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)); 7i&:DePM'q
} T^J>ZDA
for(int i=0;i<nEndPos.length-1;i++) E4m`
{ \]$IDt(s
nEndPos = nStartPos[i+1]; K2%w0ohC
} p+)YTzzc
nEndPos[nEndPos.length-1] = nFileLength; 3U_2!zF3_
} V<k8N^
} C8z{XSo
o,|[GhtHqs
[1.+HyJ}
//启动子线程 >4t+:Ut:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; UTXSeNP
for(int i=0;i<nStartPos.length;i++) OS8q( 2z?s
{ (?nCyHC%g
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0RoU}r@z4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^Q+g({
nStartPos,nEndPos,i); /0Ax*919j
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z+@2"%W
fileSplitterFetch.start(); E Cyyl
} U8 nH;}i
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {%_L=2n6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "etPT@gF
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8#vc(04(
nEndPos = " + nFileLength); %2v4<icvq
// fileSplitterFetch[nPos.length-1].start(); )"pF R4
\L"kV!>
72'5%*1
//等待子线程结束 pR~U`r5z
//int count = 0; 8<Hf"M
//是否结束while循环 5LOo8xN
boolean breakWhile = false; _4g.j
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e=.]F*:J
while(!bStop) -Z's@'*
{ VNY%R,6
write_nPos(); D*lKn62
Utility.sleep(500); K5lmVF\$P
breakWhile = true; EY tQw(!Q
fk&8]tK4
1')%`~
for(int i=0;i<nStartPos.length;i++) '3g[]M@M
{ b9!FC$^J
if(!fileSplitterFetch.bDownOver) WYr/oRO
{ BqT y~{)+
breakWhile = false; r(P(Rj2~
break; @Z12CrJ
} =zz~kon9
} #"B\UN
if(breakWhile) M]J^N#
break; HPZ}*m'
Ftr5k^!
%\:[ o
//count++; V;v8=1t!
//if(count>4) R~PA1wDZ
// siteStop(); #)nSr
} Om5Y|v"*
s=;uc]9g
w 47tgPPk
System.err.println("文件下载结束！"); n^g|Ja
} (=om,g}
catch(Exception e){e.printStackTrace ();} _WRFsDZ'
} 3eF-8Z(f
sc}~8T
<_-hRbS
//获得文件长度 ~Yy>zUH^X
public long getFileSize() Rd#WMo2Xd
{ ojanBg
int nFileLength = -1; Ys\Wj%6A
try{ Rx}$0c0
URL url = new URL(siteInfoBean.getSSiteURL()); '!eKTC>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~GZY5HF
httpConnection.setRequestProperty("User-Agent","NetFox"); ):[7E(F=
o{y9r{~A
}F#okU
int responseCode=httpConnection.getResponseCode(); ,Pdf,2
if(responseCode>=400) IhVO@KJI
{ vwxXgk
processErrorCode(responseCode); ?k(7 LX0j
return -2; //-2 represent access is error ;;#qmGoE
} r2,.abo
N(Fp0
{A05u3}
String sHeader; 'ZDp5pCC;
.N ,3od@
AT2nVakL
for(int i=1;;i++) zdYy^8V|z
{ =\H!GT
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); PoxK{Y
//Utility.log(in.readLine()); +lHjC$
sHeader=httpConnection.getHeaderFieldKey(i); t%E!o0+8Z
if(sHeader!=null) `)T13Xv
{ KbA?7^zo`
if(sHeader.equals("Content-Length")) n$$SNWgM
{ R}*_~7r5
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8Djc c z
break; *%%g{ 3$
} VHIOwzC
} w5Y04J
else 7/I,HxXp!
break; 3h$6t7=C
} < HVl(O
} &m-PC(W+
catch(IOException e){e.printStackTrace ();} E87Ww,z8
catch(Exception e){e.printStackTrace ();} tMf}
6ZP(E^.
LG9+y
Utility.log(nFileLength); leTf&W
W\d{a(*
=THpdtL
return nFileLength; J IUx
} JB<Sl4
]:XoRyIZ1[
,$s8GAmq
//保存下载信息（文件指针位置） 9\_eK,*B
private void write_nPos() ;$.J3!
