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)); EzNmsbtZ(
} hNx`=D9[7
for(int i=0;i<nEndPos.length-1;i++) d0-}Xl
{ pbqa
nEndPos = nStartPos[i+1]; "Wi`S;
} &}T`[ d_Z
nEndPos[nEndPos.length-1] = nFileLength; )>\Ne~%
} ,?&hqM\
} E}NX+ vYF
CKh-+8j
7%7_i%6wP
//启动子线程 tm]75*?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fiw~"2U
for(int i=0;i<nStartPos.length;i++) Z?nMt
{ z[t$[Qg
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ybS7uo
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), J|xqfY@+
nStartPos,nEndPos,i); a*SJHBB
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qsJA|z&6x
fileSplitterFetch.start(); EiJSLL
} !]kn=7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PI?-gc?[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ' J-(v
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _|A)ueY
nEndPos = " + nFileLength); Z]SCIU @+
// fileSplitterFetch[nPos.length-1].start(); Nm,vE7M
<[~x]-
Hlz4f+#I
//等待子线程结束 +!_^MBkk
//int count = 0; ;U20g:K
//是否结束while循环 Q 5@~0
boolean breakWhile = false; W{-N,?z
f2{4Y)
}WCz*v1Wq
while(!bStop) 2o\\qEYg
{ =_ rn8
write_nPos(); V7lDuiAI
Utility.sleep(500); -q+Fj;El
breakWhile = true; 0A1l"$_|
tkuN$Jl
u8?ceM^r
for(int i=0;i<nStartPos.length;i++) R8],}6,;E}
{ zb;'}l;+
if(!fileSplitterFetch.bDownOver) 4&y_+
{ L\-T[w),z7
breakWhile = false; q>Q|:g&:
break; siD Sm
} .5dZaI)
} @Rx/]wyH
if(breakWhile) K/%aoTO}
break; {qx"/;3V
QGLm4 Wl9
.IKK.G
//count++; " g_\W
//if(count>4) BV!Kiw
// siteStop(); `E|IMUB~
} we} sC,
dUe"qH29s
{Ua5bSbh
System.err.println("文件下载结束！"); {X"X.`p
} 8"<!8Img
catch(Exception e){e.printStackTrace ();} W B!$qie\
} (yXVp2k
N`zHe*=[~
g:2/!tujL
//获得文件长度 mB1)!
public long getFileSize() rBny*!n
{ BR0bf5T/
int nFileLength = -1; u@gYEx}
try{ =vK(-h
URL url = new URL(siteInfoBean.getSSiteURL()); T.(SBP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F8=6!Qj
httpConnection.setRequestProperty("User-Agent","NetFox"); G4RsH/
Ko%rB+d
qlgh$9
int responseCode=httpConnection.getResponseCode(); Uc6U!X
if(responseCode>=400) ~Snw':
{ qy-BZ%3
processErrorCode(responseCode); 2XXEg>CU
return -2; //-2 represent access is error *uv\V@0
} d->b9
UWusSi3+LG
O!j@8~='
String sHeader; p[/n[@<8=
XBr>K>(
z?gJHN<
for(int i=1;;i++) Zv-6H*zM6
{ ]3I_H+hU
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); N9*$'
//Utility.log(in.readLine()); tP:xx2N_
sHeader=httpConnection.getHeaderFieldKey(i); DX!$k[
if(sHeader!=null) 6g.@I!j E
{ ?.Kl/8ml
if(sHeader.equals("Content-Length")) >eEf|tKO
{ FCP5EN
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); X'u`\<&W
break; |BW956fBU
} }YSH8d
} Qy$QOtrv
else PAc~p8S
break; MRC5c:(
} -!}1{
} 1u`Z?S(
catch(IOException e){e.printStackTrace ();} S\X_!|
catch(Exception e){e.printStackTrace ();} $jzk4V
u(~s$ENl
H{}6`;W
Utility.log(nFileLength); ]':C~-RV{
(%r:PcGMEV
AVJF[t,
return nFileLength; #/ 4Wcz<
} -Kc-eU-&q
|/(5GX,X
r;'!qwr
//保存下载信息（文件指针位置） Th8Q~*v
private void write_nPos() L*l( ~t)vF
{ V*TG%V -
try{ b,@:eVQ7
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2`},;i~[
output.writeInt(nStartPos.length); [Dt\E4
for(int i=0;i<nStartPos.length;i++) z7K?rgH
{ "ulaF+
// output.writeLong(nPos); JBYQ7SsAS0
output.writeLong(fileSplitterFetch.nStartPos); dKMuo'H'%
output.writeLong(fileSplitterFetch.nEndPos); @V-ZV
} F-R`'{ ka
output.close(); c49#aNR
} "d#s|_n,d)
catch(IOException e){e.printStackTrace ();} #zQkQvAT9
catch(Exception e){e.printStackTrace ();} rvG qUmSUs
} cK258mY
NMDNls&)k
O]Hg4">f
//读取保存的下载信息（文件指针位置） ?y '.sQ
private void read_nPos() vbFAS:Y:+
{ |'J3"am'
try{ i3GvTg-X
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;'Y?wH[
int nCount = input.readInt(); -@73"w/
nStartPos = new long[nCount]; cn#a/Hx
nEndPos = new long[nCount]; yO($KL+
for(int i=0;i<nStartPos.length;i++) Z5U~g?
