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)); j4xr1y3^
} ^s~n[
for(int i=0;i<nEndPos.length-1;i++) 6q[!X0u
{ ,."(Gp
nEndPos = nStartPos[i+1]; nl9Cdi]o
} :KP'xf.
nEndPos[nEndPos.length-1] = nFileLength; B=bI'S8\
} 0#fG4D_
} UX'NJ1f
-0o6*?[Z
0 ;_wAk
//启动子线程 {dA ~#fW<
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; BH0#Q5
for(int i=0;i<nStartPos.length;i++) LL[#b2CKa
{ EY&C[=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), tP Efz+1N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), hJo^Wo
nStartPos,nEndPos,i); VUC <0WV
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^GrkIh0nL
fileSplitterFetch.start(); E'^]zW=9
} #O9*$eMw
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k\c &2T]W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); EcU'*
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", -iDEh_pts
nEndPos = " + nFileLength); *Iwk47J ;a
// fileSplitterFetch[nPos.length-1].start(); |] !o*7"4
mOgOHb2
q$?7 ~*M;x
//等待子线程结束 uz#PBV8Q
//int count = 0; q_]
//是否结束while循环 )ehB)X
boolean breakWhile = false; y+";
Qyv'nx0=
!jnqA Z
while(!bStop) [Ql?Y$QB`4
{ B3>Uba*-)}
write_nPos(); \l]pe|0EW
Utility.sleep(500); %g0z)J
breakWhile = true; #x5N{8
mfngbFa1
|J<pLz
for(int i=0;i<nStartPos.length;i++) _(6B.
{ [+'BQ
if(!fileSplitterFetch.bDownOver) wyrI8UY
{ -Y8ks7
breakWhile = false; rO(TG
break; HZDaV&)@
} YQ@dl
} 0^&(u:~
if(breakWhile) RO%tuU,-
break; ;c X^8;F0
[-E{}FL|
<E[HlL
//count++; ^%5~;
//if(count>4) J+@MzkpK
// siteStop(); i.&Kpw9;m
} XSp x''l
O2q=gYX>\
\]U<hub
System.err.println("文件下载结束！"); hC|5e|S
} @L[PW@:SZ
catch(Exception e){e.printStackTrace ();} /lr1hW~Dbk
} :kb1}Wu
8<yV
']ITuP8
//获得文件长度 KUp
public long getFileSize() T/GgF&i3
{ U0h)pdo
int nFileLength = -1; T2:oWjC3$
try{ :dY.D|j*
URL url = new URL(siteInfoBean.getSSiteURL()); f@! fW&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "%oH@ =
httpConnection.setRequestProperty("User-Agent","NetFox"); _K0izKTA.
HPtTv}l
V8sH{R-
int responseCode=httpConnection.getResponseCode(); abROFI5.L
if(responseCode>=400) $u; >hk
{ @V* ju
processErrorCode(responseCode); ~aJW"\{
return -2; //-2 represent access is error YY#s=
} 5u;Rr 1D
!,? <zg
ka5#<J7<p
String sHeader; }uF[Ra
?W[J[cb
j-lSFTo
for(int i=1;;i++) &'5@azU
{ I&TTr7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); JrCf,?L^
//Utility.log(in.readLine()); L_THU4^j
sHeader=httpConnection.getHeaderFieldKey(i); mL:m;>JJ n
if(sHeader!=null) 2^)D .&
{ c*x J=Gz6d
if(sHeader.equals("Content-Length")) KInUe(g<9M
{ ^&+zA,aL,A
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7tpAZ<{
break; qri}=du&F
} Ws-6W!Ib%
} .'t (-eT,
else 2BoFyL*
break; gYTyH.
