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)); aGBd~y@e
} 1d~d1Rd
for(int i=0;i<nEndPos.length-1;i++) je@&|9h
{ (a0(ZOKH
nEndPos = nStartPos[i+1]; Mk~U/oq
} e]nP7TIU
nEndPos[nEndPos.length-1] = nFileLength; oKYa?
} 8o[gzW:Q)U
} 'Kk/ J+6U
>;XtJJS
[ :)F-
//启动子线程 CuK>1_Dq
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; T_!F I29
for(int i=0;i<nStartPos.length;i++) cHt4L]n8n
{ kQe<a1 8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %3*|Su%uC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \?oT.z5VG&
nStartPos,nEndPos,i); k;jl3GV
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yKuZJXGVo
fileSplitterFetch.start(); '$Z@oCY#
} [) 0JI6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |||m5(`S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); VXiU5n^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )sW!s3>S>
nEndPos = " + nFileLength); pfu"vo(t_
// fileSplitterFetch[nPos.length-1].start(); |{(JUXo6K
GZWqPM4S\
epKr6 xq
//等待子线程结束 I{0cnq/
//int count = 0; !@])Ut@tN
//是否结束while循环 0ETT@/)]z
boolean breakWhile = false; w&f>VB~,1
CVvl &on
G62;p#
while(!bStop) V,rR*a&p
{ u:']jw=f
write_nPos(); n_4.`vs
Utility.sleep(500); 6eUGE4NF(
breakWhile = true; M*bsA/Z
Y[vP]7-
2+I5VPf
for(int i=0;i<nStartPos.length;i++) [u;(4sa}
{ H>D sAHS
if(!fileSplitterFetch.bDownOver) Y@:l!4DI
{ _f8H%Kgk;
breakWhile = false; MM]0}65KG
break; t\LE\[XM>
} 50dN~(;p
} )b (+=
if(breakWhile) WMnSkO
break; 7D,nxx(`
dl[%C6
7FkiT
//count++; BJ]L@L%
//if(count>4) FX9WXb4w
// siteStop(); *J]p/<> {
} \a7m!v
IJKdVb~
c~/poFj
System.err.println("文件下载结束！"); O7_y QQAA
} G /$+e
catch(Exception e){e.printStackTrace ();} ygV_"=+|N
} pGD-K41O]
v(R^LqE
f+ZOE?"
//获得文件长度 +zbCYA
public long getFileSize() :R +BC2x
{ n7B2rRJH
int nFileLength = -1; lK/4"&
try{ ^wc:qll
URL url = new URL(siteInfoBean.getSSiteURL()); @=Pc{xp
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *~4<CP+"0
httpConnection.setRequestProperty("User-Agent","NetFox"); o/ 51RH
AV|:v3
yPT o,,ca=
int responseCode=httpConnection.getResponseCode(); 5D=U.UdR
if(responseCode>=400) ]@cI_n
{ F'>yBDm*OM
processErrorCode(responseCode); }f_@@#KB?
