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)); \R m2c8Z2
} v#HaZT]u
for(int i=0;i<nEndPos.length-1;i++) Awip qDAu
{ $r>\y (W
nEndPos = nStartPos[i+1]; dn"&j1@KY
} `|t X[':
nEndPos[nEndPos.length-1] = nFileLength; 72YL
} efK3{
} d]kP@flOV
>z(AQ
-zzM!1@F
//启动子线程 vf|lF9@U
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !I7bxDzK$
for(int i=0;i<nStartPos.length;i++) ~If{`zWoC
{ 0:,8Ce
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yq?7!X
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /SXms'C
nStartPos,nEndPos,i); _fVC\18T
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S%+$
fileSplitterFetch.start(); ]~')OSjw
} %(9BWO
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &WqKsH$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8Wa&&YTB
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", GN7\p)
nEndPos = " + nFileLength); >N&C-6W
// fileSplitterFetch[nPos.length-1].start(); Tb2Tb2C
\Y EV 5
.7BB*!CP
//等待子线程结束 OG M9e!
//int count = 0; 1z4s1Y
//是否结束while循环 |k # ~
boolean breakWhile = false; qtx5N)J6
z%F68f73
[i8,rOa7
while(!bStop) _n[4+S*v(
{ M"E ]r=1
write_nPos(); *jBn ^
Utility.sleep(500); BUuU#e5
breakWhile = true; c|kQ3(
!A.Kb74
@IB+@RmL
for(int i=0;i<nStartPos.length;i++) Esc*+}ck
{ 6Y#V;/gK!5
if(!fileSplitterFetch.bDownOver) #4WA2EW
{ 6l{=[\.Xa
breakWhile = false; D92#&,KD
break; <2\4eusk
} +2}aCoL\
} N+<`Er
if(breakWhile) Qx_K)
break; d/Sx+1 "{T
SqiLp!Y`
J!%cHqR
//count++; m[@7!.0=
//if(count>4) [7QIpt+FSo
// siteStop(); \X'{ ee
} F-^#EkEGe
7R$]BY=
?c vXuxCm
System.err.println("文件下载结束！"); \Z +O9T%
} %cDTy]ILu
catch(Exception e){e.printStackTrace ();} )/'y'd<r
} /r4QDwu
#-QQ_
_;A?w8z
//获得文件长度 =4;GIiF@
public long getFileSize() lC/4CPKtV
{ )xJo/{?
int nFileLength = -1; uW.)(l
try{ Eua\N<!aai
URL url = new URL(siteInfoBean.getSSiteURL()); }tH$/-qnJE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lgxG:zAC
httpConnection.setRequestProperty("User-Agent","NetFox"); FyXz(l:
</K"\EU
`_IgH
int responseCode=httpConnection.getResponseCode(); Ha~g8R&
if(responseCode>=400) +["t@Q4IQ
{ NFc@Kz<H
processErrorCode(responseCode); ar0y8>]3
return -2; //-2 represent access is error F5CV<-jB
} zh hHA9
xDf<@
@wWro?s'p
String sHeader; yDt3)fP#
!MOgM
ZMSP8(V
for(int i=1;;i++) -U6" Ce
{ JRMe(,u
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); oGzZ.K3 A
//Utility.log(in.readLine()); FFTh}>>
sHeader=httpConnection.getHeaderFieldKey(i); *siN#,5
if(sHeader!=null) 0|0<[:(hc
{ 0Ywqv)gg
if(sHeader.equals("Content-Length")) 3pSkk
{ 2 {lo
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); J%?'Q{
break; %ZF6%m0S
} c}nXMA^^
} giy4<
else JrF\7*rh9
break; =K<8X!xUW
} 8ODrW!o
} t]Ey~-Rx
catch(IOException e){e.printStackTrace ();} \Rc7$bS2H
catch(Exception e){e.printStackTrace ();} b|i94y(
* \@u,[,
^L&hwXAO:
Utility.log(nFileLength); [.}-nAN
LbGyD;#_
+jcg[|-'/
return nFileLength; Ybr&z7# 2
} Y'NQt?h
sR`WV6!9
LTsG
//保存下载信息（文件指针位置） pKrol]cth8
private void write_nPos() 9/LI[{
{ h9)QQPP
try{ a7#J af
output = new DataOutputStream(new FileOutputStream(tmpFile)); &e\A v.n@-
output.writeInt(nStartPos.length); $ctY#:;pV{
for(int i=0;i<nStartPos.length;i++) Ku{DdiTg>
{ p]*BeiT#n%
// output.writeLong(nPos); D.2HM
output.writeLong(fileSplitterFetch.nStartPos); B]K@'#
output.writeLong(fileSplitterFetch.nEndPos); xF*C0B;QL
} $x&\9CRM
output.close(); \2!v~&S
} * %p6+D-C
catch(IOException e){e.printStackTrace ();} Zy2@1-z6
catch(Exception e){e.printStackTrace ();} ,Yg<Z1
} !$'s?rnh
fDmGgD?