} ^M`>YOU2+
} jo9J%vo
catch(IOException e){e.printStackTrace ();} `z9)YH
catch(Exception e){e.printStackTrace ();} VHXI@UT*
wGEWr2$
#4P8Rzl$/
Utility.log(nFileLength); V";mWws+?#
K#qoR/:
&`9j)3^J.
return nFileLength; { 1+Cw?1d
} A",eS6
i\t753<Ys
xS=_yO9-
//保存下载信息（文件指针位置） 8weSrm
private void write_nPos() 0JmFQ^g(
{ c3=-Mq9Q
try{ ,>D ja59
output = new DataOutputStream(new FileOutputStream(tmpFile)); _1I K$gb[
output.writeInt(nStartPos.length); @%6)^]m}r
for(int i=0;i<nStartPos.length;i++) cC^W2\
{ r5t;'eCea
// output.writeLong(nPos); _*O7l
output.writeLong(fileSplitterFetch.nStartPos); 3p:=xL
output.writeLong(fileSplitterFetch.nEndPos); X AQGG>
} PT3>E5`Nu
output.close(); =WIE>*3[
} WMW1B}Z3
catch(IOException e){e.printStackTrace ();} J'oDOn.M
catch(Exception e){e.printStackTrace ();} 8';m)Jc
} fv|]= e
&Fw[YGJayz
`TUZZz
//读取保存的下载信息（文件指针位置） 'S =sj}X
private void read_nPos() 1TKEm9j]u
{ hHcJN
try{ P+[QI U
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); TqIAWbb&
int nCount = input.readInt(); "gFxfWIA
nStartPos = new long[nCount]; s(Z(e %
nEndPos = new long[nCount]; YTQ5sFuGM
for(int i=0;i<nStartPos.length;i++) j]rXoV>
{ %1Yz'AiW[
nStartPos = input.readLong(); oFWt(r
nEndPos = input.readLong(); +`ai1-vw
} ZAMeqPt
input.close(); DW#Bfo
} }K2 /&kZ
catch(IOException e){e.printStackTrace ();} !_qskDc-
catch(Exception e){e.printStackTrace ();} b)N[[sOt
} xpF](>LC(
x Sv-;!y
WrNLGkt
private void processErrorCode(int nErrorCode) NwguP
{ UcgG
System.err.println("Error Code : " + nErrorCode); rVY?6OMkd
} IE2CRBfs
1j11|~
N1%p"(
//停止文件下载 f0vJm
public void siteStop() WP}ixcq#
{ 1@xP(XS
bStop = true; Q8p=!K
for(int i=0;i<nStartPos.length;i++) UEzsDJu
fileSplitterFetch.splitterStop(); C;9t">prk
R,%_deV\(
n=q=zn;
} 7AFE-'S
} hi!`9k
//负责部分文件的抓取 %dc3z"u
**FileSplitterFetch.java WJfES2N
*/ 2UiR~P]%
package NetFox; GD!- qH
e9&+vsRmA
_g[-=y{Bb
import java.io.*; '_V #;DI
import java.net.*; t-WjL@$F/
tR1FO%nC
o]<jZ_|gB
public class FileSplitterFetch extends Thread { vYdR ht\(
G8eD7%{b:)
zCt\o
String sURL; //File URL ygN>"eP
long nStartPos; //File Snippet Start Position um7o!yg,
long nEndPos; //File Snippet End Position /be=u@KV
int nThreadID; //Thread's ID n#4Gv|{XMD
boolean bDownOver = false; //Downing is over I.1D*!tz
boolean bStop = false; //Stop identical w]nX?S8
FileAccessI fileAccessI = null; //File Access interface Z&Ue|Z4Qt
)n( Q
UP2}q?4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException obO}NF*g^
{ yYY Nu`
this.sURL = sURL; L;S}s, 2x
this.nStartPos = nStart; WWNu:,
this.nEndPos = nEnd; kx:jI^
nThreadID = id; GX }q9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /4*WDiH
} >^=gDJ\a
~M5:=zKQ
7NJFWz!