return -2; //-2 represent access is error RhmkpboucC
} ctHQZ#.[(
o3\^9-jmp
f3n^Sw&Q(Q
String sHeader; t5_76'@cX
Z ztp %2c
y${`W94
for(int i=1;;i++) -hfkF+=U'
{ suIYfjh
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); o<p4r}*AVJ
//Utility.log(in.readLine()); %-fS:~$
sHeader=httpConnection.getHeaderFieldKey(i); p %.Adxx
if(sHeader!=null) rN7JJHV
{ *2N0r2t&
if(sHeader.equals("Content-Length")) "M+I$*]
{ \v+c.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )(yaX
break; :-U&_%#w
} @:B}QxC
} Y@q9
else oiR9NB&<
break; (pM&eow}
} ^fsC]9NS
} _g9j_ x:=
catch(IOException e){e.printStackTrace ();} ZU0*iA
catch(Exception e){e.printStackTrace ();} 4`9ROC
As5l36
M6quPj
Utility.log(nFileLength); I(kEvfxc"
js;YSg{m
Y1>OhHuN
return nFileLength; a%a0/!U[
} AqQ5L>:Gq
R>~I8k9mM
\(=xc2
//保存下载信息（文件指针位置） [-"ZuUG
private void write_nPos() :6%ivS
{ 9ghUiBPiL:
try{ ? p[Rv
output = new DataOutputStream(new FileOutputStream(tmpFile)); S76MY&Vx23
output.writeInt(nStartPos.length); YMNLn9
for(int i=0;i<nStartPos.length;i++) -Vb5d!(
{ htrtiJ1
// output.writeLong(nPos); eJn_gKWb
output.writeLong(fileSplitterFetch.nStartPos); K?e16;
output.writeLong(fileSplitterFetch.nEndPos); [~cz|C#
} K0o${%'@7
output.close(); wpC.!T
} ki2`gLK
catch(IOException e){e.printStackTrace ();} .X(qs1
catch(Exception e){e.printStackTrace ();} p/u
} ek/zQM@%
lb*;Z7fx<'
">h$(WCK
//读取保存的下载信息（文件指针位置） 0*kS\R=P
private void read_nPos() `'P&={p8
{ vaHtWz!P
try{ Voq/0,d
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ps8tr:T^=
int nCount = input.readInt(); P*}aeu&lnD
nStartPos = new long[nCount]; Y`$\o
nEndPos = new long[nCount]; Unq~lt%2
for(int i=0;i<nStartPos.length;i++) pmurG
{ tQxxm=>
nStartPos = input.readLong(); W?!rqo2SP
nEndPos = input.readLong(); ^ T`T?*h
} m:~y:.
input.close(); .q:6F*,1M
} 8yDsl
catch(IOException e){e.printStackTrace ();} J{kS4v*J
catch(Exception e){e.printStackTrace ();} #h9Gl@|
} vF~q".imC
P|lDW|}D@
Z-_Xt^N
private void processErrorCode(int nErrorCode) omPxU2Jw
{ u#y)+A2&!
System.err.println("Error Code : " + nErrorCode); qe e_wx
} car|&b
n_Y7*3/b-o
uTJz"c`F
//停止文件下载 zLg$|@E&
public void siteStop() XDyo=A]
{ gcO$T`
bStop = true; & @_PY
for(int i=0;i<nStartPos.length;i++) Ku uiU= (L
fileSplitterFetch.splitterStop(); xI#rnx*
p15dbr1
2 w! 0$
} 3,*A VcQA
} "H@I~X=
//负责部分文件的抓取 WD[jEWMV7D
**FileSplitterFetch.java aTvLQ@MQ
*/ c(b`eUOO
package NetFox; 6CGk*s
L*4=b (3
*A}td8(
import java.io.*; ~ oq.yn/1
import java.net.*; 7(C)vtEO:
saQo]6#
Vj8-[ww!
public class FileSplitterFetch extends Thread { \`2EfYJ{
0jxXUWO
>XRf= :3
String sURL; //File URL gVJh@]8)
long nStartPos; //File Snippet Start Position usoyH0t!?
long nEndPos; //File Snippet End Position u$ci{<
int nThreadID; //Thread's ID @;{ZnRv14
boolean bDownOver = false; //Downing is over $$Ibr]$5
boolean bStop = false; //Stop identical KiE'O{Y
FileAccessI fileAccessI = null; //File Access interface .A6pPRy e
r9b(d]
? IlT[yMw
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException OS>%pgv
{ 87)/dHc
this.sURL = sURL; At[SkG}b
this.nStartPos = nStart; i*&b@.7N
this.nEndPos = nEnd; R `ob;>[Q
nThreadID = id; VJCj=jX
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Y<N#{)Q
} I)r6*|mz
}&s |~
1E4`&?
public void run() d#ab"&$bv
{ SymlirL
while(nStartPos < nEndPos && !bStop) _o+OkvhU
{ M9~'dS'XI
B7[#z{8'#
dPV<:uO
try{ b%C7 kL-
URL url = new URL(sURL); el<[Ng[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]1h9:PF
httpConnection.setRequestProperty("User-Agent","NetFox"); sdd%u~4,X
String sProperty = "bytes="+nStartPos+"-"; 9>&p:+D
httpConnection.setRequestProperty("RANGE",sProperty); : ?Z9
Utility.log(sProperty); W!=ur,F+
>*+n`"6
7<2^8`
InputStream input = httpConnection.getInputStream(); LCHw.