{ PY2`RZ/@
nStartPos = input.readLong(); 9w(j2i q
nEndPos = input.readLong(); K1hw'AaQ
} -`;8~wMN
input.close(); _+. t7q^
} u,pm\
catch(IOException e){e.printStackTrace ();} {NFeX'5bP
catch(Exception e){e.printStackTrace ();} y, Z#?O
} =#u2Rx%V
a} /Vu"
jn7}jWA
private void processErrorCode(int nErrorCode) $-y+97
{ 646yeQ1
System.err.println("Error Code : " + nErrorCode); M&K@><6k,k
} ufJFS+?
IQ_0[
Cjh&$aq
//停止文件下载 Q?>#sN,
public void siteStop() wiVQMgi`
{ ?1{`~)"
bStop = true; @U)'UrNr~
for(int i=0;i<nStartPos.length;i++) 6M6QMg^
fileSplitterFetch.splitterStop(); ,'9tR&S$_
a_ P[J8j
! $iR:ji
} Y}Dp{
} DYl^6]
//负责部分文件的抓取 dbLX}>
**FileSplitterFetch.java 3UaP7p+d
*/ j\vK`.z
package NetFox; JTI m`t"d=
. 9 NS
q!,do2T
import java.io.*; D;L :a`Y
import java.net.*; TM}F9!*je
D6vn3*,&
7^; OjO@8
public class FileSplitterFetch extends Thread { d#*5U9\z
N!v@!z9Mu
ArEpH"}@
String sURL; //File URL `8-aHPF-
long nStartPos; //File Snippet Start Position 6?lg 6a/eO
long nEndPos; //File Snippet End Position rNAu@B
int nThreadID; //Thread's ID J'EK5=H
boolean bDownOver = false; //Downing is over h<M7[p=
boolean bStop = false; //Stop identical 98]t"ny [
FileAccessI fileAccessI = null; //File Access interface 0 mQ3P.9
HB}gn2.1&
$7r wara
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `SW " RLS3
{ 2mO#vTX4
this.sURL = sURL; c>R(Fs|6
this.nStartPos = nStart; (w-u"1&
this.nEndPos = nEnd; @r43F$bcqo
nThreadID = id; ~Qsj)9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2%8Y-o?
} 3oKGeB;Ja
[0LqZ<\5
%(Ys-GeGr
public void run() ""+*Gn7^8
{ pd1m/:
while(nStartPos < nEndPos && !bStop) Psa8OJan
{ E oR(/*'
9H}&Ri%
7`/qL "
try{ CJOl|"UyJ
URL url = new URL(sURL); ]aRD6F:L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qWpCe*C
httpConnection.setRequestProperty("User-Agent","NetFox"); &V3oW1*W
String sProperty = "bytes="+nStartPos+"-"; gdK/:%u3
httpConnection.setRequestProperty("RANGE",sProperty); $.1'Ym
Utility.log(sProperty); HH#i.s2
PPPwDsJ
/RC!Yi
InputStream input = httpConnection.getInputStream(); de6dLT>m
//logResponseHead(httpConnection); nnNg^<[k3
t4*A+"~j
%MJ7u}
byte[] b = new byte[1024]; &-:yn&f7
int nRead; l{U3;
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6y_Z'@L
{ [J`G`s!
