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)); Us&~d"n
} PR7bu%Y*eD
for(int i=0;i<nEndPos.length-1;i++) yyVJb3n5:!
{ ,0Udz0
nEndPos = nStartPos[i+1]; K nn<q=';G
} G7-.d/8|^
nEndPos[nEndPos.length-1] = nFileLength; =1B;<aZH!
} ) { "}bMf
} "[L+LPET
\@6w;tyi
IU}g[OCu
//启动子线程 G"yhu +
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; C0e oV}
for(int i=0;i<nStartPos.length;i++) y3'K+?4
{ viS7+E|O
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %.IW H9P7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ap|V}jC
nStartPos,nEndPos,i); [ dVRVm0N
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x2]chN
fileSplitterFetch.start(); .a]av
} _32 o7}!x
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :bp8S@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Wzh#dO?7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Qo["K}Ty
nEndPos = " + nFileLength); )Oj%3
// fileSplitterFetch[nPos.length-1].start(); g7LS
(TGG?V
j=b-Y
//等待子线程结束 P<xCg
//int count = 0; ~rz%TDX0\
//是否结束while循环 %Zu+=IZ
boolean breakWhile = false; 'F8:|g
za4:Jdr
DVyxe}
while(!bStop) AUkePp78
{ ~c GH+M@
write_nPos(); uchz<z1
Utility.sleep(500); 0R?LWm j
breakWhile = true; ]M9r<x*
M}F) P&Y
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for(int i=0;i<nStartPos.length;i++) 5l(NX
{ _/[(&}M
if(!fileSplitterFetch.bDownOver) 2Yd;#i)
{ e~BUAz
breakWhile = false; #]o#~:S=
break; Rlf#)4
} 'St\$X
} z2A1h!Me
if(breakWhile) m3K .\3
break; {d,~=s0T
ob.=QQQs
&!FWo@
//count++; !tofO|E5
//if(count>4) |b:91l
// siteStop(); KF`@o@,
} rwou[QU
>NN&j#;x~
HBnnIbEtF'
System.err.println("文件下载结束！"); Vam4/6
} y\"Kur*O
catch(Exception e){e.printStackTrace ();} J'>i3eLq
} ep2#a#&'
uCNi&.
T"$yh2tSY
//获得文件长度 <U() *0
public long getFileSize() ta 66AEc9
{ hzjEO2
int nFileLength = -1; Lk|%2XGO&
try{ <);Nc1
URL url = new URL(siteInfoBean.getSSiteURL()); _7"G&nZ0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g4 |s9RMD
httpConnection.setRequestProperty("User-Agent","NetFox"); wfxg@<WR
xui.63/
2,X~a;+
int responseCode=httpConnection.getResponseCode(); Sc zYL?w^
if(responseCode>=400) _*O^|QbM
{ >~sAa+Oxi
processErrorCode(responseCode); 80M"`6
return -2; //-2 represent access is error 2Y@:Vgg
} q-fxs8+m|
`'{>2d%\g
M6P`~emX2
String sHeader; >wpC45n)9N
}qf)L.