T,h,)|:I^
//读取保存的下载信息（文件指针位置） $wa )e
private void read_nPos() ?@ ei_<A{
{ *pN,@ZV$
try{ i)V-q9\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); o6^^hc\
int nCount = input.readInt(); fL7ym,?
nStartPos = new long[nCount]; Hh=D:kE
nEndPos = new long[nCount]; `F:PWG`
for(int i=0;i<nStartPos.length;i++) hia_CuY#
{ wVD-}n1"
nStartPos = input.readLong(); D/_=rAl1
nEndPos = input.readLong(); ``o:N`
} 6Cut[*lj^
input.close(); 6KmF 9
} .$>?2|gRv
catch(IOException e){e.printStackTrace ();} rt5UT~
catch(Exception e){e.printStackTrace ();} MjMPbGUX{
} jyPY]r
_s./^B_w!
{9KG06%+
private void processErrorCode(int nErrorCode) xUE9%qO
{ 7~[1%`
System.err.println("Error Code : " + nErrorCode); 0(VQwGC[
} T`46\KkN
uY;-x~Z
X%!#Ic]Q
//停止文件下载 Y418k
public void siteStop() 2s,wC!',
{ ;p%a!Im_<
bStop = true; j'i-XIs
for(int i=0;i<nStartPos.length;i++) Fs7/3
fileSplitterFetch.splitterStop(); v4sc
@Nb&f<+gi
fL4F ~@`9l
} krm&.J
} Nko;I?Fn
//负责部分文件的抓取 v`B7[B4K3
**FileSplitterFetch.java 6Gjr8
*/ aX6.XHWbDf
package NetFox; VA_\Z
m*h d%1D
%(b`i C9
import java.io.*; =vBxwa^
import java.net.*; r'fNQJ >
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C\UD0r'p?
public class FileSplitterFetch extends Thread { c]O3pcU
LjjE(Yrv{
uYiM~^0
String sURL; //File URL f+Nq?GvwBQ
long nStartPos; //File Snippet Start Position 68R[Lc9q5
long nEndPos; //File Snippet End Position oQ@X}6B%S
int nThreadID; //Thread's ID ]t]s/;9]K
boolean bDownOver = false; //Downing is over @jg*L2L6
boolean bStop = false; //Stop identical nn$,|/
FileAccessI fileAccessI = null; //File Access interface |/zE(ePc{
Zr'VA,v
LOi5 ^Um|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException j&)+qTV
{ +](^gaDw<L
this.sURL = sURL; R@t?!`f!+
this.nStartPos = nStart; 25h.u>6@{
this.nEndPos = nEnd; u!mUUFl
nThreadID = id; Ph2jj,K
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #sy)-xM
} Ra[{K@
95>(NwST4
5YMjvhr?W
public void run() zCj]mH`es'
{ ZffK];D
while(nStartPos < nEndPos && !bStop) %O>ehIerD
{ _!H{\kU
Uaj8}7v
Y<%$;fx$Sx
try{ rgdDkWLXC
URL url = new URL(sURL); !.H< dQS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0RN]_z$;H
httpConnection.setRequestProperty("User-Agent","NetFox"); =K~<& l8
String sProperty = "bytes="+nStartPos+"-"; ^tIs57!
