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)); ,X/j6\VBO
} :}_hz )
for(int i=0;i<nEndPos.length-1;i++) ?q6#M&|j/I
{ Pz50etJ
nEndPos = nStartPos[i+1]; LB@<Q.b,U
} 8YZ9
nEndPos[nEndPos.length-1] = nFileLength; feXo"J
} -O &>HA
} wai3g-`
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&wi+)d
//启动子线程 La6 9or
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; rQzdHA
for(int i=0;i<nStartPos.length;i++) !v2/sq$G
{ }/J"/ T
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RrxbsG1HP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,|c;x1|O
nStartPos,nEndPos,i); IWYQ67Yj
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k*_Gg
fileSplitterFetch.start(); 'n h^;
} O#.YTTj
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =?|$}vDO[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); pbKmFweq
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (pH)QG
nEndPos = " + nFileLength); {n>.Y-=
// fileSplitterFetch[nPos.length-1].start(); 8`S1E0s
38sLyoG=i
=b66H]h?
//等待子线程结束 l4DBGZB
//int count = 0; q=^;lWs4
//是否结束while循环 qBF|' .$^
boolean breakWhile = false; (?A c`H
.]E"w9~
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while(!bStop) e oE)Mq
{ xqSZ{E:
write_nPos(); Dt!KgI3
Utility.sleep(500); $mK;{9Z
breakWhile = true; ~AWn 1vFc
1Z0Qkd(
*& w/*h$!
for(int i=0;i<nStartPos.length;i++) pku\)
{ iUz?mt;k
if(!fileSplitterFetch.bDownOver) BqJ|l7+
{ 7&,$
breakWhile = false; C'@I!m._i
break; `(j~b=PP
} =m<b+@?T
} `[$>S
if(breakWhile) ty5# a
break; >Ec;6V e
?9xWTVa8
0(o2<d7
//count++; J#:`'eEG
//if(count>4) V9/2y9u
// siteStop(); S.[L?uE~F
} B _ J2Bf
h% >ZN-K)
#Ey_.4S
System.err.println("文件下载结束！"); ,fiV xnQ
} qJ5b;=
catch(Exception e){e.printStackTrace ();} F&`%L#s|
} LV ]10v6
BZv:E?1z
t[;-gi,,
//获得文件长度 Wlg1t~1=
public long getFileSize() zvGncjMkC
{ 5222"yn"c
int nFileLength = -1; 7 2i&-`&4
try{ '=G6$O2
URL url = new URL(siteInfoBean.getSSiteURL()); L_T+KaQCH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |;:Kn*0/]
httpConnection.setRequestProperty("User-Agent","NetFox"); s5v}S'uO{
"%Ief4
n?c[ E+i;
int responseCode=httpConnection.getResponseCode(); #"oLz"{
if(responseCode>=400) pFs/ipZX^*
{ ,2 xD>+=
processErrorCode(responseCode); t"9r`0>
return -2; //-2 represent access is error mph9/ %]S
} ^fN/
?*UWg[
Uo9@Y{<B
String sHeader; @ o<OI
[g`4$_9S
<8~c7kT'
for(int i=1;;i++) _9"ZMUZ{
{ L{1[:a)']B
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ` >>]$ZJ
//Utility.log(in.readLine()); PDH|=meXM
sHeader=httpConnection.getHeaderFieldKey(i); Vxo?%Dj
if(sHeader!=null) daCkjDGl\
{ Rt,po
if(sHeader.equals("Content-Length")) 3-AOB3](
{ w('}QB`xad
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Za?BpV~
break; >bI\pJ
} `*0VN(gf'
} UdcV<#
else P}=n^*8(I
break; <}.!G>X
} 45BpZ~-
} E|oOd<z
catch(IOException e){e.printStackTrace ();} {|0YcL
catch(Exception e){e.printStackTrace ();} OK-*TPrc
T+gH38!e
YHY*dk*|C
Utility.log(nFileLength); yzl}!& E
)b%zYD9p
mQt0?c _
return nFileLength; PB*G#2W
} N/#x
2^=.f?_YR
Ll%}nti
//保存下载信息（文件指针位置） 6uUzky
private void write_nPos() .i )n1
{ E:uTjXt
try{ Jq"3xj
output = new DataOutputStream(new FileOutputStream(tmpFile)); !K2QD[x
output.writeInt(nStartPos.length); xEq?[M
for(int i=0;i<nStartPos.length;i++) O`!XW8
{ jrS$!cEo
// output.writeLong(nPos); sUQ Q/F6
output.writeLong(fileSplitterFetch.nStartPos); ,*\s
output.writeLong(fileSplitterFetch.nEndPos); (]?M=?0\
} 6cjCn
output.close(); LEN=pqGJ.
