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)); lV]l`$XI
} 'J!P:.=a>
for(int i=0;i<nEndPos.length-1;i++) Onot<}K
{ *:YW@Gbm
nEndPos = nStartPos[i+1]; SvI
} /x$jd)C
nEndPos[nEndPos.length-1] = nFileLength; o"[qPZd>
} OY[N%wr!
} 7F+f6(hB
xg3G
$#t&W&
//启动子线程 3l4k2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]j1BEO!Bg
for(int i=0;i<nStartPos.length;i++) $#KSvo{otI
{ y99G3t
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7RdL/21K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), N.&)22<m9
nStartPos,nEndPos,i); uX.Aq@j
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {Ziq~{W_
fileSplitterFetch.start(); X^aujK^@
} yGS._;#R
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T( ;BEyc?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Oh8;YE-%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |$1j;#h
nEndPos = " + nFileLength); g{<3*,
// fileSplitterFetch[nPos.length-1].start(); anl?4q3;9
!_x-aro3<
xss D2*l
//等待子线程结束 apw8wL2
//int count = 0; t`F%$q
//是否结束while循环 DK4V/>@8
boolean breakWhile = false; xhimRi
&3u* zV$
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while(!bStop) i ;X'1TN(y
{ hKX-]+6"
write_nPos(); }r,k*I'K
Utility.sleep(500); u!g<y
breakWhile = true; VK$+Nm)
N:&^ql4
*a$z!Ma3h
for(int i=0;i<nStartPos.length;i++) rRsLl/d
{ u_:" u
if(!fileSplitterFetch.bDownOver) 7&T1RB'>
{ u9VJ{F
breakWhile = false; Y9PG
break; 6'qs=Ql
} B&.XGo)
} B3I< $
if(breakWhile) j\Q_NevV
break; 3!*J;Y
yq;gBIiZ
lIOLR-:4j
//count++; )9@Ftzg|
//if(count>4) T_B$
// siteStop(); noL<pkks~R
} Dk[[f<H_{
lT$A;7[
U)c,ZxE
System.err.println("文件下载结束！"); sq :ff
} pLk?<y
catch(Exception e){e.printStackTrace ();} t,=khZ
} u1>|2D
N$_Rzh"9rr
eb+[=nmP
//获得文件长度 5ue{&z @T
public long getFileSize() 81aY*\
{ ^Z}INUv]7
int nFileLength = -1; iL5+Uf)E3
try{ seq S*^7
URL url = new URL(siteInfoBean.getSSiteURL()); Kb4u)~S:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NCl={O9<j
httpConnection.setRequestProperty("User-Agent","NetFox"); \UN7lDH
>gVR5o
KeXQ'.x5O
int responseCode=httpConnection.getResponseCode(); 0!!pNK%(
if(responseCode>=400) JO1c9NyKr
{ .\1XR
processErrorCode(responseCode); xT=|Uc0
return -2; //-2 represent access is error w3yI;P
} [g<6i.<I
BBy/bc!