//logResponseHead(httpConnection); ! 8Ro5),
W~l.feW$i
m>!o Yy_
byte[] b = new byte[1024]; +I:/8,&-x
int nRead; w-@6qMJ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) a|]}uFr
{ 6aWnj*dF
nStartPos += fileAccessI.write(b,0,nRead); 4>B=k
//if(nThreadID == 1) =dWqB&
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g]?>6 %#rA
} C8(0|XX
.+lx}#-#
$}0\sj%
Utility.log("Thread " + nThreadID + " is over!"); |gT8QP
bDownOver = true; ,,S 2>X*L
//nPos = fileAccessI.write (b,0,nRead); e_S,N0
} D7jbo[GgS
catch(Exception e){e.printStackTrace ();} usi3z9P>n
} }`76yH^c
} 4:s,e<Tc4v
^7*zi_Q
,~Lx7 5{
//打印回应的头信息 52'6wwv6?
public void logResponseHead(HttpURLConnection con) 7WNUHLEt
{ _0iV6Bj
for(int i=1;;i++) =66'33l2
{ $B]_^
String header=con.getHeaderFieldKey(i); g/w<T+v
if(header!=null) |h.@Xy
//responseHeaders.put(header,httpConnection.getHeaderField(header)); g6?5
Utility.log(header+" : "+con.getHeaderField(header)); x-q_sZ^8
else u})8)
break; | `?J2WGe
} Q>G% *?
} emT/H95|,
fUq #mkq}
)3 '8T>^<K
public void splitterStop() <Iil*\SC
{ iBY16_q
bStop = true; .kfx\,lgm
} xd+aO=)Td
[z'jL'\4
/3;]e3x
} 3/,}&SX
kJCeQK:W
EO/41O
/* >h$Q%w{V
**FileAccess.java bUuQ"!>ppu
*//文件访问(定位，写) :8A@4vMS)?
package NetFox; P9jSLM
import java.io.*; ]L k- -\
T^#d\2
}>b@=5O
public class FileAccessI implements Serializable{ CSBDSz
A,?6|g`q'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ehZ/J5
RandomAccessFile oSavedFile; ,}l|_GGj
long nPos; 3sl6$NKo
qCF&o7*oN
6$H`wDh#(&
public FileAccessI() throws IOException O;0VKNn['
{ ?gMq:[XN
this("",0); D"IxQ2}k
} Ou+bce
#6C<P!]V
f @Vd'k<
public FileAccessI(String sName,long nPos) throws IOException \:2z!\iP`
{ 6!([Hu#= *
oSavedFile = new RandomAccessFile(sName,"rw"); *Xh#W7,<
this.nPos = nPos; E,Xl8rC
oSavedFile.seek(nPos); $h5QLN
} &%u m#XE
p ^9o*k`u
4P#4RB
public synchronized int write(byte[] b,int nStart,int nLen) ~6+>2|wIS
{ \~l"
int n = -1; a;\a>N4
try{ apnpy\in
oSavedFile.write(b,nStart,nLen); [I7=]X
n = nLen; 2#s8Dxt
} |\94a
catch(IOException e) e{^^u$C1.e
{ (i1p6
e.printStackTrace (); B;2#Sa.
} 3Zwhv+CP[
#c~-8=
'lOQb)
return n; }rF4M1+B\
} zjzEmX
3ug~m-_
i(V
} j]aIJbi
,bP8"|e
a%?v/Ku
/* _,igN>
**SiteInfoBean.java ~yA^6[a=
*/ O9N+<sU=X
package NetFox; O'QnfpQ*9
uO1^nK
@q{.
public class SiteInfoBean { D[4%CQ1m
VFm)!'=I
Yu9VtC1
private String sSiteURL; //Site's URL 8?|W-rN
private String sFilePath; //Saved File's Path ft0tRv(s:
private String sFileName; //Saved File's Name 3}C-Hg+gt
private int nSplitter; //Count of Splited Downloading File JOs kf(
<vu~EY0.
