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)); A!kyga6F5
} Mt Z(\&~
for(int i=0;i<nEndPos.length-1;i++) QBy*y $
{ ,H?p9L; qp
nEndPos = nStartPos[i+1]; jb2:O,+!
} eQx"nl3U%
nEndPos[nEndPos.length-1] = nFileLength; #c>MUC(?s:
} h<.[U $,
} !q/lgpEi
[mPdT^h
20qVzXi
//启动子线程 Q ?t
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [VW;L l
for(int i=0;i<nStartPos.length;i++) zFr}$
{ 9%qMZP0]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NLl~/smMS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (r4VIlap
nStartPos,nEndPos,i); iL, XBoE
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Fzs'@*
fileSplitterFetch.start(); Fc~w`~tv
} 5uer [1A
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }A7qIys$4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /8>/"Z2S
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 0Y2^}u@5
nEndPos = " + nFileLength); [BBKj)IK
// fileSplitterFetch[nPos.length-1].start(); af(JoX*U
e;5Lv9?C8
rk|(BA
//等待子线程结束 %6'D!H?d
//int count = 0; )1}g7:
//是否结束while循环 J#DcT@
boolean breakWhile = false; HJR<d&l;p
zYdtQjv
bl?%:qb.V
while(!bStop) )^Pvm
{ jPNfLwVkl:
write_nPos(); i_Z5SMZ
Utility.sleep(500); P{!:pxu[
breakWhile = true; YnWl'{[ C
mN 6`8 [
}%ThnFFBw
for(int i=0;i<nStartPos.length;i++) Y0\\(0j64
{ IJY5wP1"
if(!fileSplitterFetch.bDownOver) i q:Q$z&
{ 5]l7Z35
breakWhile = false; PAU+C_P
break; [B3aRi0AQ
} BpG'e-2
} FT>~ES]cQd
if(breakWhile) TrU@mYnE
break; je4&'vyU
bV*zMoD#
A9Wqz"[
//count++; ('q vYQ
//if(count>4) az;jMnPpR5
// siteStop(); <]^;/2.B
} 6QXQ<ah"
gQ[^gPWP"
9[{>JRm.
System.err.println("文件下载结束！"); `L#?eQ{
} LIC~Kehi
catch(Exception e){e.printStackTrace ();} l\;mP.!
} Jx$#GUl#j
)?&kQ^@v
Y;F R"~^
//获得文件长度 ?s)sPM?
public long getFileSize() 1`]IU_)1B
{ <-:@} |br
int nFileLength = -1; 7EP|X.
try{ rHgdvDc
URL url = new URL(siteInfoBean.getSSiteURL()); `]P5,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +`zi>=
httpConnection.setRequestProperty("User-Agent","NetFox"); s.^9HuM
#2R%H.*t
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int responseCode=httpConnection.getResponseCode(); 1DLG]-j}
if(responseCode>=400) K6{bYho
{ C%_
processErrorCode(responseCode); (}1v^~FXj
return -2; //-2 represent access is error - (_e=3$
} p?$G>nkdq
)YMlFzYr
NJ)2+
String sHeader; 3U"')
04PoBv~g
.k,Jt+
for(int i=1;;i++) mzE$aFu8
{ Mq:'-`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /;NE]{K
//Utility.log(in.readLine()); Bd9hf`%2
sHeader=httpConnection.getHeaderFieldKey(i); +lgF/y6
if(sHeader!=null) 3V Mh)
{ CQjZAv
if(sHeader.equals("Content-Length")) [s{r$!Gl
{ Y3$PQwn .P
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); dH2]ZE0V
break; gO:Z6}3vM
} 3$N %iE6
} ^jha:d
else i<wU.JX&h
break; B >u,)
} D<bU~Gd,P
} ,+/9K)X
catch(IOException e){e.printStackTrace ();} [Ba2b: l6v
catch(Exception e){e.printStackTrace ();} ]\RSHz
{LT4u]#
Z-t}6c'Kg
Utility.log(nFileLength); :-u-hO5*8
`e?;vA&
G?1x+H;o5
return nFileLength; qTTn51
} 9R@abm,I
m c\ C
2#b<d?"
