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)); SQWwxFJ
} EU TTeFp
for(int i=0;i<nEndPos.length-1;i++) [oKc<o7)~"
{ k uU,7<o
nEndPos = nStartPos[i+1]; ,d<wEB?\`
} /!oi`8D
nEndPos[nEndPos.length-1] = nFileLength; N \[Cuh8Fe
} Pe!uk4}w
} d"uR1rTk
CT3wd?)z`
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//启动子线程 T/MbEqAf
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :,y V?E6]
for(int i=0;i<nStartPos.length;i++) q0jzng
{ W@AZ<(RI:
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), G+ Y`65
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :D}xT]
nStartPos,nEndPos,i); V/$qD
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8V`r*:\
fileSplitterFetch.start(); Yq4_ss'nB
} }E[S%W[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), a"EP`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7=u\D
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", R0_%M
nEndPos = " + nFileLength); ;n00kel$
// fileSplitterFetch[nPos.length-1].start(); X8<<;?L
s{x2RDAt
r75,mX
//等待子线程结束 {6~v oVkj
//int count = 0; [IF3,C
//是否结束while循环 ;gTdiwfgZ=
boolean breakWhile = false; <tMiI)0%
sKB])mf]
|L.QIr,jCC
while(!bStop) `Q<hL{AH
{ ? Sj,HLo@U
write_nPos(); BC%t[H} >R
Utility.sleep(500); _OZrH(8
breakWhile = true; ' ]l,
~A}"s-Kq5
.d^8w97
for(int i=0;i<nStartPos.length;i++) &sh %]o8
{ ox{)O/aj
if(!fileSplitterFetch.bDownOver) o>311(:
{ Q*ZqY
breakWhile = false; Z9cch-u~
break; @ T'!;)
} Dh BUMDoB
} K;,n?Q w
if(breakWhile) h<4WY#Y
break; SWY?0Pu
A/lxXy}D
[53rSr
//count++; F +D2 xN@
//if(count>4) `LVItP(GUM
// siteStop(); pi q%b]
} {vx{Hwyv
aDm$^yP
z,87;4-
System.err.println("文件下载结束！"); }N#jA yp!
} j0>S)Q
catch(Exception e){e.printStackTrace ();} I5wf|wB-
} _]E"hr6a
K8XXO"
;}#tm9S;
//获得文件长度 ]t\fw'
public long getFileSize() xqmP/1=NO
{ Xnt`7L<L
int nFileLength = -1; zq80}5%2CT
try{ RvZi%)
URL url = new URL(siteInfoBean.getSSiteURL()); 7h<B:~(K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b&"=W9(V
httpConnection.setRequestProperty("User-Agent","NetFox"); BLgmFE2
>7!4o9)c
B%6>2S=E
int responseCode=httpConnection.getResponseCode(); T-xcd
if(responseCode>=400) pR4{}=g,
{ <,(6*b
processErrorCode(responseCode); X<Rh-1$8F
return -2; //-2 represent access is error 4};iL)
} Y\(Q
q{n~v>wU
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String sHeader; w1KLQd:yq
z2i?7)(?;A
Fx~=mYU
for(int i=1;;i++) cR 4xy26s
{ W(E!:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); f]^(|*6
//Utility.log(in.readLine()); 6k%N\!_TUW
sHeader=httpConnection.getHeaderFieldKey(i); F[ N{7C3
if(sHeader!=null) W @Y$!V<
{ \S[:
if(sHeader.equals("Content-Length")) j/TsHJ=
{ -MbnYs)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?5K.#>{
break; FTI[YR8?Y
} rV<yM$IA
} 2P`hdg
else 36`aG Y
break; |eAl!k
} :J`:Q3@
} l}j5EWe
catch(IOException e){e.printStackTrace ();} oZHsCQ%
catch(Exception e){e.printStackTrace ();} SouPk/-B80
@aN<nd`q)
n7i;^=9mM
Utility.log(nFileLength); .e!dEF)D
3+u11'0=t
x$QOOE]
return nFileLength; ,'v]U@WK
} @QV|<NeH
:/c=."z.