public void run() X P;Bhz3j
{ Z.'syGuV
while(nStartPos < nEndPos && !bStop) w~|1Wd<v
{ u`_*g^5q"
pISp*&
dFW.}"^c
try{ L2fZ{bgy
URL url = new URL(sURL); ,(N[*)G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yS!(Ap
httpConnection.setRequestProperty("User-Agent","NetFox"); 8O7Yv<
String sProperty = "bytes="+nStartPos+"-"; =xL)$DTg)
httpConnection.setRequestProperty("RANGE",sProperty); L[y Pjw:0
Utility.log(sProperty); n*<v]1
1oty*c
o_f-GO
InputStream input = httpConnection.getInputStream(); e\F}q)_
//logResponseHead(httpConnection); F}36IM9/:
@pFj9[N
L%t@,O#,
byte[] b = new byte[1024]; m|O1QM;T
int nRead; $i#?v
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) D//=m=
{ !:3.D,
nStartPos += fileAccessI.write(b,0,nRead); &eQJfc\a
//if(nThreadID == 1) O("Uq../3
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); aC!EWgwW[
} .WX,Nd3@
^:KO_{3E
<{Q'&T
Utility.log("Thread " + nThreadID + " is over!"); |quij0_'e
bDownOver = true; F}Srn;V
//nPos = fileAccessI.write (b,0,nRead); X(Qu{HhI
} $4m*kQ
catch(Exception e){e.printStackTrace ();} $SY]fNJQ
} I4t*?
} TTZe$>f
~aTKG|74
<jA105U"m>
//打印回应的头信息 p?# pT}1
public void logResponseHead(HttpURLConnection con) nlc.u}#
{ },@``&e
for(int i=1;;i++) 5MF#&v
{ C&<~f#lB
String header=con.getHeaderFieldKey(i); pHC/(6?
if(header!=null) 7K;!iX<d
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @?kJ).
Utility.log(header+" : "+con.getHeaderField(header)); #_JYh?
else Q@S-f:!
break; 3n]79+w@z
} * F4UAQzYb
} nP3 E
h6v077qG
b5a.go
public void splitterStop() [f/I2
{ -c*\o3)
bStop = true; =&nW~<- v
} ,Nm$i"Lg
ZDt?j
k N7Bd}
} ztll}
5B4Ssrs5W~
%,P>%'0
/* *ZrSiIPP
**FileAccess.java !t#F/C
*//文件访问(定位，写) WFTvOFj
package NetFox; eiVC"0-c}
import java.io.*; L|j%S
!&^gaUa{
K.~q+IYP[
public class FileAccessI implements Serializable{ 3Q^fVn$tk
Na{Y}0=^y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L2UsqVU
RandomAccessFile oSavedFile; 1q7tiMvV-
long nPos; ino:N5&;;
xc@Ss[
j<<3Pr
public FileAccessI() throws IOException O`[aU%4b
{ 5GzFoy)j>
this("",0); 3FE(}G
} soRv1)el
yx38g ca
}H> ^o9
public FileAccessI(String sName,long nPos) throws IOException \M<3}t
{ 4T6 {Y
oSavedFile = new RandomAccessFile(sName,"rw"); IxZb$h[
this.nPos = nPos; 64>krmVIe
oSavedFile.seek(nPos); Z<?OwAWz
} @(g_<@Jz
baV>N[F&
W/$Zvl
public synchronized int write(byte[] b,int nStart,int nLen) QS[L~97m2M
{ PNs~[
int n = -1; =FP0\cQ.
try{ 4GdX/6C.
oSavedFile.write(b,nStart,nLen); 58Xzup_"
n = nLen; NoE*/!Sr
} ia@'%8
catch(IOException e) v=@TWEE
{ FzQTDu9
e.printStackTrace (); Mj#-j/{x{5
} Q4*?1`IsR
T;TA7{B
@gC=$A#
return n; -VKS~{
} +ZMls [
@mP]*$00
RGKYW>$0RR
} )SF}2?7e
`{k"8#4:qA
1RcSTg
/* U1_@F$mq<
**SiteInfoBean.java >{gPN"S"a
*/ S8[=S
package NetFox; Dl(3wgA
K_)eWf0a
i':ydDOOHA
public class SiteInfoBean { fWfk[(M'9
2WX7nK;I
J]lrS
private String sSiteURL; //Site's URL (.wIe/
private String sFilePath; //Saved File's Path wI]"U2L5
private String sFileName; //Saved File's Name tz4 ]qOH8
private int nSplitter; //Count of Splited Downloading File ^z1&8k"[^
kft#R#m
McH>"`
public SiteInfoBean() 9EDfd NN
{//nSplitter的缺省值为5 L37Y+C//
//default value of nSplitter is 5 {vUN+We
this("","","",5); &,A64y
} ?Nf>]|K:Q
C2LL|jp*
An;MVA
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5pr"d@.