httpConnection.setRequestProperty("RANGE",sProperty); ko*Ir@SDv
Utility.log(sProperty); y[oc^Zuo
".onev^(
4!,x3H'
InputStream input = httpConnection.getInputStream(); ihBlP\C
//logResponseHead(httpConnection); IM|VGT0
w4<1*u@${
b;`gxXeL
byte[] b = new byte[1024]; u.x>::i&
int nRead; 3qE2mYK
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) fI;6!M#
{ ,1EyT>
nStartPos += fileAccessI.write(b,0,nRead); puA~}6C
//if(nThreadID == 1) 8-3]Bm!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q+5g+9
} @~hiL(IR'
C:xgM'~+
xDG8C39qrs
Utility.log("Thread " + nThreadID + " is over!"); pca `nN!
bDownOver = true; &eKnLGKD
//nPos = fileAccessI.write (b,0,nRead); vmm#UjwF3
} A}?n.MAX>
catch(Exception e){e.printStackTrace ();} O@6iG
} #S)+eH
} NK;%c-r0v7
'`&gSL.1a@
A^nB!veh
//打印回应的头信息 FJomUVR.
public void logResponseHead(HttpURLConnection con) X|fl_4NC>
{ \/J>I1J
for(int i=1;;i++) Fy37I/#)r&
{ q">lP(t
String header=con.getHeaderFieldKey(i); 1`J-|eH=Q
if(header!=null) )0UVT[7
//responseHeaders.put(header,httpConnection.getHeaderField(header)); AP5[}$TT
Utility.log(header+" : "+con.getHeaderField(header)); 0F> ils
else 5&Al
break; $_IvzbOh
} o|O730"2F
} y:u7*%"
>uT,Z,7O
>?>@&A/
public void splitterStop() :@#9P,"
{ -d5b,leC^
bStop = true; l*~O;do
} [Z9 lxZ|
n]:Xmi8p
UtPFkase
} Y1fcp_]m
3kfrOf.4h
z,dh?%H>X
/* )tYu3*'
**FileAccess.java !*Ex}K99
*//文件访问(定位，写) 9/2VU< K
package NetFox; @9#l3
import java.io.*; )+ifVv50
c"D%c(:4|
X.}i9a 6
public class FileAccessI implements Serializable{ X<G"GaL
Nl/^ga
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `%S 35x9
RandomAccessFile oSavedFile; 0C!f/EZK
long nPos; pGZiADT
y buKwZFC
4^uQB(}Z
public FileAccessI() throws IOException x -;tV=E}
{ 0b=1Ce+0q
this("",0); ozaM!ee\z
} <c'0-=
RW"QUT
709/'#- ^
public FileAccessI(String sName,long nPos) throws IOException m&S *S_c
{ 9-:\ NH^;
oSavedFile = new RandomAccessFile(sName,"rw"); xhcFZTj/(
this.nPos = nPos; LH}]& >F
oSavedFile.seek(nPos); }ejZk bP
} (8"advc6
a4d7;~tZ
f4'WT
public synchronized int write(byte[] b,int nStart,int nLen) ehTrjb3k
{ I<+EXH%1,
int n = -1; w'uB&z4'
try{ sdp3geBYo
oSavedFile.write(b,nStart,nLen); z]+&kNm
n = nLen; i}Q"'?
