
3xg9D.A
String sURL; //File URL qv& Bai[
long nStartPos; //File Snippet Start Position Q2/65$nW
long nEndPos; //File Snippet End Position /sfJ:KP0
int nThreadID; //Thread's ID $Nd,6w*`
boolean bDownOver = false; //Downing is over sSd/\Ap
boolean bStop = false; //Stop identical w4(L@1
FileAccessI fileAccessI = null; //File Access interface nr2 Q[9~
_Jy7` 4B.
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException N=AHS
{ Kv<f<>|L
this.sURL = sURL; pO_IUkt
this.nStartPos = nStart; }}"pQ!Z
this.nEndPos = nEnd; GLgf%A`5/_
nThreadID = id; G4uG"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |lt]9>|
} ,AmwsXN"F
)/?H]o$NU
d]poUN~x
public void run() h5SJVa
{ dgL>7X=7
while(nStartPos < nEndPos && !bStop) D/?Ec\t
{ NMe{1RM
+$|fUn{
W:,Wex^9n
try{ K>dB{w#gS
URL url = new URL(sURL); om`T/@_,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N0H=;CIQ
httpConnection.setRequestProperty("User-Agent","NetFox"); V"m S$MN
String sProperty = "bytes="+nStartPos+"-"; ^|H={pd'c0
httpConnection.setRequestProperty("RANGE",sProperty); #l ZK_N|1x
Utility.log(sProperty); w9{C"K?u=
fqhL"Ah
+x(#e'6p
InputStream input = httpConnection.getInputStream(); R*:>h8
//logResponseHead(httpConnection); V:$+$"|
RN[I%^$"
=e4 r=I
byte[] b = new byte[1024]; |~r-VV(=
int nRead; AH|gI2
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) s'h;a5Q1'Q
{ =hkYQq`Q
nStartPos += fileAccessI.write(b,0,nRead); } vmRm*8z
//if(nThreadID == 1) |RFBhB/u
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;eN ^'/4A
} &W,jR|B
&'SD1m1P
K#YQB3rX
Utility.log("Thread " + nThreadID + " is over!"); PVsKI<
bDownOver = true; #,%7tXOLR
//nPos = fileAccessI.write (b,0,nRead); R|C2O[r}
} s{-gsSmE
catch(Exception e){e.printStackTrace ();} MF8-q'upyT
} e"ehH#i
} =5q<_as
d=/0A\O
J0?kEr
//打印回应的头信息 X*QS/\
public void logResponseHead(HttpURLConnection con) P(hGkY=(
{ X_]rtG
for(int i=1;;i++) BH">#&j[
{ &3BoK/y3
String header=con.getHeaderFieldKey(i); |'q%9#
if(header!=null) >#w;67he2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ZEAUoC1E1
Utility.log(header+" : "+con.getHeaderField(header)); SVZocTt
else v1TFzcHl<
break; Ho>Np&
} xWxc1tT`
} 93>4n\
Qc; kj
x@t?7 o\&
public void splitterStop() z3Q&O$5\
{ 2yZr!Rb~*
bStop = true; "f,{d}u
} "2l`XH
@1MnJP
)S caT1I
} p+;& Gg54
%{@Q7
98>GHl'lM
/* zaqX};b
**FileAccess.java xG9Sk
*//文件访问(定位，写) 6qWUo3
package NetFox; wI$a1H
import java.io.*; {FNkPX
0NXH449I=
\84t\jKR
public class FileAccessI implements Serializable{ 9;E=w+
q,vWu(.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;-+q*@sa]
RandomAccessFile oSavedFile; or/gx3
long nPos; zx3gz7>k;
^7-zwl(>?N
CL|/I:%0
public FileAccessI() throws IOException c$O8Rhx
{ Y;"k5+ q
this("",0); X@rA2);6
} *l+#<5x
^"WVE["
0!T`.UMI
public FileAccessI(String sName,long nPos) throws IOException YmziHns`b
{ b:m+I
oSavedFile = new RandomAccessFile(sName,"rw"); [nTI\17iA
this.nPos = nPos; GJ+^t
oSavedFile.seek(nPos); K3T.l#d'L
} 6l#x1o;
8xAV[i
Mo,&h?VOM?
public synchronized int write(byte[] b,int nStart,int nLen) U1[)eD`
{ M:S-%aQ_<y
int n = -1; \N,ox(f?gW
try{ 9)Fx;GxL
oSavedFile.write(b,nStart,nLen); t|aV:x
n = nLen; Nep4J;
} &X=7b@r
catch(IOException e) CXa[%{[n
{ eb62(:=N6
e.printStackTrace (); ?=VvFfv%
} (_T{Z>C/J
A,}M ^$@
o).deP s-
return n; B5b:znW2@
} %6UF%dbYH`
'7Gv_G_
h051Ol\v*
} I;(3)^QH#
at: li
/*K2i5&X
/* #B `?}a=
**SiteInfoBean.java ;_o]$hV|
*/ ekM? '9ez
package NetFox; qt/K$'
"-J5!y*,Y
4&/CES
public class SiteInfoBean { d#k(>+%=Q
#Y'eS'lv4
U!wi;W2
private String sSiteURL; //Site's URL wP!X)p\
private String sFilePath; //Saved File's Path 3/G^V'Yu
private String sFileName; //Saved File's Name bsIG1&n'T
private int nSplitter; //Count of Splited Downloading File p_FM 2K7!