{ '>-gi}z7
try{ m qMHL2~
output = new DataOutputStream(new FileOutputStream(tmpFile)); A%KDiIA
output.writeInt(nStartPos.length); Z2qW\E^_r
for(int i=0;i<nStartPos.length;i++) /5(Yy}
{ %A1o.{H
// output.writeLong(nPos); TO]@ Zu1
output.writeLong(fileSplitterFetch.nStartPos); ~*z% e*EL
output.writeLong(fileSplitterFetch.nEndPos); gOSJM1Mr3
} ME46V6[LX]
output.close(); =P't(<
} Q(wx nm
catch(IOException e){e.printStackTrace ();} a&/#X9/
catch(Exception e){e.printStackTrace ();} TaKLzd2
} d3ZdB4L
1w@(5 ^V
Br1&8L-|%
//读取保存的下载信息（文件指针位置） %5M/s'O?i
private void read_nPos() zzTfYf)
{ e2s]{obf
try{ u0|8Tgf
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }B\a<0L/
int nCount = input.readInt(); X' H[7 ^W
nStartPos = new long[nCount]; a{^m-fSaR"
nEndPos = new long[nCount]; gQWa24
for(int i=0;i<nStartPos.length;i++) 0D\#Pq v
{ }X)&zenz
nStartPos = input.readLong(); ,':fu
nEndPos = input.readLong(); e:fy#,HEj{
} xS4w5i2
input.close(); SUCMb8
} n.!#P|
catch(IOException e){e.printStackTrace ();} RYQ<Zr$!
catch(Exception e){e.printStackTrace ();} #@YPic"n7`
} .}t~'*D
]O+Ma}dxz:
{o_X`rgrL
private void processErrorCode(int nErrorCode) _=_Px@<Q
{ ,k )w6)
System.err.println("Error Code : " + nErrorCode); 1+szG1U=
} ~.{/0T
DS+}UO
+)!YrKuu
//停止文件下载 Q sZx) bO
public void siteStop() PRu 6xsyA
{ .7e2YI,S
bStop = true; JD)(oK%C
for(int i=0;i<nStartPos.length;i++) <*16(!k0
fileSplitterFetch.splitterStop(); tItX y
mn, =i
}zkHJxZgE
} Jj!vh{
} I4/8 _)b^
//负责部分文件的抓取 "6MVvpy"
**FileSplitterFetch.java QdT}wkX
*/ CR8/Ke
package NetFox; 1"zDin!A
MLw7}[
0 HGM4[)=
import java.io.*; sGyeb5c
import java.net.*; [Y|8\Ph`&
~ELNyI11
=XA;[PVx:#
public class FileSplitterFetch extends Thread { UW N*j_9i
Oft-w)cYz,
-I*^-+>H
String sURL; //File URL Y2a5bc P
long nStartPos; //File Snippet Start Position t2/#&J]
long nEndPos; //File Snippet End Position 6IBgt!=,
int nThreadID; //Thread's ID Yw4n-0g
boolean bDownOver = false; //Downing is over R)_%i<nq\
boolean bStop = false; //Stop identical fol,xMc&
FileAccessI fileAccessI = null; //File Access interface tNO-e|~'
HJLu'KY}
M2PAy! J
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `NCwK6/i
{ od IV:(
this.sURL = sURL; d/PiiiFf,
this.nStartPos = nStart; U{7w#>V .
