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)); iuAq.$oi{
} \ P/W8{
for(int i=0;i<nEndPos.length-1;i++) ; B$*)X9
{ L.)yXuo4
nEndPos = nStartPos[i+1]; |C-y}iQ:6~
} :5# V^\3*
nEndPos[nEndPos.length-1] = nFileLength; TOT PzB
} S/Oxr%H
} oXGZK5w<l
MCy~@)-IN
! D1zXXq
//启动子线程 !nw[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; YoSQN/Z
for(int i=0;i<nStartPos.length;i++) @ss):FwA
{ +R\~3uj[7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 36A;!1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), EXbTCT}`x
nStartPos,nEndPos,i); p\D >z("
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V SAafux
fileSplitterFetch.start(); =vEkMJOs
} Zu#<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ay$>(;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); u,9q<&,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =cp;Q,t'9L
nEndPos = " + nFileLength); #7W.s!#}Dd
// fileSplitterFetch[nPos.length-1].start(); 2d&^Sp&11
0XIxwc0Iw
I'InZ0J2
//等待子线程结束 AQh["1{yJ
//int count = 0; 8S>>7z!U
//是否结束while循环 {D(,ft;s^
boolean breakWhile = false; yazZw}};
3$_2weZxYn
UR:n5V4
while(!bStop) ScJu_Af
{ 6>B \|
write_nPos(); fPz=KoN
Utility.sleep(500); `:5,e/5,
breakWhile = true; Vy;_GfT$
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+x]e-P%
for(int i=0;i<nStartPos.length;i++) C*pLq5s
{ uUS)#qM|
if(!fileSplitterFetch.bDownOver) ^ f{qJ[,
{ Q8Te'1Ln!
breakWhile = false; l1RlYl5
break; `|,tCM&-
} AM/lbMr
} l<N?'&
if(breakWhile) -$R5
break; P"Rk?lL
/Ynt<S9"
UK:M:9
//count++; 0w}{(P;
//if(count>4) ]h8/M7k
// siteStop(); L>:FGNf^H
} m X:bA5db
"1%*'B^}bw
cYD1~JX.
System.err.println("文件下载结束！"); `~E<Sf<M
} 5f3!NeI
catch(Exception e){e.printStackTrace ();} *a4 b
} :SeLkQC
V8v,jS$l4
Wa/geQE1<
//获得文件长度 mxhW|}_-j
public long getFileSize() OfLM
{ ]+,nA R
int nFileLength = -1; 9OZ>y0)K~
try{ )$F6
URL url = new URL(siteInfoBean.getSSiteURL()); 1gAc,s2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z1qUz7
httpConnection.setRequestProperty("User-Agent","NetFox"); 05g?jV
my=~"bw4
-faw:
int responseCode=httpConnection.getResponseCode(); #tP )-ww
if(responseCode>=400) Iq@IUFpc7~
{ 44|03Ty
processErrorCode(responseCode); 6\mC$:F
return -2; //-2 represent access is error 2w7@u/OC'
} 9BurjG1k?
_!;\R7]
%\_h7:
String sHeader; gyg|Tno
4sQ~&@[Q+
Bf(Mot^
for(int i=1;;i++) )#mW7m9M#
{ !$XO U'n
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); G`WzJS*}v
//Utility.log(in.readLine()); #nDL
sHeader=httpConnection.getHeaderFieldKey(i); 5Wl,J _<F
if(sHeader!=null) (ai72#nFtb
{ C64eDX^
if(sHeader.equals("Content-Length")) -%N}A3m!5
{ wEv*1y4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); rl41#6
break; a6 *Y%?