nStartPos += fileAccessI.write(b,0,nRead); F"H!CJJu&
//if(nThreadID == 1) cQ41NX@I
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Uq.~3V+u
} N]}+F w\5
5ecz'eA%
}tZAU\z
Utility.log("Thread " + nThreadID + " is over!"); N)*e^Nfb
bDownOver = true; +-\9'Q
//nPos = fileAccessI.write (b,0,nRead); P` F'Nf2U
} ;QQ7vo
catch(Exception e){e.printStackTrace ();} bW^QH-t
} 3x0wk9lND
} -C}59G8
_0["J:s9
b=UMoWS
//打印回应的头信息 4.B*B3
public void logResponseHead(HttpURLConnection con) PJ@,01
{ *UoHzaIqz
for(int i=1;;i++) ()#tR^T
{ "3|"rc&F#
String header=con.getHeaderFieldKey(i); !#I/be]
if(header!=null) &n.uNe
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5{0>7c|.
Utility.log(header+" : "+con.getHeaderField(header)); eKz~viM'
else nE0~Y2
break; /7@2Qc2
} 8ysK VF
} eJGos!>*
jgKL88J*\
].P(/~FS9
public void splitterStop() }l?_Cfvu
{ U<Y'.!
bStop = true; W7=_u+0d
} \y`3LhY
YIQ]]q8R!L
z~e~K`S
} /_OZ1jX
;T{/;
/)?P>!#;\
/* K_|~3g
**FileAccess.java P&3/nL$9N
*//文件访问(定位，写) _L'cyH.cn
package NetFox; ;u};&sm
import java.io.*; E9B*K2l^{
#K1BJ#KUt
Y0yO`W4
public class FileAccessI implements Serializable{ \seG2vw$
Rfc&OV
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %Fg8l{H3
RandomAccessFile oSavedFile; ,e FQ}&^A
long nPos; N%rL=zE
FgQ_a/*
fk7Cf"[w
public FileAccessI() throws IOException NZC='3Uz
{ N3yB1_
this("",0); 1|WpKaMoq
} t-m9n*\j1
kad;Wa#h
V"by9p|V`
public FileAccessI(String sName,long nPos) throws IOException hRa(<ZK
{ #f3;}1(
oSavedFile = new RandomAccessFile(sName,"rw"); KCh
this.nPos = nPos; Mev-M2A
oSavedFile.seek(nPos); zt[4_;2Y
} +:]Aqyc\
EPe]-C`
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public synchronized int write(byte[] b,int nStart,int nLen) X'#$e{
{ }\939Y
int n = -1; .)@tXH=}+
try{ n*m"L|:ff
oSavedFile.write(b,nStart,nLen); }K/}(zuy1Y
n = nLen; TjUZv1(L
} fAMD2C
catch(IOException e) ,B~lwF9
{ rbK#a)7
e.printStackTrace (); _:gGD8
} Cj !i)-
$EQT"ZX>%i
[|[sYo
return n; mfngbFa1
} |J<pLz
~1=.?Ho
?z@v3(b[
} %O&m#)|
sUbz)BS#.
:PD`PgQ
/* `\ef0
**SiteInfoBean.java }(+=/$C"#
*/ uZo`IKJ
package NetFox; c{,y{2c]LT
=X`]Ct8Z
/NW>;J}C
public class SiteInfoBean { &,N3uy;Gc
(~G5t(+
Gf H*,1x
private String sSiteURL; //Site's URL ii_|)udz
private String sFilePath; //Saved File's Path :m*!?QGdL
private String sFileName; //Saved File's Name G9i&#)nWr
private int nSplitter; //Count of Splited Downloading File $m:2&lU3
&Mhv XHI
[+%d3+27
public SiteInfoBean() {1Ju}=69
{//nSplitter的缺省值为5 1 ;\]D9i
//default value of nSplitter is 5 X;OsH
this("","","",5); ]g>m?\'n
} <+T\F;
*K+jsVDY
]_ejDN\>{V
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) cuQ7kECV
{ 29a_ZU7e6
sSiteURL= sURL; hJw |@V
sFilePath = sPath; FQk_#BkK
sFileName = sName; Mhb '^\px
this.nSplitter = nSpiltter; H@%7\g,`
vo(g0Au)
pcI&
} M<{5pH(K
!fi &@k
9h:jFhsA9
public String getSSiteURL() Lp:Nw4_
{ nDHHYp
return sSiteURL; H.YIv50E
} 4|> rwQ~t
p^KlH=1n.6
Rwc[:6;fn
public void setSSiteURL(String value) I&TTr7
{ "x#]i aDjf
sSiteURL = value; L_THU4^j
} mL:m;>JJ n
DKy>]Hca
~\IF9!
