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)); . 70=xH
} '&,p>aM
for(int i=0;i<nEndPos.length-1;i++) ,:J[|9
{ #&r}J
nEndPos = nStartPos[i+1]; V3cKdlu Na
} DBaZcO(U
nEndPos[nEndPos.length-1] = nFileLength; y>E:]#F
} @73kry v
} hO3 q|SL
$)KODI>|
YRBJ(v"9
//启动子线程 iZ}c[hC'3`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }0anssC
for(int i=0;i<nStartPos.length;i++) t}Td$K7
{ z?Z"*z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d(^HO~p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6A.%)whI;
nStartPos,nEndPos,i); %vZHHBylu
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \*{MgwF
fileSplitterFetch.start(); Ths~8{dMb
} BGj!/E
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T_UJ?W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); pi#a!Quf\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", u0=&_Q(=
nEndPos = " + nFileLength); R6Md_t\
// fileSplitterFetch[nPos.length-1].start(); Vrlqje_Q
tw zV-8\
RR+kjK?
//等待子线程结束 P/WGB~NH
//int count = 0; @uV]7d"z(
//是否结束while循环 M1NdlAAf
boolean breakWhile = false; 6[R6P:v&'G
4<PupJ
pRE^; 4}z
while(!bStop) rloxM~7!,)
{ j<BRaT
write_nPos(); GLZ*5kw
Utility.sleep(500); NhNd+SCZ@
breakWhile = true; y!x[N!a
M"p%CbcI]
C_q2bI
for(int i=0;i<nStartPos.length;i++) oO3^9?Z
{ svxjad@l/
if(!fileSplitterFetch.bDownOver) V*2*5hx
{ {4/*2IRN9h
breakWhile = false; ?#&[1.= u
break; (vD==n9Hd
} \P":V
} `\"<%CCe
if(breakWhile) *}#HBZe(9
break; [!3cWJCt
)jUPMIo
[ypE[
//count++; *$R9'Yo}F
//if(count>4) -^`s#0( y^
// siteStop(); _](y<O^9yO
} b5]<!~Fv:`
T;{}bc&I
L.-qTh^P
System.err.println("文件下载结束！"); AsuugcN*
} z(.,BB[
catch(Exception e){e.printStackTrace ();} ^["D>@yIR
} s.;'-oA
r|uR!=*|?
N>a~k}pPH
//获得文件长度 ^q& Rl\
public long getFileSize() 7CF>cpw
{ ^pew'pHQ
int nFileLength = -1; ^:ny
try{ `~lG5|
URL url = new URL(siteInfoBean.getSSiteURL()); ]:2Ro:4Yv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); . bUmT!
httpConnection.setRequestProperty("User-Agent","NetFox"); ~fL`aU&
z!b:|*m]w
%1#|>^
int responseCode=httpConnection.getResponseCode(); dZ*&3.#D5
if(responseCode>=400) Y$Rte.?
{ m*iSW]&
processErrorCode(responseCode); NPO!J^^
return -2; //-2 represent access is error EFI!b60mc
} gG.+3=
p-(V2SP/)t
%qeNC\6N
String sHeader; o2$A2L9P
OKau3T]
d^tY?*n
for(int i=1;;i++) ' i5}`\
{ bcuUej:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); VFnxj52<
//Utility.log(in.readLine()); C{t}q*fG 5
sHeader=httpConnection.getHeaderFieldKey(i); @44*<!da
if(sHeader!=null) !h}Vz
{ aA>!p{/x
if(sHeader.equals("Content-Length")) y,jpd#Y
{ ir\)Hz2P
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !U2<\!_
break; HL$7Ou
} `\ IaeMvo
} `<T4En
else Vx5fQ mx
break; dikX_ Q>D
} "mU2^4q
} XJl 3\*
catch(IOException e){e.printStackTrace ();} RHvKWt
catch(Exception e){e.printStackTrace ();} #7:ah
ER&\2,fZ
Ji=`XsV
Utility.log(nFileLength); mrKIiaU<J
${ DSH
mrG#ox4$
return nFileLength; ]0(ZlpT
} N^F5J
m@D :t5
kDRxu!/
//保存下载信息（文件指针位置） @_c&lToj_
private void write_nPos() g.;2N9
{ &F[N$6:v
try{ N(J#<;!yb
output = new DataOutputStream(new FileOutputStream(tmpFile)); wNFx1u^/)
output.writeInt(nStartPos.length); >XuPg(Ow
for(int i=0;i<nStartPos.length;i++) }9z$72;Qdq
{ u9c^YCBM
// output.writeLong(nPos); t(.vX
output.writeLong(fileSplitterFetch.nStartPos); l`X?C~JhJ
output.writeLong(fileSplitterFetch.nEndPos); r~,3
} 9]G~i`QQ
output.close(); D]'8BS3
} vt(}8C+
catch(IOException e){e.printStackTrace ();} XS&;8 PO
catch(Exception e){e.printStackTrace ();} 9MQwc
} |KPNl\%ID
/Gb)BJk!