} 3me&isKL
catch(IOException e){e.printStackTrace ();} 6~>h;wC
catch(Exception e){e.printStackTrace ();} o*E32#l
} > Xij+tt{
Xwu&K8q21
j%ZBAk)}
//读取保存的下载信息（文件指针位置） eNH9`Aa
private void read_nPos() I!(BwYd
{ ttB>PTg#
try{ Q t>|TGz
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); uK#2vgT
int nCount = input.readInt(); g-u4E^,*|
nStartPos = new long[nCount]; )p#L"r^)
nEndPos = new long[nCount]; wi%ls8F
for(int i=0;i<nStartPos.length;i++) LOG>x!
{ 8 .K; 2
nStartPos = input.readLong(); 0ap'6
nEndPos = input.readLong(); 1fM`n5?"
} eHIcfp@&
input.close(); 8N |K
} GpO*As_2
catch(IOException e){e.printStackTrace ();} FI$ -."F
catch(Exception e){e.printStackTrace ();} MO| Dwuaf
} CbxWK#aMmB
WlW%z(RC
7 _"G@h
private void processErrorCode(int nErrorCode) )_>'D4l?
{ {KK/mAp{
System.err.println("Error Code : " + nErrorCode); {:\LFB_
} rf`xY4I\
RFSwX*!
OwNo$b]h`
//停止文件下载 @.)[U:N
public void siteStop() o!&+ _BKw
{ Vo.~1^
bStop = true; fo~*Bp()-E
for(int i=0;i<nStartPos.length;i++) 9@mvG^
fileSplitterFetch.splitterStop(); +!:=Mm
UUvCi+W
bVa?yWb.
} %2B1E( r%M
} /2*BdE[yG
//负责部分文件的抓取 |TQ4:P1T
**FileSplitterFetch.java cf^i!X0
*/ U9Ea}aN
package NetFox; M '%zA;Wl
@Jqo'\~&
#_K<-m%9
import java.io.*; Wi,)a{
import java.net.*; RED@|[Qh
Xx2t0AIB
!)`*e>]x
public class FileSplitterFetch extends Thread { D6fd(=t1Z
'qG-)2 t
/?b{*<TK
String sURL; //File URL o=Mm=;H
long nStartPos; //File Snippet Start Position \P"Ol\@
long nEndPos; //File Snippet End Position *XYp~b
int nThreadID; //Thread's ID Z( "-7_
boolean bDownOver = false; //Downing is over w8:
boolean bStop = false; //Stop identical 5:5d=7WX
FileAccessI fileAccessI = null; //File Access interface ^ uwth
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9x8Vsd
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %BT]h3dcSS
{ u~JR]T
this.sURL = sURL; ^^n (s_g
this.nStartPos = nStart; u i$4
this.nEndPos = nEnd; Bu?Qyz2O
nThreadID = id; E'6/@xM
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {.;qz4d`
} hM>.xr
,Jn` qvmi
nqTOAL9FF
public void run() WIAukM8~
{ k{hNv|:,
while(nStartPos < nEndPos && !bStop) BnDCK@+|Q
{ ^ZRZ0:rZ
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jP2#w{xq
try{ |b^UPrz)VS
URL url = new URL(sURL); rce._w }
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a"t~K
httpConnection.setRequestProperty("User-Agent","NetFox"); 4%_xTo
String sProperty = "bytes="+nStartPos+"-"; 4vvQ7e7
httpConnection.setRequestProperty("RANGE",sProperty); R(8?9-w
Utility.log(sProperty); %XZhSmlf
6R$Yh0%
o-AF_N
InputStream input = httpConnection.getInputStream(); ;+#Nb/M
//logResponseHead(httpConnection); 7`^Y*:(
