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)); ]rS:#LK
} WvN{f*
for(int i=0;i<nEndPos.length-1;i++) $, vXyZ
{ e.Gjp{
nEndPos = nStartPos[i+1]; (8td0zq
} ]WvV*FL9D3
nEndPos[nEndPos.length-1] = nFileLength; S>;+zVF]
} ,TlYQ/j%h
} 1haNpLfS>
oXFo
epGC Ta
//启动子线程 IcJQC
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; PdqyNn=
for(int i=0;i<nStartPos.length;i++) ZE:!>VXa87
{ QruclNW{Bv
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?^gq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), >!3r7LgK
nStartPos,nEndPos,i); ;)23@6{R%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l>*L Am5
fileSplitterFetch.start(); ^Rh`XE
} =Q~@dP
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), SQ la]%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); XP^[,)E
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,!vI@>nhG
nEndPos = " + nFileLength); ddzMwucjp
// fileSplitterFetch[nPos.length-1].start(); #5yz~&
HAmAmEc,
FjV)QP H
//等待子线程结束 V/Q/Ujgg
//int count = 0; ((AIrE>Rr
//是否结束while循环 BF/l#)$yK
boolean breakWhile = false; w`_"R6
0q o]nw
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while(!bStop) a)QSq<2*
{ U(:Di]>{
write_nPos(); p+#]Jr
Utility.sleep(500); jK\AVjn
breakWhile = true; $&X-ay o
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for(int i=0;i<nStartPos.length;i++) #+8G`
{ Sb.%B^O
if(!fileSplitterFetch.bDownOver) vLIaTr gz
{ &3f^]n!@
breakWhile = false; VQ8Q=!]
break; <.=-9O6
} \49s;\I]
} MW|R)gt
if(breakWhile) Ya;y@44
break; lf\x`3Vd
^@f.~4P*I
'x<o{Hi"\B
//count++; l#TE$d^ym
//if(count>4) nL+y"O
// siteStop(); +!mEP>
} t"?)x&dS
D"CU J?
RMHJI6?LB
System.err.println("文件下载结束！"); m4?a'z"
} LZDJ\"a-
catch(Exception e){e.printStackTrace ();} Y=D\
} L&0aS:
3.6Gh|7
rV}&G!V_t
//获得文件长度 uyvjo)T
public long getFileSize() Lk.tEuj=82
{ 9V|)3GF
int nFileLength = -1; ZF@$3
try{ [l}H%S
URL url = new URL(siteInfoBean.getSSiteURL()); 40G'3HOp
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S0`u!l89(
httpConnection.setRequestProperty("User-Agent","NetFox"); VIg6'
|nBs(>b
U|Uc|6
int responseCode=httpConnection.getResponseCode(); \_x~lRqJJ
if(responseCode>=400) 54#P
{ 'Pxq>Os
processErrorCode(responseCode); CU:HTz=
return -2; //-2 represent access is error \027>~u {
} JCci*F#r
MzH'<`;BP
?JBA`,-
String sHeader; M(vX.kF
W;?e@}
PMT}fg
for(int i=1;;i++) 9"zp>VR
{ $b)t`r+
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (4|R}jv
//Utility.log(in.readLine()); n`V?n
sHeader=httpConnection.getHeaderFieldKey(i); qRHT~ta-?
if(sHeader!=null) 2I283%xr
{ mpQu:i|W
if(sHeader.equals("Content-Length")) Lngf,Of.e
{ dDa&:L
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); QH_Ds,oH=
break; v#?;PyeF
} dZX;k0
} u4$R ZTC
else fZcA{$Vc]N
break; }WhRJr`a
} 5fRrd;
} B$qTH5)W
catch(IOException e){e.printStackTrace ();} 5?[hr5E.E
catch(Exception e){e.printStackTrace ();} Q%524%f$
q]U!n
]D4lZK>H
Utility.log(nFileLength); @^/aS;B$>
^7yaMB!