public String getSFilePath() $ \Q<K@{
{ /h}PEu3y
return sFilePath; I.^X2
} pqyWv;
aBXYri
;cv.f>Cm
public void setSFilePath(String value) zwM"`z
{ T}n N=Q4
sFilePath = value; ^>N8*=y
} 4Qa@`
)XLj[6j0
>Z#uFt0<Pm
public String getSFileName() )-bD2YA{
{ 5h`m]#YEG
return sFileName; NuC-qG#
} rNxrQ
K\RWC4
J+ Jt4
public void setSFileName(String value) AMbKN2h1f
{ DMF?5GX
sFileName = value; J[e}
} $|4cJ#;^L
!oZQ2z~
|-~b$nUe
public int getNSplitter() 0LetsDN7I
{ y;Qy"-)qb
return nSplitter; D:=t*2-Iv
} @v>l[6]>^
3jvx2
r5t;'eCea
public void setNSplitter(int nCount) _*O7l
{ 3p:=xL
nSplitter = nCount; Z5((1J9
} jCU=+b=
} \Dn&"YG7
z%OuI 8"'
R=!kbBK>\
/* Q;4}gUmI$
**Utility.java FoE|Js
*/ xDR9_
package NetFox; 60xa?8<cg
K@B" ]6
<^d!Vzr]
public class Utility { cNe0x2Z$?
h,^BC^VU9-
u3U4UK
public Utility() 30D:ZmlY
{ !n|#|.0m
EJ1Bq>u7
ARPKzF`Wq
} 10mK}HT>4B
}7K@e;YUg
//线程睡眠 \ jECSV|
public static void sleep(int nSecond) ToV6lS"
{ 4w'lu"U
try{ `,+#!)
Thread.sleep(nSecond); Z;#%t.
} "[k1D_PZ
catch(Exception e) w#oGX
{ xpF](>LC(
e.printStackTrace (); .:rmA8U[
} b3}Q#Y\G
} k!T|)\nc+
q(,cYu
//日志 !{;[xXK4M
public static void log(String sMsg) 2z4<N2!M
{ '!p=aF9L
System.err.println(sMsg); grr'd+_e
} aSel* L
aYqm0HCT
:pRF*^eU
public static void log(int sMsg) +#4]o }6G
{ tv0Ha A
System.err.println(sMsg); T=WNBqKo]
} UH[<&v
} uKv&7p@|_)
hi!`9k
%dc3z"u
/* .;9jdGBf
**TestMethod.java *.oKI@
*/ W;4Lkk$
package NetFox; Ejv%,q/T(
cph~4wCS[U
-;$nb~y
public class TestMethod { ;J]25j]]
w!\3ICB
TXjloGv^
public TestMethod() 'TL2%T/)t
{ ///xx/weblogic60b2_win.exe 9e!vA6Fx
try{ -IadHX}]t
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); C6|(ktt
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); D|l,08n"?
SiteFileFetch fileFetch = new SiteFileFetch(bean); r4u z} jl{
fileFetch.start(); X1oGp+&
} Oa! m
catch(Exception e){e.printStackTrace ();} |m)kN2w
K/^ +eoW(
WfZF~$li`
} #;]2=@
.oEbEs
iRNLKi
public static void main(String[] args) 3Hw[s0[$
{ ;FU|7L$H
new TestMethod(); }k7_'p&yk
} YGp)Oy}:
} /;Yy@oc
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