(hn@+hc
for(int i=1;;i++) ,5_Hen=PI
{ iwl\&uNQU
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ni@N/Z?!pA
//Utility.log(in.readLine()); <Yk#MeiEp
sHeader=httpConnection.getHeaderFieldKey(i); BQcrF{q
if(sHeader!=null) y[s* %yP3l
{ aD1G\*AFJ
if(sHeader.equals("Content-Length")) %!G]H
{ f"j"ZM{~U
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6mnj!p]3
break; \WnI&nu
} rVx%"_'*-
} oc>ne]_'
else _Kp{b"G
break; q89#Ftkt
} <wt#m`Za
} #[^?f[9r
catch(IOException e){e.printStackTrace ();} G H N
catch(Exception e){e.printStackTrace ();} O3JN?25s
@tY)s
Lzzf`jN]
Utility.log(nFileLength); I-E}D"F;p[
8,BNs5
ZqHh$QBD 9
return nFileLength; %C_RBd
} HB+\2jEE
4}FuoQL
^FJ=/#@T
//保存下载信息（文件指针位置） -'FzH?q:
private void write_nPos() uP\?y(="
{ k#8,:B2
try{ S{7*uK3$
output = new DataOutputStream(new FileOutputStream(tmpFile)); e7f3dqn0
output.writeInt(nStartPos.length); _7(>0GY
for(int i=0;i<nStartPos.length;i++) Vx5ioA]{
{ .z u0GsU=
// output.writeLong(nPos); G2]/g
output.writeLong(fileSplitterFetch.nStartPos); `B{N3Kxbp
output.writeLong(fileSplitterFetch.nEndPos); A2{u("^[6
} d`D<PT(\
output.close(); Hmt}@
} -hav/7g
catch(IOException e){e.printStackTrace ();} >t|u 8/P
catch(Exception e){e.printStackTrace ();} $=7[.z&
} TFbMrIF
^YddVp
`A8nAgbe
//读取保存的下载信息（文件指针位置） S}Wj+H;
private void read_nPos() 9NTBdo%u
{ X/
try{ f>k<I[C<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <]6])f,y\
int nCount = input.readInt(); tG(#&54
nStartPos = new long[nCount]; [A?Dx-R;(
nEndPos = new long[nCount]; 0?} ),8v>
for(int i=0;i<nStartPos.length;i++) Hi$J@xU
{ (9r\YNK
nStartPos = input.readLong(); b4GD}kR
nEndPos = input.readLong(); xSFY8
} 8W$uw~|dw
input.close(); GAONgz|ZI
} 1!,xB]v1Ri
catch(IOException e){e.printStackTrace ();} . :Q[Z
catch(Exception e){e.printStackTrace ();} Y4cIYUSc
} j(4BMk
TwBwqQ)t
(Zi(6 T\z
private void processErrorCode(int nErrorCode) \}SA{)
{ Xx_v>Jn!
System.err.println("Error Code : " + nErrorCode); C8qA+dri
} lub(chCE[
zPWX%1Qr
DIR_W-z
//停止文件下载 GxWA=Xp^~G
public void siteStop() KE3/sw0
{ vL"U=Q+/eY
bStop = true; pI2g\cH>
for(int i=0;i<nStartPos.length;i++) qdoJIP{
fileSplitterFetch.splitterStop(); x<#Z3Kla
?I{pv4G:
<Cc}MDM604
} _" 0VM>
} B{'x2I#,
//负责部分文件的抓取 __HPwOCG7
**FileSplitterFetch.java #g,JNJ}
*/ U$o\?4
package NetFox; |:_WdU"Q]
ZS51QB
B0Ql1x#x
import java.io.*; bl. y4
import java.net.*; jQjtO"\JG
~A<1xszC
MQc|j'vEY
public class FileSplitterFetch extends Thread { u4QPO:,a4
C'x?riJ/
B WdR~|2
String sURL; //File URL rblEyCR
long nStartPos; //File Snippet Start Position ld58R
long nEndPos; //File Snippet End Position dKyJ.p
int nThreadID; //Thread's ID 49b#$Xq
boolean bDownOver = false; //Downing is over rZ<n0w
boolean bStop = false; //Stop identical E!.>*`)?.
FileAccessI fileAccessI = null; //File Access interface >?iL_YTX
K3jKOV8
ER0nrTlB<
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7PG&G5
{ yRt]i>
this.sURL = sURL; Vae}:8'}
this.nStartPos = nStart; r7w1~z
this.nEndPos = nEnd; 4%L`~J4 wr
nThreadID = id; ZMO7o 1"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1eue.iuQ
} !#0Lo->OO
61e)SIRz9I
*?'nA{a)E
public void run() * SH5p
{ <SeK3@Gi
while(nStartPos < nEndPos && !bStop) SV%;w>
{ },9Hq~TA
`I|$U)'
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try{ aO:wedfl
URL url = new URL(sURL); 5yPw[ EY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ciRn"X=l
httpConnection.setRequestProperty("User-Agent","NetFox"); rro92(y
String sProperty = "bytes="+nStartPos+"-"; x6Q,$B
httpConnection.setRequestProperty("RANGE",sProperty); ];& @T\Rj
Utility.log(sProperty); 'Rbv3U
&''lOS|
#-S%aeB
InputStream input = httpConnection.getInputStream(); F+yu[Dh:
//logResponseHead(httpConnection); v@_}R_pX
T,z7U2O
W"j&':xD
byte[] b = new byte[1024]; Z$qLY<aV
int nRead; OW}ny
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *E$&
{ Ql`N)!