rKT.~ZP\
">20`Mj8
byte[] b = new byte[1024]; _%\%
int nRead; 6-g>(g
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ]|=`-)AP3
{ /EegP@[
nStartPos += fileAccessI.write(b,0,nRead); _Y}cK|3
//if(nThreadID == 1) )~ &gBX
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ab.B?bx
} o61rTj
fgC@(dvfk
:qj;f];|
Utility.log("Thread " + nThreadID + " is over!"); YTTij|(
bDownOver = true; G-R83Orl
//nPos = fileAccessI.write (b,0,nRead); Ai^0{kF6
} JL{fW>5y|
catch(Exception e){e.printStackTrace ();} <r>Sj/w<D
} WiQVZ{
} o1*P|.`
3p?nQ O)L
\DBEs02
//打印回应的头信息 fOdqr
public void logResponseHead(HttpURLConnection con) }QQ 7jE
{ `R7dn/
for(int i=1;;i++) X?&{< vz
{ _6`GHx
String header=con.getHeaderFieldKey(i); MA}}w&
if(header!=null) X%N!gy
//responseHeaders.put(header,httpConnection.getHeaderField(header)); PBFpV8P,
Utility.log(header+" : "+con.getHeaderField(header)); s1#A0%gx
else bKzG5|Qu
break; D&G?Klq
} #Ak|p#7 ^
} 1wdc4>
~Eb:AC5
v<<ATs%w
public void splitterStop() _g( aO70Zu
{ wi+L4v
bStop = true; Yo=$@~vN]
} nD]MgT
("}C& 6)cB
9k6/D.Dz
} ;cPPx`0$9
Y|J=72!]
YK$[)x\S
/* Qb55q`'z
**FileAccess.java ~{-Ka>A
*//文件访问(定位，写) ])%UZM6
package NetFox; h|`R[
import java.io.*; 0E,QOF{o
fR+{gazk n
G-K{
public class FileAccessI implements Serializable{ ^;9l3P{
=n_z`I
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,oSn<$%/q
RandomAccessFile oSavedFile; qN9 ?$\
long nPos; YktZXc?iI<
x>tm[k
jt: *Y
public FileAccessI() throws IOException 4<)*a]\c5M
{ Z#(Y%6[u
this("",0); i "X" -)#
} #3{}(T7
*QIYq
wJp1Fl~
public FileAccessI(String sName,long nPos) throws IOException I|>.&nb
{ J7aYi]vI
oSavedFile = new RandomAccessFile(sName,"rw"); ST~YO
this.nPos = nPos; pFZ$z?lI
oSavedFile.seek(nPos); TX@ed
} 9^`cVjD5
&,:!gYN
>&R@L KP
public synchronized int write(byte[] b,int nStart,int nLen) 2Ub-ufkU
{ Li0+%ijM
int n = -1; i gjn9p&_
try{ 5K682+^5
oSavedFile.write(b,nStart,nLen); v&7<f$5
n = nLen; 84reyA
} *:"60fkoU
catch(IOException e) e8oAGh"
{ f&$;iE
e.printStackTrace (); f#m@eb
} >,'guaa
Y6hV ;[\F
PApr8Xe
return n; D^P0X:T]
} %zRuIDmv
P>)J:.tr0
r!eW]M
} 8t, &dq
RW1+y/#%P
T5e#Ll/
/* R^sgafGl=
**SiteInfoBean.java Z(tO]tQE
*/ 0aI@m
package NetFox; ,/TmTX--d
NZADHO@0
.f. tPm
public class SiteInfoBean { :oC;.u<*8
*8;<w~
' S,g3
private String sSiteURL; //Site's URL gzH;`,
private String sFilePath; //Saved File's Path *n# =3D
private String sFileName; //Saved File's Name @JLN3
private int nSplitter; //Count of Splited Downloading File }NGP!
x?u@ j7[
S?a4IK
public SiteInfoBean() ~)>.%`v&
{//nSplitter的缺省值为5 ZGI<L
//default value of nSplitter is 5 ?p 4iXHE
this("","","",5); V>E7!LIn.