} jK^Q5iD
catch(IOException e) uH{oJSrK
{ i0}f@pCB?X
e.printStackTrace (); 8 $qj&2 N
} HPryq)z
_DouVv>
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return n; TJ_Wze-lQ
} MCO2(E-
}3O 0nab
]\Z8MxFD
} jK-b#h.gL
3N[Rrxe2
a%nf )-}|
/* c/DK31K
**SiteInfoBean.java (S~kNbIa
*/ FUVp}>#U
package NetFox; i 558&:
<k?pnBI_
AqiH1LAE
public class SiteInfoBean { .H@b zm
~^TH5n
PrHoN2y5E
private String sSiteURL; //Site's URL ,njlKkFw^Z
private String sFilePath; //Saved File's Path Xf#+^cQ
private String sFileName; //Saved File's Name 2@N9Zk{{J
private int nSplitter; //Count of Splited Downloading File h! Bg}B~
W{%X1::q$
h% eGtd$n
public SiteInfoBean() PI.Zd1r
{//nSplitter的缺省值为5 HLkI?mW<
//default value of nSplitter is 5 lc8g$Xw3
this("","","",5); _\.4ofK(
} h/Yxm2
j{j5TvsrY
!r8_'K5R(
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ..kFn!5(g
{ h,?%,GI
sSiteURL= sURL; TSD7R
sFilePath = sPath; Lf)JO|o
sFileName = sName; Uc,MZV4
this.nSplitter = nSpiltter; PJ)l{c
~N%+ZXh&E
-{}h6r
} km*Y#`{
H:|.e)$i
Fge["p?GF
public String getSSiteURL() le' Kp V
{ 80=LT-%#
return sSiteURL; 1>uAVPa
} :c|Om{;
!Rc %
U9\\8
public void setSSiteURL(String value) 74ho=
{ gW<6dP'v
sSiteURL = value; nU' qE
} m_;fj~m
P-a8S*RRa
)Q62I\
public String getSFilePath() !u'xdV+bf
{ rFGPS%STS
return sFilePath; D;s%cL`
} <S=(`D
'pT13RFD
EjFn\|VK
public void setSFilePath(String value) [-VK!9pQ
{ tkH]_cH'w
sFilePath = value; "P0!cY8r
} >|c?ZqW
Ka6u*:/
4#}aLP
public String getSFileName() Gh/nNwyu<
{ &TY74w*
return sFileName; \i/HHP[%
} 'YB[4Q /0
tT!'qL.*
xVw@pR;
public void setSFileName(String value) :'B(DzUR
{ <$yA*
sFileName = value; Wlxmp['Bh
} Ufl\ uq3'H
'iF%mnJ
p:TE##
public int getNSplitter() /='0W3+o*L
{ pHoHngyi&
return nSplitter; }2@Z{5sh)
} y%ij)vQY
-N% V5 TN
u.|%@
public void setNSplitter(int nCount) ~CT]&({
{ U+qyS|i
nSplitter = nCount; (_|*&au J
} g=[OH
} o S=!6h
QK?V^E
eM_;rMCr}
/* j&,Gv@
**Utility.java kBhjqI*
*/ 5"@>>"3U
package NetFox; e,epKtL
~1D^C |%
l>K+4
public class Utility { A[uE#T^
)-_^vB
tu<<pR>
public Utility() 3!b $R?kZ
{ w.w{L=p:<"
L4Zt4Yuw
,eBC]4)B6
} \KnRQtlI
B;eka[xU
//线程睡眠 )][U6e
public static void sleep(int nSecond) :c~SH/qS
{ 5aizWz
try{ '";#v.!
Thread.sleep(nSecond); D#L(ZlD4
} M i& ;1!bg
catch(Exception e) ^T!Zz"/:
{ R|8vdZ%@
e.printStackTrace (); ,)Q-o2(C
} ekvs3a^
} uVUU1@
x6`mv8~9Db
//日志 WVRIq'
public static void log(String sMsg) llP V{
{ gSwV:hm
System.err.println(sMsg); i"}z9Ae~.
} VkFh(Br<{
6ieul@?*u*
Q4m> 3I
public static void log(int sMsg) 3<&:av3
{ ~D9Cu>d9
System.err.println(sMsg); U0_)J1Yp
} 9s^$tgH
} $_"u2"p
U`qkeNd
qUd7O](b=?
/* GK}52,NM
**TestMethod.java LZn'+{\`
*/ =@Oo3*>
package NetFox; G1 "QX
ByY2KJ7
xn3 _ED
public class TestMethod { m`-);y
Ma|4nLC}
RxMsP;be
public TestMethod() ~o!-[
{ ///xx/weblogic60b2_win.exe X(ph$,[
try{ \Osu1]Jn>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,,{;G'R|
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?$6H',u
SiteFileFetch fileFetch = new SiteFileFetch(bean); i\6CE|
fileFetch.start(); >}V?GK36
} !"F;wg$
catch(Exception e){e.printStackTrace ();} @PvO;]]%
:/T\E\Qr
BTkx}KK
} b)I-do+
|/gt;H~:
cX-M9Cz
public static void main(String[] args) qi4P(s-i
{ Dx-P]j)4x
new TestMethod(); ">bhxXeiN
} ln82pQD2Y~
} Q~U\f$N
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