http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); ?c fFJl
} &RHx8zScP
for(int i=0;i<nEndPos.length-1;i++) K\lu;
{ zE}ry!{
nEndPos = nStartPos[i+1]; <]`|HJoy
} ,n>K$
nEndPos[nEndPos.length-1] = nFileLength; d:z7 U
} 6s!=de
} \K Kt&bKL
bNvc@oo
v//Drj
//启动子线程 `'bu8JK
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1u }2}c|
for(int i=0;i<nStartPos.length;i++) {HVsRpNEf
{ |F~U
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w(y 9y9r]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), criNeKa
nStartPos,nEndPos,i); kp)1s>c
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [4PiQyr
fileSplitterFetch.start(); d=g,s[FMm
} !(j<Y0xo:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =C^4nP-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [zCKJR
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", A- #c1KU!
nEndPos = " + nFileLength); ,C'mE''x
// fileSplitterFetch[nPos.length-1].start(); `yRt?UQRS
es$<Vkbp
|Ur$H!oe?'
//等待子线程结束 ]<_v;Q<t
//int count = 0; s|:j~>53
//是否结束while循环 Orlf5{P
boolean breakWhile = false; Cv`dK=n>
Z?eedVV@
0o 8V8 :
while(!bStop) 6D*x5L-1o
{ 9}G<\y
write_nPos(); Qb86*
Utility.sleep(500); q-+_Y `_\
breakWhile = true; 7;sF0oB5e
'H1k
EM'#'fBZ>Y
for(int i=0;i<nStartPos.length;i++) ;T>.
{ `2G%&R,k"D
if(!fileSplitterFetch.bDownOver) kNrd=s,-]D
{ ng[LSB*57Y
breakWhile = false; |1+mHp
break; rGQ([e
} GM0pHmC
} tRTJQ
if(breakWhile) ;,@Fz
break; YJZ`Clp?
AnBD~h h
+3R/g@n
//count++; W)odaab7
//if(count>4) YE-}1&8
// siteStop(); ~=$d>ZNQ
} ,e*WJh8k[
AIM<mU
'W p~8}i@
System.err.println("文件下载结束！"); mbIHzzW>
} (+bt{Ma
catch(Exception e){e.printStackTrace ();} %^;rYn3
} *adwCiB
9%?a\#C
,Q+.kAh !G
//获得文件长度 h,i=Y+1
public long getFileSize() 2)|G%f_lS
{ Okd7ua-f
int nFileLength = -1; *UdP1?Y
try{ p2wDk^$
URL url = new URL(siteInfoBean.getSSiteURL()); )JR&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [5MV$)"!j
httpConnection.setRequestProperty("User-Agent","NetFox"); [85tZr]
Cuom_+wV&
$69d9g8-(!
int responseCode=httpConnection.getResponseCode(); p!`S]\XEB
if(responseCode>=400) D+4$l+\u
{ G,@Jo[e
processErrorCode(responseCode); :LTjV"f
return -2; //-2 represent access is error B5#>ieM*
} Y\9zjewc
?Pt*4NaT;
(ZD~Q_O-
String sHeader; ~Z;.np(T
p3cb_
]P4?jKI
for(int i=1;;i++) 2-@z-XKn
{ F@-8J?Hl:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4{ED~w|
//Utility.log(in.readLine()); :io[9B [
sHeader=httpConnection.getHeaderFieldKey(i); >q1rdq
if(sHeader!=null) Y]"lcr}
{ tAS[T9B
if(sHeader.equals("Content-Length")) -N1X=4/fg
{ {6>:=?7]R
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); S2~im?^21
break; _j\8u`^n
} AXPdgo6
} XWUi_{zn
else X[1w(dU[
break; ##yH*{/&
} zQsW*)L
} -dH]_
catch(IOException e){e.printStackTrace ();} V`"Cd?R0Z
catch(Exception e){e.printStackTrace ();} d+IN-lR(
0@}:`OynX
F Xp_`9.zH