Ho&f[T(
//读取保存的下载信息（文件指针位置） S @!z'$&
private void read_nPos() "_BWUY
{ !VudZ]Sg
try{ ?wIEXKI
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); s6;ZaU
int nCount = input.readInt(); tdu:imH~
nStartPos = new long[nCount]; A+\rGVNH'S
nEndPos = new long[nCount]; e!C,<W&B\
for(int i=0;i<nStartPos.length;i++) *U8,Q]gS
{ 5yV>-XT+-
nStartPos = input.readLong(); mQU t 'j4
nEndPos = input.readLong(); .]<iRf[\[
} Gcxz$.(
input.close(); M#8_Qbvfk
} JH2-'
catch(IOException e){e.printStackTrace ();} Rf=-Q %
catch(Exception e){e.printStackTrace ();} $|!3ks
} HG5E,^1n
Pum&\.l
Y~#.otBL&
private void processErrorCode(int nErrorCode) w; f LnEz_
{ \l5G
System.err.println("Error Code : " + nErrorCode); F6+4Yy+
} l[WX77bp=
:8+x&zn
A&-2f]L tl
//停止文件下载 j&8GtE1b
public void siteStop() Ck/w:i@>?
{ 4VsttT
bStop = true; fP( n3Q
for(int i=0;i<nStartPos.length;i++) =gd~rk9
fileSplitterFetch.splitterStop(); k%N$eO$
Vm I Afe
Z{F^qwne
} +j8-l-o
} :F"NF
//负责部分文件的抓取 cvtn,Ml6
**FileSplitterFetch.java 7s0y.i~
*/ +&M>J|
package NetFox; x;STt3M~
!0KNA1w,
=C)2DWJ1
import java.io.*; e>uq/|.!
import java.net.*; tjne[p
ojIGfQV
"%rU1/@#
public class FileSplitterFetch extends Thread { J~ z00p`E
69odE+-X.
V4,\vgGu
String sURL; //File URL n2'XWbMaL
long nStartPos; //File Snippet Start Position bK!uR&i^l
long nEndPos; //File Snippet End Position hb)83mH}
int nThreadID; //Thread's ID [cfXcl
boolean bDownOver = false; //Downing is over ,x[~|J!
boolean bStop = false; //Stop identical ob[G3rfd@Z
FileAccessI fileAccessI = null; //File Access interface 5'wFZ=>vMt
ZNDjk
QbWeQ[V{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException u*7>0o|H:
{ i>pUTT _[
this.sURL = sURL; mJVru0
this.nStartPos = nStart; ]qk`Yi
this.nEndPos = nEnd; a5`9mR)Y$'
nThreadID = id; p%\&M bA
fileAccessI = new FileAccessI(sName,nStartPos);//定位 eFQz G+/
} H]{`q
)@.0ai
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public void run() j#H&~f
{ S09Xe_q
while(nStartPos < nEndPos && !bStop) ]4\6_J&
{ %w3tzE1Hq
7U&<{U<
`]/0&S
try{ q-+_Y `_\
URL url = new URL(sURL); ]^QO^{Sz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VY!A]S"
httpConnection.setRequestProperty("User-Agent","NetFox"); _Vt CC/
String sProperty = "bytes="+nStartPos+"-"; ^/$U(4
httpConnection.setRequestProperty("RANGE",sProperty); 2(9~G|C.