this.nEndPos = nEnd; ~HTmO;HNf"
nThreadID = id; xf<at->
fileAccessI = new FileAccessI(sName,nStartPos);//定位 mw_~*Nc'9
} 5's87Z;6
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9>l*lCA
public void run() Ov5"
{ w`4=_J=GO
while(nStartPos < nEndPos && !bStop) 7E!IF>`
{ >6NRi/[
rf $QxJ
v25R_""~
try{ 4" Cb/y3
URL url = new URL(sURL); "S8uoSF`>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "fG8?)d;
httpConnection.setRequestProperty("User-Agent","NetFox"); n!YKz"$
String sProperty = "bytes="+nStartPos+"-"; !TAlBkj
httpConnection.setRequestProperty("RANGE",sProperty); f%SZg!+t
Utility.log(sProperty); DK$X2B"cV
JLnH&(O
RHmgD;7`
InputStream input = httpConnection.getInputStream(); >"|B9Woc
//logResponseHead(httpConnection); I;e=0!9U
\n$u)Xj~6^
,5i`-OI
byte[] b = new byte[1024]; `bFff%_
int nRead; I KqQ>Z-q~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) dCE0$3'5
{ < vL,*.zd
nStartPos += fileAccessI.write(b,0,nRead); HBy[FYa4
//if(nThreadID == 1) 1,6}_MA
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9KDEM gCW
} Lx\8Z=
QN #U)wn:
J3e96t~u
Utility.log("Thread " + nThreadID + " is over!"); N*"p|yhd]
bDownOver = true; '10oK {m$
//nPos = fileAccessI.write (b,0,nRead); (zgW%{V@
} 0xxg|;h.,g
catch(Exception e){e.printStackTrace ();} O[I\A[*
} @OV|]u
} *AG#316
:yRo3c
KV]X@7`@
//打印回应的头信息 &,}j#3<
public void logResponseHead(HttpURLConnection con) JW{rA6?
{ q)Lu_6 mg
for(int i=1;;i++) 3Ndq>
{ 8cU}I4|
String header=con.getHeaderFieldKey(i); k,85Y$`'
if(header!=null) M.x=<:upp
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gnFr}L&j
Utility.log(header+" : "+con.getHeaderField(header)); C9~52+S
else ",^Mxm{
break; kqM045W7
} ]^Qn
} oI=fx Sjd
ukIQr/k
o^^rJk
public void splitterStop() GR +[UG
{ z2MWN\?8
bStop = true; eFaO7mz5V%
} "]"|"0#i
|bq$xp
/.3}aj;6
} RZHd9v$
2[Z,J%:0
N!ls j \-
/* ! ='rc-E
**FileAccess.java 'JCZ]pZ
*//文件访问(定位，写) VXYK?Qc'
package NetFox; S& SQ
import java.io.*; OHeT,@(mh
8"U. Hnu
hM;lp1l
public class FileAccessI implements Serializable{ R$q; !
2^y^q2(r
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 jE}33"
RandomAccessFile oSavedFile; &^#VN%{
long nPos; H7d/X
+wEac g>>E
*]AdUEV?
public FileAccessI() throws IOException -db_E#
{ P+s!|7'
this("",0); nSW=LjrO~<
} eCqHvMp
"Q!(52_@J
~Lm$i6E<
public FileAccessI(String sName,long nPos) throws IOException :<hXH^n
{ F@mQQ
oSavedFile = new RandomAccessFile(sName,"rw"); r~/
this.nPos = nPos; rf>0H^r
oSavedFile.seek(nPos); ?$*SjZt
} VtnRgdJ
:+qF8t[L
z2g3FUTX)b
public synchronized int write(byte[] b,int nStart,int nLen) AyNI$Q6Z
{ *VFf.aPwYi
int n = -1; fz\9 S
try{ t"= E^r
oSavedFile.write(b,nStart,nLen); 2nSSFx r
n = nLen; >33=<~#n
} ' 0J1vG~c
catch(IOException e) g]4(g<:O
{ >Db;yC&
e.printStackTrace (); Ov-icDMm
} OW3sS+y
w2 a1mU/
\HKxh:F'
return n; YL]Z<%aKt
} |G?htZF
Y8m1M-#w
X$ s:>[H
} t=Xv;=daB
SZ,YS 4M
|y0(Q V
/* CDP U\ZG
**SiteInfoBean.java {OXFN;2
*/ ,q}MLTSi
package NetFox; H@q?v+2
U*22h` S
ujlY!-GM
public class SiteInfoBean { _H j!2 '
Xs~[&
lu<xv
private String sSiteURL; //Site's URL H5Z$*4%G
private String sFilePath; //Saved File's Path q35f&O;
private String sFileName; //Saved File's Name 7]blrN]
private int nSplitter; //Count of Splited Downloading File 4)A#2
/H8g(
RxI(:i?