8HTV"60hTs
String sHeader; oYqlN6n,=6
^#"!uCq]gM
oOJN?97!k
for(int i=1;;i++) E#_}y}7JY
{ rY($+O@a<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %iF< px?Vc
//Utility.log(in.readLine()); qY0GeE>N
sHeader=httpConnection.getHeaderFieldKey(i); %]
if(sHeader!=null) 8tPq5i
{ Q=w\)qJ
if(sHeader.equals("Content-Length")) )e{~x u
{ 6AzH'HF
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); uZW1 :cx
break; H\)on"
} Ym0Xl(Se
} (MbI8B>
else Oja)J-QXb
break; 2:2rwH }e
} ;XGG&M%3
} V&NOp
catch(IOException e){e.printStackTrace ();} ^$yr-p%-
catch(Exception e){e.printStackTrace ();} G?8,&jP~T
CXJ0N
Ku&0bXP
Utility.log(nFileLength); 6C) G
v>0xHQD*<M
TX8,+s+
return nFileLength; @\[&_DZ
} %.[GR
>dZ x+7
eGnc6)x@C
//保存下载信息（文件指针位置） 0}HKmEM
private void write_nPos() ks'25tv}F
{ SOeL@!_
try{ v#D9yttO{
output = new DataOutputStream(new FileOutputStream(tmpFile)); SAXjB;VH6
output.writeInt(nStartPos.length); f'R^MX2
for(int i=0;i<nStartPos.length;i++) ~@L$}Eu
{ PZH]9[H
// output.writeLong(nPos); W^al`lg+y
output.writeLong(fileSplitterFetch.nStartPos); 0nA17^W
output.writeLong(fileSplitterFetch.nEndPos); hC5ivJ
} GQ)hZt0
output.close(); 8M:;9a8fh
} R-hqaEB
catch(IOException e){e.printStackTrace ();} Z/56JYt!~
catch(Exception e){e.printStackTrace ();} g4%x7#vz0
} &87D.Yy^
1<fEz
J%D'Xlb
//读取保存的下载信息（文件指针位置） d) G7U$z~
private void read_nPos() Px'%5TKN
{ E%jOJA
try{ tse(iX/D
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); UHweV:(|T
int nCount = input.readInt(); 8pt;''
nStartPos = new long[nCount]; sDWX} NV
nEndPos = new long[nCount]; _vvnxG!x&
for(int i=0;i<nStartPos.length;i++) h^34{pKDn
{ Y.jg }oV
nStartPos = input.readLong(); jw#'f%*
nEndPos = input.readLong(); ToDN^qE+
} b)'Ew27
input.close(); *F~"4g
} nM)]
catch(IOException e){e.printStackTrace ();} gwR ^Z{
catch(Exception e){e.printStackTrace ();} ~D<o}ItRF
} u[PO'6Kzd
WB$Z<m:
1 dI
private void processErrorCode(int nErrorCode) )#i]exZ
{ #Rjm3#gc
System.err.println("Error Code : " + nErrorCode); OFCkQEG=y>
} ,GZ(>|
yq\)8Fe
~"brfjd|
//停止文件下载 =4+UX*&i?.
public void siteStop() kw|bEL9!u
{ '_@=9 \<
bStop = true; 5K{(V^88F
for(int i=0;i<nStartPos.length;i++) kB"Sh_:m
fileSplitterFetch.splitterStop(); mMu3B2nke=
<F>\Vl:
KdYT5VUM/
} )v8;\1`s:
} pg*'2AT
//负责部分文件的抓取 #j iQa"
**FileSplitterFetch.java tkV:kh< L~
*/ E"pq ZP =
package NetFox; `Qaw]&O
'WxcA)z0cQ
l_>^LFOA
import java.io.*; 8yB
import java.net.*; ;u!>( QQ
Mm^o3vl
3MNo&0M9
public class FileSplitterFetch extends Thread { ]*ZL>fuD|
B=u@u([.
sJw3o7@pg
String sURL; //File URL 9_5Fl,u z
long nStartPos; //File Snippet Start Position Tj<W4+p{
long nEndPos; //File Snippet End Position Ko>pwhR}
int nThreadID; //Thread's ID {p yo
boolean bDownOver = false; //Downing is over $@}6P,mg
boolean bStop = false; //Stop identical |a3)U%rUEQ
FileAccessI fileAccessI = null; //File Access interface )z2Tm4>iql
\96?OCdr
D0lgKQ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `:-{8Vo7
{ L*D-RYW
this.sURL = sURL; z"=#<C
this.nStartPos = nStart; C;G~_if4PR
this.nEndPos = nEnd; WnvuB.(@3
nThreadID = id; {-7];e
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +>44'M^Z|(
} T% Kj >-
@m1vB!
x AkM_<
public void run() \_De( p
{ #wk'&XsC#z
while(nStartPos < nEndPos && !bStop) Z+(V'e;
{ "_}Hzpy5k
J0C,KU(
8`U5/!6fu
try{ $*9h\W-)`Q
URL url = new URL(sURL); Do=*bZ;A
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); k .KN9=o
httpConnection.setRequestProperty("User-Agent","NetFox"); H.'MQ
String sProperty = "bytes="+nStartPos+"-"; .FXq4who
httpConnection.setRequestProperty("RANGE",sProperty); K/g\x0
Utility.log(sProperty); ,*@m<{DX)
kJZBQ<^
HZkC3$
InputStream input = httpConnection.getInputStream(); Ac^}wXp
//logResponseHead(httpConnection); _F;(#D
FC.y%P,
l`[*b_ Xt
byte[] b = new byte[1024]; /V$[M
int nRead; UStZ3A'
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) PfF7*}P
{ UyEyk$6SU
nStartPos += fileAccessI.write(b,0,nRead); N6Vn/7I5%
//if(nThreadID == 1) 6AUXYbK,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); & WYIfx{
} }f;Zx)!