hkdF
return nFileLength; FY`t7_Y?GV
} $%4<q0-
CbpzYv32
Qq'e#nI@
//保存下载信息（文件指针位置） zB/VS_^^W:
private void write_nPos() o]]sm}3N
{ ) O&zb_{n
try{ q[9N4nj$<
output = new DataOutputStream(new FileOutputStream(tmpFile)); r&IDTS#
output.writeInt(nStartPos.length); AD+OQLG]`
for(int i=0;i<nStartPos.length;i++) &TL"Hd
{ J*38GX+
// output.writeLong(nPos); \(--$9
output.writeLong(fileSplitterFetch.nStartPos); /pV N1Yt
output.writeLong(fileSplitterFetch.nEndPos); 3D^cPkX
} qHT73_R
output.close(); }=Xlac_U
} gAVD-]`
catch(IOException e){e.printStackTrace ();} !cdY`f6x
catch(Exception e){e.printStackTrace ();} I9m9`4BK
} e<(6x[_
o1"N{Eu
%hlgLM
//读取保存的下载信息（文件指针位置） sVGQSJJ5
private void read_nPos() yFS{8yrRUU
{ }Q@~_3,UJ
try{ "n)AlAV@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1;'-$K`}
int nCount = input.readInt(); }h1eB~6M
nStartPos = new long[nCount]; R.DUfU"gp
nEndPos = new long[nCount]; \98N8p;,I
for(int i=0;i<nStartPos.length;i++) *?$M=tH
{ n`@dk_%yI
nStartPos = input.readLong(); &SNH1b#>E
nEndPos = input.readLong(); 'sNiJ>
} W;l0GxOxQ
input.close(); L62%s[
} D[}^G5
catch(IOException e){e.printStackTrace ();} t&NpC;>v
catch(Exception e){e.printStackTrace ();} RWX!d54&
} :H&G}T(#
a>rDJw:
&W c$VDC
private void processErrorCode(int nErrorCode) Go^TTL
{ ><>%;HZ
System.err.println("Error Code : " + nErrorCode); hgzNEx%^q
} qozvNJm)
[S8*b^t4
MT:VQ>fC
//停止文件下载 UO#`Ak
public void siteStop() QleVW
{ z@w}+fYO
bStop = true; JZ~wacDd
for(int i=0;i<nStartPos.length;i++) %n GjP^
fileSplitterFetch.splitterStop(); 4Gh\T`=
<=D a
~MXhp5PI
} bo(w$& VW
} BFg&@7.X
//负责部分文件的抓取 3Pgokj
**FileSplitterFetch.java #HW<@E
*/ vU5}E\Ny
package NetFox; VIN0kRQ#
RgW#z-PZF
mwyB~,[d+W
import java.io.*; A_WaRYG
import java.net.*; F3]VSI6^E,
Lq1?Y
K#AexA
public class FileSplitterFetch extends Thread { &:IcwD&
E/*&'Osq
cIG7Q"4
String sURL; //File URL "a}fwg9Y
long nStartPos; //File Snippet Start Position mF|KjX~s
long nEndPos; //File Snippet End Position )7[#Ti
int nThreadID; //Thread's ID u"m(a:jQ
boolean bDownOver = false; //Downing is over ^Il*`&+?P
boolean bStop = false; //Stop identical `CC=?E
FileAccessI fileAccessI = null; //File Access interface &6 <a<S
h_+
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException j;7E+Yp
{ D6l.x]K
this.sURL = sURL; 9jX_Eoxy
this.nStartPos = nStart; >KvK'Mus/
this.nEndPos = nEnd; ^Y+Lf]zz*
nThreadID = id; GN9kCyPK
fileAccessI = new FileAccessI(sName,nStartPos);//定位 a@<-L
} %+Y wzL{
?@;)2B|q
s,8zj<dUv
public void run() >`SeX:
{ 02trjp.f
while(nStartPos < nEndPos && !bStop) B>m*!n:l
{ 9xhc:@B1J
V>,=%r4f
'P" i9j
try{ )7.DF|A
URL url = new URL(sURL); &e;Qabwxva
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c-}[v<o
httpConnection.setRequestProperty("User-Agent","NetFox"); % @+j@i`&
String sProperty = "bytes="+nStartPos+"-"; QIevps*
httpConnection.setRequestProperty("RANGE",sProperty); 'L-DMNxBr
Utility.log(sProperty); M@<9/xPS
f,Dic%$q
X(X[v]
InputStream input = httpConnection.getInputStream(); ,Kl?-W@
//logResponseHead(httpConnection); X-kOp9/.