{ +/,icA}PI
sSiteURL= sURL; @SZM82qU2z
sFilePath = sPath; UcBe'r}G
sFileName = sName; \PDd$syDA
this.nSplitter = nSpiltter; NI#X@
NH$r Z7$
+zXEYc
} ]8q3>
JlMT<;7\
#e' }.4cr
public String getSSiteURL() ]f+ csB
{ p' M%XBu
return sSiteURL; Ox#\M0Wn$3
} 3_~cMlr3T.
t`*!w|}(1
~\{^%~[48
public void setSSiteURL(String value) *Qugv^-
{ ~U;rw&'H
sSiteURL = value; 5N%93{L
} hxCvk/7sT
}|PY!O
/}Jj
public String getSFilePath() >e\9Bf_
{ 3a.kBzus
return sFilePath; :Y9NLbv
} f$NMM >z
NR;1z
ml\4xp,
public void setSFilePath(String value) G}&Sle]
{ X[f=h=|
sFilePath = value; \j&^aAp r
} UnI48Y
-S3MH1TZ
$O9^SB
public String getSFileName() Fx-8M!
{ 9U$EJN_G
return sFileName; T&Lb<'f
} ^i:`ZfA#
(aD_zG=k5
!\&;h
public void setSFileName(String value) z9aY]lHY
{ K~@Mg1R
sFileName = value; A&nU]R8S
} gy&[?m6M=
W5SJ^,d)J
&f&z_WU
public int getNSplitter() J_s>N
{ <.Nx[!'~&d
return nSplitter; G:zua`u[
} H54R8O$
&|/| ''A)
5 ~TdD6}
public void setNSplitter(int nCount) [Q=dCX9%
{ bV ZMW/w
nSplitter = nCount; ]Dw]p!@
} `FoxP
} 7Hm3;P.
(V4 ~`i4V
&hRvol\J
/* xO-+i\ ZV
**Utility.java y~)1 1]'>
*/ aH^RoG}
package NetFox; &^W|iXi#
I1PuHf Qs
=}.EY iD
public class Utility { m9/}~Y#k
m=YU2!Mb
K_dOq68_
public Utility() 8MSC.0
{ trAkcYd
<:?r:fQX
OF\rgz
} L'u\w
2Lx3=[ik
//线程睡眠 aG^4BpIP
public static void sleep(int nSecond) iezO9`
{ gG/!,Q.Qh
try{ fMOU$0]$<
Thread.sleep(nSecond); R~Ne|V2
} 9(@\&>)
catch(Exception e) U\Z?taXB
{ qHxqQ'ks;
e.printStackTrace (); y\a1iy
} '0FhL)x?"T
} daYx76yP_?
l8?>>.<P=
//日志 2$Tj84'X
public static void log(String sMsg) #5f-`~^C{
{ M@5?ZZ4L
System.err.println(sMsg); 5=f|7yl
} KN*
eM+!Y>8Y
dH-s2r%s
public static void log(int sMsg) |o\8
{ y~FV2$
System.err.println(sMsg); lBaR
} uuQ(&
} o93`|yWl
0zi~p>*nJC
-4cXRv]
/* >(;{C<6|^
**TestMethod.java /oriW;OF
*/ ;72T|e
package NetFox; gXjV?"^kUl
<kCU@SK
3? HhG
public class TestMethod { \Cii1\R=
}5hqDBK?
(2=Zm@Zpf
public TestMethod() kO}AxeQ
{ ///xx/weblogic60b2_win.exe ?:)]h c
try{ ?O8ViB?2
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9M:O0)s
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7R`mf
SiteFileFetch fileFetch = new SiteFileFetch(bean); v#!%GEg1r
fileFetch.start(); v61[.oS
} ia MUsa{
catch(Exception e){e.printStackTrace ();} <"_d]?,
IyPwP*A
:AE&Ny4
} |cR;{Z8?_
` eXaT8
'nwx9]q
public static void main(String[] args) ~x|F)~:0=
{ uH(f$A
new TestMethod(); /C6k+0ApMT
} N|6MP e
} 8@tPm$
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