//保存下载信息（文件指针位置） IQw %|^
private void write_nPos() 974eY
{ PPCTc|G
try{ GL5^_`n
output = new DataOutputStream(new FileOutputStream(tmpFile)); i9;27tT~<
output.writeInt(nStartPos.length); r2SJp@f
for(int i=0;i<nStartPos.length;i++) uGa(_ut
{ 'l' X^LMD
// output.writeLong(nPos); Qb?y@>-[
output.writeLong(fileSplitterFetch.nStartPos); AGEZ8(h
output.writeLong(fileSplitterFetch.nEndPos); ~)wwX:;B_
} h7EUIlh"
output.close(); 7~ *;=,mw
} a*6wSAA )
catch(IOException e){e.printStackTrace ();} R5K-KSvW
catch(Exception e){e.printStackTrace ();} R2N^'
} 13.{Y)
bk7^%O>
U+.PuC[3
//读取保存的下载信息（文件指针位置） .>kccLr:z
private void read_nPos() a:yB%:2
{ XhE$&Ff
try{ np-T&Pz2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); K}PvrcO1
int nCount = input.readInt(); :'d76pM-
nStartPos = new long[nCount]; emv;m/&8
nEndPos = new long[nCount]; (|<h^] y3
for(int i=0;i<nStartPos.length;i++) <Spr6U9p7
{ 56Sh
nStartPos = input.readLong(); h-r6PY=i
nEndPos = input.readLong(); B:O+*3j
} '!wPnYT@D
input.close(); |"CJ
} AZxrJ2G
catch(IOException e){e.printStackTrace ();} 0{0;1.ZP
catch(Exception e){e.printStackTrace ();} PyC;f8n'(
} "u(S2'DW'(
wTTTrk
>`hSye{
private void processErrorCode(int nErrorCode) Gva}J6{
{ ?eL='>Ne
System.err.println("Error Code : " + nErrorCode); r7Nu>[r5
} j6tP)f^tD
k40Ep(M}
vIVw'Z(g}
//停止文件下载 # #k #q=4
public void siteStop() e=gboR
{ z}>4,d
bStop = true; u}Ei_ O<z
for(int i=0;i<nStartPos.length;i++) c8#T:HM|`
fileSplitterFetch.splitterStop(); GFdZ`i
ZR/R'prW
5mI?pfm
} 6Cl+KcJH
} v]WH8GI
//负责部分文件的抓取 x*unye7
**FileSplitterFetch.java ElQJ\%
*/ uQ:Qb|
package NetFox; AA))KBXq
>vQ6V'F
_&W0e}4
import java.io.*; <TI3@9\qXE
import java.net.*; G%2P
k(zs>kiP
GhqgRzX
public class FileSplitterFetch extends Thread { R(: 4s
=QrA0kQR
Rr+qgt;f5
String sURL; //File URL iY0,WT}&n
long nStartPos; //File Snippet Start Position 13ipaz
long nEndPos; //File Snippet End Position n&_YYEHx
int nThreadID; //Thread's ID @<vF]\Ce
boolean bDownOver = false; //Downing is over _/|8%])
boolean bStop = false; //Stop identical i[^k.W3gf
FileAccessI fileAccessI = null; //File Access interface 1KW3l<v-6
3hc#FmLr2b
`6rrXU6|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException T|;^.TZ
{ McEmd.S<n
this.sURL = sURL; }l.KpdRT2
this.nStartPos = nStart; 7}<Sg
this.nEndPos = nEnd; 'oC$6l'rQ
nThreadID = id; )*!1bgXQ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 54=}GnZN
} jo_o`j
3QCMK^#Z:
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public void run() S&n[4*
{ q z=yMIy=
while(nStartPos < nEndPos && !bStop) b![t6-f^z
{ "\`>2
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DXKyRkn6e
try{ Ip>^O/}$1
URL url = new URL(sURL); h=hoV5d@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DeA@0HOxh
httpConnection.setRequestProperty("User-Agent","NetFox"); }g}6qCv7
String sProperty = "bytes="+nStartPos+"-"; a ]>VZOet
httpConnection.setRequestProperty("RANGE",sProperty); >/b^fAG
Utility.log(sProperty); <E"*)Oi
-dg}BM
u-lrTa""z
InputStream input = httpConnection.getInputStream(); N].4"0Jv-D
//logResponseHead(httpConnection); KZECo1
,SAbC*nq
GXO4x|08F
byte[] b = new byte[1024]; *0O<bm
int nRead; O-Dc[t%
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) gyC^K3}
{ otU@X 3<_
nStartPos += fileAccessI.write(b,0,nRead); _]P a>8X*
//if(nThreadID == 1) _=uviMuE
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VR"8Di&)
} MM7"a?y)
=Qyqfy*@D?