Ytmt+9
//保存下载信息（文件指针位置） o/@.*Rj>Bg
private void write_nPos() 'b]GcAL
{ dms R>Q
try{ ..UmbJJ.u
output = new DataOutputStream(new FileOutputStream(tmpFile)); fLA!oeq{&}
output.writeInt(nStartPos.length); sn '#]yM
for(int i=0;i<nStartPos.length;i++) +v2Fr}
{ }_u1'
// output.writeLong(nPos); &, hhH_W
output.writeLong(fileSplitterFetch.nStartPos); 5&D)W>{d
output.writeLong(fileSplitterFetch.nEndPos); (s4w0z
} %*>=L$A
output.close(); u7ZSs-LuHw
} wo5"f}vd#
catch(IOException e){e.printStackTrace ();} v~[=|_{
catch(Exception e){e.printStackTrace ();} v3x_8n$C9
} dqwAQ-x
|G&<@8O
\\AufAkJ
//读取保存的下载信息（文件指针位置） y2gI]A
private void read_nPos() lO3$V JI
{ fWhwI+
try{ xbnx*4o0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); JaoRkl?F
int nCount = input.readInt(); 5"%r,GMU
nStartPos = new long[nCount]; I7ZY9W(S
nEndPos = new long[nCount]; }`E5I&r4
for(int i=0;i<nStartPos.length;i++) Rx<m+=
{ {Lwgj7|~
nStartPos = input.readLong(); `*mctjSN
nEndPos = input.readLong(); jq yqOhb4
} *kY\,r&!P
input.close(); }dX[u`zQ
} ~McmlJzJG
catch(IOException e){e.printStackTrace ();} 2>p K
catch(Exception e){e.printStackTrace ();} 58\Rl
} bq/m?;
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S;sggeP7,
private void processErrorCode(int nErrorCode) :CH "cbo
{ >&6pBtC_
System.err.println("Error Code : " + nErrorCode); ~UA-GWb
} N3 .!E|
c"Kl@[1\~
DygMavA.
//停止文件下载 Q*&>Ui[&
public void siteStop() e` Z;}& ,
{ .I$Q3%s
bStop = true; )XV|D
for(int i=0;i<nStartPos.length;i++) P+ONQN|
fileSplitterFetch.splitterStop(); j|gQe .,1
_U(b
3TVp oB`
} B38_1X7
} bO]^TRaiJ
//负责部分文件的抓取 #_0OYL`(mE
**FileSplitterFetch.java (JHzwI8+
*/ =># S7=
package NetFox; c ]M!4.
?$i`K|
f4YcZyBGv
import java.io.*; ,~u5SR
import java.net.*; F$<>JEdX
l5_RG,O0A
! 7A _UA8
public class FileSplitterFetch extends Thread { T;K@3]FbX
E/2kX3}
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String sURL; //File URL (jd)sf6Tj[
long nStartPos; //File Snippet Start Position JJ`RF
long nEndPos; //File Snippet End Position J}U);A
int nThreadID; //Thread's ID ;#$ 67G$
boolean bDownOver = false; //Downing is over H&\[iZ|-N
boolean bStop = false; //Stop identical 1Z%^U ?