} c93 Ok|
&`vThs[x
kTT%< e
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #.fJ M:"tG
{ _s5FYb#
sSiteURL= sURL; #Cy3x-!
sFilePath = sPath; |22vNt_
sFileName = sName; ZG#:3d*)
this.nSplitter = nSpiltter; ^;( dF<?'r
5 $$Cav
X%JyC_~<
} \v<S:cTf
AcH!KbYf
I*(kv7(c0
public String getSSiteURL() n_ ?+QF
{ yD.(j*bMK;
return sSiteURL; Rbr:Q]zGN
} gi5X,:[
+F-Y^):
^-mWk?>
public void setSSiteURL(String value) n+Conp/
{ 9mv0}I
sSiteURL = value; %{cVG-<_iz
} :V#xrH8R
a_{'I6a*,
C!+PBk[9
public String getSFilePath() tX1`/}``
{ )\2KDXc
return sFilePath; /38I(0
} V lO^0r^z
FV aC8Kw
z[R dM#L
public void setSFilePath(String value) ZU.E}Rn:
{ Bz>f
sFilePath = value; qvGmJN0
} COw!a\Jl
0Bkz)4R
Cc`-34/%
public String getSFileName() a MFUj+^
{ tQUKw@@Q
return sFileName; upZc~k!1\
} #*"V'dj;e
5=p<"*zJ
*3@8,~_tp
public void setSFileName(String value) O\Z!7UQ$
{ L>E{~yh
sFileName = value; eLXL5&}`fh
} Lyn{Uag
;~[}B v
1tiOf~)
public int getNSplitter() w\N\J^5,Q
{ ^4Xsdh5
return nSplitter; |]?W`KN0
} 8f)pf$v`
fi~@J`
)t7MD(
public void setNSplitter(int nCount) eX}aa0
{ A:z
nSplitter = nCount; Z(R0IW
} hy%5LV<(
} Vjo[rUW
:7obxW1X
=ONM#DxH
/* QXL .4r%
**Utility.java ggM~Chr
*/ J]S30&?
package NetFox; S*J\YcqSC
S>*i\OnI'
ycOnPTh
public class Utility { #<sK3PT
!T ,=kh
@.}Y'`9L
public Utility() `Je1$)%
{ QOrMz`OA
$""kZ
#=ij</
} 8No'8(dPX
`Eu,SvkFw
//线程睡眠 h>cjRH?e
public static void sleep(int nSecond) cT/mi":8{
{ %0}}Qt
try{ 2DJg__("
Thread.sleep(nSecond); /Lm~GmPt
} cVO-iPK
catch(Exception e) [cznhIvyO
{ K{@xZ)
e.printStackTrace (); @o'L!5Y
} 83'+q((<
} {+d)M
~[og\QZX
//日志 Vmh$c*TE
public static void log(String sMsg) vRf$#fBEQ
{ ~@X3qja
System.err.println(sMsg); RF'nwzM3
} s] ;P<
D2gyn-]\
wxPl[)E
public static void log(int sMsg) $ywROa]
{ P7bb2"_9
System.err.println(sMsg); /7p(%vr
} 41+WIa L
} l`:u5\ rM
1ZYo-a;)
T:2f*!r
/* @)[8m8paV
**TestMethod.java R)*l)bpZ#
*/ p$jAq~C
package NetFox; >b5 ;I1o=y
g"Ueo'd*
zF{~Md1
public class TestMethod { K`<HZK
Pi9?l>
XD0a :T)
public TestMethod() 6Uq;]@k%
{ ///xx/weblogic60b2_win.exe LayK&RwL
try{ 4(oU88z
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;~d$OM
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,RY;dX-#
SiteFileFetch fileFetch = new SiteFileFetch(bean); c|aX4=Z
fileFetch.start(); =h|cs{eT\2
} Zby3.=.e
catch(Exception e){e.printStackTrace ();} .oTS7rYw
t)?K@{ 9
Y`4 LMK[]
} ) )FLM^dj
&ynAB)
|s(Ih_Zn
public static void main(String[] args) l`A&LQ[
{ 0rI/$
new TestMethod(); IhZn
} ;bg]H >$U7
} Sf.OBU1rs
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