nhV"V`|d
RBX<>*
public SiteInfoBean() .E4*>@M5
{//nSplitter的缺省值为5 E5k)~P`|
//default value of nSplitter is 5 k]b*&.EY1
this("","","",5); TdtV (
} swKkY`g
+vBi7#&
Y G+|r
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Q;M\fBQO}&
{ \Wbmmd}8
sSiteURL= sURL; TT$Ao
sFilePath = sPath; ys[Li.s:
sFileName = sName; }F`|_8L*v)
this.nSplitter = nSpiltter; oMh$:jR$
odRiCiMH
6Rc=!_v^
} Knq9"k
K1& QAXyP
/ f%mYL
public String getSSiteURL() yI0bSu<j-
{ 55[ 4)*
return sSiteURL; t@q'm.:uw<
} +H)'(<
YeH!v, >
7_0p& 3
public void setSSiteURL(String value) |)-kUu
{ j8Z,:op
sSiteURL = value; k+<945kC
} ^^y eC|~N:
fgLjF,Y
\}jMC
public String getSFilePath() _fAgp_)
{ Z8$}Rpo
return sFilePath; n 8cA8<
} %@$UIO,(
0I}e>]:I
'B@`gA
public void setSFilePath(String value) m[hL GD'Fi
{ %!aU{E|@_
sFilePath = value; oA1_W).wJ
} rfXxg^
ys_2?uv
Nw;qJ58@
public String getSFileName() 0|3I^b
{ &|yLTx
return sFileName; 7& M-^Ev
} {#,<)wFV\
}^"6:;,
.;#T<S"
public void setSFileName(String value) q=1 N&#RG
{ uuzV,q
sFileName = value; N& _~y|
} Z6!Up1
B#sCB&(
)6|L]'dsZ
public int getNSplitter() NOb`)qb
{ "oP^2|${
return nSplitter; z;OYPGvkw
} Rr) 5[
+WX/4_STV
}gp@0ri%5
public void setNSplitter(int nCount) B(Sy.n
{ [&x9<f6
nSplitter = nCount; `lhw*{3A
} 8K%N7RL|
} G0FzXtu)q
%mI0*YRma
'yo@5*x7
/* FX:`7c]:9
**Utility.java #]#9Xq
*/ x*7@b8J
package NetFox; Q>niJ'7WF
i'tMpS3
!MbzFs~
public class Utility { [%W'd9`>
86&M Zdv6
KK|w30\f
public Utility() 1wSAwpz
{ NvK9L.K
EF/d7
{X{R]
} z^Hc'oVXj:
0<M-asI?
//线程睡眠 W.wPy@yi
public static void sleep(int nSecond) q0sf\|'<}
{ dFg>uo
try{ tV}!_
Thread.sleep(nSecond); h~dQ5%
} #w$Y1bjn
catch(Exception e) {Jr1K,
{ &L|oqXE0L
e.printStackTrace (); q'3{M]Tk
} -4Qub{Uym
} -V$|t<
jNZ.Fb
//日志 )u?f| D
public static void log(String sMsg) 4pmeu:26
{ =lacfPS
System.err.println(sMsg); U,GSWMI/K
} zzmC[,u}
_,3ljf?WQM
bG;fwgAr
public static void log(int sMsg) Vaxg
{ !-I,Dh-A
System.err.println(sMsg); DE13x*2
} I8#2+$Be+@
} w,|@e_|J
ns[/M~_r
5eAZfe%H
/* UmKE]1Yw4r
**TestMethod.java SmXJQ@jN
*/ 7?lz$.*Avp
package NetFox; Bk8}K=%w
<JPN< Kv
i4D(8;
public class TestMethod { bpu`'Vx
1(' wg!
7UTfafOGX
public TestMethod() 5Ds[?
{ ///xx/weblogic60b2_win.exe [@$ SLl^Y
try{ ]:%DDlRb
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ?G{0{c2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >t+ ENYb
SiteFileFetch fileFetch = new SiteFileFetch(bean); &61U1"&$R
fileFetch.start(); lZzW- %K
} )@]%:m!ER
catch(Exception e){e.printStackTrace ();} m\teE]8x
"O$bq::(]e
G?4@[m
} O]:9va
=4TQ*;V:
$v>q'8d
public static void main(String[] args) M1jT+
{ :s)cTq|3
new TestMethod(); If'q8G3]-
} }:$cK(|
} ?;~!C2Zs
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