} {cX7<7N
} B8>FCF&}E
else 2nYiG)tg
break; "$4hv6 s
} GZ.?MnG
} -ca]Q|m8
catch(IOException e){e.printStackTrace ();} 81cv:|"
catch(Exception e){e.printStackTrace ();} tTE3H_
=b|)Wnt2f
s}<)BRZi
Utility.log(nFileLength); B##C{^5A`
P'gT6*an,"
v3!byN^
return nFileLength; = c/3^e
} O]4W|WI3
#SK#k<&P
U8U/?zW/&
//保存下载信息（文件指针位置） >n#g9vK
private void write_nPos() Yoj~|qL
{ 18J.vcP
try{ JJ*0M(GG
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^glbxbhI4
output.writeInt(nStartPos.length); 1h&)I%`?
for(int i=0;i<nStartPos.length;i++) )moo?Q
{ Py}!C@e
// output.writeLong(nPos); \qRjXadj
output.writeLong(fileSplitterFetch.nStartPos); nqUH6(
output.writeLong(fileSplitterFetch.nEndPos); #r-j.f}yx
} 0 [*nAo
output.close(); -aTg>Q|g&
} Z={UM/6w
catch(IOException e){e.printStackTrace ();} OME!W w
catch(Exception e){e.printStackTrace ();} mJ7`.
} /0X0#+kn
|~Htj4K/
LAOdH/*:
//读取保存的下载信息（文件指针位置） LZ3rr-
private void read_nPos() #wq;^)>
{ q^Q|.&_k /
try{ M^0w/
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); WX+< 4j
int nCount = input.readInt(); FA<Z37:
nStartPos = new long[nCount]; Z5{*? 2
nEndPos = new long[nCount]; xF2f/y
for(int i=0;i<nStartPos.length;i++) "`y W]v
{ m,xy4
nStartPos = input.readLong(); *S,v$ VX
nEndPos = input.readLong(); ,S7~=S
} :qt82tbn
input.close(); k4]R]=Fh.
} +5N^TnBtBL
catch(IOException e){e.printStackTrace ();} KzxW?Ji$S
catch(Exception e){e.printStackTrace ();} Hz8Jgp
} rjhs?
9F-ViDI.
Qu,)wfp~
private void processErrorCode(int nErrorCode) hqwz~Ky}
{ 3ZT/>a>@
System.err.println("Error Code : " + nErrorCode); 0e[ tKn(
} 5)/4)0
c"oQ/x
\= )[
//停止文件下载 (\[jf39e
public void siteStop() 3D[:Rf[
{ ROlzs}
bStop = true; 9;m#>a@Y
for(int i=0;i<nStartPos.length;i++) :y<Cd[/
fileSplitterFetch.splitterStop(); <S:,`v&Z
hO:)=}+H
=6L:Ix
} ^D>/wX\u
} ;[;S_|vZ=)
//负责部分文件的抓取 P:bVcta9g
**FileSplitterFetch.java x);?jxd
*/ 61t-
package NetFox; )dzjz%B)
^5^ zo~^o
TZ`]#^kU
import java.io.*; )%nt61P\W
import java.net.*; &B{Jxc`VA
FW6E)df
f%(e,KgW=
public class FileSplitterFetch extends Thread { \?p9qR;"4
J$eZLj
T`(;;%
String sURL; //File URL B7x"ef
long nStartPos; //File Snippet Start Position eO"\UDBV
long nEndPos; //File Snippet End Position }]Z,\lA
int nThreadID; //Thread's ID 'J&@jp
boolean bDownOver = false; //Downing is over cfO^CC
boolean bStop = false; //Stop identical Kuzy&NI^w
FileAccessI fileAccessI = null; //File Access interface &6~ncQWu
4I]/
=Un6|]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &<[]X@ bY
{ qjdahVY
this.sURL = sURL; q>Ar.5&M_
this.nStartPos = nStart; `G:qtHn"Q<
this.nEndPos = nEnd; ?_<UOb*
nThreadID = id; ~O7cUsAi'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 da7x 1n$D
} uDMUy"8&!