public SiteInfoBean() v^#~98g]
{//nSplitter的缺省值为5 j`~Ms>
//default value of nSplitter is 5 wE?'Cl
this("","","",5); KwPOO{4]g
} B"!l2
a-=8xs'
^; )8VP6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @\f^0^G
{ S/9DtXQ
sSiteURL= sURL; ,n3a gkPO>
sFilePath = sPath; \l9qt5rS
sFileName = sName; Dey<OE&
this.nSplitter = nSpiltter; G+X Sfr
xlA$:M&
vUohtS*
} 2QJ{a46}
dwDcR,z?a
u*Pibgd<
public String getSSiteURL() <Bw^!.jAF
{ X!9 B2w
return sSiteURL; #,":vr
} j$?{\iXZ
AlAYiUw{
9}PhN<Gd
public void setSSiteURL(String value) i*/Yz*<
{ f;W|\z'
sSiteURL = value; 7?GIS '
} 8B\2Zfe
^,/RO5
-o$QS,
public String getSFilePath() `f*Q$Ulqx
{ Gn ~6X-l
return sFilePath; r76J N
} @ycDCB(D}
;/r1}tl+3>
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public void setSFilePath(String value) tt0f-:#
{ @zU6t|mhz
sFilePath = value; HY&aV2|A1
} }bdmomV
W-?()dX{
]6TATPIr
public String getSFileName() ms*(9l.hOK
{ I%sFqh>
return sFileName; o<COm9)i
} 0K`#>}W#X
y5?RVlKJ
Ji>o!
public void setSFileName(String value) !cO]<CWPq
{ 95A1:A^t
sFileName = value; Xq_5Qv
} YjxF}VI~<
3%E }JU?MM
cx&>#8s&
public int getNSplitter() }o(zj=7
{ MvK !u
return nSplitter; PIu1+k.r?
} yku5SEJ\
bpH^:fyLU`
62k^KO6Y
public void setNSplitter(int nCount) a yCY~=i
{ JtEo'As:[
nSplitter = nCount; "Zl5<
} fI{&#~f4C
} [5G6VNh=
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.1KhBgy^K
/* d1AioQ9
**Utility.java oSyyd
*/ YwDbPX
package NetFox; lQ" p !
gkES5Q
pEBM3r!X
public class Utility { (tIo:j
gy#/D& N[
xJ>fm%{5
public Utility() OBOtuu.
{ p"n$!ilbm
fGUE<l
=t9\^RIx)?
} Cs9.&Y
8u6:=fxb
//线程睡眠 VH9dleZ
public static void sleep(int nSecond) ^l9N48]|?
{ D8Ykg >B;&
try{ 95 ;x=ju
Thread.sleep(nSecond); B@&4i?yJ
} M?Dfu .t
catch(Exception e) DI:]GED"=
{ NdMb)l)m
e.printStackTrace (); nuk*.Su
} =Xi07_8Ic<
} v|uAzM{73
ABQ('#78
//日志 ';3{T:I
public static void log(String sMsg) "P7nNa
{ C-Q28lD}f
System.err.println(sMsg); sH{4Y-J
} 1_9<3,7
j(m.$:
9^oKtkoDZ
public static void log(int sMsg) <0b)YJb4M
{ c~z82iXNO
System.err.println(sMsg); l`oZ)?ur
} )bS yB29S
} llcb~
?[@J8
f .Q\Z'S^
/* AL9chYP}/
**TestMethod.java n^Hm;BiE#
*/ hQYL`Dni
package NetFox; D{GfLib"U
F*IzQ(#HW
11o.c;
public class TestMethod { vdAr|4^qB
#|L8tuWW
+R3k-' >
public TestMethod() [<n2Uz7MP
{ ///xx/weblogic60b2_win.exe gG0!C))8
try{ ojcA<60 '
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5rw 7;'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); dP3CG8w5
SiteFileFetch fileFetch = new SiteFileFetch(bean); i3tg6o4C
fileFetch.start(); GeyvId03H
} Ag9vU7
catch(Exception e){e.printStackTrace ();} 7j@Hs[ *
t|g4m[kr
C 3^JAP
} 6 Q%jA7
8IlunJ
Gr*r=s
public static void main(String[] args) 6wBx;y |
{ QoI3>Oj=
new TestMethod(); W0dSsjNio
} o_XflzC
} .c8g:WB<
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