6mwvI4)
Utility.log("Thread " + nThreadID + " is over!"); .Nc_n5D6
bDownOver = true; Pow|:Lau!
//nPos = fileAccessI.write (b,0,nRead); ,`<]>;s
} Bgf=\7;5
catch(Exception e){e.printStackTrace ();} TNx_Rc}
} \F[n`C"Is
} ?k"0w)8
7 xUE,)?
mIRAS"Q!m
//打印回应的头信息 C}9Kx }q
public void logResponseHead(HttpURLConnection con) .U<F6I:<md
{ C]/&vh7ta
for(int i=1;;i++) FK6K6wU52m
{ 6Hda]y
String header=con.getHeaderFieldKey(i); #aa1<-&H
if(header!=null) \OP9_J(*
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _y>}#6B
Utility.log(header+" : "+con.getHeaderField(header)); 'v\j.j/i
else W;.{]x.0
break; .`Sw,XL5
} :xM}gPj"
} YhS{$Z
mzu<C)9d,
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public void splitterStop() <E SvvTf
{ |!oXvXU
bStop = true; lO[E[c G
} 0#<WOns1
uNy!<u
n_J5zQJ
} Jns/v6
]Ym=+lgi
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/* VxkEez'|
**FileAccess.java X CzXS.
*//文件访问(定位，写) +|9f%f6vp
package NetFox; y[7C% Wj
import java.io.*; /,X7.t_-
Uh}+"h5
nW11wtiO.
public class FileAccessI implements Serializable{ g**5z'7
^Wm*-4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 N2T&,&,t
RandomAccessFile oSavedFile; JxHv<p[
long nPos; ).Q[!lly
'=p?
BR3wX4i\
public FileAccessI() throws IOException -n-Z/5~ X
{ (V!0'9c
this("",0); PGkCOmq
} C;ptir1G;
1)'Iu`k/
[EER4@_
public FileAccessI(String sName,long nPos) throws IOException 7/ t:YBR
{ {<!hlB
oSavedFile = new RandomAccessFile(sName,"rw"); 7C?E z%a@
this.nPos = nPos; Tv1]v.
oSavedFile.seek(nPos); ;5N41_hG
} ^;4YZwW5w
a5)JkC
1U'ZVJ5bpK
public synchronized int write(byte[] b,int nStart,int nLen) fq=:h\\G
{ AC'lS >7s
int n = -1; >P<'L4;
try{ zC#%6@P\
oSavedFile.write(b,nStart,nLen); 2 ZK%)vq0
n = nLen; m2Q$+p@
} i\ "{#
catch(IOException e) EWO /u.z
{ @%:E }
e.printStackTrace (); h"r!q[MNo
} @<a|
M|H2kvl
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return n; Y0}4WWV
} i(Vm!Y82
7VY8CcL
x%pRDytA
} onib x^Fcd
NNmM#eB:4
S}b~_}
/* F)7j@h^
**SiteInfoBean.java 9$wAm89
*/ ##GY<\",;
package NetFox; {m'AY)
c})wD+1
vzG ABP
public class SiteInfoBean { e,"FnW
3e *-\TP-
)P%4:P
private String sSiteURL; //Site's URL E<k^S{
private String sFilePath; //Saved File's Path fdLBhe#9M
private String sFileName; //Saved File's Name 9(Jy0]E~
private int nSplitter; //Count of Splited Downloading File R(`]n!V2
gs>A=A(VYf
gvlFumg2
public SiteInfoBean() #2N_/J(U
{//nSplitter的缺省值为5 X|'2R^V.