nStartPos += fileAccessI.write(b,0,nRead); ^0oOiZs
//if(nThreadID == 1) D#VUx9kugv
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); NDsF<2A4
} V~nqPh!Jc
@smjXeFo
*F:f\9
Utility.log("Thread " + nThreadID + " is over!"); (^h2'uB
bDownOver = true; tf1iRXf8
//nPos = fileAccessI.write (b,0,nRead); ?K5S{qG'O
} 3zC<k2B
catch(Exception e){e.printStackTrace ();} PfF5@W;E;
} o$PY0~#
} C/34K(
,3+#?H
KK-}&N8
//打印回应的头信息 CKB~&>xx
public void logResponseHead(HttpURLConnection con) /6Bm <k%
{ _x+)Tv
for(int i=1;;i++) `i~kW
{ '!\t!@I$
String header=con.getHeaderFieldKey(i); _k'?eZB
if(header!=null) 0Y|"Bo9k
//responseHeaders.put(header,httpConnection.getHeaderField(header)); c&>S
Utility.log(header+" : "+con.getHeaderField(header)); >#u9W'@|
else $U*b;'o
break; msf%i!
} H6o_*Y
} -l(G"]tRB
q8m[ S4Q]g
(R^qY"H 2
public void splitterStop() 7T69tQZ<
{ }.L:(z^L,Y
bStop = true; 8x~'fzf;Sq
} zg}#X6\G<_
}5b,u6
xwhS[d
} %(}%#-X
yg WwUpY
HrK7qLw7
/* PP{s&(
**FileAccess.java z(dDX%k@
*//文件访问(定位，写) +*`>7m<^
package NetFox; $z,rN\[
import java.io.*; WF_24Mw
W.sH
2J&J
public class FileAccessI implements Serializable{ os[i
*|B5,Ey
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @W.0YU0|J
RandomAccessFile oSavedFile; Iy;bzHXs
long nPos; mV;)V8'
Ae8P'FWB>
tGwQUn
public FileAccessI() throws IOException lPA:ho/`:
{ ?WBA:?=$58
this("",0); )Im3';qt
} ;mauA#vd
Ih_=yk
2PViY,V|
public FileAccessI(String sName,long nPos) throws IOException f)#nXTXeC
{ 7hAc6M$h;
oSavedFile = new RandomAccessFile(sName,"rw"); l0BYv&tu
this.nPos = nPos; ?'mi6jFFh
oSavedFile.seek(nPos); *?R<gWCF
} BDcA_=^R&
w9,w?%F
YPmgR]=6
public synchronized int write(byte[] b,int nStart,int nLen) Eemk2>iP?
{ Lw<%?F (
int n = -1; f}:W1&LhI?
try{ PbIir=
oSavedFile.write(b,nStart,nLen); n_S)9C'=
n = nLen; - -ZSl
} 5^e|802
catch(IOException e) JU!vVA_
{ 8?[#\KgH1
e.printStackTrace (); BE,H`G #h
} KFf6um
HyJ&;4rf
9D H}6fO
return n; Qg5-I$0
} (k<__W c_t
cE7IHQ
}^Ky)**
} (E<QA
?T7ndXX
11BfJvs:
/* F:cenIaBF
**SiteInfoBean.java &BkdC,o
*/ l3;MjNB^V
package NetFox; g;Lk 'Ky6
8 FqhSzw
|<q9Ee
public class SiteInfoBean { )O~V3a
!7KSNwGu
W]t!I}yPR
private String sSiteURL; //Site's URL z+Cw*v\Y
private String sFilePath; //Saved File's Path dcGs0b
private String sFileName; //Saved File's Name L:(>ON
private int nSplitter; //Count of Splited Downloading File ?1G7=R
1gTW*vLM\
r[TTG0|
public SiteInfoBean() I,:R~^qJ8v
{//nSplitter的缺省值为5 38[ko3
//default value of nSplitter is 5 qXH\e|
this("","","",5); Q^iE,_Zq
} .[1"3!T
n]N+
J*lKXFq7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Bj ~bsT@a.
