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)); [gQ*y~N
} q/<.^X
for(int i=0;i<nEndPos.length-1;i++) hyVuZ\9B
{ f4CwyL6ur
nEndPos = nStartPos[i+1]; 'C!b($Y
} 0=yKE J
nEndPos[nEndPos.length-1] = nFileLength; 3QZw
} $yI!YX&
} ?:~Y%4;
}vPDCUZ
d*7 Tjs{\
//启动子线程 C/tn0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -D`*$rp,
for(int i=0;i<nStartPos.length;i++) )9l5gZX'I
{ VLkK6W.u
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _Z@- q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0ppZ~}&
nStartPos,nEndPos,i); #p6#,PZ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5<Xq7|Jt
fileSplitterFetch.start(); &iId<.SiJ
} CXb)k.L
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), lpj$\WI=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %koHTWT+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `` 6?;Y
nEndPos = " + nFileLength); C$b$)uI;
// fileSplitterFetch[nPos.length-1].start(); VD<W
0".pw; .}
-_4U+Cfmtl
//等待子线程结束 MX xRM~
//int count = 0; xmT(yv,
//是否结束while循环 Ud\Jc:DG
boolean breakWhile = false; WpWnwQY`#
\:'=ccf
U;LbP-{B
while(!bStop) m("! M~1
{ 9=&LMjTQ
write_nPos(); ZBB^?FF
Utility.sleep(500); 7fgA)dU:K
breakWhile = true; +79?}|
OGzth$7A
uy9k^4Cqa
for(int i=0;i<nStartPos.length;i++) }2|>Y[v2j
{ Ir_K83VM
if(!fileSplitterFetch.bDownOver) W]4Gs;
{ 3<AZ,gF1
breakWhile = false; 9pb4!=g*
break; /q ;MihK
} 6dt]$
} ?R&,1~h
if(breakWhile) 1aS[e%9Mg
break; Y\Odj~Mj
2n2{Oy>L
`u3to{
//count++; $,bLK|<hi
//if(count>4) 6OkN(tL&.
// siteStop(); _iO,GT=J-
} =P<gZ-Cm
Wt"fn&R}
:CNHN2 J
System.err.println("文件下载结束！"); :lcZ)6&S
} g PU|Gv5
catch(Exception e){e.printStackTrace ();} $o?Wum
} Z}5;K"T/
zC\ pd#
pE[ul
//获得文件长度 c6:"5};_
public long getFileSize() )F,H(LblH
{ jV;&*4if
int nFileLength = -1; !i&^H,
try{ <iajtq<Z
URL url = new URL(siteInfoBean.getSSiteURL()); ek1YaE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q.`+d[Q2
httpConnection.setRequestProperty("User-Agent","NetFox"); 4=9To|U*
Ix93/FAn
qrsPY d
int responseCode=httpConnection.getResponseCode(); yS_,lS
if(responseCode>=400) cE '`W7&A
{ Y4sf 2w
processErrorCode(responseCode); (f,D$mX
return -2; //-2 represent access is error 0Y,_ DU
} 7?:7}xb-
GU8b_~Gk?
rZ/,^[T
String sHeader; E5w.wx
{0+gPTp
,Drd s"H
for(int i=1;;i++) )cNG)F
{ "2o,XF
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "gADHt=MIR
//Utility.log(in.readLine()); qPK3"fzH
sHeader=httpConnection.getHeaderFieldKey(i); _%Sorr
if(sHeader!=null) *-(J$4RNz
{ n_Px=s!1p@
if(sHeader.equals("Content-Length")) >wS52ng
{ ~+d?d6*c
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ({ads_l
break; XO~xbG7>gZ
} T]l_B2.