*o4a<.hd2
Rz|@BxB>n
byte[] b = new byte[1024]; gGUKB2)
int nRead; g#^MO]pY
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !khEep}
{ s</qT6@
nStartPos += fileAccessI.write(b,0,nRead); 6h,!;`8O
//if(nThreadID == 1) M<n'ZDK`W
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {srxc4R`
} `&7tADFB
D9A%8[Yo
jVQ89vf ~
Utility.log("Thread " + nThreadID + " is over!"); RR ^7/-
bDownOver = true; DyiJ4m}kh
//nPos = fileAccessI.write (b,0,nRead); X!^|Tass
} 9J?s:"j
catch(Exception e){e.printStackTrace ();} -~lq <M
} xk% 62W
} {vCtp
1^X)vck
O0xqA\
//打印回应的头信息 y32$b,%Xi,
public void logResponseHead(HttpURLConnection con) 3]*1%=~X/
{ I4?oBq
for(int i=1;;i++) /\h*v!:
{ ?_^{9q%9
String header=con.getHeaderFieldKey(i); Q N#bd~
if(header!=null) _UPfqC ?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); o!KDeY
Utility.log(header+" : "+con.getHeaderField(header)); dCTyfXou[=
else OQB7C0+ &
break; HNv~ZAzBG-
} [K\b"^=<
} 2wIJ;rh
!e~[U-
C`ky=
public void splitterStop() >20dK
{ `(0B09~7
bStop = true; PBCGC^0{
} ix4]^
SnQT1U%
ybE2N
} YnU)f@b#
pC>h"Hy
CCe>*tdf
/* |&rCXfC
**FileAccess.java BB(6[V"SV
*//文件访问(定位，写) LrbD%2U$j5
package NetFox; A8Q^y AP^
import java.io.*; {#k[-\|;
CL4N/[UM
7\,9Gcv1
public class FileAccessI implements Serializable{ bC1G5`v_D
!LwHKCj
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~Q]5g7k=&
RandomAccessFile oSavedFile; ,Q7;(&x~
long nPos; )B0%"0?`8
>!xyA;
/0XMQy
public FileAccessI() throws IOException mA+:)?e5~
{ ()l3X.t,$
this("",0); ~BmA!BZV`
} ji1vLu4|t
{XmCG%%L
C\GP}:[T3
public FileAccessI(String sName,long nPos) throws IOException &~Hed_
{ znwKwc8,
oSavedFile = new RandomAccessFile(sName,"rw"); Nb`qM]&
this.nPos = nPos; (;},~( 2B
oSavedFile.seek(nPos); IUFc_uL@\
} @nY]S\if
F9u?+y-xb
5MAfuHq^
public synchronized int write(byte[] b,int nStart,int nLen) ^F+7<$2
{ TjEXR$:<
int n = -1; =#S.t:HQ*
try{ JN|6+.GG
oSavedFile.write(b,nStart,nLen); kY~4AH
n = nLen; j/*1zu8Y
} *b. >
catch(IOException e) nJ2x;';lA
{ PU/<7P*
e.printStackTrace (); 96(Mu% l
} 6^[4.D
L!If~6oD(
njaMI8|Pa
return n; ujX;wGje
} k_=yb^6[U
Ptv'.<-
T+F]hv'
} 0\= du
TB!I
-$Hu$Y}>
/* wgS,U}/i
**SiteInfoBean.java F#sm^%_2
*/ dWvVK("Wj
package NetFox; RDp
(O5Yd 6u
*{DTxEy
public class SiteInfoBean { ZP<<cyY
.+/d08]
d}[cX9U/
private String sSiteURL; //Site's URL ro{!X,_$,
private String sFilePath; //Saved File's Path +1!iwmch>
private String sFileName; //Saved File's Name Kf[d@L
private int nSplitter; //Count of Splited Downloading File rR> X<
S=(O6+U
o[Jzx2A<
public SiteInfoBean() (?na|yd
{//nSplitter的缺省值为5 }|kFHodo
//default value of nSplitter is 5 k||t<&`Ze