Utility.log(nFileLength); f.ws\^v%
Z67'/z$0
`_<O_
return nFileLength; cIXqnb
} 8AmB0W>e
6JE_rAab
E-HK=D&W/
//保存下载信息（文件指针位置） &bCk`]j:
private void write_nPos() 1<pb=H
{ (iu IeJ^Z
try{ 'M%uw85
output = new DataOutputStream(new FileOutputStream(tmpFile)); Wf-Pa9
output.writeInt(nStartPos.length); Y]+KsiOL
for(int i=0;i<nStartPos.length;i++) -;&-b>b
{ _5v]69C#
// output.writeLong(nPos); Jr,**,wA
output.writeLong(fileSplitterFetch.nStartPos); lQ?_1H~4=
output.writeLong(fileSplitterFetch.nEndPos); O+ J0X*&x
} Q^Q6| n
output.close(); mC!^`y)
} H:,Hr_;nC
catch(IOException e){e.printStackTrace ();} FLaj|Z~#)
catch(Exception e){e.printStackTrace ();} wRe2sjM
} Ca#T?HL
&*o{-kw
8>!-|VSn
//读取保存的下载信息（文件指针位置） (bGk=q=M
private void read_nPos() #c`/ f6z
{ L?b;TjLe
try{ x{,W<oXg
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); FtybF
int nCount = input.readInt(); -}"nb-RR\
nStartPos = new long[nCount]; HXQ }B$V
nEndPos = new long[nCount]; T)Pr%kF
for(int i=0;i<nStartPos.length;i++) nF=[m; ~
{ 9]^NAlno
nStartPos = input.readLong(); a- 7RJ.
nEndPos = input.readLong(); lLNI5C
} $x(p:+TI\4
input.close(); v)LSH;<
} r/RX|M
catch(IOException e){e.printStackTrace ();} v=x)]<E"_
catch(Exception e){e.printStackTrace ();} XiAflO
} lO8GnkLE
H8qWY"<Vd
)Xice=x9
private void processErrorCode(int nErrorCode) :Oi}X7\
{ ;!#IRR
System.err.println("Error Code : " + nErrorCode); X-cP'"
} `/o|1vv@_
%H=^U8WB
M8f[ck
//停止文件下载 \}; 4rm}V
public void siteStop() |pR'#M4j4A
{ (%*~5%l\
bStop = true; Ny]]L
for(int i=0;i<nStartPos.length;i++) 3PaMq6Ca
fileSplitterFetch.splitterStop(); 82yfPQ&UI
z]1g;j
E^x/v_,$w!
} e}2[g
} 8D`TN8[W
//负责部分文件的抓取 LN=#&7=$c
**FileSplitterFetch.java a!;CY1>
*/ #[y2nK3zF
package NetFox; |5\: E}1
*):s**BJ$
)C$1))
import java.io.*; 1A N)%
import java.net.*; @g1T??h
kf_*=ER
iy|xF~
public class FileSplitterFetch extends Thread { =+"-8tz8FV
`i6q\-12n
xm> y3WC
String sURL; //File URL q`HK4~i,
long nStartPos; //File Snippet Start Position __)"-\w-_(
long nEndPos; //File Snippet End Position ,~XAV ;+
int nThreadID; //Thread's ID G+K`FUNA
boolean bDownOver = false; //Downing is over 0D}k ^W
boolean bStop = false; //Stop identical .zvvk
FileAccessI fileAccessI = null; //File Access interface J&;' gT
>UV?nXP}
0|]qWcD
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException JUTlJyx8
{ KqWO9d?w.
this.sURL = sURL; {/!Yavx
this.nStartPos = nStart; )9kp[hY
this.nEndPos = nEnd; cxnEcX\
nThreadID = id; &8hW~G>(m
fileAccessI = new FileAccessI(sName,nStartPos);//定位 k j&hn
} @Pf['BF"
7h\U}!
QX+&[G!DZH
public void run() [B%:!Q)@
{ {N@tJ,Fh{
while(nStartPos < nEndPos && !bStop) 6x@4gPy[
{ ~oeX0l>F
6tup^Rlo;$
#x(3>}
try{ LEY k
URL url = new URL(sURL); k<%y+v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (^^}Ke{J
httpConnection.setRequestProperty("User-Agent","NetFox"); oC(.u?