z;z'`A
FC/>L
public void run() "KQ\F0/
{ o*5e14W(:
while(nStartPos < nEndPos && !bStop) ~[bMfkc3
{ G~mB=]
El8.D3
Lqf#,J
try{ 83O^e&Bt
URL url = new URL(sURL); pCud` :o"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ZLFdnC@
httpConnection.setRequestProperty("User-Agent","NetFox"); J{'zkR?Lr
String sProperty = "bytes="+nStartPos+"-"; cJp1 <R
httpConnection.setRequestProperty("RANGE",sProperty); Dv\:b*
Utility.log(sProperty); ^FpiQF
=[CS2VQ'
jP{]LJ2.6\
InputStream input = httpConnection.getInputStream(); <:_]Yl
//logResponseHead(httpConnection); DIcyXZH<
*U[Q=w
p|O-I&Xd
byte[] b = new byte[1024]; XP Iu]F
int nRead; +~v3D^L15
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .L5T4)
{ 2H32wpY ,l
nStartPos += fileAccessI.write(b,0,nRead); 9FR1Bruf
//if(nThreadID == 1) +'6ea+$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z_ FL=S\
} ~d<`L[
iLQt9Hyk
HS7 G_
Utility.log("Thread " + nThreadID + " is over!"); V,*0<7h
bDownOver = true; ?@uK s4
//nPos = fileAccessI.write (b,0,nRead); ?PU(<A+
} ,`B>}
catch(Exception e){e.printStackTrace ();} j2v[-N4 {J
} 2/<WWfX'
} ;V(}F!U\z
'Q;?_,`
k=q%FlE
//打印回应的头信息 `OpC-Z&
public void logResponseHead(HttpURLConnection con) C Wl95g
{ jwE(]u
for(int i=1;;i++) Fq\`1Ee{
{ J*4_|j;Z-E
String header=con.getHeaderFieldKey(i); 3@WI*PMc
if(header!=null) "u$]q1S
//responseHeaders.put(header,httpConnection.getHeaderField(header)); d'@H@
Utility.log(header+" : "+con.getHeaderField(header)); Fl|&eO,e
else EO!cv,[a
break; 1*`JcUn,>
} IfI$
} L08;z
5~rY=0t
T!eh?^E
public void splitterStop() 8X~vJ^X9@y
{ 5r}(|86O/
bStop = true; `uJ l<kHI
} L\'qAfRZ
O%h 97^%k
w+TuS).
} *gMP_I
j`-y"6)
|^9ig_k`
/* !urd $Ta
**FileAccess.java [tw<TV"\
*//文件访问(定位，写) N#-\JlJ)
package NetFox; 9'L0Al~L
import java.io.*; Q X5#$-H@
thboHPml{
g,]5&C T3v
public class FileAccessI implements Serializable{ -VT?/=Y s
zpQ/E
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 fi@+swfc
RandomAccessFile oSavedFile; kFs kn55
long nPos; UDqKF85H
iKTU28x
_=$!T;}lE
public FileAccessI() throws IOException z_0lMX`
{ T%#P??k
this("",0); V<I${i$]0
} L|Gk}n
;,hoX6D$
>" 8j{s
public FileAccessI(String sName,long nPos) throws IOException }K]VlFR
{ i'LTKj
oSavedFile = new RandomAccessFile(sName,"rw"); *bC^X'
this.nPos = nPos; }^bL'
oSavedFile.seek(nPos); 3 AF]en
} |(8h:g
w!k4&Rb3
J0z0%p
public synchronized int write(byte[] b,int nStart,int nLen) ">^]^wa08
{ >~8Df61o`
int n = -1; b4OR`dd*J
try{ C+IE<=%F
oSavedFile.write(b,nStart,nLen); cr;`0
n = nLen; :iC\#i]6
} VNot4 62L
catch(IOException e) 1:Gd{z
{ 5"]2@@b4
e.printStackTrace (); +>%+r
} )Ea_:C'
Xr;noV-X
W3j|%
return n; l[0P*(I,
} 6spk* 8e
u(a&x|WY
c<x6_H6[8
} HcUz2Rm5XP
K1WoIv<Ym
-KiS6$-
/* uk/+ i`=
**SiteInfoBean.java DfFPGFv
*/ 0PbIWy'
package NetFox; =5eDT~=2{U
2= mD
vw6FvE`lC
public class SiteInfoBean { muq|^Hfb
@S:/6__
nx]b\A
private String sSiteURL; //Site's URL *<j@+Ch
private String sFilePath; //Saved File's Path N!~NQ-Re'
private String sFileName; //Saved File's Name aRP+?}b">
private int nSplitter; //Count of Splited Downloading File hjT1SW\I
9m9=O&C~-<
mwhn=y#]*
public SiteInfoBean() dz9-+C{m
{//nSplitter的缺省值为5 <TuSU[]
//default value of nSplitter is 5 ,p1]_D&
this("","","",5); ml2z
} >Tx;<G
PFw"ICs
)5OU!c
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1dO8[5uM7a
{ 4!qDG+m
sSiteURL= sURL; qnRzs
sFilePath = sPath; !r <|F
sFileName = sName; Qq`\C0RZ
this.nSplitter = nSpiltter; /)|y+<E]}
,]"u!,yHb
a~"X.xT\R
} 0G 1o3[F
~` hcgCi%
K),wAZI!7j
public String getSSiteURL() xxn&{\ ?