} yd2v_
else 3/RmJ`c{
break; W'hE,
} zM%ILv4
} br*L|s\P\9
catch(IOException e){e.printStackTrace ();} )sWdN(E3
catch(Exception e){e.printStackTrace ();} oM/(&"
-yHVydu=
RUC V!L
Utility.log(nFileLength); *lRP ZN
2cY7sE068
TK<~(Dk
return nFileLength; dPwe.:
} <cW$ \P}hV
Va/LMw
T>2)YOx
//保存下载信息（文件指针位置） d?C8rkV'
private void write_nPos() cobq+Iyu
{ +/y 3]}
try{ M)C.bo{p
output = new DataOutputStream(new FileOutputStream(tmpFile)); }2:/&H'
output.writeInt(nStartPos.length); Y O;N9wu3f
for(int i=0;i<nStartPos.length;i++) Sd'!(M^k3
{ dtw1Am#Ci
// output.writeLong(nPos); u0`~ |K
output.writeLong(fileSplitterFetch.nStartPos); P*_!^2
output.writeLong(fileSplitterFetch.nEndPos); Kf2Ob1
} PLf
output.close(); p1 > D
} rC V&&09
catch(IOException e){e.printStackTrace ();} >H?l[*9
catch(Exception e){e.printStackTrace ();} 9=7),`$
} j38>,9u,
XP~bmh,T,
&@u;xc| v
//读取保存的下载信息（文件指针位置） -fFM-gt^t
private void read_nPos() o6,$;-?F_
{ lp3 A B
try{ 7K>FCT
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &;S.1tg
int nCount = input.readInt(); t-*oVX3D
nStartPos = new long[nCount]; c-.t8X,5(~
nEndPos = new long[nCount]; rK)aR
for(int i=0;i<nStartPos.length;i++) 2j&-3W$^
{ h$.y)v
nStartPos = input.readLong(); KSU?Tg&JR
nEndPos = input.readLong(); 6*9hAnH
} % \p:S)R
input.close(); iD+Q\l;%
} b3N>RPsHS
catch(IOException e){e.printStackTrace ();} ig:,:KN
catch(Exception e){e.printStackTrace ();} P -0
} k_?xiOSh
xtMN<4#E
xzTTK+D@
private void processErrorCode(int nErrorCode) ,=whwl "tA
{ fYU/Jn#
System.err.println("Error Code : " + nErrorCode); OBaG'lrZy
} @ de_|*c
&0Yv*,4]
]vj=M-:+
//停止文件下载 F* "
public void siteStop() 6KC.l}Y*
{ a<9gD,]P
bStop = true; Q= IA|rN
for(int i=0;i<nStartPos.length;i++) HTiqErD2_
fileSplitterFetch.splitterStop(); |!:ImX@
tn!z^W
gBfYm
} ZLw7-H6Fh
} f(~xdR))eh
//负责部分文件的抓取 u&Ts'j
**FileSplitterFetch.java ZRN*.
*/ .|`JS?L[
package NetFox; d1VNTB
g]?&qF}
{E`[`Kf
import java.io.*; m?bd6'&FR
import java.net.*; YSERQo
xp-.,^q\w
p.^glz>B
public class FileSplitterFetch extends Thread { ]7" W(
mpfc2>6Il.
'7AlE!7%
String sURL; //File URL KLD)h,]
long nStartPos; //File Snippet Start Position ^*(*tS|M
long nEndPos; //File Snippet End Position A.tONPi
int nThreadID; //Thread's ID j]th6
boolean bDownOver = false; //Downing is over |6/k2d{,(
boolean bStop = false; //Stop identical A8 V7\
FileAccessI fileAccessI = null; //File Access interface O|j(CaF
1H sfCky{
?RL[#d+y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException o}H7;v8H
{ {`5Sh1b
this.sURL = sURL; m`luMt9
this.nStartPos = nStart; 8JxJ>I-9p
this.nEndPos = nEnd; F|p&v7T
nThreadID = id; )N h67P3X"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 EUH&"8 L
} ^_W+
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0gdFXh$!e
public void run() (XW\4msB)I
{ 6d/;GyG
while(nStartPos < nEndPos && !bStop) AuIb>@a
{ iIWz\FM
5|S|S))_Q
Pqiw[+a$
try{ &|>CW:)&1"
URL url = new URL(sURL); .%)FK#s-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;Q"xXT`;:
httpConnection.setRequestProperty("User-Agent","NetFox"); Ay\=&4dv
String sProperty = "bytes="+nStartPos+"-"; eX7dyM
httpConnection.setRequestProperty("RANGE",sProperty); ~/Gx~P]
Utility.log(sProperty); =kvfe" N0e
HE GMwRJG
n,D~ whZx
InputStream input = httpConnection.getInputStream(); y'\BpP
//logResponseHead(httpConnection); wBz?OnD/D
+-tvNX%IJ
.^6;_s>FN
byte[] b = new byte[1024]; a+A^njk
int nRead; +oa\'.~?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,#&\1Vxf
{ KwGk8$ U
nStartPos += fileAccessI.write(b,0,nRead); gB/4ro8
//if(nThreadID == 1) f P'qUN
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7u[U%yd
} cQ(zBf
&)jBr^x#>
4q sIJJ[.