String sProperty = "bytes="+nStartPos+"-"; RHuc#b0
httpConnection.setRequestProperty("RANGE",sProperty); Enqs|fkbN
Utility.log(sProperty); #6nuiSF
}Hb_8P
sDyt3xN
InputStream input = httpConnection.getInputStream(); +xBM\Dz8
//logResponseHead(httpConnection); !$fF3^8-
4JGU`L:~
)D ':bWP
byte[] b = new byte[1024]; h~k+!\
int nRead; _j|U>s
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) HvW6=d(#
{ FyRr/0C>
nStartPos += fileAccessI.write(b,0,nRead); J%8hf%!ud
//if(nThreadID == 1) l,ra24
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d 2z!i^:
} r%%<
(sEZNo5n
i^V3u
Utility.log("Thread " + nThreadID + " is over!"); fs*OR2YG7
bDownOver = true; +}NQ|y V
//nPos = fileAccessI.write (b,0,nRead); zO3}c3D~q
} "Fqrk>Q~
catch(Exception e){e.printStackTrace ();} G_6!w//
} #=I5_u
} u7bji>j
nLnzl
%?!TqJT?{
//打印回应的头信息 Z+Ppd=||,
public void logResponseHead(HttpURLConnection con) BzI(
{ Klqte*!
for(int i=1;;i++) wK Je^7
{ [)nU?l
String header=con.getHeaderFieldKey(i); 64f6D"."
if(header!=null) rqhRrG{L|&
//responseHeaders.put(header,httpConnection.getHeaderField(header)); P^'}3*8S
Utility.log(header+" : "+con.getHeaderField(header)); !6`&0eY
else H;RgYu2J
break; t&rr;W]
} i&JI"Dd7
} z=DK(b;$z
M.KXDD#O
Ir3|PehB
public void splitterStop() \,yg@R
{ 9a{9|p>L
bStop = true; (h%xqXs
} ib~EQ?u{
gBo~NLrf
@jD#Tn-*
} }Z% j=c"d
wW0m}L
>TS=tK
/* |=EwZmj-c
**FileAccess.java 1Ewg_/R
*//文件访问(定位，写) ~}s0~j~
package NetFox; B{lL}"++0
import java.io.*; (t"rzH
5z"[{#/
]VK9d;0D
public class FileAccessI implements Serializable{ xO;Qr.3PX
N#7_)S[@0l
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 PsI{y&.
RandomAccessFile oSavedFile; wbh^ZMQ
long nPos; seNH/pRb
qF4DX$$<
}r:8w*47
public FileAccessI() throws IOException ~D!Y] SK
{ 8iN@n8O
this("",0); RJLhR_t7n
} bk4G+wGw
q4ej7T8
@{x+ln1r
public FileAccessI(String sName,long nPos) throws IOException ;Yn_*M/*
{ EtA,ow
oSavedFile = new RandomAccessFile(sName,"rw"); u|\K kk
this.nPos = nPos; @1)C3(=A
oSavedFile.seek(nPos); 7kQ,D,c'
} -|_io,eL;
mcSZ1d~,(
gBE1aw;
public synchronized int write(byte[] b,int nStart,int nLen) <&=3g/Y
{ gYfOa`k
int n = -1; ^uIKwql
try{ 73(5.'F
oSavedFile.write(b,nStart,nLen); %)j^>W5
n = nLen; dhI+_z
} zK&J2P`
catch(IOException e) f9J]-#Iif
{ l[{Ci|4
e.printStackTrace (); o)Nm5g
} 5C"A*Fg?;
~Ec@hz]js
tq5o
return n; +yIO
} xwu,<M v`
WvHy}1W
IR<*OnKn
} nF{>RD
p0j-$*F
3G-f+HN^E
/* Kw,ln<)2
**SiteInfoBean.java }#9 |au`
*/ `pYL/[5
package NetFox; 3Tr}t.mt
U%_6'5s{^
PoRL35
public class SiteInfoBean { M@O<b-
T eBJ
S3_QOL
private String sSiteURL; //Site's URL =!PUKa3f<
private String sFilePath; //Saved File's Path 5b%zpx0Y
private String sFileName; //Saved File's Name 0+"P1/
private int nSplitter; //Count of Splited Downloading File 9NcC.}#-5
Lcy>!3q3~
`jH0FJQ
public SiteInfoBean() ?&r>`H E
{//nSplitter的缺省值为5 vA,tW,
//default value of nSplitter is 5 RaY=~g
this("","","",5); s h^&3}
} 5 }F6s
>`+-Yi$(\
R3} Z"
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) aW#_"Y}v'
{ h*?/[XY
sSiteURL= sURL; t^@4n&Dg
sFilePath = sPath; 0Kenyn4?