esLPJx
kzbgy)PK3
Utility.log("Thread " + nThreadID + " is over!"); q/XZb@rt
bDownOver = true; Pi40w+/
//nPos = fileAccessI.write (b,0,nRead); \2L%%M
} V\r5
catch(Exception e){e.printStackTrace ();} t(\d;ybyx
} x5c pv
} ])7t!<
[`6|~E"F
k8GcHqNHx
//打印回应的头信息 :@`Ll;G
public void logResponseHead(HttpURLConnection con) X%h1r`h&
{ [6FCbzS_W
for(int i=1;;i++) u;F++$=
{ &g\D-At
String header=con.getHeaderFieldKey(i); =L#tSa=M"
if(header!=null) <DvpqlT
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <q~&g &&+
Utility.log(header+" : "+con.getHeaderField(header)); @Vr?)_0
else Hh(_sewo
break; /=FQ{tLr
} zX"@QB3E
} )^|zuYzN
dScit!T"
{I@@i8)]
public void splitterStop() `-hFk88
{ \(cu<{=rU
bStop = true; WW:@%cQ@
} bO>Mvf
/E2/3z
51*o&:eim
} 94 H\,}i8
HfFP4#C,
Gm}ecW
/* b*no.eB
**FileAccess.java &\F`M|c
*//文件访问(定位，写) G)?VC^Q
package NetFox; 8*V3g_z
import java.io.*; c]P`U(q9TV
Be68 Fu0
G[)Ll=
public class FileAccessI implements Serializable{ m;>HUTj
5 UpN/\He
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7i`@`0
RandomAccessFile oSavedFile; HC@E&t
long nPos; b%2+g<UKh
i5T&1W i
u%Bk"noCa
public FileAccessI() throws IOException *T$`5|
{ +?),BRCce
this("",0); DBWe>Ef(
} m*6C *M
;[R{oW Nw
k#_B^J&d
public FileAccessI(String sName,long nPos) throws IOException f\nF2rlu
{ |bk.gh
oSavedFile = new RandomAccessFile(sName,"rw"); ^8,HJG,!
this.nPos = nPos; "~:o#~F6
oSavedFile.seek(nPos); v/ dSz/<]
} :rnn`/L
ryy".'v
zF[kb%o
public synchronized int write(byte[] b,int nStart,int nLen) >)YaWcI
{ *)gbKXb
int n = -1; E?l_*[G
try{ xL3-(K6e
oSavedFile.write(b,nStart,nLen); ycg5S rg
n = nLen; ow,I|A
} ;f:}gMK
catch(IOException e) *,.WI )@
{ #eD@sEn
e.printStackTrace (); )`!i"
} y m<3
HFu#-}iNV
^vS+xq|4"
return n; D4g$x'
} y*0bHzJ
.E-)R
R*lJe6
} '#mv-/<t*
ma)Y@Uw M
Q|q.~x<RQ
/* CvW*/d q
**SiteInfoBean.java e|Rd#
*/ _&_#uV<WG0
package NetFox; 6nV]Ec~3[
7dhip
PJA%aRP,:
public class SiteInfoBean { d#9 \]Ul&
|_@ '_
#]>Z4=]v
private String sSiteURL; //Site's URL Tp2`eY5
private String sFilePath; //Saved File's Path '!>LF1W=
private String sFileName; //Saved File's Name 2fM*6CaS
private int nSplitter; //Count of Splited Downloading File U6;,<-bL
bx`s;r=
tn&~~G~#
public SiteInfoBean() 8x#SpDI
{//nSplitter的缺省值为5 6,"86
//default value of nSplitter is 5 3e+ Ih2
this("","","",5); G[z!;Zuf
} &sleV5V
[LDsn]{
7t &KKKV
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 99j^<)
{ T~@$WM(
sSiteURL= sURL; }wJ-*By{+