Utility.log("Thread " + nThreadID + " is over!"); x\taG.'zX
bDownOver = true; y+b4sFf
//nPos = fileAccessI.write (b,0,nRead); 9gNQ,c \gT
} <vxj*M;
catch(Exception e){e.printStackTrace ();} 7)&}riQ
} zbQ-l1E
} h^_Sd"l3
~2 L{m[s|
`4^-@}
//打印回应的头信息 TG4?"0`I5
public void logResponseHead(HttpURLConnection con) B#RBR<MFC
{ #OlU|I
for(int i=1;;i++) hx|Cam"
{ reo
String header=con.getHeaderFieldKey(i); b=nQi./f
if(header!=null) =`RogjbP
//responseHeaders.put(header,httpConnection.getHeaderField(header)); g<C_3ap/
Utility.log(header+" : "+con.getHeaderField(header)); {Up@\M
else TZ#(G
break; h'*>\eC6
} _$s ;QI]x
} *sNZ.Y:.
yB][ 3?lv
[:M:6JJ
public void splitterStop() UcaLi&
{ /.PjHTM<
bStop = true; Gk~QgD/Pix
} p4l^b[p
YrlOvXW
`PML4P[
} }dnO7K
I+nKaN+8i
G@s]HJ:
/* j7LuN
**FileAccess.java Td!@i[6%H
*//文件访问(定位，写) kb"g
package NetFox; b{T". @b
import java.io.*; b4TZnO
qg521o$*
vo48\w7[
public class FileAccessI implements Serializable{ 2R}9wDP
-+1_ 1!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7G,{BBB
RandomAccessFile oSavedFile; 1Z9_sd~/6
long nPos; !~X[qT
s?qRy 2
%V r vu5
public FileAccessI() throws IOException k^A17Nf`2
{ 6T3uv,2
this("",0); "J51\8G@@
} ~W?F.
y"N7r1Pf
<*D{uMw
public FileAccessI(String sName,long nPos) throws IOException ryhme\%l;f
{ ;%-f>'KhI7
oSavedFile = new RandomAccessFile(sName,"rw"); rHS;wT
this.nPos = nPos; =E{e|(1+u
oSavedFile.seek(nPos); 6yDc4AX
} pwj?
<P)U Ggd
8GRp1'\Hi
public synchronized int write(byte[] b,int nStart,int nLen) jC<1bf$K
{ syuW>Z8s
int n = -1; 2'R;z<_
try{ F.9SyB$
oSavedFile.write(b,nStart,nLen); M5$YFGGR
n = nLen; %}< e;t-O
} $e(]L(o;
catch(IOException e) jg2UX
{ cvoE4&m!
e.printStackTrace (); +TA'P$j
} \BIa:}9O
+w'"N
!_zp'V]?
return n; U)v['5%
} WCa>~dF>
/g|H?F0
cJ CKxj
} +ZuT\P&kR5
I+qg'mo
:0G_n\
/* XUI9)Ne
**SiteInfoBean.java $-HP5Kj(k-
*/ F0yvV6;
package NetFox; t r)[6o#
5AX AIPn)
{2|[7oNT6
public class SiteInfoBean { z]/;?
j41)X'MgJ
M4%u~Z:4h+
private String sSiteURL; //Site's URL CV9o,rL
private String sFilePath; //Saved File's Path J%8M+!`F
private String sFileName; //Saved File's Name 4CUoXs'
private int nSplitter; //Count of Splited Downloading File 2(SU# /,
(P(=6-0
E5^P*6c(
public SiteInfoBean() O=,[u?