sFileName = sName; %TRH,-@3h
this.nSplitter = nSpiltter; n"Q fW~U
[:C!g#o
Xu&4|$wB+
} MA5BTq<&
NpF}~$2
A49HYX-l
public String getSSiteURL() }-ysP$
{ zj9aaZ}
return sSiteURL; >l|dLyiae
} YfOO]{x,X
O{`r.H1',
CF+:9PG
public void setSSiteURL(String value) vt-53fa|
{ b-,]21
sSiteURL = value; F6\r"63
} 'aW<C>
E>6:59+
'Z(4Wuwb
public String getSFilePath() =8)q-{p3
{ IEJp!P,E
return sFilePath; IOi6' 1l
} B|+tK
;yK:.Vg
Z]Iyj 97
public void setSFilePath(String value) Gn%gSH/
{ [sH[bmLR
sFilePath = value; za@`,Yq
} {BKr/) H
H&zhYKw
SvR? nN|
public String getSFileName() '^Ce9r}
{ ,zY!EHpx
return sFileName; +R?d6IjH
} _K"X
)51H\o
8y, ]>n
public void setSFileName(String value) ="*8ja-K
{ O;*.dR
sFileName = value; p%6j2;D
} t'0dyQ%u
`[5QouPV
sj?7}(s
public int getNSplitter() +#!! 'XP
{ 5=--+8[ bV
return nSplitter; lj!f\C}d
} H|iY<7@
i%)Nn^a;T
?5L.]Isa5
public void setNSplitter(int nCount) [1*3 kt*h
{ W!BIz&SY:-
nSplitter = nCount; JH0L^p
} W}U-u{Z
} W+0VrH 0F
V+kU^mI
^l\^\>8
/* 8+<vumnw
**Utility.java 2!35Tj"RFE
*/ $xf{m9 8
package NetFox; ,@Izx
L4'FL?~I
*OQr:e<}
public class Utility { G:2m)0bW
;9hi2_luV
P]G`Y>#$r
public Utility() z@0*QZ.y1
{ {~"6/L
!~&vcz0>)9
R2af>R
} Ibd na9z7
O0gLu1*1v
//线程睡眠 *XK9-%3
public static void sleep(int nSecond) MMfcY 3#%
{ oZV=vg5Dq
try{ =wW3Tr7~
Thread.sleep(nSecond); {rG`Upp
} [J|)DUjt
catch(Exception e) THM\-abz
{ u9*}@{,
e.printStackTrace (); v@0lTl_
} =U5lPsiv,3
} xED`8PCfu
x_oL~~@
//日志 t4H@ZvAH0
public static void log(String sMsg) |QvG;{!
{ {zc<:^r^
System.err.println(sMsg); e:Zc-
} v^h \E+@
?N,'1I
38%xB<Y
public static void log(int sMsg) E Cx_ [|3{
{ <ealt
System.err.println(sMsg); e%'$Vx0kA
} :H$D-pbJ4
} 6N&S3<c4JO
$GyO+xF
"bRg_]\q6
/* >Udb*76 D
**TestMethod.java ~R]E=/m|
*/ {Tp0#fi
package NetFox; p0xd c3
tj ,*-).4%
Eg"DiI)7
public class TestMethod { G"=tQ$ZU
N;A#3Ter
\vB-0w
public TestMethod() Ey77]\
{ ///xx/weblogic60b2_win.exe g< cR/
try{ ,*2%6t`N?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); bUC-}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); fn zj@_{|
SiteFileFetch fileFetch = new SiteFileFetch(bean); @xJ qG"
fileFetch.start(); "-4V48ci
} PnsQ[}.
catch(Exception e){e.printStackTrace ();} mAFqA
,uD F#xjl,
0KyujU?sF
} A/N$
I)E+
/(w:XTO<
public static void main(String[] args) EdA_Hf
{ EOrWax@k$}
new TestMethod(); ~y}M GUEC
} z[DUktZl
} URDb
点击下载更多相关资料