FileAccessI fileAccessI = null; //File Access interface 6$$4!R-
0NrUB
soh)IfZ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @yiAi:v@
{ H~IR:WOw
this.sURL = sURL; {:BAh5e|
this.nStartPos = nStart; Y'7f"W
this.nEndPos = nEnd; lVF}G[B
nThreadID = id; "#1KO1@G
fileAccessI = new FileAccessI(sName,nStartPos);//定位 e/hA>
} f'&30lF
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tS#=I.ET
public void run() C#{s[l\]
{ nAIV]9RAZ%
while(nStartPos < nEndPos && !bStop) 1bjhEOW
{ "P.H
Z Ear~
gZ vX~
try{ ~Sy/q]4ys*
URL url = new URL(sURL); 5-'jYp/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P`r@<cgb=
httpConnection.setRequestProperty("User-Agent","NetFox"); #tX\m;
String sProperty = "bytes="+nStartPos+"-"; iR}3 [
httpConnection.setRequestProperty("RANGE",sProperty); _`3'D`s
Utility.log(sProperty); ;[@);-9q
q)0?aL
4)MKYhm
InputStream input = httpConnection.getInputStream(); =)_9GO
//logResponseHead(httpConnection); v0uDL7
-OV:y],-
IIrh|>d_7
byte[] b = new byte[1024]; ?pSb,kN}'
int nRead; eaLR-+vEB
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) RhwqAok|lj
{ U8TH}9Q
nStartPos += fileAccessI.write(b,0,nRead); U9^o"vT
//if(nThreadID == 1) BkywYCWZ )
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |dNJx<-
} FvpaU\D
]^aOYtKX
/zxLnT; 5
Utility.log("Thread " + nThreadID + " is over!"); dJyf.VJ
bDownOver = true; X*f#S:kiNU
//nPos = fileAccessI.write (b,0,nRead); 6zv-nMZc
} 6&,n\EXF
catch(Exception e){e.printStackTrace ();} me-Tv7WL
} .Ukejx
} |e{F;8
l Ozi|
zgre&BV0q
//打印回应的头信息 obA}SF
public void logResponseHead(HttpURLConnection con) Cka&b
{ .*N]SbU<8
for(int i=1;;i++) t!}QG"ma
{ #?=?<"*j
String header=con.getHeaderFieldKey(i); yTt,/+I%gJ
if(header!=null) q8&2M
//responseHeaders.put(header,httpConnection.getHeaderField(header)); j"G1D-S:
Utility.log(header+" : "+con.getHeaderField(header)); 2cv!85
else g-G;8x'n
break; \3nu &8d
} ":=\ci]e%
} RNa59b
(41BUX
GD*rTtDWn
public void splitterStop() ]M^k~Xa
{ i/Zv@GF
bStop = true; vbFi#|EU
} ,Sz`$'^c
\tv^],^`
tc-pVw:TV
} t<8vgdD
Oz8"s4Y7
TpnJm%9`)t
/* </xz V<Pi
**FileAccess.java K|n%8hRy
*//文件访问(定位，写) #fB&Hv #s7
package NetFox; U(xN}Y?
import java.io.*; RLy2d'DS
VTS7K2lBvX
y$i^C:N
public class FileAccessI implements Serializable{ 0)<\jo1 F
WY>r9+A?W
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 q,Oj
RandomAccessFile oSavedFile; 7TDt2:;]
long nPos; R'Gka1v
VkFvV><"
FYwMmb ~3
public FileAccessI() throws IOException Tt;h?
{ \xCI8 *W
this("",0); JAt$WW{
} Rs$fNW@P
8|]r>L$Wk
o7:~C]
public FileAccessI(String sName,long nPos) throws IOException RN,5>.w
{ ShP&ss
oSavedFile = new RandomAccessFile(sName,"rw"); X283.?
this.nPos = nPos; &^q!,7.J
oSavedFile.seek(nPos); c:*[HO\
} [ADSGnw
9_=0:GHk
aNt+;M7g`
public synchronized int write(byte[] b,int nStart,int nLen) 4*`AYx(
{ MWGs:tpL4
int n = -1; Z--A:D>
try{ d+caGpaR
oSavedFile.write(b,nStart,nLen); 9\dpJ\
n = nLen; R #f*QXv
} n'?AZ4&z
catch(IOException e) EWb'#+BP
{ k<&zVV'
e.printStackTrace (); XY_hTHJ
} <w,NMu"
dnwTD\),
Etj0k} A
return n; j ."L=
} Ee~<PDzB
biLNR"/E
+6zW(Ql/
} k?bIu
y 4 wV]1
"V=IG{.
/* I ~U1vtgp
**SiteInfoBean.java )7aUDsu>4
*/ *\-$.w)k
package NetFox; CI#6r8u
JJQS7,vG
QLPb5{>KDS
public class SiteInfoBean { iH`Q4
*dAQ{E(rO
*XU2%"Sc
private String sSiteURL; //Site's URL N1',`L5
private String sFilePath; //Saved File's Path X_3*DqY
private String sFileName; //Saved File's Name -n:~m p
private int nSplitter; //Count of Splited Downloading File AT:L&~O.