{//nSplitter的缺省值为5 _J|TCm
//default value of nSplitter is 5 [#+yL
this("","","",5); P}YtT3.K
} *u?QO4>
2#<)-Cak
kTC'`xv
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :K:oH}4oh
{ *=sMJY9#jE
sSiteURL= sURL; x,U'!F
sFilePath = sPath; 0_!')+
sFileName = sName; 2sezZeMV
this.nSplitter = nSpiltter; tHhau.!
s} I8:ufT
W0zRV9"P
} ]xx}\k
F&tU^(7<
JEw+5MO@
public String getSSiteURL() 4tQ~Z6Jn;
{ J$aE:g6'
return sSiteURL; SG5GJCkc
} [`F}<L."
S]}hh,A
w^AY= Fc
public void setSSiteURL(String value) $nkvp`A
{ I_/E0qSJI
sSiteURL = value; Yk;-]qi7
} jOkc'
,A$#gLyk<
{7'Evfn)
public String getSFilePath() t2L}
{ ~CtLSyB
return sFilePath; >)Udb//
} 6KvoHo
wjq;9%eXk
Fjs:rZ#{
public void setSFilePath(String value) cuw 7P
{ e9LP!"@EY
sFilePath = value; S'%|40U
} -qbx:Kk(
[NxC7p:Lo
B4D#TlB
public String getSFileName() yt5Sy
{ }Wk^7[Y
return sFileName; 1Fg*--8[r
} A^2n i=b
7J[DD5
.83{NF
public void setSFileName(String value) q&DM*!Jq
{ wV604eO(
sFileName = value; N4[`pXM6
} .jXD0~N8q
Kl Kk?6>
8gHOs#\
public int getNSplitter() 483/ZgzT`
{ @#j?Z7E|
return nSplitter; iL$~d@AEn
} FI(iqSJ6
d3[O!4<T
>=6 j:
public void setNSplitter(int nCount) <Jf[N=
{ |3bCq(ZR\P
nSplitter = nCount; s3/iG37K
} nF)b4`Nd
} f@j)t%mh
_.{I1*6Y2
>1$vG
/* @W1F4HYds
**Utility.java 2Y7u M;8
*/ N|rB~
package NetFox; baO'FyCs9&
9cnLf#
yrF"`/zv6|
public class Utility { SSAf<44e
LmZ"_
Y'{F^VxA/
public Utility() W"v"mjYud
{ z@8W
+_T`tmQ
lz [s
} @2`$ XWD
!U"?vSl
//线程睡眠 <k'%rz
public static void sleep(int nSecond) uxOeD%Z>
{ &)$}Nk
try{ ?;YymD_
Thread.sleep(nSecond); tRCz[M&
} TPF5?
catch(Exception e) @}<b42
{ S]x\Asj;w
e.printStackTrace (); `3e>JIl"0
} \3WQ<t)W
} Wb%t6N?
V{{Xz:
//日志 Bnfp_SM
public static void log(String sMsg) g}OZ!mKd
{ 1!=^mu8
System.err.println(sMsg); 6bwzNY 7
} 6Bf aB:
mUdj2vB$+'
*DcB?8%
public static void log(int sMsg) y,xJ5BI$
{ !de`K |
System.err.println(sMsg); Rn_FYP
} BW x=Q
} 6%B)
):-Ub4A\
*A([1l&]i
/* wj2z?0}o
**TestMethod.java ;i,3KJ[L
*/ /Y`u4G()
package NetFox; '/'dg5bfV
m>9j dsqB
9SQcChG~j
public class TestMethod { 2r"J"C
P^57a?[`
' 4.T1i,
public TestMethod() f 0r?cZ
{ ///xx/weblogic60b2_win.exe AF\gB2^
try{ Fnc MIzp
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); G@+R!IG
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ZZ324UuATX
SiteFileFetch fileFetch = new SiteFileFetch(bean); gZ>) S@
fileFetch.start(); [J8;V|v
} 045_0+r"@
catch(Exception e){e.printStackTrace ();} `LOW)|6r`
sXwa`_{
F#)@ c
} E<[Y KY
fZavZ\qU
y#{v\h Cz
public static void main(String[] args) yi;pn Z
{ \P;2s<6i\
new TestMethod(); jdX*
} )wNcz~ Y
} [?55vYt
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