Utility.log(sProperty); 07,&weQ
"haJwV6-
O<?.iF%
InputStream input = httpConnection.getInputStream(); 7VfPS5se
//logResponseHead(httpConnection); U\"FYTC
v dU)
ofCN[u
byte[] b = new byte[1024]; pEG!j ~
int nRead; Tx$bg(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,@8*c0Y~<!
{ aq^OzKP?
nStartPos += fileAccessI.write(b,0,nRead); m9$lOk4/
//if(nThreadID == 1) YE-}1&8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {>X2\.Rl
} v 5&8C
C'joJEo
O F?o
Utility.log("Thread " + nThreadID + " is over!"); ^`9O$.'@
bDownOver = true; .H86f !=
//nPos = fileAccessI.write (b,0,nRead); A] f^9F@
} %^;rYn3
catch(Exception e){e.printStackTrace ();} *adwCiB
} B(R$5Xp
} -JdNA2P
h,i=Y+1
2)|G%f_lS
//打印回应的头信息 Okd7ua-f
public void logResponseHead(HttpURLConnection con) *UdP1?Y
{ ,GF(pCZzG
for(int i=1;;i++) fvV5G,lD3h
{ sN/8OLc
String header=con.getHeaderFieldKey(i); CYhSCT!-?
if(header!=null) 6{[uCxxl
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }Q;^C
Utility.log(header+" : "+con.getHeaderField(header)); ByjgM`
else iz6+jHu'l
break; vyruUYFWe
} xGw|@d
} GrM`\MIO
$1|65j[e
fRcy$
public void splitterStop() di~ [Ivw
{ AZbFj-^4
bStop = true; %07vH&<C.
} E qt\It9
3s,a%GOk
FOSC#W9E
} BvpUcICJ
0gJ{fcI
ua%j}%G(
/* |k/;1.b!9(
**FileAccess.java -^$IjK-N
*//文件访问(定位，写) kOv37c'
package NetFox; +)*oPSQ5
import java.io.*; o?wEX%
"lBYn2W
UH7FIM7kX
public class FileAccessI implements Serializable{ a)rT3gl
81S0:=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -dH]_
RandomAccessFile oSavedFile; V`"Cd?R0Z
long nPos; d+IN-lR(
0@}:`OynX
F Xp_`9.zH
public FileAccessI() throws IOException jlaC: (6
{ 0$.;EGP
this("",0); m=D9V-P
} BVxk}#d
cbv%1DT3
}?,Eb~q
public FileAccessI(String sName,long nPos) throws IOException XGDJCN
{ 1 o\COnt
oSavedFile = new RandomAccessFile(sName,"rw"); s'k} .}
this.nPos = nPos; y7.oy"
oSavedFile.seek(nPos); ,TQ;DxB}=E
} g"X!&$&
O7zj8
?q}:ojrs1
public synchronized int write(byte[] b,int nStart,int nLen) NxN~"bfh
{ Z" dU$,n
int n = -1; ~{{@m]P
try{ C9nCSbGMY{
oSavedFile.write(b,nStart,nLen); y:R+;91
n = nLen; =nG>aAG
} 7Q #A
catch(IOException e) k,jcLX.