//default value of nSplitter is 5 MnS+nH!d
this("","","",5); =+\$e1Mb*
} O+b6lg)q
AOAO8%|I
\OY}GRKt
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) j76%UG\Ga
{ K[]K53Nk
sSiteURL= sURL; v^TkDf(Oz
sFilePath = sPath; %/!+(7 D
sFileName = sName; <]'|$8&jY
this.nSplitter = nSpiltter; V)h y0_
~ aA;<#
t#~XLCE
} _*n)mlLln
e=L*&X
0qR$J
public String getSSiteURL() ^cn@?k((A
{ Yt*vqm[WV
return sSiteURL; 4DM*^=9E
} d- kZt@DL=
OpUA{P
Y;eoTJ
public void setSSiteURL(String value) Tyd h9I
{ 6]ZO'Nwo
sSiteURL = value; |6*Va%LYO-
} 0 u2Ny&6w
9(OAKUQ
ju.OW`GM
public String getSFilePath() K_&_z
{ vpV$$=Qwp
return sFilePath; Qsji0ikG
} 37jQ'O U
LihdZ )
N iISJWk6'
public void setSFilePath(String value) `;/XK,m-
{ uY]T:UVk
sFilePath = value; ]5)"gL%H`
} `I#`:hj
lRH0)5`
LD_M 3 P
public String getSFileName() /ao<A\KR
{ 7 Kjj?~RA
return sFileName; %"+4 D,'l
} Fs)
qRl/Sl#F
4m\([EO
public void setSFileName(String value) DJ|BM+
{ *m&%vj.Kc
sFileName = value; jzMg'z/@J
} `)2[ST
oLw|uU-|
gmDR{loX
public int getNSplitter() h1c{?xH2r
{ K"^cq~
return nSplitter; O{u[+g
} !t%Q{`p
qK,V$l(4#
1!1DuQ
public void setNSplitter(int nCount) =hhvmo
{ ,2_w=<hq
nSplitter = nCount; F9O`HFVK
} lvPpCAXY
} wE4;Rk1
vcM~i^24)
:~erh}~ps
/* gCL{Cw
**Utility.java <r3Jf}%tT
*/ W #47Cz
package NetFox; ~b#OFnyG
PT05DH
ftaBilkjp
public class Utility { :G0+;[?N
4i`S+`#
>j:|3atb
public Utility() cd+^=esSO
{ DyIV/
-!~vA+jw1
kF?S 2(vH
} b|6!EGh
SBz/VQ
//线程睡眠 >>j+LRf*
public static void sleep(int nSecond) #4N >d~
{ qw2)v*Fn
try{ XECikld>
Thread.sleep(nSecond); s6/cL|Ex
} 2m_H*1HJ
catch(Exception e) Rf?%Tv0\
{ /`}6rXnw9
e.printStackTrace (); mYzcVhV
} >]-<uT_
} p7$3`t6u
)tvc/)&A}
//日志 7PA=)a\
public static void log(String sMsg) A6Q c;v+
{ ?R282l
System.err.println(sMsg); Lrlk*
} FCAJavOGH
H4 =IY
U1jSUkqb
public static void log(int sMsg) @2?=3Wf
{ ]1tN|ODY*W
System.err.println(sMsg); PF`:1;PU
} m|mG;8}pI
} hwp/jO:7\
wa2~C [
Hva{A #
/* a}w&dE$!-
**TestMethod.java 3<3t;&e
*/ Z@u ;Z[@
package NetFox; ]o `4Z"
?`"<DH~:0B
m EFWo
public class TestMethod { [?|5oaK
pj+tjF6Np
=/m}rcDN
public TestMethod() PYaOH_X.
{ ///xx/weblogic60b2_win.exe }^Z< dbt
try{ t:disL&!E
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6kC)\uy
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `u$24h'!
SiteFileFetch fileFetch = new SiteFileFetch(bean); CM"s9E8y
fileFetch.start(); ;2BPPZ
} f)WPOTEY
catch(Exception e){e.printStackTrace ();} pRmEryR(U
sY_fq.Z
WFXx70n
} ${e -ffyy
ijg,'a~3E
w2' 3S#nZ
public static void main(String[] args) |NXFla
{ ypxC1E
new TestMethod(); S;BP`g<l=
} N*? WUn9]
} CO7CNN
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