i?3~Gog
" jBc5*
public SiteInfoBean() u?Uu>9@Z
{//nSplitter的缺省值为5 )X2/_3
//default value of nSplitter is 5 jW8,}Xs
this("","","",5); ?lPn{oB9"
} `MLOf
]Pp}=hcD
p{vGc-zP.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) _Xqa_6+/
{ '5)PYjMnH
sSiteURL= sURL; m{w'&\T
sFilePath = sPath; BNw};.lO
sFileName = sName; f0|wN\
this.nSplitter = nSpiltter; ?~:4O}5Ax
uGc0Lv4i/
1PN!1=F}
} 3|0wD:Dy
`;}w!U
^\f1zg9I
public String getSSiteURL() hNRN`\5Z
{ mXPA1#qo
return sSiteURL; \[J\I
} 5r` x\
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Bjp4:;Bb
public void setSSiteURL(String value) `DFo:w!k
{ 5%jy7)8C
sSiteURL = value; n~Yr`5+Z
} rj ] ~g
$~,J8?)(z
2CF5qn}T
public String getSFilePath() U^;|as
{ )z_5I (?&
return sFilePath; <\'aUfF v
} QPyHos`
dJ9v/k_
Y6[O s1
public void setSFilePath(String value) m S4N%Q
{ /8? u2 q
sFilePath = value; h J H
} LTTMxiq[*
edL sn>\*#
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public String getSFileName() 6pdek3pOCt
{ m##_U9O
return sFileName; _B?Hw[cc
} re xMS
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;U&~tpd
public void setSFileName(String value) B;^1W{%J
{ vNQ|tmn
sFileName = value; .O&[9`"'
} xdgbs-a)
'!"rE1e
2w;Cw~<=d
public int getNSplitter() .Q!pQ"5
{ s>I~%+V.?:
return nSplitter; W) ?s''WE;
} F|&%Z(@a
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+&4@HHU{G
public void setNSplitter(int nCount) &U_T1-UR2
{ mM2DZ^"j(
nSplitter = nCount; EEP&Y?
} Od+nBJ
} jpkKdQX)
jSQM3+`b
GQ0(lS
/* =bOMtQ]
**Utility.java v@,`(\Ca'
*/ 8K9RA<
package NetFox; Ww0dU_
~^J9v+
8I7JsCj
public class Utility { 2<E@f0BVAy
wWVB'MRXB,
tkP& =$
public Utility() [ e#[j{
{ 6t{G{ ]
4xF}rm
cp&1yB
} ge]Z5E(1
tP89gN^PA|
//线程睡眠 }\QXPU{UVd
public static void sleep(int nSecond) -U{!'e8YiN
{ ETm:KbS
try{ ~g}blv0q+B
Thread.sleep(nSecond); lXRB"z
} MM*9Q`cB
catch(Exception e) E <N%
{ T>irW(
e.printStackTrace (); +bk+0k9k5
} 2S//5@~_m
} sWKv>bx
kbSl.V%)
//日志 n]8*yoge
public static void log(String sMsg) {S`Rr/E|%
{ 5R6QZVc
System.err.println(sMsg); 7#j9"*
} ,U~in)\ U
%edTW[C`
L>pSE'}
public static void log(int sMsg) ~i0>[S3'
{ O&Y22mu
System.err.println(sMsg); b_)SMAsO7
} #n+sbx5~7
} Of#"nu
tm.&k6%
p.5 *`, )
/* _6->D[dB
**TestMethod.java ]}pAZd
*/ :BF WX
package NetFox; _TyQC1 d
ZU`HaL$
I7C+XUQkQ
public class TestMethod { ,=2)1I]
dKmPKeJM
Lr Kx
public TestMethod() RN$q,f[#
{ ///xx/weblogic60b2_win.exe MEOfVh
try{ E O"
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); KVHK~Y-G
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1pqYB]*u_
SiteFileFetch fileFetch = new SiteFileFetch(bean); X*a7`aL
fileFetch.start(); $#_^uWN-M
} iZ0.rcQj'o
catch(Exception e){e.printStackTrace ();} KP!7hJhw
nyZ?m
'i;ofJ[.c
} 'cY@Dqg1
I#xhmsF
OkphbAX
public static void main(String[] args) h1#l12k^'
{ U+uIuhz
new TestMethod(); OA7=kH@3c
} :I^4ILQCD
} M#yUdl7d
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