{ ePiZHqIsv/
e.printStackTrace (); c^}DBvG,
} UZ7ukn-
23P7%\
3u1\zse
return n; \&^U9=uq
} p)*x7~3e
OT}P0 ~4s
~Da-|FKa>
} QT[4\)
G$6mtw6[M
u'Z^|IVfo
/* 88A,ll%
**SiteInfoBean.java >$;,1N $bd
*/ PS`F
package NetFox; \kC'y9k
d(9C7GLC,
7$Pf
public class SiteInfoBean { -n6e;p]
DWk2=cO
<ua! ]~
private String sSiteURL; //Site's URL .}iRe}=
private String sFilePath; //Saved File's Path <l$ vnq
private String sFileName; //Saved File's Name :hDv^D?3
private int nSplitter; //Count of Splited Downloading File 71,GrUV:
'LG )78sk
;!#IRR
public SiteInfoBean() gmtS3,
{//nSplitter的缺省值为5 K,@} 'N
//default value of nSplitter is 5 C@@PLsMg
this("","","",5); D1Q]Z63,
} ]|B_3*A
p}|<EL}Z9
9oj0X>| 1
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) nSq$,tk(
{ Bh()?{q
sSiteURL= sURL; GCp90
sFilePath = sPath; d"}lh:L9
sFileName = sName; gyOAvx
this.nSplitter = nSpiltter; <P-AlHYV-
a#+;BH1
#[y2nK3zF
} |5\: E}1
8j8~?=$a6Q
Kj#h9e
public String getSSiteURL() <|VV8r93
{ M#xol/)h
return sSiteURL; UW-`k1
} ^'4I%L"
d@{#F"o
]NY^0SqM
public void setSSiteURL(String value) #QiNSS
{ %m "9 =C
sSiteURL = value; E4xybVo@
} MG3xX;
- *xn`DH
14p{V}f3
public String getSFilePath() Mqm9i
{ Hh &s.ja
return sFilePath; L^L.;1
} $%5vJiuk
|O[ I=!
0t)5KO
public void setSFilePath(String value) HVNX"`]"
{ HUx-8<ws
sFilePath = value; L%/atl!
} 7h\U}!
QX+&[G!DZH
6' 9zpe@`
public String getSFileName() (b+o$C
{ }\vw>iHPX@
return sFileName; Gvquv\
} %`]fZr A]#
8!7`F.BX
>%85S>e
public void setSFileName(String value) U6~79Hnt
{ (o1o);AO
sFileName = value; D^A#C<Gs
} X9#i!_*
/.:&9 c
k~qZ^9QB~
public int getNSplitter() q(}#{OO
{ 57:27d0y
return nSplitter; T$tO[QR/
} *TYOsD**9
1#nY Z%
h~k+!\
public void setNSplitter(int nCount) _j|U>s
{ HvW6=d(#
nSplitter = nCount; '.#3h$d
} b%e7rY2
} l,ra24
d 2z!i^:
r%%<
/* (sEZNo5n
**Utility.java i^V3u
*/ N0UZ%,h\
package NetFox; IUQYoKz4}A
~uEI}z
Tnb5tHjnh
public class Utility { M/jdMfU
PAv<J<d
1f0maN
public Utility() %DhLU~VX
{ tdn|mX#
+=(@=PJ6
iL3k8:x
} T0K*!j}O
MMf_
//线程睡眠 Io<L! =>
public static void sleep(int nSecond) 9D51@b6k
{ ~lH2#u>g
try{ =p#:v
Thread.sleep(nSecond); ie<m)
} Vet<,;Te
catch(Exception e) Lq{/r+tt/
{ DO ,7vMO
e.printStackTrace (); D~@lpcI
} !-q)9K?
} q8Rep
fnudy%oo
//日志 S?#'Y*h
public static void log(String sMsg) tMr$N[@r
{ gBo~NLrf
System.err.println(sMsg); @jD#Tn-*
} pNc4o@-
LgA>,.
2m2$jp0
public static void log(int sMsg) {)& b6}2h
{ avxI%%|
System.err.println(sMsg); QykHB k
} pcPRkYT[M
} Is}?:ET
0ZtH
QHe:
/* Y,d|b V*FH
**TestMethod.java CpC6vA.R
*/ I9kBe}g3
package NetFox; a>Xq
SW=%>XKkh
yb'v*B]
public class TestMethod { RBOhV/f
kk+:y{0V
UymhBh
public TestMethod() &Y$)s<u8.
{ ///xx/weblogic60b2_win.exe ()yOK$"
try{ <"x *ZT
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /5C>7BC
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); YPS,[F'B.
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8YkCTJfBGu
fileFetch.start(); 7kQ,D,c'
} -|_io,eL;
catch(Exception e){e.printStackTrace ();} Fo&ecWhw
kud2O>>
&A~(9IV
} -(|}:J
t2&}
73(5.'F
public static void main(String[] args) %)j^>W5
{ dhI+_z
new TestMethod(); mbZg2TTy
} q@iZo,Yk
} l[{Ci|4
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