{ n8!qz:z/
sSiteURL= sURL; ^zMME*G
sFilePath = sPath; Zy>iaG9}
sFileName = sName; Kf.G'v46
this.nSplitter = nSpiltter; }nQni?
!w!}`|q
"K"]/3`k-
} Q bg,q
>|"mhNF
x tJ_azt
public String getSSiteURL() m5G9 B-\?
{ 7^fpbrj
return sSiteURL; j#C1+Us
} YSvZ7G(m>
:`9hgd/9
0u?{"xH{+}
public void setSSiteURL(String value) j &#A 9!
{ n>_EEw2/
sSiteURL = value; ]y4(WG;:
} H9x,C/r,
\,w*K'B_Y
rcC}4mNe
public String getSFilePath() 3H_mR j9th
{ LEq"g7YH
return sFilePath; DA/l`Pn
} LIo3a38n?y
GJUorj&
n>)'!
public void setSFilePath(String value) .%.kEJh`
{ GAZTCkB"
sFilePath = value; +s*OZ6i [
} +>em !~3
_^)Wrf+
B@:c8}2.
public String getSFileName() 9@Iz:!oqb
{ UBmD 3|Zo
return sFileName; }@6/sg
} 73-*|@6
`5[$8;
KtT.WHr(m
public void setSFileName(String value) *h<= (Y%
{ #Ub"Ii
sFileName = value; s`j QX\{
} hi{#HXa
X{n7)kgL
*wgHa6?+7
public int getNSplitter() !)jw o=l}J
{ dQ6n[$Q@N
return nSplitter; LvWl*:z
} uHBEpqC%
E<[_L!2
1'skCR|!<
public void setNSplitter(int nCount) Q?f%]uGFQ
{ [0_JS2KE
nSplitter = nCount; `y&d
} [}7j0&
} i+/:^tc;
"(@W^qF}d
~R;9a"nr
/* 63s<U/N
**Utility.java ;j#$d@VG"
*/ Q^^.@FU"x
package NetFox; "2>I?
<@BzF0
:ZP4(}
public class Utility { #RE
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x.V6C0|6"
public Utility() 0-)D`s%
{ q<Zdf
:<-,[(@bR
4$~]t:n
} r]XXN2[jO
G2FP|mf,
//线程睡眠 }yCw|B|a
public static void sleep(int nSecond) jzuOs,:R
{ _$<Q$P6y
try{ /?POIn+0o
Thread.sleep(nSecond); 5:jbd:o
} +O<0q"E
catch(Exception e) moQ><>/
{ /h4 ::,
e.printStackTrace (); 8\Y/?$on
} NLe+
} HaP0;9q
E"ju<q/Q
//日志 V\ud4
public static void log(String sMsg) \bt+46y@]
{ H'Mc]zw_,
System.err.println(sMsg); >*xa\ve
} #+V5$
MC.,n$O}6
cD-.thHO
public static void log(int sMsg) nZF(92v
{ ILt95l
System.err.println(sMsg); s52c`+
} >wK ^W{
} {~*aXu3
:kycIM]s
uN`{; Av
/* 0A%>'<
**TestMethod.java 8ALvP}H
*/ =d/\8\4
package NetFox; dw)SF,
7@g8nv(p
Wxl^f?I`:
public class TestMethod { n{F$,a
gWp\?La
nG;wQvc
public TestMethod() ![WX -"lW
{ ///xx/weblogic60b2_win.exe DpIv <m]
try{ bWv4'Y!p
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); MnvFmYgxA
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &sL(|>N
SiteFileFetch fileFetch = new SiteFileFetch(bean); @R=gJ:&a
fileFetch.start(); -bHQy:
} de{KfM`W;
catch(Exception e){e.printStackTrace ();} "J]_B
D'aq^T'
&H!3]
} ReOp,A/y
y@[}FgVOh
Evkb`dU3n
public static void main(String[] args) OKfJ
{ H4LZNko
new TestMethod(); '1A S66k
} xwa5dtcng
} A87JPX#R?
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