sFilePath = sPath; 'yd<<BM`
sFileName = sName; 4+qoq$F</
this.nSplitter = nSpiltter; >_bH,/D'
3@P 2]Q~D
kXK D>."E*
} qT7E"|.$
<\l@`x96"D
OPHf9T3H
public String getSSiteURL() oKjQ? 4
{ GY@(%^
return sSiteURL; !8S$tk
} zXWf($^&E
5xKo(XNp
w-9M{Es+j
public void setSSiteURL(String value) 4d~Sn81xW
{ </~!5x62Oy
sSiteURL = value; &qKJN#NM@
} V`Ve__5;
Rg@W0Bc)
C{AVV<
public String getSFilePath() WfYu-TK*
{ *F7ksLH|q
return sFilePath; l>p S23
} |t](4
/sVy"48-
,?s3%<\2
public void setSFilePath(String value) E{+V_.tlu
{ ], Xva`"
sFilePath = value; 7J?`gl&C
} 4mNg(w=NF
v53qpqc
Ovu!G q
public String getSFileName() [AgS@^"sf5
{ 6bj.z
return sFileName; Fv_rDTo
} gYb}<[O!
kex4U6&OQB
?VVtEmIN
public void setSFileName(String value) 7S+_eL^
{ h:%L% Y9z
sFileName = value; Y)="of
} U8Rko)
}s i{
&,~0*&r0
public int getNSplitter() <*I%U]
{ ?}<4LK]
return nSplitter; ipy1tXc
} l!UF`C0g
\Nd8,hE
CF"u8yE
public void setNSplitter(int nCount) 'Bul_D4B
{ Dxj&9Ra
nSplitter = nCount; ]!l]^/.
} Y*oT(
} 6, =oTmFP
NJ" d`
R Ptc \4
/* (vL-Z[M!
**Utility.java H#yBWvj*H
*/ v(PwE B]
package NetFox; dG5p`N%
^B)iBfZ
.8[Uk^q
public class Utility { ibe#Y
@&H Tt
liu%K9-r
public Utility() !=sM `(=~
{ 6KT]3*B
}@VdtH
ue?e}hF
} ]r6S|;:
R`%C]uG
//线程睡眠 )L^GGy8w
public static void sleep(int nSecond) e}V3dC^pU
{ dw6U}
try{ aE]/w1a
Thread.sleep(nSecond); kTJz .
} GJ1ap^k
catch(Exception e) 7Q_AZR4
{ E RnuM
e.printStackTrace (); V)HX+D>
} P[E:=p
} j A/xe
(A@~]N,U/
//日志 Z+# =]Kw)
public static void log(String sMsg) ^Bkwbj
{ `R\aNgCS}
System.err.println(sMsg); tXZE@JyuC
} s+9q`k^
V(/ @$&
(7v]bqfw
public static void log(int sMsg) AHa%?wb
{ lt:xN?--A?
System.err.println(sMsg); u;-_%?
} 0f"9wPC
} 99xs5!4s
2QUZBrs s
SEf:u
/* "Q{)H8,E)x
**TestMethod.java {\HEUIa]w
*/ x d9+P
package NetFox; -1~-uE.~4d
eN]AJ%Ig
8 K7.; t1
public class TestMethod { km%c0:
'*`25BiQ
w]<a$C8*y:
public TestMethod() OHEl.p]|
{ ///xx/weblogic60b2_win.exe pi/Jto25z
try{ 6p;G~,bd~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); dCbRlW
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |Z), OW
SiteFileFetch fileFetch = new SiteFileFetch(bean); $ NNd4d*
fileFetch.start(); -> $]`h"
} }(*eRF'
catch(Exception e){e.printStackTrace ();} gd#j{yI/Xf
dp&8:jy
0[\^Y<ec
} H]^hEQ3DT
w+,Kpb<x[0
,RP"m#l!\
public static void main(String[] args) G&eRhif
{ LIm{Y`XU
new TestMethod(); <FaF67[Q
} 8XS_I{}?
} ](^$5Am
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