{ g_X7@Dt
return sSiteURL; h)`vc#"65k
} `:4cb$
AUV$ S2
d(Ou\7
public void setSSiteURL(String value) UQ~rVUo.c
{ =h;!#ZC
sSiteURL = value; Q(3x"+
} z+I-3v
b1o(CG(}*
!Esiq<Yh
public String getSFilePath() dY.uOafr
{ KJfyh=AD(
return sFilePath; Dw3! ibg
} Oc`fQqYy
BE)l77=/
t_Wn<)XA
public void setSFilePath(String value) o3kj7U:'x
{ uNg.y$>CX
sFilePath = value; #!Fs[A5%
} [\yI<^_a
d:''qgz`
=1qkoc~
public String getSFileName() [_-K
{ AK =k@hT
return sFileName; @=c='V]
} Nb1lawC
7d5x4^EYE
-y(V-
public void setSFileName(String value) B=Os?'2[
{ 0]~n8mB>
sFileName = value; .Ps;O
} XN;eehB?aE
Yw<:I&
0oMMJ6"i
public int getNSplitter() '=@x2`U/
{ !%@{S8IP.v
return nSplitter; B!v1gh
} *?+!(E
WXL.D_=+
!@X#{
public void setNSplitter(int nCount) OUPpz_y
{ ?`>yl4
nSplitter = nCount; dp"w=~53
} Me>'QVr
} DI7trR`
E \RU[
<]nI)W(
/* 2srz) xEe
**Utility.java 0^4*[?l9q
*/ D4wB &~U
package NetFox; 2H#vA
/MC\!,K
tWFJx}H
public class Utility { 4o8!p\a
8] *{i
? 6l::M
public Utility() :jPAA`,
{ ajAEGD2Zq
r.GjM#X
wF(FV4#gs
} lI 8"o>-~
mx yT==E
//线程睡眠 /Kvb$]F+!
public static void sleep(int nSecond) Fk43sqU6~
{ a lR}|ez
try{ U#}.r<
Thread.sleep(nSecond); 8z-Td-R6
} 83a Rq&(R
catch(Exception e) 9maw+c!~
{ gyK"#-/_d
e.printStackTrace (); K*<n<;W
} M: 6cma5
} L!Ro`6|7;
D-.>Dw:
//日志 O\w%E@9Fh
public static void log(String sMsg) (LjY<dQO
{ UgP5^3F2
System.err.println(sMsg); /d4xHt5a
} P<hqr;
-~q]0>
o\#C] pp
public static void log(int sMsg) ) l)5^7=W
{ P/Zo
System.err.println(sMsg); 6D OE6
} 9pgct6BO
} 0[];c$r<
uFqH_04
BSz\9 eT
/* e.T5F`Du
**TestMethod.java ZDf9Npe
*/ wmIq{CXx,
package NetFox; + |,CIl+
,y.0Cb0
vcmS]$}
public class TestMethod { b6lL8KOu
sDiYm}W
.UcS4JU
public TestMethod() <3qbgn>}b
{ ///xx/weblogic60b2_win.exe ^\!p;R
try{ e:l 6;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); R3~&|>7/T
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); (F)zj<{f
SiteFileFetch fileFetch = new SiteFileFetch(bean); ivm.ng[
fileFetch.start(); A9#2.5
} t*x;{{jL#(
catch(Exception e){e.printStackTrace ();} %(E6ADB
+[F8>9o&
s{/nO)
} QWoEo
L*Y}pO
=[WccF
public static void main(String[] args) gUMUh]j
{ _,}Ye,(^=
new TestMethod(); _i 8oWy1
} \rJk[Kec
} ZjcJYtD
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