^N`KT
public SiteInfoBean() LxiN9
{//nSplitter的缺省值为5 CZ%KC$l.5
//default value of nSplitter is 5 }iLi5Qkx
this("","","",5); fG{3S:TQq
} =l6WO*
ZVit]3hd
Oi{J}2U
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) qoW$Iw*q)B
{ :`0,f?cE
sSiteURL= sURL; > kwhZ/x
sFilePath = sPath; llCE}Vdh
sFileName = sName; XXQC`%-]<i
this.nSplitter = nSpiltter; L:Faq1MG
KvI/!hl\
=PnNett}a
} ~bis!(}p-
Iv{iJoe;UH
auM1k]
public String getSSiteURL() $jBi~QqOf
{ vq@"y%C4
return sSiteURL; }"q#"s
} Oo ^AE
_ -,[U{
0XE(vc!
public void setSSiteURL(String value) (X (:h\^
{ CI+liH
sSiteURL = value; R1.Yx?
} 7dlMDHp\Y
b0tbS[j
psS^
public String getSFilePath() ur]WNk8bN
{ ':utU1dL
return sFilePath; 8zwH^q[`r
} ?pA_/wwp
"k),;1
K5(T7S
public void setSFilePath(String value) SO~pe$c-
{ sr~VvciIy
sFilePath = value; GW]t~EL
} dO-Zj#%7z8
n9 Jev_!A
#!rH}A>n+
public String getSFileName() F-$NoEL
{ {4%ddJn[.)
return sFileName; g](&H$g
} &3*r-9BZ
-{yG+1
uR!'v
public void setSFileName(String value) O[=W%2I!i
{ u#->?
sFileName = value; y!j>_m){w
} 6-nf+!#G
eJEcLK3u
1+tPd7U
public int getNSplitter() |J^I8gx+
{ ZjnWbnW
return nSplitter; 7[}WvfN8#
} ~\c j
\,`iu=YZv
XK(aH~7xme
public void setNSplitter(int nCount) \/r]Ra
{ E7]a#
nSplitter = nCount; [bN_0T.YI
} 1ay{uU!EL
} t1aKq)?
J5\2`U_FZ
=5h,ZB2A
/* 'ExQG$t
**Utility.java iP?=5j=4
*/ X""}]@B9z
package NetFox; 4eS(dPI0
|C\XU5}
$60]RCu
public class Utility { Oxh.&
5U(ry6fI=
p%CcD]o
public Utility() W; ?'
{ n UD;y}}n
':T6m=yv
K_BF=C.k
} $C6O<A
1=Q3WMT
//线程睡眠 AW`+lE'?
public static void sleep(int nSecond) BoPJ;6?>}
{ ro@`S:
try{ eHI7= [h
Thread.sleep(nSecond); irzWk3@:
} Dad*6;+N
catch(Exception e) },tn
{ 7j\jOklV
e.printStackTrace (); tje
} sVT\e*4m}
} /9soUt
+8q]O%B
//日志 :jljM(\
public static void log(String sMsg) !4!Y~7sI"\
{ $~2qEe.h
System.err.println(sMsg); uE{nnNZy
} S,TK;g
vFGFFA/K}N
!&OybjQ
public static void log(int sMsg) )6:nJ"j#
{ 3xGk@ 333
System.err.println(sMsg); ?Wm.'S'to
} GT} =(sD L
} N!&$fhY)
C~dD'Tq]
U[UjL)U
/* i0-zGEMB.
**TestMethod.java Z6I^HG{:
*/ L5tSS=
package NetFox; O7z-4r
>O:j.(*!
Jr4^@]78o<
public class TestMethod { p%v+\T2r
2|n~5\K|t
0*KU"JcXd
public TestMethod() [LJ1wBMw
{ ///xx/weblogic60b2_win.exe T};fy+iq
try{ v&GBu
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8s_'tw/{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); RRGCO+)*
SiteFileFetch fileFetch = new SiteFileFetch(bean); `_{^&W WS
fileFetch.start(); LL1HDG>l
} T>ds<MaLP
catch(Exception e){e.printStackTrace ();} >1=sw qa
.?YLD+\A
[9E<z2H
} {$ghf"
C4 &1M
7VdG6`TDR
public static void main(String[] args) P+Ta|-
{ (Wu_RXfCw_
new TestMethod(); yI 6AafS~
} W c"f
} 'bpx
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