this("","","",5); S'jg#*$
} T$xBH
;/j2(O^
>CqzC8JF
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E[]5Od5#
{ No'?8+i
sSiteURL= sURL; ecghY=%
sFilePath = sPath; vA1YyaB
sFileName = sName; E+]9!fDy<
this.nSplitter = nSpiltter; N>!:bF
_qxI9Q}<"
) CP
} cQU;PH]
-Z"4W
N]A# ecm
public String getSSiteURL() "La;$7ds
{ r!mRUw'u
return sSiteURL; ?l0Qi
} lir=0oq<
T }}2J/sj
'+PKGmRW
public void setSSiteURL(String value) `<C<[JP:o
{ 9{toPED
sSiteURL = value; 6Yj{% G
} lM6pYYEq=
Gmz^vpQ]t
0@ Y#P|QF
public String getSFilePath() AG N/kx
{ i+*!"/De
return sFilePath; P=QxfX0B
} 'r?ULft1
~zqb{o^pT
/,Xl8<~#
public void setSFilePath(String value) Hc)z:x;Sj
{ {{?g%mQ6
sFilePath = value; Xu]~vik
} HC%Hbc~S_Q
.A2$C|a*
=&WIa#!=
public String getSFileName() 'a['lF
{ 8D='N`cN+
return sFileName; Jj"{C]
} {>f"&I<xw
1@F-t94I
ZEP?~zV\A
public void setSFileName(String value) HL38iXQ( 3
{ h: ' |)O
sFileName = value; #Iw(+%D
} g4IF~\QRVi
lB,1dw2(T
w&p+mJL.
public int getNSplitter() 3 jZMXEG)
{ 4b8G 1fm
return nSplitter; C0wtMD:G
} ~]?:v,UIm(
Aqyw
1)ue-(o5
public void setNSplitter(int nCount) v ,8;: sD
{ <RGH+4LF
nSplitter = nCount; sTM;l,
} T6U/}&{O
} S /hx\TzC
;M:AcQZ|_
`2mddx8
/* X0lPRk53(
**Utility.java p['RV
*/ U'fP
package NetFox; s^h@b!'7
ar3L|MN
"rv~I_zl
public class Utility { aZOn01v;!&
Pq;OShU_
7oE0;'
public Utility() 2}hJe+#v
{ A3jxjQ
G 3Z"U
D)d]o&
} sg2;"E@
i}-uK,^
//线程睡眠 AI|vL4*Xd
public static void sleep(int nSecond) @(t3<g
{ =+zDE0Qs
try{ smP4KC"I(d
Thread.sleep(nSecond); *_(X$qfoW
} Nu5|tf9%A
catch(Exception e) iQ'*QbP'Z
{ pRd.KY -<
e.printStackTrace (); yPN'@{ 5#
} I652Fcj
} :Sq]|)
)GD7rsC`<
//日志 &d_^k.%y
public static void log(String sMsg) WR;1
{ HK;NR.D
System.err.println(sMsg); LP2~UVq
} [h/T IGE\
;Shu
lA^1}
public static void log(int sMsg) _D '(R
{ [&)]-2w2
System.err.println(sMsg); J<$@X JLS
} ARH~dN*C
} /0s1;?
osW"wh_
>B BV/C'9
/* kK6OZhLH
**TestMethod.java g`XngRb|j
*/ W }NUU
package NetFox; {{G)Ry*pb
H>~CL
7sot?gF
public class TestMethod { jLAEHEs
z0z@LA4k6@
Qb536RpcTY
public TestMethod() E&M(QX5
{ ///xx/weblogic60b2_win.exe -+R,="nRQ
try{ vObZ|>.J~O
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); UP~28%>X
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `m,4#P-kj
SiteFileFetch fileFetch = new SiteFileFetch(bean); (MwRe?Ih
fileFetch.start(); ,}oAc
} &f*orM:
catch(Exception e){e.printStackTrace ();} b^o4Q[
b8mH.g&l
PDNl]?
} VYk:c`E
J9^NHU
]Q^)9uE\D
public static void main(String[] args) Cf% qap#
{ YT\`R
new TestMethod(); ;%e&6
} T{{:p\<]_
} I/E9:
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